Fish Diseases and Disorders Vol 1 - Protozoan and Metazoan Infections
Fish Diseases and Disorders Vol 1 - Protozoan and Metazoan Infections
Fish Diseases and Disorders Vol 1 - Protozoan and Metazoan Infections
Edited by
P.T.K. Woo
University of Guelph
Canada
CAB International 2006. All rights reserved. No part of this publication may be
reproduced in any form or by any means, electronically, mechanically, by
photocopying, recording or otherwise, without the prior permission of the
copyright owners.
A catalogue record for this book is available from the British Library, London, UK.
Library of Congress Cataloging-in-Publication Data
Fish diseases and disorders.--2nd ed.
p. cm.
Includes bibliographical references and index.
ISBN-10: 0-85199-015-0 (alk. paper)
ISBN-13: 978-0-85199-015-6 (alk. paper)
1. Fishes--Diseases. 2. Fishes--Infections. I. Woo, P.T.K. II. Title.
SH171.F562 2006
639.3--dc22
2005018533
Typeset by AMA DataSet Ltd, UK
Printed and bound in the UK by Biddles, Kings Lynn
iv
Contents
Contributors
Preface to the Second Edition
Patrick T.K. Woo
Preface to the First Edition
P.T.K. Woo
1.
Phylum Amoebozoa
Dina Zilberg, Ben-Gurion University of the Negev, Israel, and
Barry L. Munday, University of Tasmania, Australia
2.
Phylum Dinoflagellata
Edward J. Noga and Michael G. Levy, North Carolina State University, USA
3.
vii
ix
16
46
4.
116
5.
154
6.
Phylum Apicomplexa
Klmn Molnr, Veterinary Medical Research Institute, Hungary
183
7.
Phylum Microspora
Iva Dykov, Institute of Parasitology, Czech Republic
205
8.
Phylum Myxozoa
Stephen W. Feist and Matt Longshaw, CEFAS Weymouth Laboratory, UK
230
vi
9.
Contents
297
10.
345
11.
391
12.
Phylum Nematoda
Klmn Molnr, Veterinary Medical Research Institute, Hungary,
Kurt Buchmann, Royal Veterinary and Agricultural University, Denmark
and Csaba Szkely, Veterinary Medical Research Institute, Hungary
417
13.
Phylum Acanthocephala
Brent B. Nickol, University of Nebraska-Lincoln, USA
444
14.
Phylum Arthropoda
Robert J.G. Lester and Craig J. Hayward, University of Queensland, Australia
466
15.
566
16.
592
17.
629
18.
678
19.
702
20.
725
Glossary
753
Index
775
Contributors
vii
viii
Contributors
Michael G. Levy, Department of Population Health and Pathobiology, North Carolina State
University College of Veterinary Medicine, 4700 Hillsborough Street, Raleigh, NC 27606,
USA
Matt Longshaw, CEFAS Weymouth Laboratory, Barrack Road, The Nothe, Weymouth,
Dorset DT4 8UB, UK
Klmn Molnr, Veterinary Medical Research Institute, Hungarian Academy of Sciences,
H-1581 Budapest, Hungary
Barry L. Munday, School of Human Life Sciences, University of Tasmania, Locked Bag
1-320, Launceston, Tasmania 7250, Australia
Brent B. Nickol, School of Biological Sciences, University of Nebraska-Lincoln, Lincoln,
NE 68588-0118, USA
Edward J. Noga, Department of Clinical Sciences, North Carolina State University College
of Veterinary Medicine, 4700 Hillsborough Street, Raleigh, NC 27606, USA
Ilan Paperna, Department of Animal Science, Faculty of Agricultural, Food and
Environmental Quality Sciences, Hebrew University of Jerusalem, Rehovot 76100, Israel
Csaba Szkely, Veterinary Medical Research Institute, Hungarian Academy of Sciences,
H-1581 Budapest, Hungary
Jo Van As, Department of Zoology and Entomology, University of the Free State,
Bloemfontein, South Africa
Willem B. Van Muiswinkel, Cell Biology and Immunology Group, Wageningen Institute of
Animal Sciences, Wageningen University, PO Box 338, 6700 AH Wageningen, The
Netherlands
Brenda Vervoorn-Van Der Wal, Cell Biology and Immunology Group, Wageningen
Institute of Aminal Sciences, Wageningen University, PO Box 338, 6700 AH,
Wageningen, The Netherlands
Patrick T.K. Woo, Axelrod Institute of Ichthyology and Department of Integrative Biology,
College of Biological Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1
Dina Zilberg, The Albert Katz Department of Dryland Biotechnologies, Jacob Blaustein
Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus,
84990 Israel
Worldwide consumption of fish and fish products has continued to escalate in the last few
decades as the population increases and with the realization that fish is an excellent
protein. The aquaculture industry is now the single fastest-growing food production process in the world, this is partly because fish is also less expensive to produce. Since the
publication of the first edition of this trilogy on fish diseases and disorders, a tremendous
volume of research has been conducted on parasites, especially those that cause morbidity
and mortality in fish. This is reflected in the current enlarged edition; however, the aims,
philosophy, focus, audience and format of this edition have remained unchanged.
Significant changes in coverage in this edition include the addition of three new
chapters (Chapters 1, 19 and 20), and four of the original chapters have been completely
rewritten and are by new authors (Chapters 5, 8, 9 and 12). The remaining chapters have
been updated and revised, and many of them also have new co-authors. The fact that these
changes are possible bodes well for the study of fish diseases as it indicates a very dynamic
and rapidly evolving discipline with considerable expertise. This is especially evident in
the identification of new areas of research, in the development of expertise in the younger
generation of scientists and in the application of new technologies to better understand
these pathogens and to devise strategies to minimize their impact on fish health.
On a more personal note, I am delighted to welcome our 16 new authors and
co-authors, and I am confident their expertise, experience and insights into fish health will
without a doubt make this a significantly better book. To our original authors, I am most
grateful for their continued support and contributions.
As with the first edition I am hopeful that this edition will be useful to colleagues, and
that it will also serve to highlight the relevance and importance of our discipline to the
aquaculture industry.
Patrick T.K. Woo
ix
Fin fish is the primary source of protein for humans in many parts of the world and this
is especially true in most developing countries. The catch-fish industry has declined
significantly and the decline is due to a series of factors which include over-fishing, loss of
fish habitats and environmental pollution. In the past few decades numerous international
agencies and national governments have encouraged and continue to encourage private
industries to be involved in aquaculture or have themselves gone into intensive fish
culture, usually under artificial and/or semi-artificial conditions. Disease outbreaks
(infectious and non-infectious) with resulting high mortalities occur more often when fish
are held under relatively crowded and confined conditions. Also, mass mortality of
healthy fish may occur even under good environmental conditions when an infectious
agent is accidentally introduced into the culture system.
This volume is the first of three proposed volumes on diseases and disorders of freshwater and marine fishes (fin and shellfish). It is on parasitic infections while the second
and third volumes are on microbial and non-infectious diseases/disorders. No single
author can hope to write these volumes with any authority, hence I have chosen well qualified, internationally recognized experts to write the chapters. Each chapter deals with a
specific disease/disorder or a group of closely related diseases. The primary purpose is to
produce comprehensive and authoritative reviews by experts who are actively working in
the area or have contributed greatly to our understanding of the disease/disorder.
The principal audience for the books is research scientists in the aquaculture industry
and universities, fish health consultants and managers of private and government fish
health laboratories. The books are also appropriate for graduate and senior undergraduate
students who are studying diseases of aquatic organisms. The series may also serve as
reference text books for undergraduate and graduate courses in general parasitology, microbiology, environmental studies and for courses on impacts of diseases in aquaculture.
The secondary audience is research scientists with expertise in related disciplines
(e.g. immunology, molecular biology) who wish to know about specific important fish
disease(s) so that they may be able to initiate research programmes in their areas of
expertise. I expect this secondary audience to increase as it becomes evident that fish
disease is an important component of the aquaculture industry and that fish health can be
used as an indicator of problems in the aquatic ecosystem.
P.T.K. Woo
Phylum Amoebozoa
Introduction
Phylum Amoebozoa
HostParasite Relationship
Clinical and pathological features
Peak mortalities in infected Atlantic salmon
smolts in Tasmania may reach 10% per week
(Foster and Percival, 1988b) while those in
turbot (500 g) in Spain may range between 5
and 20% over a period of 3 months, from
October to December (Dykova et al., 1998a).
Clinical signs include lethargy and
respiratory distress, with salmonids rising
to the surface of the water and displaying
increased opercular movements (Kent et al.,
1988; Munday et al., 1990; Rodger and
McArdle, 1996). However, in experimental
studies, Powell et al. (2000) were unable
to confirm that AGD-infected fish actually
had a measurable increase in ventilation
frequency.
In Atlantic salmon, macroscopic lesions
are usually multifocal patches of white to
grey swollen gill tissue with associated
excess mucus (Fig. 1.3; Munday et al., 1990;
Rodger and McArdle, 1996). These are most
numerous in the dorsal portions of the gill
arch (Adams, 2000; Adams and Nowak, 2001).
In rainbow trout the mucoid branchitis is
more diffuse (Munday et al., 2001). Infected
turbot have
behavioural alterations,
namely, reduced feeding and reverse posture (ventral side up), gills covered with
excess mucus, clubbed, necrotic gill filaments with patches of greyish peripheral
discoloration (Dykova et al., 1998a).
Histopathological lesions in salmonids
and turbot are similar, with the main lesion
being hyperplasia and hypertrophy of the
gill epithelium (Kent et al., 1988; Roubal
et al., 1989; Munday et al., 1990; Dykova
et al., 1995; Rodger and McArdle, 1996;
Zilberg and Munday, 2000). The sequential
development of the disease in experimentally infected Atlantic salmon was described
Fig. 1.4. Hyperplastic and oedematous gill tissue (h) at 14 DPE to fish with AGD. N. pemaquidensis (n)
can be seen between gill filaments, both attached to and detached from the epithelium (H & E, 480)
(Zilberg and Munday, 2000).
Fig. 1.5. Extensive hyperplasia and associated N. pemaquidensis on gills of fish at 28 DPE to fish with
AGD. N. pemaquidensis (n) both attached to the epithelium and associated with exfoliated hyperplastic
cells (h) (400) (Zilberg and Munday, 2000).
Pathogenesis
N. pemaquidensis is capable of colonizing the
normal gill epithelium (Zilberg and Munday,
2000), probably by lectin/glycoconjugate
Phylum Amoebozoa
Epizootiology
There is some evidence from experimental
studies that N. pemaquidensis becomes more
virulent with sequential passage through
nave hosts (Findlay et al., 2000). The minimum infectious dose for Atlantic salmon in
an experimental setting is about 230 N. pemaquidensis per litre of water (Zilberg et al.,
2001). A single smolt with AGD may have
several hundred thousands of amoebae (D.
Zilberg and B.L. Munday, 1999, Tasmania,
unpublished); consequently the danger
posed by a cage of infected fish is tremendous. Even dead fish have live N. pemaquidensis for up to 3 days post mortem
(Douglas-Helders et al., 2000b) so the danger
does not cease with the demise of the fish.
Atlantic salmon and rainbow trout
appear to be the most susceptible salmonids.
There is good field and experimental evidence that previously exposed fish acquire
a degree of resistance to reinfection after
a freshwater bath (Foster and Percival,
1988a; Findlay et al., 1995; Findlay and
Munday, 1998). However, this is only relative and can be overcome by a large challenge dose. Minor hyperplastic lesions on
the gills are associated with some increase
in severity of AGD (Nowak and Munday,
1994; Zilberg and Munday, 2000) but are
probably not significant in deciding the
eventual outcome. Severe gill lesions from
jellyfish damage and clubbing and necrosis gill syndrome are sometimes rapidly
Diagnosis of Infection
It is important to distinguish between AGD
and the presence of N. pemaquidensis with
no or inconsequential gill pathology. For
the aquaculturist the former is the crucial
diagnosis, whereas clinicians and particularly researchers have an interest in both
these aspects of the diagnosis. On-farm
diagnosis is done by counting the typical
mucoid patches on the gills (Alexander,
1991). While this has been shown to be
highly correlated with the presence of
N. pemaquidensis in experimental infections
on Atlantic salmon (Zilberg and Munday,
Phylum Amoebozoa
As only severely affected fish have hypernatraemia (Findlay, 2001), reversal of this
change is likely to be of only minor
importance.
A large number of other treatments
have been tried. The chemicals that have
some effects on pre-existing AGD are narasin
((4S)-4-methylsalinomycin)) (Cameron, 1992),
levamisole (1-2,3,5,6-tetrahydro-6-phenylimidazo[2,1-b]thiazole) (Zilberg et al., 2000),
chlorine dioxide and chloramine-T (Powell
and Clark, 2001; Powell et al., 2002). However, none is as effective and safe as freshwater baths.
Control
Control of AGD on salmonids in Tasmania
has revolved mainly around the timing of
freshwater baths, some of which are
regarded as prophylactic (Douglas-Helders
et al., 2001b), and some farmers avoid the
problem entirely or partially by utilizing
low-salinity sites for all or part of the
marine culture phase.
The Tasmanian industry has kept
multiple classes of stock (spring smolts,
out-of-season smolts, etc.) on a single site.
Although no objective data are available,
the apparent increase in virulence of
N. pemaquidensis with serial passage under
experimental conditions suggests that the
all-in all-out strategy may be more desirable. In this strategy, once smolts are stocked
at a site they are grown and harvested, and
only then can the next stocking be carried
out. Similarly, increased biomass at individual lease sites inevitably reduces distances between cages, thereby rendering
more likely the transfer of infection from
cages with clinically affected fish to other
cages. Undoubtedly, the effects of management strategies on the occurrence and
severity of AGD will require more intensive
investigation in the future.
Although chinook salmon are more
difficult to culture than Atlantic salmon
and rainbow trout, there could be merit in
having at least a proportion of these fish at a
site if their apparent relative resistance to
AGD can be confirmed.
Table 1.1.
Different species of amoeba that were reported in the literature, isolated from different species of aquatic organisms around the world.
Host
Organ
Geographic location
Reference
Acanthamoeba sp.
Brain, liver,
Spleen
Brain
Brain, kidney
Kidney
Spleen
Intestine
Czech Republic
New York
South-eastern USA
Taylor, 1977
A. polyphaga
Cochlipodium sp.2
C. minus
Flaballula citata 2
F. calkinsi 2
Hartmannella sp.
H. vermiformis 3
Naegleria sp.
N. australinesis
N. gruberi
Paramoeba invadens1
Gills
Liver, kidney, brain,
spleen, gills
Gills
Gills
Intestine
Kidney
Gills
Spleen, kidney
Brain
Gills
Brain
Intestine
Thailand (farm)
New York
Continued
Phylum Amoebozoa
Species
Continued. Different species of amoeba that were reported in the literature, isolated from different species of aquatic organisms around the world.
Host
Organ
Geographic location
Reference
P. perniciosa1
Blue crab
Maryland and
Virginia, USA
Platyamoeba sp.2
P. longae 2
P. murchelanoi 2
P. weinsteini 2
P. douversi 2
P. leei 2
P. plurinucleolus 2
Rosculus ithacus
Saccamoeba sp.
Thecamoeba sp.2
T. hoffmani 2
Turbot
Turbot
Connective tissue,
haemal spaces,
blood vessels
Gills
Gills
Spain
Spain
Tilapia nilotica
Atlantic salmon (Salmo salar)
Rainbow trout
Rainbow trout, coho salmon
(Oncorhynchus kisutch),
chinook salmon (O. tschawytscha)
Blue tilapia, largemouth bass,
brown trout (Salmo trutta)
Turbot
Kidney
Gills
Gills
?
South-eastern USA
Taylor, 1977
Gills
Spain
Czech Republic
Germany
Unidentified 2
Unidentified 2
Kidney
Brain
Liver
Gills, kidney, liver,
spleen, intestine
Gills
Gills
Czech Republic
Vexillifera expectata
Unidentified 2
Canada
West Virginia, USA
Speare, 1999
Bullock et al., 1994
Vahlkampfia sp.
Vannella
caledonica,2
V. septentrionalis,2
V. anglica 2
V. platypodia
1Isolation
Species
10
Table 1.1.
Phylum Amoebozoa
Parasite factors
1. More research is required to identify
differences (apart from pathogenicity)
between N. pemaquidensis isolated from
carrier fish and from fish with AGD, and to
identify virulence factor(s) in the pathogen.
2. Since Padilla-Vaca et al. (1999) have
shown that the glycoconjugate profile of the
bacteria used as the nutritional lawn for
Entamoeba histolytica is crucial in determining the pathogenicity of the organism, it
is important to conduct similar studies for
N. pemaquidensis.
3. More studies are required to understand the salinity effects on strains of
N. pemaquidensis.
11
OTHER AMOEBAE
There is information in the literature regarding the isolation and identification of a
large number of different species of amoeba
from aquatic organisms. Some findings are
incidental, unassociated with specific disease conditions, and others are associated
with morbidity and mortality. Species of
Paramoeba infect internal organs and cause
morbidity and mortality in sea urchin
(Jones, 1985; Jones and Scheibling, 1985)
and in blue crab (Sprague and Beckett, 1969;
Johnson, 1977; Table 1.1). In fish, N. pemaquidensis is the only amoeba that was confirmed to be a primary disease-causing agent.
Several species of amoeba can cause disease
as secondary pathogens, following a primary
gill infection that is caused by bacteria
(Bullock et al., 1994; Noble et al., 1997) or
by N. pemaquidensis (Dykova et al., 1999a).
Some of the amoebae associated with disease conditions seem generally to be freeliving, and change their mode of life under
conditions that are unfavourable to the fish
(except for N. pemaquidensis), and some
are probably a part of the normally associated fauna. Table 1.1 summarizes much of
the published literature on amoebae associated with aquatic organisms. Their effect
as disease-causing agents, in many of the
reported cases, is yet to be determined.
Management factors
1. The effects of introducing sequential
populations of nave fish into a single production site need to be monitored.
2. The use of epidemiological modelling
to forecast the potential effects of increasing
fish and/or cage numbers at any one site
needs to be examined closely.
Acknowledgements
Our research reported in this review was
supported by the Cooperative Research
Center for Aquaculture in Australia. We
thank Dr Ariel Diamant for reviewing the
draft of this manuscript.
References
Adams, M. (2000) AGD: hostpathogen interactions. In: Nowak, B.F. (ed.) AGD in the New Millennium.
Tasmanian Aquaculture and Fisheries Institute, Taroona, Tasmania, Australia.
Adams, M.B. and Nowak, B.F. (2001) Lesion distribution and structure in the gills of Atlantic salmon
(Salmo salar L.) affected with amoebic gill disease. In: Battaglene, S.C. and Cobcoft, J.M. (eds) The First
12
Scientific Conference of the Atlantic Salmon Subprogram Handbook. CSIRO Marine Laboratories,
Hobart, Tasmania, Australia, pp. 2829.
Akhlaghi, M., Munday, B.L., Rough, K. and Whittington, R.J. (1996) Immunological aspects of amoebic gill
disease in salmonids. Diseases of Aquatic Organisms 25, 2331.
Alexander, J.M. (1991) Treatment of amoebic gill disease: field trials, 1990/1991. In: Valentine, P.
(ed.) Proceedings of the Saltas Research and Review Seminar. Hobart, Tasmania, Australia,
pp. 51102.
Bullock, G., Herman, R., Heinen, J., Noble, A. and Hankins, J. (1994) Observation on the occurrence of
bacterial gill disease and amoeba gill infestation in rainbow trout cultured in a water recirculating
system. Journal of Aquatic Animal Health 6, 310317.
Cameron, D.E. (1992) Amoebic gill disease field research 1991/92. In: Valentine, P. (ed.) Proceedings of the
Saltas Research and Development Review Seminar. Hobart, Tasmania, Australia, pp. 123133.
Cann, J.P. and Page, F.C. (1982) Fine structure of small free-living Paramoeba (Amoebida) and taxonomy of
the genus. Journal of the Marine Biological Association of the UK 62, 2543.
Clark, A. and Nowak, B.F. (1999) Field investigations of amoebic gill disease in Atlantic salmon, Salmo salar L.,
in Tasmania. Journal of Fish Diseases 22, 433443.
Clark, A., Nowak, B.F. and Powell, M. (2000) Long term effects of freshwater bathing. In: Nowak, B.F. (ed.)
AGD in the New Millennium. Tasmanian Aquaculture and Fisheries Institute, Taroona, Tasmania,
Australia.
Crosbie, P., Carson, J. and Nowak, B. (2002) Detection of Neoparamoeba pemaquidensis in marine sediments
at Tasmania. In: Battaglene, S. and Cobcroft, J. (eds) The Second Scientific Conference of the Atlantic
Salmon Aquaculture Subprogram. Hobart, Tasmania, Australia. pp. 2526.
Dawson, D. (1999) Gill parasites and pathology of wild marine fish in Tasmania. Honors thesis, University of
Tasmania, Launceston, Tasmania, Australia.
Douglas-Helders, M., Carson, J., Nowak, B.F. and Wagner, T.M. (2000a) A new dot blot for the rapid
detection of Paramoeba pemaquidensis used in the epidemiological studies of amoebic gill disease.
In: Nowak, B.F. (ed.) AGD in the New Millennium. Tasmanian Aquaculture and Fisheries Institute,
Taroona, Tasmania, Australia.
Douglas-Helders, M., Nowak, B.F., Zilberg, D. and Carson, J. (2000b) Survival of Paramoeba pemaquidensis
on dead salmon: implication for management of cage hygiene. Bulletin of the European Association of
Fish Pathologists 20, 167169.
Douglas-Helders, M., Carson, J., Howard, T. and Nowak, B. (2001a) Development and validation of a new
dot blot test for the detection of Paramoeba pemaquidensis (Page) in fish. Journal of Fish Diseases 24,
273280.
Douglas-Helders, M., Nowak, B. and Carson, J. (2001b) Implication of management strategies on AGD prevalence and fish performance of cultured salmonids. In: Battaglene, S.C. and Cobcoft, J.M. (eds) The First
Scientific Conference of the Atlantic Salmon Subprogram Handbook. CSIRO Marine Laboratories,
Hobart, Tasmania, Australia, pp. 2527.
Douglas-Helders, M., Sakasida, S., Raverty, S. and Nowak, B. (2001c) Temperature as a risk factor for
outbreaks of amoebic gill disease in farmed Atlantic salmon (Salmo salar). Bulletin of the European Association of Fish Pathologists 21, 114116.
Douglas-Helders, M., Dawson, D.R., Carson, J. and Nowak, B.F. (2002) Wild fish are not a significant reservoir of Neoparamoeba pemaquidensis (Page 1987). Journal of Fish Diseases 25, 569574.
Douglas-Helders, M., Tan, C., Carson, J. and Nowak, B.F. (2003a) Effects of copper-based antifouling treatment
on the presence of Neoparamoeba pemaquidensis Page, 1987 on nets and gills of reared Atlantic salmon
(Salmo salar). Aquaculture 221, 1322.
Douglas-Helders, M., OBrien, D.P., McCorkell, B.E., Zilberg, D., Gross, A., Carson, J. and Nowak, B.F.
(2003b) Temporal and spatial distribution of Paramoeba in the water column a pilot study. Journal of
Fish Diseases 26, 231240.
Dykova, I. and Novoa, B. (2001) Comments of diagnosis of amoebic gill disease (AGD) in turbot,
Scophthalmus maximus. Bulletin of the European Association of Fish Pathologists 21, 4044.
Dykova I., Figueras, A. and Novoa, B. (1995) Amoebic gill infection of turbot, Scophthalmus maximus. Folia
Parasitologica 42, 9196.
Dykova, I., Machackova, B. and Peckova, H. (1997) Amoeba isolated from organs of farmed tilapias,
Oreochromis niloticus. Folia Parasitologica 44, 8190.
Dykova I., Figueras A., Novoa, B. and Casal, J.F. (1998a) Paramoeba sp., an agent of amoebic gill disease of
turbot, Scophthalmus maximus. Diseases of Aquatic Organisms 33, 137141.
Phylum Amoebozoa
13
Dykova, I., Lom, J. and Machackova, B. (1998b) Cochliopodium minus, a scale-bearing amoeba isolated from
organs of perch Perca fluviatilis. Diseases of Aquatic Organisms 34, 205210.
Dykova, I., Lom, J., Machackova, B. and Peckova, H. (1998c) Vexillifera expectata sp. n. and other non-encysting
amoebae isolated from organs of freshwater fish. Folia Parasitologica 45, 1726.
Dykova I., Figueras, A. and Novoa, B. (1999a) Epizoic amoeba from the gills of turbot Scophthalmus
maximus. Diseases of Aquatic Organisms 38, 3338.
Dykova, I., Lom, J., Schroeder-Diedrich, J.M., Booton, G.C. and Byers, T.J. (1999b) Acanthamoeba strains isolated from organs of freshwater fishes. Journal of Parasitology 85, 11061113.
Dykova, I., Figueras, A. and Peric, Z. (2000) Neoparamoeba Page 1987: light and electron microscopic observations on six strains of different origin. Diseases of Aquatic Organisms 43, 217223.
Dykova, I., Kyselova, I., Peckova, H., Obornik, M. and Lukes, J. (2001) Identity of Naegleria strains isolated
from organs of freshwater fishes. Diseases of Aquatic Organisms 46, 115121.
Dykova, I., Veverkova, M., Fiala, I. and Machackova, B. (2002) A free-living amoeba with unusual pattern
of mitochondrial structure isolated from Atlantic salmon, Salmo salar L. Acta Protozoologica 41,
415419.
Elliot, N., Wong, F. and Carson, J. (2001) Detection of Neoparamoeba pemaquidensis in the environment. In:
Battaglene, S.C. and Cobcoft, J.M. (eds) The First Scientific Conference of the Atlantic Salmon
Subprogram Handbook. CSIRO Marine Laboratories, Hobart, Tasmania, Australia, pp. 1920.
Findlay, V.L. (2001) Demonstration and manipulation of acquired resistance to amoebic gill disease of Atlantic
salmon, Salmo salar L. PhD thesis, University of Tasmania, Launceston, Tasmania, Australia.
Findlay, V.L. and Munday, B.L. (1998) Further studies on acquired resistance to amoebic gill disease (AGD) in
Atlantic salmon, Salmo salar L. Journal of Fish Diseases 21, 121125.
Findlay, V.L., Helders, M., Munday, B.L. and Gurney, R. (1995) Demonstration of resistance to reinfection
with Paramoeba sp. by Atlantic salmon, Salmo salar L. Journal of Fish Diseases 18, 639642.
Findlay, V.L., Zilberg, D. and Munday, B.L. (2000) Evaluation of levamisole as a treatment for amoebic gill
disease of Atlantic salmon, Salmo salar L. Journal of Fish Diseases 23, 193198.
Foster, C. and Percival, S. (1988a) Treatment of Paramoebic Gill Disease in Salmon and Trout. Saltas
Aquanote No. 14, May, Salmon Enterprises of Tasmania Pty Ltd, Dover, Tasmania, Australia.
Foster, C. and Percival, S. (1988b) Paramoebic Gill Disease. Occurrence of Paramoeba in Tasmania. Saltas
Aquanote No. 15, May, Salmon Enterprises of Tasmania Pty Ltd, Dover, Tasmania, Australia.
Franke, E.D. and Mackiewicz, J.S. (1982) Isolation of Acanthamoeba and Naegleria from the intestinal contents of freshwater fishes and their potential pathogenicity. Journal of Parasitology 68, 164166.
Hollande, A. (1980) Identification du parasome (Nebenkern) de Janickina pigmentifera un symbionte
(Perkinsiella amoeba) apparente aux flagelles kintoplastidies. Protistologica 16, 613625.
Howard, T.S. and Carson, J. (1993) Are there alternatives to freshwater treatment of AGD? In: Valentine, P.
(ed.) Proceedings of the Saltas Research and Development Review Seminar. Saltas, Hobart, Tasmania,
Australia, pp. 8187.
Howard, T.S., Carson, J. and Lewis, T. (1993) Development of a model of infection for amoebic gill disease.
In: Valentine, P. (ed.) Proceedings of the Saltas Research and Development Review Seminar. Saltas,
Hobart, Tasmania, Australia, pp. 103111.
Johnson, P.T. (1977) Paramoebiasis in the blue crab, Callinectes sapidus. Journal of Invertebrate Pathology 29,
308320.
Jones, G.M. (1985) Paramoeba invadens n. sp. (Amoebida, Paramoebidae), a pathogenic amoeba from the sea
urchin, Strongylocentrotus droebachiensis, in eastern Canada. Journal of Protozoology 32, 564569.
Jones, G.M. and Scheibling, R.E. (1985) Paramoeba sp. (Amoebida, Paramoebidae) as the possible causative
agent of sea urchin mass mortality in Nova Scotia. Journal of Parasitology 71, 559565.
Kent, M.L., Sawyer, T.K. and Hedrick, R.P. (1988) Paramoeba pemaquidensis (Sarcomastigophora:
Paramoebidae) infestation of the gills of coho salmon Oncorhynchus kisutch reared in sea water.
Diseases of Aquatic Organisms 5, 163169.
Leiro, J., Paniagua, E., Ortega, M., Parama, A., Fernandez, J. and Sanmartin, M.L. (1998) An amoeba associated with gill disease in turbot, Scophthalmus maximus (L.). Journal of Fish Diseases 21, 281288.
Mitchell, D. (2001) HAC experience of AGD. In: Battaglene, S.C. and Cobcoft, J.M. (eds) The First Scientific
Conference of the Atlantic Salmon Subprogram Handbook. CSIRO Marine Laboratories, Hobart,
Tasmania, Australia, pp. 2122.
Munday, B.L. (1985) Diseases of salmonids. In: Humphrey, J.D. and Langdon, J.S. (eds) Proceedings of the
Workshop on Diseases of Australian Fish and Shellfish. Department of Agriculture and Rural Affairs,
Benalla, Victoria, Australia, pp. 127141.
14
Munday, B.L., Foster, C.K., Roubal, F.R. and Lester, R.J.G. (1990) Paramoebic gill infection and associated
pathology of Atlantic salmon, Salmo salar L., and rainbow trout, Salmo gairdneri, in Tasmania. In:
Perkins, F.O. and Cheng, T.C. (eds) Pathology in Marine Science. Academic Press, San Diego, California,
pp. 215222.
Munday, B.L., Lange, K., Foster, C., Lester, R.J.G. and Handlinger, J. (1993) Amoebic gill disease of sea-caged
salmonids in Tasmanian waters. Tasmanian Fisheries Research 28, 1419.
Munday, B.L., Zilberg, D. and Findlay, V. (2001) Gill disease of marine fish caused by infection with
Neoparamoeba pemaquidensis, a review. Journal of Fish Diseases 24, 497507.
Nash, G., Nash, M. and Schlotfeldt, H.J. (1988) Systemic amoebiasis in cultured European catfish, Silurus
glanis L. Journal of Fish Diseases 11, 5771.
Noble, A.C., Herman, R.L., Noga, E.J. and Bullock, G.L. (1997) Recurrent amoebic gill infestation in rainbow trout cultured in a semiclosed water recirculation system. Journal of Aquatic Animal Health 9,
6469.
Nowak, B. and Munday, B.L. (1994) Histology of gills of Atlantic salmon during the first few months following
transfer to sea water. Bulletin of the European Association of Fish Pathologists 14, 7781.
Nowak, B., Douglas-Helders, M. and Dawson, D. (2000) AGD effects of environmental and husbandry
factors. In: Nowak, B.F. (ed.) AGD in the New Millennium. Tasmanian Aquaculture and Fisheries
Institute, Taroona, Tasmania, Australia. pp. 5052.
Nowak, B.F., Douglas-Helders, M., Gross, K., Bridle, A., Morrison, R., Crosbie, P., Bagley, C., Adams, M.,
Butler, R. and Carson, J. (2002) Amoebic gill disease research highlights. In: Battaglene, S. and
Cobcroft, J. (eds) The Second Scientific Conference of the Atlantic Salmon Aquaculture Subprogram.
Hobart, Tasmania, Australia.
Padilla-Vaca, F., Ankri, S., Bracha, R., Koole, L.A. and Mirelman, D. (1999) Down regulation of Entamoeba
histolytica virulence by monoxenic cultivation with Escherichia coli O55 is related to a decrease in
expression of the light (35-kilodalton) subunit of the Gal/GalNAc lectin. Infection and Immunity 67,
20962102.
Page, F.C. (1970) Two new species of Paramoeba from Maine. Journal of Protozoology 17, 421427.
Page, F.C. (1973) Paramoeba: a common marine genus. Hydrobiologia 41, 183188.
Page, F.C. (1987) The classification of the naked amoeba of the phylum Rhizopoda. Archiv fr
Protistenkunde 133, 199217.
Palmer, R., Carson, J., Ruttledge, M., Drinan, E. and Wagner, T. (1997) Gill disease associated with
Paramoeba in sea-reared Atlantic salmon in Ireland. Bulletin of the European Association of Fish Pathologists 17, 112114.
Parsons, H., Nowak, B.F., Fisk, D. and Powell, M. (2001) Effectiveness of commercial freshwater bathing as
treatment against amoebic gill disease in Atlantic salmon. Aquaculture 195, 205210.
Perkins, F.O. and Castagna, M. (1971) Ultrastructure of the Nebenkorper or secondary nucleus of the parasitic amoeba Paramoeba perniciosa (Amoebida, Paramoebidae). Journal of Invertebrate Pathology 17,
180193.
Powell, M.D. and Clark, G.A. (2001) Bath additives for removal of Paramoeba from salmon gills: efficacy and
toxicity. In: Battaglene, S.C. and Cobcoft, J.M. (eds) The First Scientific Conference of the Atlantic Salmon
Subprogram Handbook. CSIRO Marine Laboratories, Hobart, Tasmania, Australia, pp. 1718.
Powell, M.D. and Nowak, B.F. (2001) Cardiovascular effects of AGD: preliminary investigation. In:
Battaglene, S.C. and Cobcoft, J.M. (eds) The First Scientific Conference of the Atlantic Salmon
Subprogram Handbook. CSIRO Marine Laboratories, Hobart, Tasmania, Australia, pp. 1516.
Powell, M.D., Fisk, D. and Nowak, B. (2000) Effects of graded hypoxia on Atlantic salmon infected with
amoebic gill disease. Journal of Fish Biology 56, 10471057.
Powell, M., Harris, J., Attard, M., Green, T. and Sadler, J. (2002) Chloramine-T as a treatment for the removal
of gill amoebae in seawater. In: Battaglene, S. and Cobcroft, J. (eds) The Second Scientific Conference of
the Atlantic Salmon Aquaculture Subprogram. Hobart, Tasmania, Australia, pp. 5861.
Roberts, S. and Powell, M. (2002) Improving freshwater bathing as a treatment for amoebic gill disease.
In: Battaglene, S. and Cobcroft, J. (eds) The Second Scientific Conference of the Atlantic Salmon
Aquaculture Subprogram. Hobart, Tasmania, Australia, 6264.
Rodger, H.D. and McArdle, J.F. (1996) An outbreak of amoebic gill disease in Ireland. Veterinary Record 139,
348349.
Roubal, F.R., Lester, R.J.G. and Foster, C.K. (1989) Studies on culture and gill-attached Paramoeba sp.
(Gymnamoebae: Paramoebidae) and the cytopathology of paramoebic gill disease in Atlantic salmon,
Salmo salar L. from Tasmania. Journal of Fish Diseases 12, 481492.
Phylum Amoebozoa
15
Sawyer, T.K., Hnath, J.G. and Conrad, J.F. (1974) Thecamoeba hoffmani sp. n. (Amoebida: Thecamoebidae)
from gills of fingerling salmonid fish. Journal of Parasitology 60, 677682.
Sawyer, T.K., Hoffman, G.L., Hnath, J.G. and Conrad, J.F. (1975) Infection of salmonid fish gills by aquatic
amoebas (Amoebida: Thecamoebidae) In: Ribelin, W.E and Magaki, G. (eds) The Pathology of Fishes.
University of Wisconsin Press, Madison, Wisconsin, pp. 143150.
Sims, G.P., Rogerson, A. and Aitken, R. (1999) Primary and secondary structure of the small-subunit RNA of
the naked, marine amoeba Vanella anglica: phylogenetic implications. Journal of Molecular Evolution
48, 740749.
Speare, D.J. (1999) Nodular gill disease (amoebic gill infestation) in Arctic char, Salvelinus alpinus. Journal of
Comparative Pathology 121, 277282.
Sprague, V. and Beckett, R.L. (1969) A new species of Paramoeba (Amoebida, Paramoebidae) parasitic in the
crab Callinectes sapidus. Journal of Invertebrate Pathology 14, 167174.
Tan, C., Nowak, B.F. and Hodson, S. (2000) Biofouling as a reservoir of Paramoeba pemaquidensis
(Page 1970). In: Nowak, B.F. (ed.) AGD in the New Millennium. Tasmanian Aquaculture and Fisheries
Institute, Taroona, Tasmania, Australia.
Tan, C., Nowak, B.F. and Hodson, S. (2002) Biofouling as a reservoir of Neoparamoeba pemaquidensis
(Page 1970), the causative agent of amoebic gill disease in Atlantic salmon. Aquaculture 210, 4958.
Taylor, P.W. (1977) Isolation and experimental infection of free-living amoebae in freshwater fishes. Journal
of Parasitology 63, 232237.
Wong, F. and Elliot, N. (2000) Update on CSIRO genetic research into AGD. In: Nowak, B.F. (ed.) AGD in the
New Millennium. Tasmanian Aquaculture and Fisheries Institute, Taroona, Tasmania, Australia.
Zilberg, D. and Munday, B.L. (2000) Pathology of experimental amoebic gill disease in Atlantic salmon
(Salmo salar L.) and the effect of pre-maintenance in seawater. Journal of Fish Diseases 23, 401407.
Zilberg, D. and Munday, B.L. (2001a) Responses of Atlantic salmon, Salmo salar L., to Paramoeba antigens
administered by a variety of routes. Journal of Fish Diseases 24, 181183.
Zilberg, D. and Munday, B.L. (2001b) The effect of anti-Paramoeba antibodies on Paramoeba sp., the causative agent of amoebic gill disease. Journal of Fish Diseases 24, 345350.
Zilberg, D., Nowak, B., Carson, J. and Wagner, T. (1999) Simple gill smear staining for the diagnosis of amoebic gill disease. Bulletin of the European Association of Fish Pathologists 19, 186189.
Zilberg, D., Findlay, V.L., Girling, P. and Munday, B.L. (2000) Effects of treatment with levamisole and
glucans on mortality rates in Atlantic salmon (Salmo salar L.) suffering from amoebic gill disease. Bulletin
of the European Association of Fish Pathologists 20, 1519.
Zilberg, D., Gross, A. and Munday, B.L. (2001) Production of salmonid amoebic gill disease by exposure to
Paramoeba sp. harvested from gills of infected fish. Journal of Fish Diseases 24, 7982.
Phylum Dinoflagellata
Introduction/Economic Importance
Dinoflagellates are commonly found in
aquatic ecosystems. They are important primary producers and consumers, as well
as endosymbionts in many invertebrates
(Taylor, 1987; Fensome et al., 1993). Many
dinoflagellates produce ichthyotoxins, which
have caused mass mortalities in wild and
cultured fish (Noga, 1998; Rensel and Whyte,
2003). About 140 of the approximately 2000
known living species are parasites, most
being parasites of invertebrates (Drebes,
1984). Five genera have been reported as fish
parasites: Amyloodinium, Piscinoodinium,
Crepidoodinium, Ichthyodinium and Oodinioides. One unclassified dinoflagellate has
also been described (Buckland-Nicks and
Reimchen, 1995). Only Amyloodinium,
Piscinoodium and Ichthyodinium are of any
known or potential economic significance.
While there is evidence that the toxic dinoflagellate Pfiesteria can also exhibit parasitic tendencies (Vogelbein et al., 2002), it is
not a typical parasite and thus will not be
discussed in this review.
Amyloodinium
Amyloodinium ocellatum is the most common
and important dinoflagellate parasitizing fish
16
Piscinoodinium
Piscinoodinium is morphologically and
developmentally similar to Amyloodinium
and causes a highly similar disease in tropical freshwater fish. Most reports of the parasite have been in fish held in aquaria (Jacobs,
1946; Schperclaus, 1951; ReichenbacheKlinke, 1955; Geus, 1960; van Duijn, 1973;
Lom and Schubert, 1983) but it has more
recently been recognized as a commercial
Table 2.1.
Geographical location
Hosts
References
Phylum Dinoflagellata
Continued
17
18
Table 2.1.
Geographical location
Hosts
References
Sea bream
European sea bass
Sea bream
European sea bass
Mullet (Mugilidae)
Tilapia (Oreochromis mossambicus)
Sobaity sea bream (Acanthopagrus cuvieri )
Pacific threadfin (Polydactylus sexfilis)
Grey mullet
Ayu (Plecoglossus altivelis)
Mulloway (Argyrosomus japonicus)
Barramundi (Lates calcarifer )
list includes reported infections only where the contagion was identified in a local source or was introduced into local waters with the fish. It does not
include numerous other reports from captive aquarium fishes worldwide.
2Note that almost all cases were diagnosed as A. ocellatum via light microscopy; ultrastructural confirmation was not performed in most instances.
Phylum Dinoflagellata
Host Range
Amyloodinium
A. ocellatum is one of the few fish parasites
that can infest both elasmobranchs and
teleosts (Lawler, 1980) and almost all fish
that live within its ecological range are susceptible to infestation. Amyloodinium has
continued to be one of the most serious
impediments to warmwater mariculture,
with well over 100 species known to be susceptible. Even freshwater fish, such as
centrarchids (Lepomis), tilapia (Tilapia) or
guppies (Poecilia reticulata), are highly susceptible to infestation when they are in saline
waters (Lawler, 1980; Noga and Bower, 1987;
Kuperman and Matey, 1999; Table 2.1). In
one instance, it has been observed to even
infect a monogenean worm, another fish
ectoparasite (Colorni, 1994), attesting to its
cosmopolitan feeding habits.
Piscinoodinium
Many tropical fish are susceptible to
Piscinoodinium, with anabantids (Siamese
fighting fish, gouramis), cyprinids (goldfish,
barbs) and cyprinodontids (killifish) frequently affected (Noga, 1996). Tilapia have
19
20
Taxonomy/Systematics
Effective control of parasitic dinoflagellates
requires a thorough understanding of their
epidemiology, including host and geographical range, as well as other factors affecting
transmission. These factors can only be discerned via a thorough understanding of the
phylogenetic relationships among the different parasite isolates. Such studies may also
lead to more effective methods for diagnosis
of specific pathogens.
Having characteristics of both plants
and animals, dinoflagellates are classified
as both zoological and botanical taxa. Our
review will use the botanical nomenclature,
since the most recent taxonomic studies
of these parasites have followed this classification scheme. Two groups within the
phylum Dinoflagellida have fish-parasitic
species: the class Blastodiniphyceae, order
Blastodiniales, family Oodiniaceae (having
the genera Amyloodinium, Piscinoodinium
and Crepidoodinium); and the class
Syndiniophyceae, order Syndiniales, family
Syndinidae (having the genus Ichthyodinium) (Fensome et al., 1993). There is
increasing evidence that, even within the
Table 2.2.
Amyloodinium
Piscinoodinium
Crepidoodinium
Severe
Moderate
Mild
Deep
Moderate
None
Stomopode
Clove-like
bodies
Stigma
Chloroplasts
Food
vacuoles
Lytic
bodies
Mucocysts
Starch
granules
Y
N
N
Y
N
N
Y
N?1
N
N
Y
Y
Y
N
N
Y
N
N
Y
Y
Y
Y
Y
Y
Phylum Dinoflagellata
Genus
Host
cytopathology
1P.
pillulare dinospores have been reported by Hirschmann and Partsch (1953) as having a stigma. However, others have not observed a stigma in either
P. pillulare (Lom, 1981) or P. limneticum (Jacobs, 1946).
21
22
Phylum Dinoflagellata
Syndinid dinoflagellates
The syndinids include intracellular parasites and those that inhabit cavities.
Ichthyodinium Hollande and Cachon, 1953
(I. chabelardi Hollande and Cachon, 1953)
was classified by Taylor (1987) as a member
of the subclass Syndiniophycidae, order
Syndiniales, family Syndiniaceae. However,
molecular studies will be needed to confirm
its taxonomic placement and determine
whether one or several species are involved.
23
Unclassified dinoflagellate
The stickleback parasite from British
Columbia has not yet been classified. Interestingly, this parasite has only been found
in a single lake in British Columbia and
it has been suggested that it might have
co-evolved with its highly geographically
restricted stickleback host (Buckland-Nicks
and Reimchen, 1995).
Fig. 2.1. Life cycle of oodinid parasites of fish (from Noga, 1987; courtesy of Science).
(A) Parasitic trophont that feeds on the skin and gill epithelium. (B) Encysted tomont stage that divides to
produce free-swimming infective dinospores (C).
24
Oodinids
Amyloodinium,
Piscinoodinium
and
Crepidoodinium have the same life cycle
(Fig. 2.1). They feed as sessile, sac-like
trophozoites (trophonts) on the skin or gill
epithelium (Figs 2.2, 2.3). Trophonts are
bounded by a cell wall with a thin, resistant, pellicular envelope. Beneath the
cell membrane is a layer of flat amphiesmal
vesicles, as is found in free-living dinoflagellates (Dodge and Crawford, 1970). Various organelles, including chloroplasts,
mitochondria, Golgi apparatus, trichocysts
and mucocysts, may be present.
Trophonts have a prominent stalk
(Fig. 2.4), a cytoplasmic evagination with
holdfasts that anchors the parasite to the
host and in some cases absorbs nutrients.
The stalk is a characteristic of oodinid (and
blastodinid) dinoflagellates. After feeding,
the trophont detaches and withdraws its
stalk, forms a reproductive cyst (tomont) and
divides asexually several times (Fig. 2.2B).
After the last asexual division, motile forms
(dinospores; also referred to as gymnospores
or zoospores) are released, which are capable of infecting a new host. This type of
reproduction is termed palintomy. Dinospores have a girdle, sulcus and two flagella
(Fig. 2.3B). Recently, it has been shown that
Amylooodinium dinospores also have a
peduncle (which might form the trophonts
stomopode) as well as an associated rhizoidlike complex (Landsberg et al., 1994), previously only known in the trophont. Dinospores
are fairly uniform in size and the number of
dinospores produced per tomont is roughly
proportional to the size of the trophont.
Amyloodinium
LIFE CYCLE AND MORPHOLOGY. Light microscopic aspects of the life cycle have been
described in detail (Brown, 1934; Nigrelli,
1936; Brown and Hovasse, 1946). The
trophont is pear-shaped to ovoid and up to
350 m long (Figs 2.2, 2.3). Trophonts are
reported to have a cellulose wall consisting
of a theca with amphiesmal plates. Thecal
armour is complete except for a gap at the
Phylum Dinoflagellata
Fig. 2.2. Light micrographs of Amyloodinium (A) Trophonts (arrows) on a damselfish (Dacyllus sp.) fin.
(B) Tomonts in various stages of development: (i) single cell (just differentiated from trophont);
(ii) two-cell; (iii) nearly mature; and (iv) mature, with some dinospores already having exited the tomont
(photos courtesy of A. Colorni).
25
26
Fig. 2.3. Scanning electron micrographs of Amyloodinium: (A) A trophont attached to gill.
(B) A dinospore from a Gulf of Mexico isolate, showing armour or plates. Representative plates are
labelled (P). Note the dinospores antero-posterior compression (hamburger shape). L, longitudinal
flagellum; T, transverse flagellum (from Landsberg et al., 1994; courtesy of Diseases of Aquatic Organisms).
Phylum Dinoflagellata
27
Fig. 2.4. Host attachment mechanism of Amyloodinium. Scale is in microns. H, host cell;
AP, attachment plate; R, rhizoid; ST, stomopode tube; VF, velum-like pellicular folds;
F, flagellum; PC, pusular canal; L, fibrillar ledge; FV, food vacuole; N, nucleus; PH, phagoplasm.
(From Lom and Lawler, 1973; courtesy of Protistologica).
28
Fig. 2.5. Host attachment mechanism of Piscinoodinium. H, host cell; R, rhizocyst supposedly migrating
into the attachment disc; R, rhizocyst in position within the rhizotheca, embedded into the host cell
cytoplasm; MF, microfibrillar strands converging to form a perinema-like ring around the neck of the
attachment disc; N, notch on the upper surface of the attachment disc; above it, the theca is subtended by
a circular ribbon of microtubules and an electron-dense substance; C, chloroplast; S, starch grains; Mi,
mitochondrion; Mt, microtubular ribbons along the zone of special cytoplasm extending from nucleus into
the attachment disc; B, complex of basal bodies; F, flagellum; T, theca; L, subthecal lacunae; P, pusular
system. (From Lom, 1981; courtesy of Folia Parasitologica [Praha]).
Phylum Dinoflagellata
29
Syndinids
Ichthyodinium
I. chabelardi
parasitizes the vitelline (yolk) sac of sardines, where it rapidly multiplies, filling
the yolk sac with parasites; it causes larval
death by depleting energy reserves and rupturing the yolk sac after hatching. Sardine
eggs are mainly infected during colder
months, with peak prevalences in January
February. Up to 33% of all sampled eggs
have been infected in some surveys (Meneses
and Re, 1991). Infections are inapparent
until closure of the blastopore occurs in the
developing embryo (Meneses and Re, 1991).
In mackerel, where a similar parasite occurs,
it can be seen somewhat earlier in development (Meneses et al., 2003; www.plank.
oupjournals.org).
The life cycle is quite complicated
(Fig. 2.7). The earliest detectable parasitic
stage in the yolk sac is the primordial
schizont (Figs 2.7, 2.8), which begins as a
spherical, uninucleated trophont, 815 m
in diameter; it undergoes multiple nuclear
divisions to form a large (100200 m),
multinucleated plasmodium. The primordial schizont then cleaves into several
uninucleate, elongated secondary schizonts,
which undergo further divisions. In the
final stage, last generation schizonts are
produced, which resemble the early primordial schizonts. In the advanced stages,
parasites fill the yolk sac (Fig. 2.8). After the
host dies, the freed parasite divides once or
twice more in the water. The resultant
free-swimming dinospores survive several
days in culture but, under laboratory conditions, are not infective to sardine eggs by
LIFE CYCLE AND MORPHOLOGY.
30
Fig. 2.6. Morphology of Crepidoodinium. Scales are in microns (from Lom and Lawler, 1973; courtesy
of Protistologica). (A) Trophont with a rounded nucleus and the flattened holdfast organelle ramified into
numerous lobose or finger-like projections from which the small attachment rhizoids arise.
(B) and (C) Enlarged holdfast portions of the trophonts; only the tips of small rhizoids emanating from these
major and minor branches contact the host epithelial cells.
Fig. 2.7. Ichthyodinium developmental stages in Atlantic mackerel. (From Meneses et al., 2003;
courtesy of Journal of Plankton Research.)
Phylum Dinoflagellata
31
HostParasite Relationships
either exposure to eggs in water or direct
inoculation of dinospores into the yolk
mass (Hollande and Cachon, 1953).
Unclassified dinoflagellate
The life cycle
of the stickleback parasite from British
Amyloodinium
Amyloodinium causes amyloodiniosis,
marine velvet disease, marine Oodinium
disease and oodiniosis.
Clinical signs/pathology
Clinical signs of amyloodiniosis include
anorexia, depression, dyspnoea (swimming
32
Phylum Dinoflagellata
33
34
Fig. 2.9. Piscinoodinium infestation of the dorsal fin of a tiger barb (Barbus). Each refractile white focus
is a parasite.
Phylum Dinoflagellata
Unclassified dinoflagellate
Clinical signs/pathology
The stickleback parasite from British
Columbia induces an extremely severe epidermal hyperplasia on the skin, resulting in
a grossly visible, white gelatinous coating
that can cover a large area of the body
(Reimchen and Buckland-Nicks, 1989). This
35
In Vitro Culture
Amyloodinium
Amyloodinium can be maintained in vivo
by serial exposure of infective dinospores to
susceptible hosts (Lawler, 1980; Bower
et al., 1987), but this is very labour-intensive
and requires considerable space for holding
fish. Noga and Bower (1987) developed a
method of passaging the parasite on
gnotobiotic fish larvae. Individual tomonts
were decontaminated by repeated passage
through several baths of sterile saline with
antibiotics (Noga, 1992). Guppies (P. reticulata) were then successfully infected with
germ-free dinospores. The parasites completed at least one full life cycle on the host
fish and were serially passaged up to six
times.
In some cases, the parasites on
gnotobiotic larvae continued to grow and
reproduce long after the host had died.
This suggests that factors other than death
of the host per se are responsible for the
parasite normally leaving the host. Rapid
exodus from a dead host is common among
other fish ectoparasites (Hoffmann, 1967).
Amyloodinium survives for several days
after its host dies so long as the tissues that
support its growth are nourished (Noga and
Bower, 1987).
Organ cultures of fish larvae also supported parasite growth (Noga and Bower,
1987) and A. ocellatum readily propagates
on a fish gill cell line (G1B cells, derived
from walking catfish (Clarias batrachus),
36
Phylum Dinoflagellata
Other dinoflagellates
It has been hypothesized that the presence
of chloroplasts and lack of food vacuoles
suggest that Piscinoodinium can derive
nutrition from photosynthesis (Lom and
Schubert, 1983). The extensive ramifying
nature of the attachment organelle implies
that some nutrition is also obtained from
the host, probably by osmotrophy.
In Crepidoodinium, the minute rhizoids contact but do not penetrate enough
of an area of the host cell membrane for
osmotrophy to supply much, if any, nutrition
(Lom et al., 1993). Thus Crepidoodinium is
more appropriately termed an ectocommensal
rather than a parasite. It is an autotroph
that probably uses the fish primarily as an
attachment site.
Diagnosis of Infections
Classical methods
Gross skin infestations of oodinids are most
easily seen on dark-coloured fish. Skin
parasites are best observed using indirect
illumination, such as by shining a flashlight
on top of the fish in a darkened room.
Observing fish against a dark background
also helps. While presumptive diagnosis
of oodinid infestation may sometimes be
made from the gross clinical appearance
(e.g. velvet), microscopic identification of
37
trophonts or tomonts is required for definitive diagnosis. If fish are small, they can
be restrained in a dish of water, and eyes,
skin and fins examined under a dissecting
microscope (Fig. 2.9). Lifting the operculum
allows examination of the gills. Trophonts
are removed by gently brushing or scraping
the skin or gills, followed by microscopic
examination of the sediment, which contains detached parasites. Snips of gill are
also removed from living or recently dead
fish for examination (Lawler, 1977b, 1980;
Noga, 1996).
Freshwater dips dislodge marine
dinoflagellates and are especially useful for
small fish. Fish are placed in a beaker of
fresh water for 13 min. After 1520 min,
tomonts settle to the bottom of the beaker.
Saltwater baths can be used to dislodge
Piscinoodinium. They are detected using a
dissecting or inverted microscope (Bower
et al., 1987). Fish are best examined while
still living or soon after death, as parasites
detach shortly after host death. Interestingly, the kinetoplastid flagellate parasite
Ichthyobodo is detached from fish by treatment with tricaine anaesthetic in poorly
buffered water (Callahan and Noga, 2002).
Whether tricaine has the same effect on
oodinid dinoflagellates is unknown.
38
Phylum Dinoflagellata
39
Other dinoflagellates
Heating water to 3334C reportedly controls
Piscinoodinium infestations (Untergasser,
1989), but some aquarium fish cannot tolerate such high temperatures. However, for
all treatments, the temperature should be
raised to the parasites optimum ( 25C) to
ensure that the susceptible stage (dinospore) is rapidly exposed to the treatment.
Temperature should be raised no more
than 1C/h.
The safest and most effective treatment
for piscinoodiniosis is salt (about 1 teaspoon
NaCl or artificial seawater salt per 5 gallons
of water) for 1014 days. For infestations
requiring more immediate treatment, a 35 g/l
NaCl dip for 13 min dislodges trophonts.
Immersion for 35 days in 7 g/l NaCl
40
impact. More effective methods are especially needed to control disease caused by
Amyloodinium, the most important parasitic dinoflagellate affecting fish. It is very
difficult to eliminate the infestation and,
with the increasing regulations on the use
of drugs in aquaculture, it is necessary
to optimize the application of currently
approved drugs, as well as try other
approaches. One alternative to drugs is
environmental manipulation, but a better
understanding of environmental conditions
that affect parasite growth and survival is
needed, as well as a means for the feasible
utilization of these data in commercial
applications. The strong evidence for a protective immune response against Amyloodinium holds great promise for the eventual
development of protective vaccines. Likewise, the identification of potent non-specific
defences has the potential to allow broadspectrum protection.
Parasitic dinoflagellates are a polyphyletic group and molecular studies are
needed to clarify the taxonomic relationships among various taxa at all levels, from
major taxonomic groups to intraspecific
relationships. These data are also needed to
provide highly specific and sensitive diagnoses for effective biosecurity and management of infestations/infections in culture.
This will also help to avoid the unwanted
introduction and spread of exotic isolates
and would be especially useful for detecting latent carriers, which are the most
likely reservoirs for parasitic dinoflagellate
infestations/infections. Molecular studies
will also be critical to understanding
the taxonomic relationships and biology
of Ichthyodinium, which appears to affect
a large number of important feral fish
species.
Acknowledgements
Phylum Dinoflagellata
41
References
Aiello, P. and DAlba, A. (1986) Amyloodinium ocellatum infestation in yellowtail, Seriola dumerili, intensively reared in Sicily, Italy. Bulletin of the European Association of Fish Pathologists 6, 110111.
Alvarez-Pellitero, P., Sitja-Bobadilla, A. and Franco-Sierra, A. (1993) Protozoan parasites of wild and cultured
sea bass, Dicentrarchus labrax (L.), from the Mediterranean area. Aquaculture and Fisheries Management
24, 101108.
Barbaro, A. and Francescon, A. (1985) Parassitosi da Amyloodinium ocellatum (Dinophyceae) su larve di
Sparus aurata allevate in un impianto di riproduzione artificiale. Oebalia 11, 745752.
Baticados, M.C. and Quinitio, G.F. (1984) Occurrence and pathology of an Amyloodinium-like protozoan
parasite on the gills of grey mullet, Mugil cephalus. Helgolander Meeresunters 37, 595601.
Becker, C.D. (1977) Flagellate parasites of fishes. In: Krier, J.P. (ed.) Parasitic Protozoa. Academic Press,
New York, pp. 357416.
Benetti, D.D., Leingang, A.J., Russo, R., Powell, T.M., Cleary, D., Grabe, S.W., Feeley, M.W., Stevens, O.M.
and Main, K.L. (2001) Development of aquaculture methods for southern flounder, Paralichthys
lethostigma: II. Nursery and grow-out. Journal of Applied Aquaculture 11, 135146.
Bower, C.E. (1983) The Basic Marine Aquarium. C.H. Thomas, Springfield, Illinois, 269 pp.
Bower, C.E., Turner, D.T. and Biever, R.C. (1987) A standardized method of propagating the marine fish
parasite, Amyloodinium ocellatum. Journal of Parasitology 73, 8588.
Brown, E.M. (1931) Note on a new species of dinoflagellate from the gills and epidermis of marine fishes.
Proceedings of the Society of Zoology of London 1931, 341346.
Brown, E.M. (1934) On Oodinium ocellatum Brown, a parasite dinoflagellate causing epidemic disease in
marine fish. Proceedings of the Zoological Society of London Part 3 1934, 583607.
Brown, E.M. and Hovasse, R. (1946) Amyloodinium ocellatum (Brown), a peridinian parasitic on marine
fishes. Proceedings of the Zoological Society of London 116, 3346.
Buckland-Nicks, J. and Reimchen, T. (1995) A novel association between an endemic stickleback and a
parasitic dinoflagellate. 3. Details of the life cycle. Archiv fr Protistenkunde 145, 165175.
Burkholder, J.M. and Glasgow, H.B., Jr (1997) Pfiesteria piscicida and other Pfiesteria-like dinoflagellates:
behavior, impacts and environmental controls. Limnology and Oceanography 42, 10521075.
Burkholder, J.M., Noga, E.J., Hobbs, C., Glasgow, H.G., Jr and Smith, S.A. (1992) A new phantom
dinoflagellate, causative agent of major estuarine fish kills. Nature 358, 407410; 360, 768.
Cachon, J. and Cachon, M. (1987) Parasitic dinoflagellates. In: Taylor, F.J.R. (ed.) The Biology of
Dinoflagellates. Blackwell, Oxford, UK, pp. 71610.
Callahan, H.C. and Noga, E.J. (2002) Tricaine dramatically reduces the ability to diagnose protozoan
ectoparasite (Ichthyobodo necator) infections. Journal of Fish Diseases 25, 433437.
Cardeilhac, P. and Whitaker, B. (1988) Copper treatments: uses and precautions. Veterinary Clinics of
North America (Small Animal Practice) 18, 435448.
Carneiro, P.C.F., Martins, M.L. and Urbinati, E.B. (2002) Effect of sodium chloride on physiological responses
and the gill parasite, Piscinoodinium sp., in matrinxa, Brycon cephalus (Telostei: Characidae) subjected
to transport stress. Journal of Aquaculture in the Tropics 17, 337348.
Cecchini, S., Saroglia, M., Terova, G. and Albanesi, F. (2001) Detection of antibody response against
Amyloodinium ocellatum (Brown, 1931) in serum of naturally infected European sea bass by an enzymelinked immunoabsorbent assay (ELISA). Bulletin of the European Association of Fish Pathologists 21,
104108.
Cheung, P.J., Nigrelli, R.F. and Ruggieri, G.D. (1981) Oodinium ocellatum (Brown, 1931) (Dinoflagellata) in
the kidney and other internal tissues of pork fish, Anisostremus virginicus (L.). Journal of Fish Diseases 4,
523525.
42
Chein, C.-Y. and Huang, J.-D. (1993) An observation of infestation of Amyloodinium ocellatum in marine
aquaria and cultured marine fish in northern Taiwan. COA (Council of Agriculture) Fisheries Series (Taipei)
40, 6570.
Chonchuenchob, P., Sumpawapol, S. and Mearoh, A. (1987) Diseases of cage-cultured sea bass (Lates
calcarifer) in southwestern Thailand. Australian Centre for International Agricultural Research Proceedings Series 20, 194197.
Cobb, C.S., Levy, M.G. and Noga, E.J. (1998a) Development of immunity by the tomato clownfish
Amphiprion frenatus to the dinoflagellate parasite Amyloodinium ocellatum. Journal of Aquatic Animal
Health 10, 259263.
Cobb, C.S., Levy, M.G. and Noga, E.J. (1998b) Acquired immunity to amyloodiniosis is associated with an
antibody response. Diseases of Aquatic Organisms 34, 125133.
Collins, M.T., Gratzek, J.B., Dawe, D.L. and Nemetz, T.G. (1975) Effects of parasiticides on nitrification.
Journal of the Fisheries Research Board of Canada 32, 20332037.
Colorni, A. (1994) Hyperparasitism of Amyloodinium ocellatum (Dinoflagellida: Oodinidae) on
Neobenedenia melleni (Monogenea: Capsalidae). Diseases of Aquatic Organisms 19, 157159.
Dempster, R.P. (1972) A description of the use of copper sulfate as a cure for gill disease in marine tropical
fish tanks. Anchor 6, 450452.
Dodge, J.D. and Crawford, R.M. (1970) A survey of thecal fine structure in the Dinophyceae. Botanical
Journal of the Linnean Society 63, 5367.
Drebes, G. (1984) Life cycle and host specificity of marine parasitic dinophytes. Helgolander Meeresuntersuchungen
37, 603622.
Fajer-vila, E.J., Abdo-de la Parra, I., Aguilar-Zarate, G., Contreras-Arce, R., Zaldivar-Ramirez, J. and
Betancourt-Lozano, M. (2003) Toxicity of formalin to bullseye puffer fish (Sphoeroides annulatus Jenyns)
and its effectiveness to control ectoparasites. Aquaculture 223, 4150.
Fensome, R.A., Taylor, F.J.R., Norris, G., Sarjeant, W.A.S., Wharton, D.I. and Williams, G.L. (1993) A classification of living and fossil dinoflagellates. Micropaleontological Species Publication 7, 351.
Ferraz, E. and Sommerville, C. (1998) Pathology of Piscinoodinium sp. (Protozoa: Dinoflagellida), parasites
of the ornamental freshwater catfishes Corydoras spp. and Brochis splendens (Pisces: Callichthyidae).
Diseases of Aquatic Organisms 33, 4349.
Fielder, D.S. and Bardsley, W. (1999) A preliminary study on the effects of salinity on growth and survival of
mulloway Argyrosomus japonicus larvae and juveniles. Journal of the World Aquaculture Society 30,
380387.
Gallet de Saint-Aurin, D. (1987) Diseases of the sea bass Dicentrarchus labrax in intensive rearing programs in
Martinique French West Indies. Proceedings of the Gulf and Caribbean Fisheries Institute 38, 144163.
Gaspar, A.G. (1987) Algunas enfermedades de Pampanos cultivados experimentale en Venezuela. Revista
Latinoamericana de Acuicultura, Lima, Peru 33, 2744.
Geus, A. (1960) Nachtragliche Bemerkungen 24r Biologie des Fischpathogenen Dinoflagellater Oodinium
pillularis Schaperclaus. Aquarien Terrarien Zoologica 13, 305306.
Ghittino, P.S., Bignami, I.S., Annibali, A. and Boni, L. (1980) First record of serious oodiniasis in seabass
(Dicentrarchus labrax) intensively reared in brackish water. Rivista Italiana Piscicoltura e Ittiopatologica
15, 122127.
Giavenni, R. (1988) Some parasitic and other diseases occurring in sea-bass (Dicentrarchus labrax L.)
broodstock in Italy. Bulletin of the European Association of Fish Pathologists 8, 4546.
Hirschmann, H. and Partsch, K. (1953) Der Colisaparasit ein Dinoflagellat aus der Oodiniumgruppe.
Aquarien Terrarien Zoologica 6, 229234.
Hoffmann, G.L. (1967) Parasites of North American Freshwater Fishes. University of California Press, Berkeley,
California, 486 pp.
Hojgaard, M. (1962) Experiences made in Danmarks Akvarium concerning the treatment of Oodinium
ocellatum. Bulletin de lInstitut Ocanographique (Monaco) Numero Special 1A, 7779.
Hollande, A. and Cachon, J. (1952) Un parasite des oeufs de sardine: lIchthyodinium chabellardi, nov. gen.,
nov. sp. (peridinien parasite). Comptes Rendus Hebdomadaires Sances, Acadmie des Sciences, Paris
(Sr. D) 235, 976977.
Hollande, A. and Cachon, J. (1953) Morphologie et volutium dun pridinien parasite des oeufs de sardine
(Ichthyodinium chabelardi). Bulletin des Travaux publis par la Station dAquiculture et de Pche de
Castiglione (Alger) 4, 117.
Jacobs, D.L. (1946) A new parasitic dinoflagellate from freshwater fish. Transactions of the American Microscopic Society 65, 117.
Phylum Dinoflagellata
43
Jenkins, W.E., Heyward, L.D., Sr and Smith, T.I.J. (1998) Performance of domesticated striped bass Morone
saxatilis, palmetto bass and backcross hybrid striped bass (sunshine bass striped bass) raised in a tank
culture system. Journal of the World Aquaculture Society 29, 505509.
Johnson, S.K. (1984) Evaluation of Several Chemicals for Control of Amyloodinium ocellatum, a Parasite of
Marine Fishes. FDDL-M5, Texas A & M, College Station, Texas, 4 pp.
Kingsford, E. (1975) Treatment of Exotic Marine Fish Diseases. Palmetto Publishing, St Petersburg,
Florida, 90 pp.
Kuperman, B.L. and Matey, V.E. (1999) Massive infestation by Amyloodinium ocellatum (Dinoflagellida) of
fish in a highly saline lake, Salton Sea, California, USA. Diseases of Aquatic Organisms 39, 6573.
Kuperman, B.I., Matey, V.E. and Hurlbert, S.H. (2001) Parasites of fish from the Salton Sea, California, USA.
Hydrobiologia 466, 195208.
Landsberg, J.H., Smith, S.A., Noga, E.J. and Richards, S.A. (1992) Effect of serum and mucus of blue tilapia,
Oreochromis aureus on infectivity of the parasitic dinoflagellate, Amyloodinium ocellatum in cell
culture. Fish Pathology 27, 163169.
Landsberg, J.H., Steidinger, K.A., Blakesley, B.A. and Zondervan, R.L. (1994) Scanning electron microscope
study of dinospores of Amyloodinium cf. ocellatum, a pathogenic dinoflagellate of marine fish, and comments on its relationship to the Peridinales. Diseases of Aquatic Organisms 20, 2332.
Lauckner, G. (1984) Diseases caused by protophytans (algae). In: Kinne, O. (ed.) Diseases of Marine Animals,
Vol. IV, Part 1, Biologische Anstalt Helgoland, Hamburg, Germany, pp. 169180.
Lawler, A.R. (1967) Oodinium cyprinodontum n. sp., a parasitic dinoflagellate on gills of Cyprinodontidae of
Virginia. Chesapeake Science 8, 6768.
Lawler, A.R. (1968) Occurrence of the parasitic dinoflagellate Oodinium cyprinodontum Lawler, 1967, in
North Carolina. Virginia Journal of Science 19, 240 (abstract).
Lawler, A.R. (1977a) The parasitic dinoflagellate Amyloodinium ocellatum in marine aquaria. Drum and
Croaker 17, 1720.
Lawler, A.R. (1977b) Dinoflagellate (Amyloodinium) infestation of pompano. In: Sindermann, C.J. (ed.)
Disease Diagnosis and Control in North American Marine Aquaculture. Elsevier, Amsterdam,
pp. 257264.
Lawler, A.R. (1980) Studies on Amyloodinium ocellatum (Dinoflagellata) in Mississippi Sound: natural and
experimental hosts. Gulf Research Reports 6, 403413.
Levy, M.G., Poore, M.F., Coloni, A., Noga, E.J. and Litaker, R.W. A PCR assay for detection of Amyloodinium
ocellatum dinospores (in preparation).
Lewis, D.H., Wenxing W., Ayers, A. and Arnold, C.R. (1988) Preliminary studies on the use of chloroquine as
a systemic chemotherapeutic agent for amyloodinosis in red drum (Sciaenops ocellatus). Contributions
in Marine Science 30 (suppl.), 183189.
Litaker, R.W., Tester, P.A., Colorni, A., Levy, M.G. and Noga, E.J. (1999) The phylogenetic relationship of
Pfiesteria piscicida, cryptoperidiniopsoid sp., Amyloodinoum ocellatum and a Pfiesteria-like dinoflagellate
to other dinoflagellates and apicomplexans. Journal of Phycology 6, 13791389.
Litaker, R.W., Vandersea, M.W., Kibler, S.R., Madden, V.J., Noga, E.J. and Tester, P.A. (2002) Life cycle of the
heterotrophic dinoflagellate Pfiesteria piscicida. Journal of Phycology 38, 442463.
Lom, J. (1981) Fish invading dinoflagellates: a synopsis of existing and newly proposed genera. Folia
Parasitologica (Praha) 28, 311.
Lom, J. and Lawler, A.R. (1973) An ultrastructural study on the mode of attachment in dinoflagellates invading
the gills of Cyprinodontidae. Protistologica IX, 293309.
Lom, J. and Schubert, G. (1983) Ultrastructural study of Piscinoodinium pillulare (Schaperclaus, 1954) Lom,
1981 with special emphasis on its attachment to the fish host. Journal of Fish Diseases 6, 411428.
Lom, J., Rohde, K. and Dykova, I. (1993) Crepidoodinium australe n. sp., an ectocommensal dinoflagellate
from the gills of Sillago ciliata, an estuarine fish from the New South Wales coast of Australia. Diseases of
Aquatic Organisms 15, 6372.
McIlwain, T.D. (1976) Striped bass rearing and stocking program Mississippi. In: Completion Report
AFCS-5. National Marine Fisheries Service, p. 121.
Meneses, I. and Re, P. (1991) Infection of sardine eggs by a parasitic dinoflagellate (Ichthyodinium chabelardi
Hollande and Cachon) off the Portuguese coast. Boletin do Instituto National de Investigao das Pescas
(Portugal) 16, 6372.
Meneses, I., Vendrell, C. and Stratoudakis, Y. (2003) Mackerel (Scomber scombrus) eggs parasitized
by Ichtyodinium chabelardi in the north-east Atlantic: an overlooked source of mortality. Journal of
Plankton Research 25, 11771181.
44
Montgomery-Brock, D., Sato, V.T., Brock, J.A. and Tamaru, C.S. (2001) The application of hydrogen peroxide
as a treatment for the ectoparasite Amyloodinium ocellatum (Brown, 1931) on the Pacific threadfin
Polydactylus sexfilis. Journal of the World Aquaculture Society 32, 250254.
Nigrelli, R.F. (1936) The morphology, cytology, and life history of Oodinium ocellatum Brown, a
dinoflagellate parasitic on marine fishes. Zoologica 21, 129164.
Noga, E.J. (1987) Propagation in cell culture of the dinoflagellate Amyloodinium, an ectoparasite of marine
fishes. Science 236, 13021304.
Noga, E.J. (1989) Culture conditions affecting the in vitro propagation of Amyloodinium ocellatum. Diseases
of Aquatic Organisms 6, 137143.
Noga, E.J. (1992) Immune response to ectoparasitic protozoa: the infectivity assay. In: Stolen, J.S.,
Fletcher, T.C., Anderson, D.P., Kaattari, S.L. and Rowley, A.F. (eds) Techniques in Fish Immunology.
SOS Publications, Fair Haven, New Jersey, pp. 167176.
Noga EJ. (1996) Fish Disease: Diagnosis and Treatment. Iowa State University Press, Ames, Iowa, 376 pp.
Noga, E.J. (1998) Toxic algae, fish kills and fish disease. Fish Pathology 33, 337342.
Noga, E.J. and Bower, C.E. (1987) Propagation of the marine dinoflagellate Amyloodinium ocellatum under
germ-free conditions. Journal of Parasitology 73, 924928.
Noga, E.J., Smith, S.A. and Landsberg, J.H. (1991) Amyloodiniosis in cultured hybrid striped bass (Morone
saxatilis M. chrysops) in North Carolina. Journal of Aquatic Animal Health 3, 294297.
Noga, E.J., Colorni, A., Levy, M.G., Diamant, A., Smith, S.A., Landsberg, J.H. and Avtalion, R. (1992) The
Immune Response of Fish to Amyloodinium: a Model for the Protozoan Ectoparasites. Final Report to
Binational USIsrael Agricultural Research and Development Program Project, 90 pp.
Noga, E.J., Fan, Z. and Silphaduang, U. (2001) Histone-like proteins from fish are lethal to the parasitic
dinoflagellate Amyloodinium ocellatum. Parasitology 123, 5765.
Noga, E.J., Fan, Z. and Silphaduang, U. (2002) Host site of activity and cytological effects of histone-like proteins
against the parasitic dinoflagellate Amyloodinium ocellatum. Diseases of Aquatic Organisms 52, 207215.
Oestmann, D.J. and Lewis, D.H. (1995) A method for producing microbe-free Amyloodinium ocellatum
(Brown) with Percoll. Veterinary Parasitology 59, 169175.
Oestmann, D.J. and Lewis, D.H. (1996a) Improved cell culture propagation of Amyloodinium ocellatum.
Diseases of Aquatic Organisms 24, 173178.
Oestmann, D.J. and Lewis, D.H. (1996b) Effects of 3,N-methylglucamine lasalocid on Amyloodinium
ocellatum. Diseases of Aquatic Organisms 24, 179184.
Oestmann, D.J., Lewis, D.H. and Zettler, B.A. (1995) Clearance of Amyloodinium ocellatum dinospores by
Artemia salina. Journal of Aquatic Animal Health 7, 257261.
Ostrowski, A.C. and Molnar, A. (1998) Pacific Threadfin Polydactylus sexfilis (Moi) Hatchery Manual.
Publication No. 132, Center for Tropical and Subtropical Aquaculture, Waimanalo, Hawaii.
Overstreet, R.M. (1968) Parasites of the inshore lizardfish, Synodus foetens, from South Florida, including a
description of a new genus of Cestoda. Bulletin of Marine Science 18, 444470.
Overstreet, R.M. (1993) Parasitic diseases of fishes and their relationship with toxicants and other environmental factors. In: Couch, J.A. and Fournie, J.W. (eds) Pathobiology of Marine and Estuarine Organisms.
CRC Press, Boca Raton, Florida, pp. 111156.
Paperna, I. (1980) Amyloodinium ocellatum (Brown 1931) (Dinoflagellida) infestations in cultured marine fish
at Eilat, Red Sea: epizootiology and pathology. Journal of Fish Diseases 3, 363372.
Paperna, I. (1984) Reproduction cycle and tolerance to temperature and salinity of Amyloodinium ocellatum
(Brown 1931) (Dinoflagellida). Annales de Parasitologie Humaine et Compare 59, 730.
Paperna, I. and Zwerner, D. (1976) Parasites and diseases of striped bass, Morone saxatilis (Walbaum), from
the lower Chesapeake Bay. Journal of Fish Biology 9, 267287.
Paperna, I. and Baudin Laurencin, F. (1979) Parasitic infections of sea bass, Dicentrarchus labrax and gilt head
sea bream, Sparus aurata, in mariculture facilities in France. Aquaculture 16, 173175.
Paperna, I., Colorni, A., Ross, B. and Colorni, B. (1981) Diseases of marine fish cultured in Eilat mariculture
project based at the Gulf of Aqaba, Red Sea. European Mariculture Society Special Publication 6, 8191.
Pederson, B.H. and Koie, M. (1994) A protistan endoparasite in embryos and yolk-sac larvae of cod Gadus
morhua and turbot Scophthalmus maximus. Diseases of Aquatic Organisms 19, 3946.
Plumb, J.A. (1979) Principal Diseases of Farm-raised Catfish. Southern Cooperative Series No. 225, Auburn
University, Alabama, 92 pp.
Ramesh, K.S., Mohan, C.V., Shankar, K.M. and Amed, I. (2000) Piscinoodinium sp. infection in juveniles of
common carp (Cyprinus carpio), mahseer (Tor khudree) and tilapia (Oreochromis mossambicus). Journal
of Aquaculture in the Tropics 15, 281288.
Phylum Dinoflagellata
45
Introduction
Members of the order Diplomonadida and
class Kinetoplastea are flagellated protozoans that are generally found in the digestive tract and blood/body fluids of vertebrates
(fishes, amphibians, reptiles, birds and
mammals). In addition, some species are
ectoparasitic and are found on the body surface and/or gills of fishes.
Diplomonads (Figs 3.1 and 3.2) have
bilateral symmetry, and each parasite has
two karyomastigonts. A karyomastigont
consists of one to four flagella, of which one
is recurrent, and an axial structure of microtubules and accessory filaments (Lee, 1985).
Most of these parasites are extracellular in
the intestinal tract, and the active trophozoites multiply by binary fission. They
usually form cysts, which are passed into
the external environment with faeces, but
cysts have not been found in some species.
Transmission from host to host is direct, and
infection normally occurs via the ingestion
of cysts or trophozoites.
Kinetoplastids (Figs 3.7, 3.12 and 3.33)
have one or two flagella, an axoneme and
a paraxial rod, which arise from a flagellar
pit (Vickerman, 1976a). This parasite has a
mitochondrion that contains DNA, and it
46
47
Fig. 3.1. Trophozoites (light microscope) of Spironucleus from the blood of an experimentally infected
chinook salmon ( 1000) (Guo and Woo, unpublished).
48
P.T.K. Woo
Fig. 3.2. Trophozoite (light microscope) of Giardia microti from the intestine of a naturally infected
meadow vole (Microtus pennsylvanicus) from Guelph, Ontario, Canada ( 1150; original).
49
50
P.T.K. Woo
that the Poynton et al. (2004) study indicates that the hexamitid from rainbow trout
in Northern Ireland (Ferguson, 1979) is a
Spironucleus, but is it H. salmonis? As indicated by Sterud et al. (1997), a very important factor in a systematic study of this type
is that the parasite should be from the type
host and type locality of H. salmonis. This
obviously was not done, and it is another
reason why the proposal made by Poynton
et al. (2004) is not used in this review.
Based on gene sequences (e.g. genes for
elongation factor 1 alpha, a-tubulin) Keeling
and Doolittle (1996, 1997) suggested that
the two hexamitids isolated from the systemic disease in salmonids (Mo et al., 1990;
Kent et al., 1992; Poppe et al., 1992) are
not Spironucleus. This suggestion has not
been accepted by other workers (e.g. Sterud
et al., 1998, 2003; Guo and Woo, 2004a,b).
Keeling and Doolittle (1996, 1997) also indicated that the two isolates from salmonids,
one now described as S. barkhanus (Sterud
et al., 1997) and the other perhaps being
an undescribed species or subspecies of
Spironucleus (F.C. Guo and P.T.K. Woo,
unpublished), belong to a single species.
This latter parasite is currently under study
and will be referred to as the chinook
Spironucleus in the current discussion.
Parasite morphology, host specificity
and life cycle
Morphology
Live trophozoites of Hexamita and Spironucleus vary from elongated to nearly spherical and the two genera are usually difficult
to separate. The pyriform trophozoites
become more spherical before they divide.
The lengths of live organisms may reach
20 m and the organisms have bilateral symmetry. Each side has a nucleus and four
flagella and this is the karyomastigont. The
four kinetostomes of each karyomastigont
are arranged in two pairs, with the two anterior kinetostomes designated as K1 and K2
while the two posterior ones are K3 and R (R
is associated with the recurrent flagellum).
The six anterior flagella are for locomotion,
while the two recurrent flagella pass through
51
52
P.T.K. Woo
53
Fig. 3.4. A large ulcer on the body surface of Atlantic salmon experimentally infected with Spironucleus
barkhanus (from Guo and Woo, 2004a; courtesy of Diseases of Aquatic Organisms).
54
P.T.K. Woo
Susceptibility
Families and species of fish are known to
differ in their susceptibility to hexamitid
infection and disease; for example, codfish
(Gadidae) and porgies (Sparidae) are presumed to be susceptible to natural infections (Alexeieff, 1910), while brook trout
(Salvelinus fontinalis) is the salmonid most
susceptible to H. salmonis under hatchery
conditions (Moore, 1922). The parasite does
not cause clinical disease in coho salmon
(Oncorhynchus kisutch), while steelhead
trout (Oncorhynchus mykiss) suffer mortality (Uzmann et al., 1965). In many freshwater tropical fishes, there are no clinical
signs (presumably infected with S. vortens)
of infections, whereas, in angelfish, discus
(cichlids) and gouramis (belontiids), clinical disease is evident (Gratzek, 1988). Similarly, S. barkhanus is not known to cause
clinical disease in naturally infected grayling
and Arctic charr but causes systemic disease and mortality in Atlantic salmon
(Sterud et al., 1997, 1998; Guo and Woo,
2004b). However, Guo and Woo (2004a)
found no significant difference in the susceptibility of three families of Atlantic
salmon to experimental S. barkhanus infection. It is likely that some fish stocks
(within a susceptible host species) are more
susceptible than others, as has been shown
in salmonid cryptobiosis (see later section).
Susceptibility to disease may also, in
part, be related to the age of the host; for
example, H. salmonis is not known to cause
clinical disease in adult salmonids, while it
may be pathogenic to younger fish (Becker,
1977). This is similar in tropical aquarium
fishes (Bassleer, 1983). However, age susceptibility needs more careful laboratory studies
as some adult fish in natural populations
may have acquired immunity due to prior
exposure(s) to the parasite as juvenile fish.
Clinical signs and pathology
In general, hexamitid infections in the
intestine are usually chronic, with low
numbers of parasites, but in heavy infections clinical disease may occur. Clinical
signs of the disease in natural infections
include anorexia, emaciation, weight loss,
55
Fig. 3.5. Unilateral exophthalmia in Atlantic salmon experimentally infected with Spironucleus barkhanus
(from Guo and Woo, 2004a; courtesy of Diseases of Aquatic Organisms).
56
P.T.K. Woo
Fig. 3.6. Large nodules in the liver (a) and globulated spleen (b) in Atlantic salmon experimentally infected
with Spironucleus barkhanus (from Guo and Woo, 2004b; courtesy of Diseases of Aquatic Organisms).
TYI-S-33 medium (Keister, 1983) and antibiotics. The flagellate multiplied rapidly at
10C and multiplication was slower at 5C.
The addition of bile (30960 mg bile per litre
of medium) supported better growth than
those either without bile or with a higher
amount of bile (Uldal and Buchmann, 1996).
The modified TYI-S-33 medium
(Keister, 1983) at 10C supported rapid
in vitro multiplication of S. barkhanus from
Atlantic salmon and the chinook Spironucleus from chinook salmon (Sterud, 1998;
F.C. Guo and P.T.K. Woo, unpublished).
Both parasites multiplied rapidly by binary
fission. Also, isolates from muscle
abscesses of Atlantic salmon and from the
gall bladder of grayling were grown at 5, 10,
15 and 20C. However, the isolate from
grayling had a slightly higher optimum temperature and a higher upper temperature
limit than the salmon isolate (Sterud, 1998).
Parasite nutrition
Endocytosis and exocytosis occur at the
cytostomes (Brugerolle, 1974; Kulda and
Nohynkova, 1978; Lee, 1985; Vickerman,
1990). In Hexamita, the cytostomes can
dilate to ingest large bacteria; however, in
Spironucleus only smaller bacteria and particles are ingested because of smaller
cytostomes (Vickerman, 1990). Poynton and
Morrison (1990) suggested that S. torosa
Diagnosis of infection
In heavy infections the parasite is easily
detected using light microscopy. Samples
should be obtained from freshly killed fish,
and thin smears (e.g. along the gastrointestinal tract, from the blood and imprints of
internal organs) should be air-dried and
fixed in alcohol before staining.
To confirm the number of flagella and the
body shape which are consistent with
hexamitids, living organisms should be examined in wet mount preparations (vaselineringed cover slips) under a light microscope
using bright field or phase contrast or
Normarski illumination. The addition of viscous Protoslo or methyl cellulose will slow
the organisms for closer examinations (Lee
et al., 1985). For the flagella to stain well
(Fig. 3.1), thin smears should be post-fixed in
10% buffered formalin (Woo, 1969), as was
done for Cryptobia and Trypanosoma (see
later sections). Also, the two nuclei stain well
in post-fixed smears and organ imprints.
As indicated earlier, S. barkhanus has
an initial blood phase after infection before
the parasite disappears from the blood and
is found mainly in internal organs (Guo and
Woo, 2004a). The haematocrit centrifuge
technique, which is very useful for detecting low numbers of Trypanosoma (e.g.
Woo, 1969, 1970) and Cryptobia (e.g. Woo
and Wehnert, 1983) in the blood, is also
very sensitive for the detection of Spironucleus. The technique is especially useful
57
58
P.T.K. Woo
non-nitroimidazoles (e.g. amprolium, bithionol, febantel, praziquentel) have no detectable effects on the number of parasites in
infected fish (Tojo and Santamarina, 1998).
Dimetridazole, metronidazole and mebendazole are quite efficient in inhibiting multiplication of S. vortens under in vitro conditions
(Sangmaneedet and Smith, 1999).
Ichthyobodoses
ICHTHYOBODOSIS IN FRESHWATER FISHES
Introduction
Ichthyobodosis in freshwater fishes is
caused by the ectoparasite Ichthyobodo
necator. The disease was known as costiasis
after the previous name of the parasite, Costia
necatrix, which was originally described
from brown trout (Salmo trutta) alevins in
France. The organism has a free-living stage
in water (Figs 3.7 and 3.8) and a parasitic
stage (Fig. 3.9), which is usually attached to
dorsal fins and the tips of secondary gill
lamellae (Fig. 3.10) of fish (Fish, 1940;
Tavolga and Nigrelli, 1947). The free-living
stage has a long and a short flagellum
(Fig. 3.7); however, these flagella are not
seen when the organism attaches to epithelial cells (Fig. 3.9).
59
60
P.T.K. Woo
Hostparasite relationships
Host susceptibility
Malnourished and/or juvenile fish are
more severely affected than healthy adults
(Robertson, 1985; Rosengarten, 1985), and
high mortality (4073%) is associated with
heavy infections (e.g. Robertson, 1979;
Poppe and Hastein, 1982; Awakura et al.,
1984; Rosengarten, 1985; Urawa, 1987).
Outbreaks and infections on cyprinids
become more severe when infected fish
from outdoor ponds or tanks are transferred
to indoor tanks (e.g. Bauer, 1959; Bauer
et al., 1969). Important factors that contribute to disease outbreaks include stress on
the fish due to transfer and higher indoor
temperature, which promotes more rapid
parasite multiplication.
Swordtails (Xiphophorus hellerii) are
very susceptible and usually die 814
days after infection (Tavolga and Nigrelli,
1947), while platyfish (Platypoecilus maculates) are less susceptible. Tilapia (Tilapia
macrocephala) and guppies (Poecilia reticulata) have light infections or the infections are confined to the caudal region.
It is generally assumed that some protective immunity is acquired on recovery
from an infection. Rainbow trout (O. mykiss)
immunized with either whole Tetrahymena
thermophila or their cilia were more resistant
than nave fish (Wolf and Markiw, 1982).
Course of infection and foci of investigation
Parasitaemias on salmonids usually peak at
about 4 weeks after fish larvae start feeding
and mortality is highest between 4 and 8
weeks (Robertson, 1979). Foci of infections
on the fish include the cuff of skin sheltered
by the operculum, pectoral and pelvic fins
and the area adjacent to the dorsal fin
(Robertson et al., 1981; Robertson, 1985).
Parasites are not normally found on the
head anterior to the operculum.
Clinical signs and pathology
Fish with relatively light infections on the
body may roll in the water (flashing) and rub
against immersed objects or sides of the tank.
61
Diagnosis of infection
Clinical signs are usually used for preliminary diagnosis of the disease. The infection
is confirmed by examination of mucus from
gills and of the body surface for flagellates
under the light microscope. The parasite is
quite fragile and often ruptures during fixation and staining. Carefully prepared smears
(e.g. from the body surface) are usually fixed
in Shaudinns fixative and transferred to
ethyl alcohol before being stained (e.g.
using iron haematoxylin, carmine, periodic
acidSchiff) (Becker, 1977). At present,
there are no serological techniques that can
be used to either detect the infection or
determine the immunological state of fish.
Control
Flush treatment with formalin (166 ppm)
for 1 h or a formalin bath (1 : 4000) for
1530 min is well tolerated by salmon fry
(Fish, 1940; Imamovic, 1986; Skrudland,
1987). Also, treatment for 1 h in a formalin
bath (1 : 6000) is also very effective. Formalin treatment is not recommended if the
Fig. 3.11. Clubbing of gill filament due to heavy Ichthyobodo necator infection (from Miyazaki et al.,
1986; courtesy of Dr T. Miyazaki).
62
P.T.K. Woo
Marine Ichthyobodo
The parasite has been found on a variety of
marine fishes (Urawa et al., 1998). Bruno
(1992) showed that mean width and length
of Ichthyobodo from salmonid fry in fresh
water were significantly greater than those
of the parasite from fish in sea water. However, Brunos measurements of the marine
parasite were lower than those from other
marine fishes (Morrison and Cone, 1986;
Diamant, 1987). Roubal and Bullock (1987)
found differences in the attachment discs
and cytostome processes between freshwater and marine Ichthyobodo from salmonids. According to Lamas and Bruno (1992),
the cytostome process of marine Ichthyobodo on Atlantic salmon is smooth along its
entire length, while that of I. necator has
ridge-like projections.
I. necator from freshwater fish survived and multiplied on chums (Oncorhynchus keta) when infected salmon were
63
Cryptobiosis
Introduction
Cryptobia spp. (Figs 3.12 and 3.13) infect
and cause diseases in many species of
marine and freshwater fishes (e.g. salmonids
and flatfish). The parasite may be on the
body surface and/or gills (ectoparasitic), in
the digestive tract or in the blood (endoparasitic) of fishes. It has worldwide distribution and there are at least 52 nominal
species (Becker, 1970; Lom, 1979; Woo,
1987a). The ectoparasites are on the body
surface or attached to the gills (Figs 3.14 and
64
P.T.K. Woo
Fig. 3.14. Large numbers of Cryptobia branchialis (scanning electron microscope) attached to gill filaments
of a naturally infected tilapia (from Kuperman et al., 2002; courtesy of the late Dr B.I. Kuperman).
Fig. 3.15. Histological section of gill lamellae of a naturally infected tilapia to show hypertrophied gill
epithelial cells with a large number of Cryptobia branchialis (from Kuperman et al., 2002; courtesy of the
late Dr B.I. Kuperman).
65
66
P.T.K. Woo
67
68
P.T.K. Woo
Cross-experimental
transmissions
and
virulence (e.g. clinical signs of the disease)
studies may also be useful in deciding the
taxonomic status of C. makeevi.
C. borreli was described by Laveran
and Mesnil (1901) from red-eye (Leuciscus
erythrophthalmus) caught in ponds in
Garches, France. The parasite has since
been found in the blood and tissues of several freshwater cyprinids in Europe. It
sometimes causes heavy losses in cultured
carp, tench and crucian carp (Lom, 1979).
The parasite is not host-specific and causes
mortality in experimentally infected goldfish (C. auratus) and the common carp
(C. carpio) (Dykova and Lom, 1979; Lom,
1979). After extensive morphological and
cross-transmission studies, Lom (1979) concluded that the parasites from carp, goldfish
and crucian carp in Europe are all C. borreli,
and that the pathogenic Trypanoplasma
cyprini described by Plehn (1903) from carp
in Germany is a junior synonym of C.
borreli. Comparative antigenic and biochemical studies of parasite isolates from
cyprinids throughout Europe may help to
confirm Loms conclusion.
Parasite morphology
C. branchialis (Fig. 3.22) is found on fish
in fresh and salt water. Living specimens
from freshwater fish have body length
14.023.0 m and body width 3.56.0 m,
while fixed specimens are smaller: body
length 9.018.0 m and 2.24.8 m; anterior
flagellum 7.711.0 m; posterior flagellum
1015 m; nucleus round to oval (1.2
11.7 m). The cytoplasm contains refractile
granules and the parasite attaches to host
epithelium by its posterior flagellum (Chen,
1956; Kuperman et al., 2002).
The parasite (fixed specimens) in
young tilapia from the Salton Sea is somewhat smaller: body length 10.5 (7.511.6) m;
body width 4.1 (2.84.6) m; anterior flagellum 8.7 (6.110.2) m; recurrent flagellum
19.5 (13.828.2) m. The latter extends at
the posterior end as a free flagellum, which
attaches the parasite to the gill epithelial
cells (Kuperman et al., 2002).
C. iubilans (extracellular stage; Fig. 3.16)
is oval to elongated and measurements are
based on fixed specimens: body length
5.512.5 m; body width 3.55.5 m. The
anterior flagellum is 1.52 times its body
length and the posterior free flagellum is longer than the anterior flagellum. Its triangular
kinetoplast is located at the anterior end of
the body and is close to its round nucleus. Its
ultrastructure was studied and described in
detail (Fig. 3.17) by Nohynkova (1984a).
C. salmositica (Fig. 3.12) is an elongated organism and its body measurements
are based on air-dried stained blood smears:
body length 14.9 (6.025.0) m; body width
2.5 (1.34.0) m; anterior flagellum 16.1
(6.527.0) m; posterior free flagellum 9.0
(4.017.0) m; kinetoplast length 2.09.0 m;
kinetoplast width 0.52.0 m; nucleus length
1.53.5 m; nucleus width 1.02.5 m; ratio
of anterior flagellum to body length 1.07
(0.401.95); ratio of posterior flagellum to
body length 0.61 (0.251.15) and ratio of
69
70
P.T.K. Woo
Fig. 3.19. Purified cysteine protease and metalloprotease from Cryptobia salmositica. Lane A, crude
parasite lysate; B, partially purified cysteine protease from diethylaminoethyl (DEAE)-agarose column;
C, metalloprotease from DEAE-agarose column; D, purified metalloprotease from Sephacryl S-300 column;
M, molecular weight markers (kDa). (From Woo, 2003, which was modified from Zuo and Woo, 1997d;
courtesy of Diseases of Aquatic Organisms.)
71
Fig. 3.20. In vitro degradation of collagen type V by purified metalloprotease from Cryptobia salmositica.
Lanes AE, collagen incubated with metalloprotease for 0, 2, 5, 6 and 8 h, respectively. Lane F, collagen +
phosphate-buffered saline at 8 h. Lane M, molecular weight markers (kDa). (From Zuo and Woo, 1997d;
courtesy of Diseases of Aquatic Organisms.)
72
P.T.K. Woo
73
74
P.T.K. Woo
attenuated strain does better with disaccharides, e.g. -D (+) glucose, -lactose,
maltose and sucrose. The attenuated strain
multiplies more readily than the pathogen
when L-glutamine and D () proline are
added to the medium (Ardelli and Woo,
2003). The significance of the differences
in nutritional preferences between the two
strains is not well understood.
Both strains (pathogenic and attenuated)
of C. salmositica have a cysteine (thiol)
protease (49, 60, 66 and 97 kDa), and the
enzyme has been isolated and partially
purified (Zuo and Woo, 1997a, d, 1998a). Its
optimal activity is at pH 5.0, and it has
many properties (e.g. substrate specificity,
inhibitor sensitivity, optimal pH) similar
to those of the protease from pathogenic
mammalian trypanosomes (Zuo and Woo,
1998a). The cysteine protease (Fig. 3.19) is
a metabolic enzyme and it has been
detected in pathogenic and non-pathogenic
species of haematozoic Cryptobia (Zuo and
Woo, 1997a). Like the purified metalloprotease (Fig. 3.20), the partially purified
cysteine protease has high proteolytic activities against azocasein, haemogloblin and
fibrinogen and it also has high enzymatic
activity against albumin (Zuo and Woo,
1998a). About 80% of its in vitro activity
is inhibited by the monoclonal antibody
mAb-001 (Zuo et al., 1997). As indicated
earlier, this monoclonal antibody agglutinates live parasites, and inhibits the in vitro
multiplication and oxygen consumption of
the parasite (Feng and Woo, 1996b; Hontzeas
et al., 2001). It is therapeutic when injected
into fish with acute infections (Feng and
Woo, 1997b). These studies indicate that
the cysteine protease is an important metabolic enzyme and is probably involved in
intracellular protein catabolism, which
results in the release of amino acids for protein synthesis and parasite multiplication.
C. salmositica multiplies rapidly by
binary fission in fish (Woo, 1978). Parasite
loads are significantly higher in rainbow
trout with high (e.g. 3.5 g/dl) than with low
(e.g. 1.0 g/dl) plasma proteins (Thomas and
Woo, 1990b). Also, trout on an ascorbic aciddeficient diet have lower parasitaemias
than fish on an ascorbic acid-supplemented
75
76
P.T.K. Woo
Fig. 3.22. Cryptobia branchialis (transmission electron microscope) to show attachment of parasite
recurrent flagellum to cell membrane of gill epithelium (from Kuperman et al., 2002; courtesy of the late
Dr B.I. Kuperman).
signs, including stunted growth and emaciation, were reported in five different outbreaks of the disease in juvenile discus fish
in the USA. In one outbreak, the mortality
was 93% (280 out of 300) in 1 week and it
was assumed that C. iubilans was the primary cause of death (Yanong et al., 2004).
Nine of these fish had light trichodinid and
monogenean infections on the gills and body
surface. However, heavy infections of
Cryptobia were in the stomach, with moderate to heavy infections of hexamitids and
Capillaria in the intestine. Multifocal granulomas were seen in the liver, spleen, posterior kidney, stomach and intestine.
Development in fish
Nohynkova (1984a) did not indicate finding
obvious perforation of the gut in infected
fish. She suggested that the parasite spread
from the stomach to other organs, including
the spleen and ovary. It would be very challenging to elucidate the route and mechanism of spread of the parasite to other
organs, especially those that are not continuous with the stomach. Perhaps the infected
macrophage-like cells are responsible for
transporting the parasite to other organs.
This would indicate the significance of the
intracellular stage in this parasite.
Using scanning electron microscopy,
Yanong et al. (2004) demonstrated numerous C. iubilans on or penetrating into the
gastric mucosa in naturally infected fish.
They also confirmed that the parasite was
in vacuoles in host cells. The identification
of the parasite was based on the detection of
a triangular kinetoplast and other morphological features of C. iubilans, such as an
anterior rostrum.
Morbidity and mortality in infected discus fish seem to be related to water quality,
concurrent infections with other parasites
and bacteria, diet and the size and age of
infected fish. Metronidazole is not effective
against the parasite in fish, while bath treatments with dimetridazole (80 mg/l for 24 h
and repeated daily for 3 days) or 2-amino5-nitrothiazol (10 mg/l for 24 h and repeated
for 3 days) seem to decrease the prevalence
of the parasite (Yanong et al., 2004).
77
78
P.T.K. Woo
79
80
P.T.K. Woo
81
82
P.T.K. Woo
Fig. 3.27. Neutrophils from peripheral blood of Atlantic salmon ( 400): (a) one normal (inactivated) cell
absence of formazan after in vitro exposure to nitroblue tetrazolium (NBT) dye; (b) two activated cells
presence of formazan after in vitro exposure to NBT (original; courtesy of Adrian Chin).
Fig. 3.28. (a) Parasitaemia ( SE) and antibody titre (OD492 SE) in Atlantic salmon after being inoculated
with the live Cryptobia salmositica vaccine; (b) percentage of activated peripheral phagocytes ( SE) in the
blood of Atlantic salmon after being vaccinated with the Cryptobia salmositica vaccine an asterisk
indicates a significant difference (P < 0.05) in percentage of activated phagocytes between vaccinated and
nave groups (from Chin and Woo, 2005; courtesy of Parasitology Research).
83
84
P.T.K. Woo
injected with the DNA vaccine were consistently more anaemic than controls at
25 wpv, and agglutinating antibodies
against Cryptobia were detected in the
blood of vaccinated fish at 57 wpv. Also,
vaccinated fish consistently had lower parasitaemias, delayed peak parasitaemia and
faster recovery (Tan, 2005). Antibodies from
vaccinated fish also agglutinated a taxonomically unrelated pathogen (Spironucleus)
from chinook salmon (C.W. Tan and P.T.K.
Woo, unpublished). This cross-reaction
indicates that the Cryptobia DNA vaccine
may have the potential to be a broad-spectrum vaccine. Further careful studies are
required to follow up on this suggestion.
Immunodepression and anorexia
C. salmositica depresses the piscine immune
system during the acute phase of the disease.
Production of antibodies to sheep red cells
and Yersinia ruckeri were depressed in
infected trout (Wehnert and Woo, 1981;
Jones et al., 1986; Sin and Woo, 1993). Jones
et al. (1986) showed that Cryptobia-infected
trout exposed to Y. ruckeri suffered higher
mortality than fish infected with either
pathogen. When Cryptobia-infected fish that
were earlier exposed to Yersinia were
re-exposed to the bacteria, they were as susceptible as fish that did not have prior exposure to the bacterium.
Anorexia contributes to humoral
immunodepression in infected trout
(Thomas and Woo, 1992b); however, as indicated earlier, it is also beneficial to infected
fish as it lowers the plasma proteins and subsequently the severity of the infection
(Li and Woo, 1991). In infected rainbow
trout, the haemolytic levels of complement
are about 20% of pre-infected levels and
this persists throughout the infection
(Thomas and Woo, 1989b). Low complement
decreases phagocytic activity and antigen
presentation by macrophages and hence may
contribute to immunodepression. Further
studies are needed to elucidate the mechanism in immunodepression and the factors
that contribute to it.
Anorexia was evident at 3 wpi in juvenile trout at 10C and peaked at 4 wpi,
85
86
P.T.K. Woo
Fig. 3.29. Blood smear from a sexually mature spring chinook salmon naturally infected with Cryptobia
salmositica (courtesy of Craig Banner, Oregon Department of Fish and Wildlife, USA).
the disease as a significant cause of morbidity and mortality occurred later in the preharvest fish. According to hatchery management, the outbreak was confined to fish
exposed to unfiltered surface water and did
not appear to be linked to handling of fish.
Also, mortality seemed to be associated
with age and major stressors, such as
harassment by marine mammals. Another
outbreak in the pre-harvest chinook salmon
occurred in the same hatchery in 2001.
Cryptobia was found in large numbers in
the blood and ascites fluid of moribund
fish, and clinical signs (e.g. exophthalmia,
anaemia, anorexia) were evident in many
fish. Fish mortality varied between cages
and ranged from 3.3% to 24.9%. Briefly, the
parasite was detected in the blood of some
fish (while fish were in fresh water in the
hatchery) before they were transferred to
sea cages in AugustSeptember 1999. Parasites from moribund fish in sea cages are
morphologically similar to C. salmositica,
and cause clinical disease in experimentally infected rainbow trout. Also, the
C. salmositica vaccine protects fish from
two of these isolates (M. Eldridge and
P.T.K. Woo, unpublished). It is suggested
here that the outbreak in sea cages was initiated because of relapse in some infected
fish (possibly due to stress), and the pathogen was rapidly transmitted directly to
other fish during weighing and grading
when fish were brought into direct contact.
87
88
P.T.K. Woo
89
Fig. 3.30. Oxygen consumption and carbon dioxide production by Cryptobia salmositica after
in vitro exposure to isometamidium chloride (from Ardelli and Woo, 2001a; courtesy of Journal of
Parasitology).
90
P.T.K. Woo
Fig. 3.31. Micro-lesions in Cryptobia salmositica (transmission electron microscopy) after in vitro exposure
to isometamidium chloride: (a) normal kinetoplast not exposed to Samorin; (b) condensation of DNA in
kinetoplast after exposure to Samorin; (c) vacuole formation in kinetoplast after drug exposure;
(d) swelling of cristae after exposure to Samorin; (e) vacuole formation in cytoplasm after drug exposure
(V, vacuole; C, cristae; K, kinetoplast) (from Ardelli and Woo, 2001a; courtesy of Journal of Parasitology).
91
INNATE IMMUNITY.
ACQUIRED (ADAPTIVE) IMMUNITY. Infected goldfish that survive an infection are protected
(Lom, 1979). Sera from recovered fish agglutinate C. borreli (Scharsack et al., 2004) and
parasites are lysed by complement-fixing
antibodies in sera from immune fish (Saeij
et al., 2003b; Scharsack et al., 2004). Infected
carp rapidly produced antibodies in the
first 4 weeks of infection (Jones et al., 1993),
peak antibody production coincided with
decline in parasitaemia and most fish
recovered 812 weeks after infection.
Recovered fish were protected from challenge. Immunosuppressive agents significantly increased parasitaemias in carp,
which resulted in high fish mortalities
(Steinhagen et al., 1989b).
Daily handling stress increased susceptibility of carp to C. borreli, and in vitro
studies showed that cortisol suppressed
Cryptobia-induced expression of IL-1b,
TNF-a, serum amyloid A and nitric oxide
synthase (Saeij et al., 2003a). Macrophagedepleted carp infected with the parasite did
not have lethal parasitaemias but had lethal
bacteraemias. Those fish that survived were
protected when challenged with C. borreli
(Saeij et al., 2003c). Infected outbred carp
responded with the production of specific
antibodies, while the highly susceptible
isogenic hybrid carp did not. This suggests
92
P.T.K. Woo
Geographical distribution of
parasite and host range
C. bullocki was described from the blood of
winter flounders (P. americanus) in New
Hampshire, USA (Strout, 1965). It is found
in estuarine and inshore fishes along the
Atlantic coast of North America (from
New Brunswick to Georgia) and also in the
northern Gulf of Mexico (Strout, 1965; Laird
and Bullock, 1969; Daily, 1978; Newman,
1978; Becker and Overstreet, 1979; Burreson
and Zwerner, 1982). The parasite is common
in flounders (prevalence from 70 to 100%)
that use estuaries as nursery grounds. These
include winter and summer flounders
(P. americanus and Paralichthys dentatus)
along the Atlantic coast, and southern flounder (Paralichthys lethostigma), hogchoker
(Trinectes maculatus) and croaker (Micropogonias undulatus) on the southern Atlantic
coast to the northern Gulf of Mexico. Also,
the smooth flounder (Liopsetta putnami) in
New England and hogchoker and summer
flounder in Chesapeake Bay, USA, are commonly infected with the parasite.
Parasite morphology
Specimens from air-dried smears are longer
and more slender than those that are wetfixed in osmic vapour (Strout, 1965). The
following description is based on stained
air-dried specimens: body length 17.6
(12.523.1) m; body width 2.7 (1.24.5) m;
anterior flagellum 13.1 (8.319.1) m; posterior free flagellum 8.5 (4.415.7) m; length
of kinetoplast 3.3 (1.75.5) m; width of
kineoplast 1.1 (0.62.0) m; length of nucleus
3.4 (1.86.8) m; anterior of nucleus to
anterior end 4.2 (0.96.3) m; and anterior
of kinetoplast to anterior end 1.5 (0.14.6) m.
The cytoplasm is alveolar and darkly
stained chromatin granules are often seen
in the posterior part of the body.
Geographical distribution of
the leech vector
The marine leech, Calliobdella vivida, is the
vector. It is not host specific and is found on
fish in estuaries or near the coast from Newfoundland to the northern Gulf of Mexico. It
is present in autumn, winter and spring
(Sawyer et al., 1975; Appy and Dadswell,
1981; Madill, 1988).
93
Fig. 3.32. Severe ascites in juvenile flounder experimentally infected with Cryptobia bullocki: three views
of the same infected fish (from Burreson and Zwerner, 1984; courtesy of Dr E.M. Burreson).
94
P.T.K. Woo
Trypanosomiasis
Introduction
Trypanosomes usually have a free flagellum
at the anterior end (Fig. 3.33). About 190
95
Fig. 3.33. Trypanosoma danilewskyi in the blood of an experimentally infected goldfish: note the
monomorphic trypomastigotes, a non-nucleated abnormal form, and a pre-division stage with two
kinetoplasts, two free flagella and a nucleus ( 1150) (from Woo, 1981a; courtesy of Journal of
Parasitology).
96
P.T.K. Woo
et al., 1980; Paulin et al., 1980) and the prominent nucleolus; and chromatin patches are
attached to the inner nuclear membrane
(Paterson and Woo, 1984).
One of the major epitopes on the surface
coat of blood trypomastigotes is a mucin-like
glycoprotein, which is the target of the
humoral response (Lischke et al., 2000). The
glycoprotein has a polypeptide backbone,
consisting of threonine, glycine, serine,
alanine, valine and proline residues. Each
polypeptide is associated with carbohydrate
chains composed of about 200 monosaccharide units (galactose, N-acetylglucosamine,
xylose, sialic acid, fucose, mannose and
arabinose), which are most probably O-linked
to hydroxyl amino acids.
The parasite multiplies rapidly by
binary fission in the blood (Woo, 1981a).
The first division stage is the production
of a new flagellum and this is followed
by division of the kinetoplast. The new
flagellum flips posteriorly, and along it
new cytoplasm is produced or accumulated. The nucleus divides and one daughter nucleus migrates posteriorly past the
two kinetoplasts. Body division is by
transverse constriction at a point between
the kinetoplasts. This division process
is different from the traditional longitudinal binary division of most other
trypanosomes.
Hostparasite relationships
Course of infections and clinical signs
The parasite multiplies rapidly in goldfish
when they are kept at 20C and more
slowly at 30 or 10C (Lom, 1973; Woo et al.,
1983; Islam and Woo, 1992). The parasitaemia increases after infection in fish
maintained at 20C and starts to decline at
about 28 days after infection. These fish
eventually recover from the infection and
are immune to homologous challenge (Woo,
1981b; Islam and Woo, 1991a; Overath
et al., 1999).
The parasite causes anorexia in experimentally infected goldfish (Islam and Woo,
1991c) and this is most evident during high
parasitaemia. Fish that survive the disease
return to normal feeding.
97
Immunity
Goldfish that have recovered from acute
infections are protected on subsequent
homologous challenge (Lom, 1973; Woo,
1981b; Islam and Woo, 1991a; Overath et al.,
1999) and plasma from these immune fish
contains neutralizing antibodies (Woo, 1981b).
Passive immunization with IgM purified
from recovered fish confirms that the infection is controlled by antibodies (Overath
et al., 1999). The immunity is non-sterile as
low numbers of parasites are in the blood of
recovered fish. Intraperitoneal injection of
corticosteroid into recovered goldfish significantly increases the number of trypanosomes in the peripheral blood of immune
fish (Islam and Woo, 1991a; Overath et al.,
1999). Oestradiol can modulate the susceptibility of infected goldfish. Oestradiolimplanted fish had significantly higher
parasitaemias and mortality than shamoperated fish. Also, mitogen-induced proliferation of circulating lymphocytes from
oestradiaol-implanted fish was impaired
compared with those from sham-operated
fish (Wang and Belosevic, 1994b). Excretory/secretory products from T. danilewskyi,
when injected with Freunds complete
adjuvant, confer protection (Bienek et al.,
2002). This is encouraging and protective
antigen(s) need further characterization.
As indicated earlier, cultured T. danilewskyi is infective to goldfish (Wang and
Belosevic, 1994a) and it survives well
under in vitro conditions in normal goldfish
serum. However, if its surface proteins are
removed, using trypsin, the parasite is lysed
via the alternative pathway of complement
activation. The trypsinized parasite regains
its resistance to lysis after 24 h when cultured in a trypsin-free medium (Plouffe and
Belosevic, 2004). The significance of this is
not well understood.
Diagnosis of infection
During the acute phase of the disease, parasites are readily detected by examination of
a drop of freshly collected blood under the
light microscope. Taxonomic identification
98
P.T.K. Woo
Fig. 3.34. Drawings of small, intermediate and large forms of Trypanosoma murmanensis from the blood
of experimentally infected cod (from Khan, 1976; courtesy of Canadian Journal of Zoology).
99
Fishparasite relationships
Course of infection
The parasite is not known to multiply in the
fish host. Khan (1976) suggested that the
slight increase in the number of trypanosomes at 3 and 10 days after infection was
due to the late entry of some parasites into
the general circulation.
Clinical signs and pathology
Infected fish are anaemic and lethargic,
with emaciation and splenomegaly in
some fish (Khan, 1985). The severity of the
anaemia and decrease in plasma proteins
are associated with parasitaemias (Khan,
1977b; Khan et al., 1980c). The anaemia is
probably associated with an inactive
haemopoietic system. The condition factor
and somatic indices of liver, spleen and
heart are altered in experimentally infected
G. morhua, P. americanus, M. scorpius and
M. octodecemspinosus. Also, spleens of
infected juvenile cod are congested with
blood and melanomacrophage centres; and
they are also more common in infected than
in uninfected juvenile winter flounders
(Khan, 1985).
Mortality
The parasite caused high mortality in
experimentally infected cod and winter
Evidence of trypanosomiasis in
naturally infected fishes
There are several trypanosomes that are
presumed to cause lesions in organs and/or
changes in the blood of naturally infected
fish. Fish from the field are often infected
with a variety of pathogens and may have
also been subjected to stress factors (e.g.
toxic pollutants, nutritional deficiencies).
Hence, it is difficult to ascribe abnormalities to any one particular cause. At best,
these field reports can only be considered
as preliminary and some are briefly
included here.
Neumann (1909) found inflammation
of the brain, fatty degeneration in organs,
anaemia and eosinophilia in skates (Raja
punctata) that had high numbers of
Trypanosoma variabile. According to
Smirnova (1970), the number of red cells,
haemogloblin contents and serum protein
levels of Trypanosoma lotae-infected
burbot (Lota lota) were lowered, while the
number of phagocytic white cells was
elevated.
Fish infected with Trypanosoma vittati
and Trypanosoma maguri had low numbers
of red cells and haemogloblin (Tandon and
Joshi, 1973). However, the numbers of
white cells and immature or abnormal red
cells were higher in the infected fish.
Clarias batrachus and Channa punctatus
infected with Trypanosoma batrachi and
Trypanosoma aligaricus had lower red cell
counts and lower haemogloblin (Gupta and
Gupta, 1985). The numbers of agranulocytes
and granulocytes were higher in infected
fishes, except for neutrophils, which were
significantly lower. Blood glucose levels
were lower in C. punctatus, C. batrachus,
Heteropneustes fossilis and Mystus seenghala infected with trypanosomes (Tandon
100
P.T.K. Woo
reared fish (e.g. Woo, 1979) or an appropriate culture medium (e.g. Jones and Woo,
1991). The cloned parasite is then identified (Woo, 1994) and cultured. To determine pathogenicity, all three strains (field,
cultured and cloned strains) should be used
to experimentally infect hatchery-reared
fish. This approach would satisfy Kochs
postulates for determining the aetiological
agent for a disease.
References
Alexeieff, A. (1910) Sur les flagells intestinaux des poissons marins. Archives de Zoologie Exprimentale et
Generale Sries 5, Vol. VI, Notes et Revue, No. 1, pp. 120.
Allison, L.N. (1963) An unusual case of Hexamita (Octomitus) among yearling rainbow trout. Progressive Fish
Culturist 25 (4), 220.
Amlacher, E. (1970) Textbook of Fish Diseases (English translation). TFH Publications, Neptune, New Jersey.
Andai, G. (1933) Uber Costia necatrix. Archiv fr Protistenkunde 79 (2), 284.
Andrews, C., Exell, A. and Carrington, N. (1988) Manual of Fish Health. Salamander Books, London.
Appy, R.G. and Dadswell, M.J. (1981) Marine and estuarine piscicolid leeches (Hirudinea) of the Bay of
Fundy and adjacent waters with a key to species. Canadian Journal of Zoology 59, 183192.
Ardelli, B.F. and Woo, P.T.K. (1995) Immune response of Cryptobia-resistant and Cryptobia-susceptible
Salvelinus fontinalis to an Aeromonas salmonicida vaccine. Diseases of Aquatic Organisms 23, 3338.
Ardelli, B.F. and Woo, P.T.K. (1997) Protective antibodies and anamnestic response in Salvelinus fontinalis to
Cryptobia salmositica and innate resistance of Salvelinus namaycush to the hemoflagellate. Journal of
Parasitology 83, 943946.
Ardelli, B.F. and Woo, P.T.K. (1998) The in vitro effects of crystal violet on the pathogenic haemoflagellate
Cryptobia salmositica Katz 1951. Parasite 5, 2736.
Ardelli, B.F. and Woo, P.T.K. (1999) The therapeutic use of isometamidium chloride against Cryptobia
salmositica in rainbow trout (Oncorhynchus mykiss). Diseases of Aquatic Organisms 37, 195203.
Ardelli, B.F. and Woo, P.T.K. (2000) An antigen-capture enzyme-linked immunosorbent assay (ELISA)
to detect isometamidium chloride in Oncorhynchus spp. Diseases of Aquatic Organisms 39,
231236.
Ardelli, B.F. and Woo, P.T.K. (2001a) The in vitro effects of isometamidium chloride (Samorin) on the piscine
hemoflagellate Cryptobia salmositica (Kinetoplastida, Bodonina). Journal of Parasitology 87, 194202.
Ardelli, B.F. and Woo, P.T.K. (2001b) Therapeutic and prophylactic effects of isometamidium chloride
(Samorin) against the haemoflagellate Cryptobia salmositica in chinook salmon (Oncorhynchus
tshawytscha). Parasitology Research 87, 1826.
Ardelli, B.F. and Woo, P.T.K. (2001c) In vitro secretion of metabolic end-products by piscine haemoflagellates
Cryptobia salmositica and C. bullocki (Kinetoplastida: Bodonidae) and the relationship of these products
to the pH in the medium. Folia Parasitologica 48, 187191.
Ardelli, B.F. and Woo, P.T.K. (2001d) Conjugation of isometamidium chloride to antibodies and the use of the
conjugate against the haemoflagellate, Cryptobia salmositica: an immuno-chemotherapeutic strategy.
Journal of Fish Diseases 24, 439451.
Ardelli, B.F. and Woo, P.T.K. (2002) Experimental Cryptobia salmositica (Kinetoplastida) infections in Atlantic
salmon, Salmo salar L.: cell-mediated and humoral immune responses against the pathogenic and
vaccine strains of the parasite. Journal of Fish Diseases 25, 265274.
Ardelli, B.F. and Woo, P.T.K. (2003) In vitro nutritional requirements and metabolic products of pathogenic
and nonpathogenic strains of Cryptobia salmositica: observations on essential carbohydrates and amino
acids. Diseases of Aquatic Organisms 56, 4957.
Ardelli, B.F., Forward, G.M. and Woo, P.T.K. (1994) Brook charr (Salvelinus fontinalis) and cryptobiosis: a
potential salmonid reservoir host for Cryptobia salmositica Katz 1951. Journal of Fish Diseases 17,
567577.
101
Ardelli, B.F., Witt, J.D.S. and Woo, P.T.K. (2000) The identification of glycosomes and metabolic end
products in pathogenic and nonpathogenic strains of Cryptobia salmositica (Kinetoplastida). Diseases of
Aquatic Organisms 42, 4151.
Arthur, J.R., Margolis, L. and Arai, H.P. (1976) Parasites of fishes of Aishihik and Stevens Lakes, Yukon
Territory, and potential consequences of their interlake transfer through a proposed water diversion
from hydroelectric purposes. Journal of the Fisheries Research Board of Canada 33, 24892499.
Awakura, T., Kojima, H. and Tanaka, H. (1984) [Studies on parasites of masu salmon, Oncorhynchus masou.
VIII. Costiasis of pond-reared masu salmon fry.] Scientific Report of the Hokkaido Fish Hatchery 39,
8996 (in Japanese).
Bahmanrokh, M. and Woo, P.T.K. (2001) Relationships between histopathology and parasitaemias in
Oncorhynchus mykiss infected with Cryptobia salmositica, a pathogenic haemoflagellate. Diseases of
Aquatic Organisms 46, 4145.
Bassleer, G. (1983) Disease prevention and control: Spironucleus/Hexamita infection, hole-in-the-head
disease. Freshwater Marine Aquarium 6, 3841, 5860.
Bauer, O.N. (1959) Parasites of freshwater fishes and the biological basis for their control. Bulletin of the State
Scientific Research, Institute Lake and River Fish 49, 236 pp. Israel Program for Scientific Translation,
Jerusalem (1962).
Bauer, O.N., Mussellius, V.A. and Strelikov, Y.A. (1969) Diseases of Pond Fishes. Israel Program for Scientific
Translation, Jerusalem (1973); US Department of the Interior and the National Science Foundation,
Washington, DC.
Beamish, F.W.H., Sitja-Bobadilla, A., Jebbink, J.A. and Woo, P.T.K. (1996) Bioenergetic cost of cryptobiosis in
fish: rainbow trout (Oncorhynchus mykiss) infected with Cryptobia salmositica and with an attenuated
live vaccine. Diseases of Aquatic Organisms 25, 18.
Becker, C.D. (1970) Haematozoa of fishes, with emphasis on North American records. In: Sniezsko, S.F. (ed.)
A Symposium on Diseases of Fishes and Shellfish. Special Publication No. 5, American Fisheries Society,
Washington, pp. 82100.
Becker, C.D. (1977) Flagellate parasites of fish. In: Kreier, J.P. (ed.) Parasite Protozoa, Vol. I. Academic Press,
New York, pp. 357416.
Becker, C.D. and Katz, M. (1965a) Transmission of the haemoflagellate Cryptobia salmositica Katz 1951, by a
rhynchobdellid leech vector. Journal of Parasitology 51, 9599.
Becker, C.D. and Katz, M. (1965b) Infections of the haemoflagellate Cryptobia salmositica Katz 1951,
in freshwater teleosts of the Pacific coast. Transactions of the American Fisheries Society 94,
327333.
Becker, C.D. and Katz, M. (1965c) Distribution, ecology and biology of the salmonid leech, Piscicola
salmositica Meyer 1946 (Rhynchobdella, Piscicolidae). Journal of the Fisheries Research Board of
Canada 22, 11751195.
Becker, C.D. and Katz, M. (1966) Host relationships of Cryptobia salmositica (Protozoa, Mastigophora) in
Washington hatchery stream. Transactions of the American Fisheries Society 95, 196202.
Becker, C.D. and Overstreet, R.M. (1979) Haematozoa of marine fishes from the northern Gulf of Mexico.
Journal of Fish Diseases 2, 469479.
Bienek, D.R. and Belosevic, M. (1997) Comparative assessment of growth of Trypanosoma danilewskyi
(Laveran & Mesnil) in medium containing fish or mammalian serum. Journal of Fish Diseases 20,
217221.
Bienek, D.R. and Belosevic, M. (1999) Macrophage or fibroblast-conditioned medium potentiates growth of
Trypanosoma danilewskyi Laveran & Mesnil 1904. Journal of Fish Diseases 22, 359367.
Bienek, D.R., Plouffe, D.A., Wiegertjes, G.F. and Belosevic, M. (2002) Immunization of goldfish with
excretory/secretory molecules of Trypanosoma danilewskyi confers protection against infection. Developmental and Comparative Immunology 26, 649657.
Blanc, E., Marques, A., Bouix, G., Brugerolle, G. and Breuil, G. (1989) Cryptobia sp. from the gills of the gilt
head sea bream Spagus aurata. Bulletin, European Association of Fish Pathologists 9, 8182.
Bohl, M. (1975) [The adherent contamination of skin and gills (ichthyobodiasis = costiasis), a widespread
parasitosis in the breeding of pond fish.] Fisch Umwelt 1, 2533 (in German).
Bower, S.M. and Evelyn, T.P.T. (1988) Acquired and innate resistance to the haemoflagellate Cryptobia
salmositica in sockeye salmon (Oncorhynchus nerka). Developmental and Comparative Immunology
12, 749760.
Bower, S.M. and Margolis, L. (1983) Direct transmission of the haemoflagellate Cryptobia salmositica among
Pacific salmon (Oncorhynchus spp.). Canadian Journal of Zoology 61, 12421250.
102
P.T.K. Woo
Bower, S.M. and Margolis, L. (1984a) Detection of infection and susceptibility of different Pacific salmon
stocks (Oncorhynchus spp.) to the haemoflagellate Cryptobia salmositica. Journal of Parasitology 70,
273278.
Bower, S.M. and Margolis, L. (1984b) Distribution of Cryptobia salmositica, a haemoflagellate of fishes in
British Columbia and the seasonal pattern of infection in a coastal river. Canadian Journal of Zoology 62,
25122518.
Bower, S.M. and Margolis, L. (1985) Effects of temperature and salinity on the course of infection with the
haemoflagellate Cryptobia salmositica in juvenile Pacific salmon (Oncorhynchus spp.). Journal of Fish
Diseases 8, 2533.
Bower, S.M. and Thompson, A.B. (1987) Hatching of the Pacific salmon leech (Piscicola salmositica) from
cocoons exposed to various treatments. Aquaculture 66, 18.
Bower, S.M. and Woo, P.T.K. (1977) Morphology and host specificity of Cryptobia catostomi n. sp. (Protozoa:
Kinetoplastida) from white sucker (Catostomus commersoni) in southern Ontario. Canadian Journal of
Zoology 55, 10821092.
Bower, S.M., Margolis, L. and MacKay, R.J. (1985) Potential usefulness of chlorine for controlling Pacific
salmon leeches, Piscicola salmositica in hatcheries. Canadian Journal of Fisheries and Aquatic Sciences
42, 19861993.
Broderud, A.E. and Poppe, T.T. (1986) [Costiasis (Ichthyobodo necator infection) in farmed turbot (Psetta
maxima L.).] Norsk Veterinaertidsskrift 98, 883884 (in Norwegian).
Brugerolle, C. (1974) Contribution ltude cytologique at phyltique des diplozoaires (Zoomastigophorea,
Diplozoa, Dangeard 1910). III. tude ultrastructurale du genre Hexamita (Dujardin, 1836). Protistologica
10, 8390.
Brugerolle, G. (1975) Contribution ltude cytologique et phyltique des diplozoaires; (Zoomastigophorea,
Diplozoa, Dangeard 1910). VI. Caractres gnraux des diplozoaires. Protistologica 11, 111118.
Brugerolle, G. and Lee, J.L. (2000) Order Diplomonadida. In: Lee, J.L., Leedale, G.F. and Bradbury, P. (eds)
An Illustrated Guide to the Protozoa, Vol. 1, 2nd edn. Society of Protozoologists, Lawrence, Kansas,
pp. 11251135.
Brugerolle, G., Joyon, L. and Oktem, N. (1973) Contribution ltude cytologique et phyltique des
diplozoaires (Zoomastigophorea, Diplozoa, Dangeard 1910). II. tude ultrastructurale du genre
Spironucleus (Lavier, 1936). Protistologica 9, 495502.
Brugerolle, C., Lom, J., Nohynkova, E. and Joyon, L. (1979) Comparison et volution des structures cellulaires
chez plusieurs espces de bodonides et cryptobiides appartenant aux genres Bodo, Cryptobia et
Trypanoplasma (Kinetoplastida, Mastigophora). Protistologica 15, 197221.
Bruno, D.W. (1992) Ichthyobodo sp. on farmed Atlantic salmon, Salmo salar L., reared in the marine environment. Journal of Fish Diseases 15, 349351.
Buchmann, K. and Uldal, A. (1996) Temperature, pH and bile dependent in vitro cultivation of Hexamita
salmonis from rainbow trout Oncorhynchus mykiss intestine. Diseases of Aquatic Organisms 24,
169172.
Buchmann, K., Uldal, A. and Lyholt, H.C. (1995) Parasite infections in Danish trout farms. Acta Veterinaria
Scandinavica 36, 283298.
Bullock, A.M. (1985) The effect of ultraviolet-B radiation upon the skin of the plaice, Pleuronectes platessa L.,
infested with the bodonid ectoparasite, Ichthyobodo necator (Henneguy 1883). Journal of Fish Diseases
8, 547550.
Bullock, A.M. and Robertson, D.A. (1982) A note on the occurrence of Ichthyobodo necator (Henneguy,
1883) in a wild population of juvenile plaice, Pleuronectes platessa L. Journal of Fish Diseases 5,
531533.
Bunnajirakul, S., Steinhagen, D., Hetzel, U., Korting, W. and Drommer, W. (2000) A study of sequential
histopathology of Trypanoplasma borreli (Protozoa: Kinetoplastida) in susceptible common carp
Cyprinus carpio. Diseases of Aquatic Organisms 39, 221229.
Burreson, E.M. (1982a) The life cycle of Trypanoplasma bullocki (Zoomastigophorea, Kinetoplastida). Journal
of Protozoology 29, 7277.
Burreson, E.M. (1982b) Trypanoplasmiasis in flounder along the Atlantic coast of the United States. In:
Anderson, D.P., Dorson, M. and Dubourget, P. (eds) Les Antignes des Micro-organismes Pathognes
des Poissons. Collection Fondation Marcel Merieux, France, pp. 251260.
Burreson, E.M. and Frizzell, L.J. (1986) The seasonal antibody response in juvenile summer flounder
(Paralichthys dentatus) to the hemoflagellate Trypanoplasma bullocki. Veterinary Immunology and
Immunopathology 12, 395402.
103
Burreson, E.M. and Sypek, J.P. (1981) Cryptobia sp. (Mastigophorea, Kinetoplastida) from the gills of marine
fishes in Chesapeake Bay. Journal of Fish Diseases 4, 519522.
Burreson, E.M. and Zwerner, D.E. (1982) The role of host biology, vector biology and temperature in the
distribution of Trypanoplasma bullocki infections in the lower Chesapeake Bay. Journal of Parasitology
68, 306313.
Burreson, E.M. and Zwerner, D.E. (1984) Juvenile summer flounder, Paralichthys dentatus, mortalities in
western Atlantic Ocean caused by the haemoflagellate Trypanoplasma bullocki: evidence from field
and experimental studies. Heligolnder Meeresuntersuchungen 37, 343352.
Callahan, H.A., Litaker, R.W. and Noga, E.L.J. (2002) Molecular taxonomy of the Suborder Bodonina
(Order Kinetoplastida), including the important fish parasite, Ichthyobodo necator. Journal of Eukaryote
Microbiology 49, 119128
Callahan, H.A., Litaker, R.W. and Noga, E.J. (2005) Genetic relationships among members of the Ichthyobodo
necator complex: implications for the management of aquaculture stocks. Journal of Fish Diseases 28,
111118.
Chapman, P.F. (1994) Effects of amphotericin B, penicillin, and streptomycin on cultures of Cryptobia
salmositica. Journal of Aquatic Animal Health 6, 215219.
Chen, C.L. (1956) The protozoan parasites from four species of Chinese pond fishes, Ctenopharyngodon
idellus, Mylopharyngodon piceus, Aristicthys nobilis and Hypophthalmichthys molithrix. 1. The protozoan parasites of Ctenopharyngodon idellus. Acta Hydrobiologica Sinica 1, 123164.
Chin, A. and Woo, P.T.K. (2005) Innate cell-mediated immune response and peripheral leukocyte populations
in Atlantic salmon, Salmo salar L., to a live Cryptobia salmositica vaccine. Parasitology Research 95,
299304.
Chin, A., Eldridge, M., Glebe, B.D. and Woo, P.T.K. (2002) Salmo salar and Cryptobia salmositica: variations
in susceptibility and humoral response in families of Atlantic salmon to the pathogen. In: AquaNet II.
Annual General Meeting of AquaNet, Moncton, New Brunswick (abstract).
Chin, A., Glebe, B. and Woo, P.T.K. (2004a) Humoral response and susceptibility of five full-sib families of
Atlantic salmon (Salmo salar L.) to the haemoflagellate, Cryptobia salmositica Katz 1951. Journal of Fish
Diseases 27, 471481.
Chin, A., Guo, F.C., Bernier, N.J. and Woo, P.T.K. (2004b) Effect of Cryptobia salmositica-induced anorexia
on feeding behaviour and immune response in juvenile rainbow trout, Oncorhynchus mykiss. Diseases
of Aquatic Organisms 58, 1726.
Cone, D.K. and Wiles, M. (1984) Ichthyobodo necator (Henneguy, 1883) from winter flounder, Pseudopleuronectes americanus (Walbaum) in northwest Atlantic Ocean. Journal of Fish Diseases 7, 8789.
Crawley, H. (1909) Studies on blood parasites. II. The priority of Cryptobia Leidy 1846 over Trypanoplasma
Laveran and Mesnil, 1901. Bulletin of the US Bureau of Animal Industry 119, 1620.
Currie, J.L.M. (2004) The effects of cryptobiosis on reproduction in Oncorhynchus mykiss. MSc thesis,
University of Guelph, Guelph, Ontario, 92 pp.
Daily, D.D. (1978) Marine fish hematozoa from Maine. Journal of Parasitology 64, 361362.
Davis, H.S. (1943) A new polymastigine flagellate, Costia pyriformis, parasitic on trout. Journal of Parasitology
29, 385386.
Diamant, A. (1987) Ultrastructure and pathogenesis of Ichthyobodo sp. from wild common dab, Limanda
limanda L., in the North Sea. Journal of Fish Diseases 10, 241247.
Docampo, R. and Moreno, S.N. (1990) The metabolism and mode of action of gentian violet. Drug Metabolism Reviews 22, 161178.
Docampo, R., Moreno, S.N., Gadelha, F.R., De Souza, W. and Cruz, F.S. (1988) Prevention of Chagas
disease resulting from blood transfusion by treatment of blood: toxicity and mode of action of gentian
violet. Biomedical and Environmental Sciences 1, 406413.
Dolezel, D., Jirku, M., Maslov, D.A. and Lukes, J. (2000) Phylogeny of the bodonid flagellates (Kinetoplastida)
based on small-subunit rRNA gene sequences. International Journal of Systematic and Evolutionary
Microbiology 50, 19431951.
Dykova, I. and Lom, J. (1979) Histopathological changes in Trypanosoma danilewskyi Laveran and Mesnil,
1904 and Trypanoplasma borelli Laveran and Mesnil, 1902 infections of goldfish, Carassius aurata (L.).
Journal of Fish Diseases 2, 381390.
Einszporn-Orecka, T. (1979) Flagellates Spironucleus anguillae sp. n. parasites of eels (Anguilla anguilla L.).
Acta Protozoologica 18, 237241.
Elliott, J.M. and Mann, K.H. (1979) A Key to the British Freshwater Leeches with Notes on their Life Cycle and
Ecology. Scientific Publication No. 40, Freshwater Biological Association, Cumbria, UK, 72 pp.
104
P.T.K. Woo
Ellis, A.E. and Wootten, R. (1978) Costiasis of Atlantic salmon, Salmo salar L. smolts in sea water. Journal of
Fish Diseases 1, 389393.
Epshtein, V.M. (1962) A survey of fish leeches (Hirudinea Piscicolidae) from the northern seas of the SSSR.
Doklady Akademii Nauk SSSR 141, 11211124.
Feng, S. and Woo, P.T.K. (1996a) Cell-mediated immune response and T-like cells in thymectomized
Oncorhynchus mykiss (Walbaum) infected with or vaccinated against the pathogenic hemoflagellate
Cryptobia salmositica Katz 1951. Parasitology Research 82, 604611.
Feng, S. and Woo, P.T.K. (1996b) Biological characterization of a monoclonal antibody against a surface
membrane antigen on Cryptobia salmositica Katz 1951. Journal of Fish Diseases 19, 137143.
Feng, S. and Woo, P.T.K. (1997a) Complement fixing antibody production in thymectomized Oncorhynchus
mykiss (Walbaum), vaccinated against or infected with the pathogenic haemoflagellate Cryptobia
salmositica. Folia Parasitology 44, 188194.
Feng, S. and Woo, P.T.K. (1997b) The therapeutic and prophylactic effects of a protective monoclonal antibody (MAb-001) against the pathogenic haemoflagellate Cryptobia salmositica Katz 1951. Diseases of
Aquatic Organisms 28, 211219.
Feng, S. and Woo, P.T.K. (1998a) Characterization of a 200 kDa glycoprotein (Cs-gp2000) on the pathogenic
piscine haemoflagellate Cryptobia salmositica. Diseases of Aquatic Organisms 32, 4148.
Feng, S. and Woo, P.T.K. (1998b) Biochemical characterization of an epitope on the surface membrane
antigen (Cs-gp200) of the pathogenic piscine hemoflagellate Cryptobia salmositica Katz 1951. Experimental Parasitology 88, 310.
Feng, S. and Woo, P.T.K. (1998c) In vitro and in vivo effects of rabbit anti-thymocyte serum on circulating
leucocytes and production of complement fixing antibodies in thymectomized Oncorhynchus mykiss
(Walbaum) infected with Cryptobia salmositica Katz, 1951. Journal of Fish Diseases 21, 241248.
Feng, S. and Woo, P.T.K. (1998d) Identification of carbohydrates on the surface membrane of pathogenic and
nonpathogenic piscine haemoflagellates, Cryptobia salmositica, C. bullocki and C. catostomi
(Kinetoplastida). Diseases of Aquatic Organisms 32, 201209.
Feng, S. and Woo, P.T.K. (2001) Cell membrane glycoconjugates on virulent and avirulent strains of the
haemoflagellate Cryptobia salmositica (Kinetoplastida). Journal of Fish Diseases 24, 2332.
Ferguson, H.W. (1979) Scanning and transmission electron microscopic observations on Hexamita salmonis
(Moore, 1922) related to mortalities in rainbow trout fry Salmo gairdneri Richardson. Journal of Fish
Diseases 2, 5767.
Ferguson, H.W. (1989) Systemic Pathology of Fish. Iowa State University Press, Ames, Iowa.
Ferguson, H.W. and Moccia, R.D. (1980) Disseminated hexamitiasis in Siamese fighting fish. Journal of the
American Veterinary Medical Association 177, 854857.
Fish, F.F. (1940) Notes on Costia necatrix. Transactions of the American Fisheries Society 70, 441445.
Forward, G.M. and Woo, P.T.K. (1996) An in vitro study on the mechanism of innate immunity in
Cryptobia-resistant brook charr (Salvelinus fontinalis) against Cryptobia salmositica. Parasitology
Research 82, 238241.
Forward, G.M., Ferguson, M.M. and Woo, P.T.K. (1995) Susceptibility of brook charr, Salvelinus fontinalis
to the pathogenic haemoflagellate, Cryptobia salmositica, and the inheritance of innate resistance by
progenies of resistant fish. Parasitology 111, 337345.
Grant, D. R. and Woo, P.T.K. (1978) Comparative studies of Giardia spp. in small mammals in southern
Ontario. I. Prevalence and identity of the parasites with a taxonomic discussion of the genus. Canadian
Journal of Zoology 56, 13481359.
Gratzek, J.B. (1988) Parasites associated with ornamental fish. Veterinary Clinics of North America, Small
Animal Practice (Tropical Fish Medicine) 18, 375399.
Guo, F.C. and Woo, P.T.K. (2004a) Experimental infections of Atlantic salmon Salmo salar with Spironucleus
barkhanus. Diseases of Aquatic Organisms 61, 5966.
Guo, F.C. and Woo, P.T.K. (2004b) Detection and quantification of Spironucleus barkhanus in experimentally
infected Atlantic salmon Salmo salar. Diseases of Aquatic Organisms 61, 175178.
Gupta, N. and Gupta, D.K. (1985) Haematological changes due to Trypanosoma batrachi and T. aligaricus
infection in two fresh water teleosts. Angewandte Parasitologie 26, 193196.
Hajdu, E. and Matskasi, I. (1984) In vitro cultivation of Trypanoplasma strains isolated from pike and leech
(preliminary report). Acta Veterinaria Hungarica 32, 7981.
Helms, D.R. (1967) Use of formalin for selective control of tadpoles in the presence of fishes. Progressive Fish
Culturalist 29, 4347.
105
Hlond, S. (1963) Occurrence of Costia necatrix Henneguy on the roe of carp. Wiadomosci Parazytologiczne
9, 249251.
Hoffman, G.L. (1978) Bodomonas concava, a cryptic cryptogram for crippling Cryptobia branchialis. American
Fisheries Society, Fish Health Section Newsletter 6, 9.
Hoffman, G.L. and Meyer, F.P. (1974) Parasites of Freshwater Fishes, a Review of their Control and Treatment.
TFH Publications, Neptune City, New Jersey, 224 pp.
Honigberg, B.M., Vickerman, K., Kulda, J. and Brugerolle, G. (1981) Cytology and taxonomy of parasitic
flagellates: review of advances in parasitology. In: Proceedings of the Fourth International Congress of
Parasitology. Polish Scientific Publishers, Warsaw, Poland, pp. 205227.
Hontzeas, N., Feng, S. and Woo, P.T.K. (2001) Inhibitory effects of a monoclonal antibody (Mab-001) on
in vitro oxygen consumption and multiplication of the pathogenic haemoflagellate, Cryptobia
salmositica Katz. Journal of Fish Diseases 24, 391398.
Hora, S.L. and Pillay, T.V.R. (1962) Handbook of Fish Culture in the Indo-Pacific Region. Fish Biology Technical Paper 14, Food and Agriculture Organization, 204 pp.
Imamovic, V. (1986) [Parasites and parasitoses in fish in some salmonid hatcheries in Bosnia-Hercegovina. I.
Ichthyobodo and Hexamita infections.] Veterinaria Yugoslavia 35, 4766.
Islam, A.K.M.N. and Woo, P.T.K. (1991a) Trypanosoma danilewskyi in Carassius auratus: the nature of
protective immunity in recovered goldfish. Journal of Parasitology 77, 258262.
Islam, A.K.M.N. and Woo, P.T.K. (1991b) Anemia and its mechanism in goldfish Carassius auratus infected
with Trypanosoma danilewskyi. Diseases of Aquatic Organisms 11, 3743.
Islam, A.K.M.N. and Woo, P.T.K. (1991c) Anorexia in goldfish Carassius auratus infected with Trypanosoma
danilewskyi. Diseases of Aquatic Organisms 11, 4548.
Islam, A.K.M.N. and Woo, P.T.K. (1992) Effects of temperature on the in vivo and in vitro multiplication of
Trypanosoma danilewskyi Laveran and Mesnil. Folia Parasitologica 39, 112.
Januschka, M.M., Erlandsen, S.L., Bemrick, W.J., Schupp, D.G. and Freely, D.E. (1988) A comparison of
Giardia microti and Spironucleus muris cysts in the vole: an immunocytochemical, light and electron
microscope study. Journal of Parasitology 74, 452458.
Jones, S.R.M. (2001) The occurrence and mechanisms of innate immunity against parasites in fish. Development and Comparative Immunology 25, 841852.
Jones, S.R.M. and Woo, P.T.K. (1987) The immune response of rainbow trout Salmo gairdneri Richardson to
the haemoflagellate Cryptobia salmositica Katz 1951. Journal of Fish Diseases 10, 395402.
Jones, S.R.M. and Woo, P.T.K. (1991) Culture characteristics of Trypanosoma catostomi and Trypanosoma
phaleri from North American freshwater fishes. Parasitology 103, 237243.
Jones, S.R.M. and Woo, P.T.K. (1992) Antigenic characterization of cultured trypanosomes isolated from three
species of fishes. Systematic Parasitology 23, 4350.
Jones, S.R.M., Woo, P.T.K. and Stevenson, R.M.W. (1986) Immunosuppression in Salmo gairdneri Richardson
caused by the haemoflagellate, Cryptobia salmositica (Katz, 1951). Journal of Fish Diseases 9, 431438.
Jones, S.R.M., Palmen, M. and van Muiswinkel, W.B. (1993) Effects of inoculum route and dose on the
immune response of common carp, Cyprinus carpio to the blood parasite, Trypanoplasma borreli.
Veterinary Immunology and Immunopathology 36, 369378.
Joyon, L. and Lom, J. (1969) Etude cytologique, systmatique et pathologique dIchthyobodo necator
(Henneguy, 1883), Pinto, 1928 (Zooflagelle). Journal of Protozoology 16, 703719.
Katz, M. (1951) Two new hemoflagellates (genus Cryptobia) from some western Washington teleosts. Journal
of Parasitology 37, 245250.
Katz, M., Woodey, J.C., Becker, C.D., Woo, P.T.K. and Adams, J.R. (1966) Records of Cryptobia salmositica
from sockeye salmon from the Fraser River drainage and from the State of Washington. Journal of the
Fisheries Research Board of Canada 23, 19651966.
Keeling, P.J. and Doolittle, W.F. (1996) A non-canonical genetic code in the early diverging eukaryotic
lineage. EMBO Journal 15, 22852290.
Keeling, P.J. and Doolittle, W.F. (1997) Widespread and ancient distribution of a noncanonical genetic code
in diplomonads. Molecular Biology and Evolution 14, 895901.
Keister, D.B. (1983) Axenic culture of Giardia lamblia in TYI-S-33 medium supplemented with bile. Transactions of the Royal Society of Tropical Medicine and Hygiene 77, 487488.
Kent, M.L. (1992) Diseases of Seawater Netpen-reared Salmonid Fishes in the Pacific Northwest. Canadian
Special Publication of Fisheries and Aquatic Sciences, No. 116, Pacific Biological Station, Namaimo,
Canada, 76 pp.
106
P.T.K. Woo
Kent, M.L., Ellis, J., Fournie, J.W., Dawe, S.C., Bagshaw, J.W. and Whitaker, D.J. (1992) Systemic hexamitid
(Protozoa: Diplomonadida) infection in seawater pen-reared chinook salmon Oncorhynchus
tshawytscha. Diseases of Aquatic Organisms 14, 8189.
Keysselitz, C. (1906) Generations-und Wirtswechsel von Trypanoplasma borreli, Laveran und Mesnil. Archiv
fr Protistenkunde 7, 174.
Khan, R.A. (1972) On a trypanosome from Atlantic cod, Gadus morhua L. Canadian Journal of Zoology 50,
10511054.
Khan, R.A. (1976) The life cycle of Trypanosoma murmanensis Nikitin. Canadian Journal of Zoology 54,
18401849.
Khan, R.A. (1977a) Susceptibility of marine fish to trypanosomes. Canadian Journal of Zoology 55,
12351241.
Khan, R.A. (1977b) Blood changes in Atlantic cod (Gadus morhua) infected with Trypanosoma murmanensis.
Journal of the Fisheries Research Board of Canada 34, 21932196.
Khan, R.A. (1982) Biology of the marine piscicolid leech, Johanssonia arctica (Johansson) from
Newfoundland. Proceedings of the Helminthological Society of Washington 49, 266278.
Khan, R.A. (1985) Pathogenesis of Trypanosoma murmanensis in marine fish of the northwestern Atlantic
following experimental transmission. Canadian Journal of Zoology 63, 21412144.
Khan, R.A. (1986) Haematozoa of marine fish from Ungava Bay and adjacent northwestern Atlantic Ocean.
Canadian Journal of Zoology 64, 153159.
Khan, R.A. (1991) Trypanosome occurrence and prevalence in the marine leech Johanssonia arctica
and its host preferences in the northwestern Atlantic Ocean. Canadian Journal of Zoology 69,
23742380.
Khan, R.A., Murphy, J. and Taylor, D. (1980a) Prevalence of a trypanosome in Atlantic cod (Gadus morhua)
especially in relation to stocks in the Newfoundland area. Canadian Journal of Fisheries and Aquatic
Sciences 37, 14671475.
Khan, R.A., Barrett, M. and Murphy, J. (1980b) Blood parasites of fish from northern Atlantic Ocean.
Canadian Journal of Zoology 58, 770781.
Khan, R.A., Campbell, J. and Barrett, M. (1980c) Trypanosoma murmanensis: its effect on the longhorn
sculpin, Myoxocephalus octodecemspinosus. Journal of Wildlife Diseases 16, 359361.
Khan, R.A., Lobos, V., Garcias, F., Munoz, G., Valdebenito, V. and George-Nascimento, M. (2001) Cryptobia
neghmei sp. n. (Protozoa: Kinetoplastida) in two species of flounders, Paralichthys spp. (Pisces:
Paralichthydae) off Chile. Revista Chilena de Historia Natural 74, 763767.
Kinabo, L.D.B. and Bogan, J.A. (1987) Binding of isometamidium to calf thymus DNA and lipids; pharmacological implications. Journal of Veterinary Pharmacology and Therapeutics 10, 357362.
Kinabo, L.D.B., Bogan, J.A., McKellar, Q.A. and Murray, M. (1989) Relay bioavailability and toxicity of
isometamidium residues: a model for human risk assessment. Veterinary and Human Toxicology 31,
417421.
Kruse, P., Steinhagen, D. and Korting, W. (1989a) Development of Trypanoplasma borreli (Mastigophora,
Kinetoplastida) in the leech vector Piscicola geometra and its infectivity for the common carp, Cyprinus
carpio. Journal of Parasitology 75, 527530.
Kruse, P., Steinhagen, D., Korting, W. and Friedhoff, K.T. (1989b) Morphometrics and redescription of
Trypanoplasma borreli Laveran and Mesnil, 1901 (Mastigophora, Kinetoplastida) from experimentally
infected common carp (Cyprinus carpio L.). Journal of Protozoology 36, 408411.
Kulda, J. and Lom, J. (1964a) Remarks on the diplomastigine flagellates from the intestine of fishes. Parasitology 54, 753762.
Kulda, J. and Lom, J. (1964b) Spironucleus elegans Lavier, parasite of fish. Ceskoslovensk Parasitologie XI,
187192.
Kulda, J. and Nohynkova, E. (1978) Flagellates of the human intestine and of intestines of other species. In:
Kreier, J.P. (ed.) Parasitic Protozoa, vol. II. Academic Press, New York, pp. 1138.
Kumaraguru, A.K., Beamish, F.W.H. and Woo, P.T.K. (1995) Impact of a pathogenic haemoflagellate,
Cryptobia salmositica on the metabolism and swimming performance of rainbow trout, Oncorhynchus
mykiss (Walbaum). Journal of Fish Diseases 18, 297305.
Kuperman, B.I., Matey, V.E. and Barlow, S.B. (2002) Flagellate Cryptobia branchialis (Bodonida:
Kinetoplastida), ectoparasite of tilapia from the Salton Sea. Hydrobiologia 473, 93102.
Kusakari, M., Mori, Y. and Miura, H. (1985) Technical studies on artificial production of fish larvae.
In: Annual Report of the Hokkaido Institute of Mariculture (1984), Department of General Affairs,
Hokkaido, Japan, pp. 1561.
107
Laidley, C.W., Woo, P.T.K. and Leatherland, J.F. (1988) The stress-response of rainbow trout to experimental
infection with the blood parasite, Cryptobia salmositica Katz, 1951. Journal of Fish Biology 32, 253261.
Laird, M. and Bullock, W.H. (1969) Marine fish haematozoa from New Brunswick and New England. Journal
of the Fisheries Research Board of Canada 26, 10751102.
Lamas, J. and Bruno, D.W. (1992) Observations in the ultrastructure of the attachment plate of Ichthyobodo
sp., from Atlantic salmon, Salmo salar L., reared in the marine environment. Bulletin of the European
Association of Fish Pathologists 12, 171173.
Laveran, A. and Mesnil, F. (1901) Sur les flagelles membrane ondulante des poissons (genres Trypanosoma
Gruby et Trypanoplasma n. gen.). Compte Rendu Hebdomadaires des Sances de lAcadmie des
Sciences, Paris 133, 670675.
Laveran, A. and Mesnil, F. (1904) Trypanosomes and Trypanosomiases (translated by D. Nabarro). W.T. Keener,
Chicago, Illinois, 538 pp.
Lee, J.J. (1985) Diplomonadida. In: Lee, J.J., Hutner, S.H. and Bovee, E.C. (eds) An Illustrated Guide to the
Protozoa. Society of Protozoologists, Lawrence, Kansas, pp. 130134.
Lee, J.J., Small, E.B., Lynn, D.H. and Bovee, E.C. (1985) Some techniques for collecting, cultivating and
observing protozoa. In: Lee, J.J. Hutner, S.H. and Bovee, E.C. (eds) An Illustrated Guide to the Protozoa.
Society of Protozoologists, Lawrence, Kansas, pp. 17.
Leidy, J. (1846) Description of a new genus and species of Entozoa. Proceedings of the Academy of Natural
Sciences of Philadelphia 3, 100101.
Li, S. and Woo, P.T.K. (1991a) In vitro cultivation of Cryptobia salmositica: effects of fetal bovine serum and
glucose on multiplication. Journal of Parasitology 77, 151155.
Li, S. and Woo, P.T.K. (1991b) Anorexia reduces the severity of cryptobiosis in Oncorhynchus mykiss. Journal of
Parasitology 77, 467471.
Li, S. and Woo, P.T.K. (1995) Efficacy of a live Cryptobia salmositica vaccine, and the mechanism of protection in vaccinated Oncorhynchus mykiss (Walbaum) against cryptobiosis. Veterinary Immunology and
Immunopathology 48, 343353.
Li, S. and Woo, P.T.K. (1996) A species specific Cryptobia salmositica (Kinetoplastida) DNA probe and its uses
in salmonid cryptobiosis. Diseases of Aquatic Organisms 25, 914.
Li, S. and Woo, P.T.K. (1997) Vaccination of rainbow trout, Oncorhynchus mykiss (Walbaum) against
cryptobiosis: efficacy of the vaccine in fresh and sea water. Journal of Fish Diseases 20, 369374.
Li, S., Cowey, C.B. and Woo, P.T.K. (1996) The effects of dietary ascorbic acid on Cryptobia salmositica
infection and on vaccination against cryptobiosis in Oncorhynchus mykiss. Diseases of Aquatic Organisms 24, 1116.
Lischke, A., Klein, C., Stierhop, Y.D., Hempel, M., Mehlert, A., Almeida, I.C., Ferguson, A.J. and Overath, P.
(2000) Isolation and characterization of glycosylphosphatidylinositol-anchored, mucin-like surface
glycoproteins from bloodstream forms of the freshwater-fish parasite Trypanosoma carassii. Biochemical
Journal 345, 693700.
Lom, J. (1973) Experimental infection of goldfish with blood flagellates. In: Progress in Protozoology. 4th International Congress in Protozoology, Clermont-Ferrand, France, p. 255 (abstract).
Lom, J. (1979) Biology of trypanosomes and trypanoplasms of fish. In: Lumsden, W.H.R. and Evans, D.A. (eds)
Biology of the Kinetoplastida, vol. 2. Academic Press, London, pp. 269337.
Lom, J. (1980) Cryptobia branchialis Nie from fish gills; ultrastructural evidence of ectocommensal function.
Journal of Fish Diseases 3, 427436.
Lom, J. and Suchankova, E. (1974) Comments on the life cycle of Trypanosoma danilewskyi. In: Proceedings
of the 3rd International Congress in Parasitology, Munich, Germany, pp. 6667 (abstract).
Lom, J., Paulin, J.J. and Nohynkova, E. (1980) The fine structure of fish trypanosome, Trypanosoma
danilewskyi. I Presence of a cytopharyngeal complex in bloodstream trypomastigotes. Protistologica
16, 365373.
McElwin, I.B. and Post, C. (1968) Efficacy of cyzine for trout hexamitiasis. Progressive Fish Culturist 30,
8491.
Madill, J. (1988) New Canadian records of leeches (Annelida, Hirudinea) parasitic on fish. Canadian Field
Naturalist 102, 685688.
Makeyeva, A.P. (1956) On one of the factors of prespawning mortality of pink salmon in rivers. In: Pacific
Salmon. Israel Program for Scientific Translations, Jerusalem, 1961; Office of Technical Service, US
Department of Commerce, Washington, DC, pp. 1821.
Malecha, J. (1984) Cycle biologique de lhirudine rhynchodelle Piscicola geometra L. Hydrobiologia 118,
237243.
108
P.T.K. Woo
Mann, K.H. (1961) Leeches (Hirudinea). Their Structure, Physiology, Ecology and Embryology. Pergamon
Press, New York.
Mehta, M. and Woo, P.T.K. (2002) Acquired cell-mediated protection in rainbow trout, Oncorhynchus mykiss
against the haemoflagellate, Cryptobia salmositica. Parasitology Research 88, 956962.
Meyer, C., Ganter, M., Korting, W. and Steinhagen, D. (2002) Effects of a parasite-induced nephritis on
osmoregulation in the common carp Cyprinus carpio. Diseases of Aquatic Organisms 50, 127135.
Meyer, M.C. and Khan, R.A. (1979) Taxonomy, biology and occurrence of some marine leeches in
Newfoundland waters. Proceedings of the Helminthological Society of Washington 46, 254264.
MGonigle, R.H. (1940) Acute catarrhal enteritis of salmonid fingerlings. Transactions of the American Fisheries
Society 70, 297302.
Miyazaki, T., Rogers, W.A. and Plumb, J.A. (1986) Histopathological studies on parasitic protozoan diseases
of the channel catfish in the United States. Bulletin of the Faculty of Fisheries, Mie University 13, 19.
Mo, T.A., Poppe, T.T. and Iversen, L. (1990) Systemic hexamitosis in salt-water reared Atlantic salmon (Salmo
salar L.). Bulletin of the European Association of Fish Pathologists 10 (3), 6970.
Molnar, K. (1974) Data on the Octomitosis (Spironucleosis) of cyprinids and aquary fishes. Acta Veterinaria
Academiae Scientarum Hungaricae 24, 99106.
Moore, E. (1922) Octomitus salmonis, a new species of intestinal parasite in trout. Transactions of the American
Fisheries Society 52, 7497.
Moreira, D., Lopez-Garcia, P. and Vickerman, K. (2004) An updated view of kinetoplastid phylogeny using
environmental sequences and a closer outgroup: proposal for a new classification of the class
Kinetoplastea. International Journal of Systematic and Evolutionary Microbiology 54, 18611875.
Morrison, C.M. and Cone, D.K. (1986) A possible marine form of Ichthyobodo sp. on haddock,
Melanogrammus aeglefinus (L.) in the north-west Atlantic Ocean. Journal of Fish Diseases 9, 141142.
Naumova, A.M. (1969) [Parasitism of Cryptobia branchialis]. In: Rybovodstvo i Bolezni Ryb. Kolos, Moscow,
pp. 253254 (in Russian).
Neumann, R.O. (1909) Studien uber protozoische Parasiten im Blut von Meeresfischen. Zeitschrift fr
Hygiene und Infectionskrankheiten 64, 1112.
Newman, M.W. (1978) Pathology associated with Cryptobia infection in a summer flounder (Paralichthys
dentatus). Journal of Wildlife Diseases 14, 299304.
Nigrelli, R.F. and Hafter, E. (1947) A species of Hexamita from the skin of two cichlids. Anatomical Record 99,
683684.
Nikitin, S.A. (1927) Blood parasites of some northern vertebrates. Russian Journal of Tropical Medicine, Medical and Veterinary Parasitology 6, 350356. [in Russian]
Nohynkova, E. (1984a) A new pathogenic Cryptobia from freshwater fishes: a light and electron microscope
study. Protistologica 20, 181195.
Nohynkova, E. (1984b) In vitro cultivation of the bodonid flagellate Trypanoplasma borreli. Journal of
Protozoology 32, 52 (abstract).
OBrien, G.M., Ostland, V.E. and Ferguson, H.W. (1993) Spironucleus-associated necrotic enteritis in angelfish (Pterophyllum scalare). Canadian Veterinary Journal 34, 301303.
Opperdoes, F.R. (1988) Glycosomes may provide clues to the import of peroxisomal proteins. Trends in
Biomedical Science 13, 255260.
Opperdoes, F.R., Nohynkova, E., Van Schaftingen, E., Lambeir, A.M., Veenhuis, M. and Van Roy, J. (1988)
Demonstration of glycosomes (microbodies) in the bodonid flagellate Trypanoplasma borelli (Protozoa,
Kinetoplastida). Molecular and Biochemical Parasitology 30, 155163.
Osborn, P.E. (1966) Effective chemical control of some parasites of goldfish and other pondfish. In: Annual
Meeting of the Wildlife Disease Association (unpublished; quoted in Hoffman and Meyer, 1974).
Overath, P., Ruoff, J., Stierhof, Y.D., Haag, J. Tichy, H., Dykova, I. and Lom, J. (1998) Cultivation of
bloodstream forms of Trypanosoma carassii, a common parasite of freshwater fish. Parasitology Research
84, 343347.
Overath, P., Haag, J., Mameza, M.G. and Lischke, A. (1999) Freshwater fish trypanosomes: definition of two
types, host control by antibodies and lack of antigenic variation. Parasitology 119, 591601.
Paperna, I. and Overstreet, R.M. (1981) Parasites and diseases of mullets (Mugilidae). In: Oren, O.H. (ed.)
Aquaculture of Grey Mullets. Cambridge University Press, Cambridge, pp. 411493.
Paterson, W.B. and Woo, P.T.K. (1983) Electron microscopic observations of the bloodstream form of
Cryptobia salmositica Katz, 1951 (Kinetoplastida, Bodonina). Journal of Protozoology 39, 431437.
Paterson, W.B. and Woo, P.T.K. (1984) Ultrastructural studies on mitosis in Trypanosoma danilewskyi
(Mastigophora, Zoomastigophora). Canadian Journal of Zoology 62, 11671171.
109
Paulin, J.J., Lom, J. and Nohynkova, E. (1980) The fine structure of Trypanosoma danilewskyi. II Structure and
cytochemical properties of the cell surface. Protistologica 16, 375383.
Paull, G.C. and Matthews, R.A. (2001) Spironucleus vortens, a possible cause of hole-in-the-head disease in
cichlids. Diseases of Aquatic Organisms 45, 197202.
Pavlovskii, E.N. (1964) Key to Parasites of Freshwater Fish of the USSR. Academy of Sciences of the USSR,
Zoological Institute. Translated from Russian by Israel Program for Scientific Translations, Jerusalem,
Israel, 919 pp.
Peckova, H. and Lom, J. (1990) Growth, morphology and division of flagellates of the genus Trypanoplasma
(Protozoa, Kinetoplastida) in vitro. Parasitology Research 76, 553558.
Peregrine, A.S. (ed.) (1990) Chemotherapy for Trypanosomiasis: Proceedings of a Workshop. The International Laboratory for Research on Animal Diseases, Nairobi, Kenya.
Plehn, M. (1903) Trypanoplasma cyprini nov. sp. Archiv fr Protistenkunde 3, 175180.
Plouffe, D.A. and Belosevic, M. (2004) Enzyme treatment of Trypanosoma danilewskyi (Laveran and Mesnil)
increases its susceptibility to lysis by the alternative complement pathway of activation in goldfish,
Carassius auratus (L.). Journal of Fish Diseases 27, 277285.
Poppe, T.T. and Hastein, T. (1982) [Costiasis in salmon smolt (Salmo salar L.) in sea water.] Norsk
Veterinaertidsskrift 94, 259262 (in Norwegian).
Poppe, T.T., Mo, T.A. and Iversen, L. (1992) Disseminated hexamitosis in sea-caged Atlantic salmon, Salmo
salar. Diseases of Aquatic Organisms 14, 9197.
Post, G. (1987) Textbook of Fish Health. TFH Publications, Neptune City, New Jersey.
Poynton, S.L. and Morrison, C. (1990) Morphology of diplomonaid flagellates, Spironucleus torosa n. sp. from
Atlantic cod Gadus morhua L., and haddock Melanogrammus aeglefinus (L.) and Hexamita salmonis
from brook trout Salvelinus fontinalis (Mitchill). Journal of Protozoology 37, 369383.
Poynton, S.L. and Sterud, E. (2002) Guidelines for species descriptions of diplomonaid flagellates from fish.
Journal of Fish Diseases 25, 1531.
Poynton, S.L., Fraser, W., Francis-Floyd, R., Rutledge, P., Reed, P. and Nerad, T.A. (1995) Spironucleus
vortens n. sp. from the freshwater angelfish Pterophyllum scalare: morphology and culture. Journal of
Eukaryotic Microbiology 42, 731742.
Poynton, S.L., Fard, M.R., Jenkins, J. and Ferguson, H.W. (2004) Ultrastructure of Spironucleus salmonis n.
comb. (formerly Octomitus salmonis sensu Moore 1922, Davis 1926, and Hexamita salmonis sensu
Ferguson 1979), with a guide to Spironucleus species. Diseases of Aquatic Organisms 60, 4964.
Putz, R.E. (1972) Biological studies on the hemoflagellates Cryptobia cataractae and Cryptobia salmositica.
Technical Paper Bureau of Sport Fishery and Wildlife 63, 325.
Qadri, S.S. (1962) An experimental study of the life cycle of Trypanosoma danilewskyi in the leech,
Hemiclepsis marginata. Journal of Protozoology 9, 254258.
Roberts, R.J. and Shepherd, C.J. (1974) Handbook of Trout and Salmon Diseases. Fishing News Books,
Farnham, UK.
Robertson, D.A. (1979) Hostparasite interactions between Ichthyobodo necator (Henneguy, 1883) and
farmed salmonids. Journal of Fish Diseases 2, 481491.
Robertson, D.A. (1985) A review of Ichthyobodo necator (Henneguy, 1883): an important and damaging fish
parasite. In: Muir, J.F. and Roberts, R.J. (eds) Recent Advances in Aquaculture. Croom Helm, London,
pp. 130.
Robertson, D.A., Roberts, R.J. and Bullock, A.M. (1981) Pathogenesis and autoradiographic studies on the
epidermis of salmonids infested with Ichthyobodo necator (Henneguy, 1883). Journal of Fish Diseases 4,
113125.
Robertson, M. (1911) Transmission of flagellates of certain freshwater fishes. Philosophical Transactions of the
Royal Society of London B 202, 2950.
Rosengarten, R. (1985) [Parasitological examination of Salmo gairdneri on a trout farm in western lower
Saxony]. Inaugural dissertation, Tierarzliche Hochschule, Hanover, Germany, 125 pp (in German).
Roubal, F.R. and Bullock, A.M. (1987) Differences between the hostparasite interface of Ichthyobodo
necator (Henneguy, 1883) on the skin and gills of salmonids. Journal of Fish Diseases 10, 237240.
Roubal, F.R., Robertson, D.A. and Roberts, J.A. (1987) Ultrastructural aspects of infection by Ichthyobodo
necator (Henneguy, 1883) on the skin and gills of the salmonids, Salmo salar L. and Salmo gairdneri
Richardson. Journal of Fish Diseases 10, 181192.
Rudat, S., Steinhagen, D., Hetzel, U., Drommer, W. and Korting, W. (2000) Cytopathological observations on
renal tubule epithelium cells in common carp Cyprinus carpio under Trypanoplasma borreli (Protozoa:
Kinetoplastida) infection. Diseases of Aquatic Organisms 40, 203209.
110
P.T.K. Woo
Saeij, J.P.J., van Muiswinkel, W.B., Groeneveld, A. and Wiegertjes, G.F. (2002) Immune modulation by fish
kinetoplastid parasites: a role for nitric oxide. Parasitology 124, 7786.
Saeij, J.P.J., van Kemenade, V.B.M.L., van Muiswinkel, W.B., Groeneveld, A. and Wiegertjes, G.F. (2003a)
Daily handling stress reduces resistance of carp to Trypanoplasma borreli: in vitro modulatory effects
of cortisol on leukocyte function and apoptosis. Developmental and Comparative Immunology 27,
233245.
Saeij, J.P.J., de Vries, B.J. and Wiegertjes, G.F. (2003b) The immune response of carp to Trypanoplasma
borreli: kinetics of immune gene expression and polyclonal lymphocyte activation. Developmental and
Comparative Immunology 27, 859874.
Saeij, J.P.J., Groeneveld, A., van Rooijen, N., Haenen, O.L. and Wiegertjes, G.F. (2003c) Minor effect of
depletion of resident macrophages from peritoneal cavity on resistance of common carp Cyprinus carpio
to blood flagellates. Diseases of Aquatic Organisms 57, 6775.
Sangmaneedet, S. and Smith, S.A. (1999) Efficacy of various chemotherapeutic agents on the growth of
Spironucleus vortens, an intestinal parasite of freshwater angelfish. Diseases of Aquatic Organisms
38, 4752.
Sangmaneedet, S. and Smith, S.A. (2000) In vitro studies on optimal requirements for growth of Spironucleus
vortens, an intestinal parasite of freshwater angelfish. Diseases of Aquatic Organisms 39, 135141.
Sano, T. (1970) Etiology and histopathology of hexamitiasis and an IPN-like disease of rainbow trout. Journal
of the Tokyo University of Fisheries 56, 2330.
Savage, A. (1935) Notes on costiasis. Transactions of the American Fisheries Society 65, 332333.
Sawyer, R.T. (1986) Leech Biology and Behaviour, vol. 2. Feeding Biology, Ecology and Systematics. Oxford
Scientific Publications, Oxford, UK.
Sawyer, R.T., Lawler, A.R. and Overstreet, R.M. (1975) Marine leeches of the eastern United States and the
Gulf of Mexico with a key to the species. Journal of Natural History 9, 633667.
Schaperclaus, W. (1986) Fish Diseases I and II. Translated by M.S.R. Chari (1991); US Department of the
Interior and the National Science Foundation, Washington, DC.
Scharsack, J.P., Steinhagen, D., Kleczka, C., Schmidt, J.O., Korting, W., Michael, R.D., Leibold, W. and
Schuberth, H.J. (2003a) The haemoflagellate Trypanoplasma borreli induces the production of nitric
oxide, which is associated with modulation of carp (Cyprinus carpio L.) leucocyte functions. Fish and
Shellfish Immunology 14, 207222.
Scharsack, J.P., Steinhagen, D., Kleczka, C., Schmidt, J.O., Korting, W., Michael, R.D., Leibold, W. and
Schuberth, H.J. (2003b) Head kidney neutrophils of carp (Cyprinus carpio L.) are functionally modulated
by the haemoflagellate Trypanoplasma borreli. Fish and Shellfish Immunology 14, 389403.
Scharsack, J.P., Steinhagen, D., Korting, W., Wagner, B., Leibold, W. and Schuberth, H.J. (2004) Some
immune parameters in carp Cyprinus carpio susceptible and resistant to the haemoflagellate
Trypanoplasma borreli. Diseases of Aquatic Organisms 60, 4148.
Schubert, G. (1966) Zur Ultracytologie von Costia necatrix Leclerq, unter besonderer Berucksichtigung des
Kinetoplast-Mitochondrions. Zeitschrift fr Parasitenkunde 27, 271286.
Schubert, G. (1978) Krankheiten der Fische. Kosmos, Franckhsche Verlagshandlung, Stuttgart, Germany.
Shanavas, K.R., Ramachandran, P. and Janardanart, K.P. (1989) Trypanoplasma ompoki sp. n. from freshwater
fishes in Kerala, India, with observations on its vector-phase development and transmission. Acta
Protozoologica 28, 293302.
Siddall, M.E., Hong, H. and Desser, S.S. (1992) Phylogenetic analysis of the Diplomonadida (Wenyon, 1926)
Brugerolle, 1975: evidence for heterochrony in protozoa and against Giardia lamblia as a missing link.
Journal of Protozoology 39, 361367.
Sin, Y.M. and Woo, P.T.K. (1993) Immunosuppression in rainbow trout, Oncorhynchus mykiss, caused
by Cryptobia salmositica. In: Phang, V.P.E., Sin, Y.M., Lim, T.M., Tan, C.H., Shim, A. and
Lam, T.J. (eds) Fish Biology: From Genes to Organism. National University of Singapore, Singapore,
pp. 160169.
Sitja-Bobadilla, A. and Woo, P.T.K. (1994) An enzyme-linked immunosorbent assay (ELISA) for the detection
of antibodies against the pathogenic haemoflagellate, Cryptobia salmositica Katz, and protection against
cryptobiosis in juvenile rainbow trout, Oncorhynchus mykiss (Walbaum) inoculated with a live vaccine.
Journal of Fish Diseases 17, 399408.
Skarlato, S.O., Lom, J. and Nohynkova, E. (1987) Fine structural morphology of the nucleus of Trypanosoma
danilewskyi (Kinetoplastida, Trypanosomatina) during mitosis. Archiv fr Protistenkunde 133, 314.
Skrudland, A. (1987) [An outbreak of Ichthyobodo necator in salmon fry]. Norsk Veterinaertidsskrift 99,
729730 (in Norwegian).
111
Smirnova, T.L. (1970) Trypanosoma in the blood of Lota lota L. Trypanosoma lotae sp. n. Parasitologyia 4,
296297.
Smolikova, V., Suchankova, E. and Lom, J. (1977) Growth of the carp trypanosome, T. danilewskyi, in fish tissue culture. Journal of Protozoology 24, 54 (abstract).
Staines, G.J. and Woo, P.T.K. (1997) Immunization of susceptible chinook salmon (Oncorhynchus
tshawytscha) against cryptobiosis. In: 36th Canadian Society of Zoologists Annual Meeting, London,
Canada (abstract).
Steinhagen, D., Kruse, P. and Korting, W. (1989a) The parasitemia of cloned Trypanoplasma borreli Laveran
and Mesnil, 1901, in laboratory-infected common carp (Cyprinus carpio L.). Journal of Parasitology 75,
685689.
Steinhagen, D., Kruse, P. and Korting, W. (1989b) Effects of immunosuppressive agents on common carp
infected with the haemoflagellate Trypanoplasma borreli. Diseases of Aquatic Organisms 7, 6769.
Steinhagen, D., Kruse, P. and Korting, W. (1990) Some haematological observations on carp, Cyprinus
carpio L., experimentally infected with Trypanoplasma borreli Laveran and Mesnil, 1901 (Protozoa,
Kinetoplastida). Journal of Fish Diseases 13, 157162.
Steinhagen, D., Hedderich, W., Skouras, A., Scharsack, J.P., Schuberth, H.J., Leibold, W. and Korting, W.
(2000) In vitro cultivation of Trypanoplasma borreli (Protozoa: Kinetoplastida), a parasite from the blood
of common carp Cyprinus carpio. Diseases of Aquatic Organisms 41, 195201.
Sterud, E. (1998) In vitro cultivation and temperature-dependent growth of two strains of Spironucleus
barkhanus (Diplomonadida: Hexamitidae) from Atlantic salmon Salmo salar and grayling Thymallus
thymallus. Diseases of Aquatic Organisms 33, 5761.
Sterud, E. and Poynton, S.L. (2002) Spironucleus vortens (Diplomonadida) in the ide, Leuciscus idus (L.)
(Cyprinidae): a warm water hexamitid flagellate found in northern Europe. Journal of Eukaryotic Microbiology 49, 137145.
Sterud, E., Mo, T.A. and Poppe, T.T. (1997) Ultrastructure of Spironucleus barkhanus n. sp. (Diplomonadida:
Hexamitidae) from grayling Thymallus thymallus (L.) (Salmonidae) and Atlantic salmon Salmo salar L.
(Salmonidae). Journal of Eukaryotic Microbiology 44, 399407.
Sterud, E., Mo, T.A. and Poppe, T.T. (1998) Systemic spironucleosis in sea-farmed Atlantic salmon Salmo
salar, caused by Spironucleus barkhanus transmitted from feral Arctic charr Salvelinus alpinus? Diseases
of Aquatic Organisms 33, 6366.
Sterud, E., Poppe, T. and Borno, G. (2003) Intracellular infection with Spironucleus barkhanus
(Diplomonadida: Hexamitidae) in farmed Arctic charr Salvelinus alpinus. Diseases of Aquatic Organisms
56, 155161.
Stoskopf, M.K. (1988) Fish chemotherapeutics. Veterinary Clinics of North America, Small Animal Practice.
Tropical Fish Medicine 18, 331348.
Strout, R.G. (1962) A method for concentrating hemoflagellates. Journal of Parasitology 48, 110.
Strout, R.G. (1965) A new haemoflagellate (genus Cryptobia) from marine fishes of northern New England.
Journal of Parasitology 51, 654659.
Sypek, J.P. and Burreson, E.M. (1983) Influence of temperature on the immune response of juvenile summer
flounder, Paralichthys dentatus and its role in the elimination of Trypanoplasma bullocki infections.
Developmental and Comparative Immunology 7, 277286.
Sypek, J.P. and Howe, A.B. (1985) Trypanoplasma bullocki, natural infections in winter flounder,
Pseudopleuronectes americanus. In: International Meeting of Fish Immunology. Sandy Hook, New Jersey,
p. P3 (abstract).
Tan, C.W. (2005) Towards a DNA vaccine against salmonid cryptobiosis. MSc thesis, University of Guelph,
Guelph, Canada, 86 pp.
Tandon, R.S. and Chandra, S. (1977a) Physiology of host parasite relationship: effects on serum alkaline
phosphatase levels of fish hosts parasitized by trypanosomes. Zeitschrift fr Parasitenkunde 52,
195198.
Tandon, R.S. and Chandra, S. (1977b) Studies on ecophysiology of fish parasites: effects of trypanosome infection on the serum cholesterol levels of fishes. Zeitschrift fr Parasitenkunde 52, 199202.
Tandon, R.S. and Joshi, B.D. (1973) Studies on the physiopathology of blood of freshwater fishes infected with
two new forms of trypanosomes. Zeitschrift fr Wissenschaftliche Zoologie 185, 207221.
Tandon, R.S. and Joshi, B.D. (1974) Effect of trypanosome infection on blood glucose levels of some fresh
water teleosts. Journal of the Inland Fisheries Society of India 6, 8182.
Tavolga, W.N. and Nigrelli, R.F. (1947) Studies on Costia necatrix Henneguy. Transactions of the American
Microscopical Society 66, 366378.
112
P.T.K. Woo
Thomas, P.T. and Woo, P.T.K. (1988) Cryptobia salmositica: in vitro and in vivo study on the mechanism
of anaemia in infected rainbow trout, Salmo gairdneri Richardson. Journal of Fish Diseases 11,
425431.
Thomas, P.T. and Woo, P.T.K. (1989a) An in vitro study on the haemolytic components of Cryptobia
salmositica. Journal of Fish Diseases 12, 389393.
Thomas, P.T. and Woo, P.T.K. (1989b) Complement activity in Salmo gairdneri Richardson infected with
Cryptobia salmositica and its relationship to the anaemia in cryptobiosis. Journal of Fish Diseases 12,
395397.
Thomas, P.T. and Woo, P.T.K. (1990a) In vivo and in vitro cell-mediated immune responses of Oncorhynchus
mykiss (Walbaum) against Cryptobia salmositica Katz, 1951 (Sarcomastigophora, Kinetoplastida). Journal of Fish Diseases 13, 423433.
Thomas, P.T. and Woo, P.T.K. (1990b) Dietary modulation of humoral immune response and anaemia in
Oncorhynchus mykiss (Walbaum) infected with Cryptobia salmositica Katz, 1951. Journal of Fish
Diseases 13, 435446.
Thomas, P.T. and Woo, P.T.K. (1991) In vitro and in vivo effects of antimicrobial agents on viability of
Cryptobia salmositica (Sarcomastigophora: Kinetoplastida). Diseases of Aquatic Organisms 10, 711.
Thomas, P.T. and Woo, P.T.K. (1992a) In vitro culture and multiplication of Cryptobia catostomi and
experimental infection of white sucker (Catostomus commersoni). Canadian Journal of Zoology 70,
201204.
Thomas, P.T. and Woo, P.T.K. (1992b) Anorexia in Oncorhynchus mykiss (Walbaum) infected with Cryptobia
salmositica (Sarcomastigophora, Kinetoplastida): its onset and contribution to the immunodepression.
Journal of Fish Diseases 15, 443447.
Thomas, P.T. and Woo, P.T.K. (1995) Immunological approaches and techniques. In: Woo, P.T.K. (ed.)
Fish Diseases and Disorders, Vol. 1: Protozoan and Metazoan Infections. CAB International,
Wallingford, UK. pp. 751771.
Thomas, P.T., Ballantyne, J.S. and Woo, P.T.K. (1992) In vitro oxygen consumption and motility of Cryptobia
salmositica, Cryptobia bullocki and Cryptobia catostomi. Journal of Parasitology 78, 747749.
Thompson, J.D. (1908) Cultivation of the trypanosome found in the blood of the goldfish. Journal of Hygiene
8, 7582.
Todal, J.A., Karlsbakk, E., Isaksen, T.E., Plarre, H., Urawa, S., Mouton, A., Hoel, E., Koren, C.W.R. and
Nylund, A. (2004) Ichthyobodo necator (Kinetoplastida) a complex of sibling species. Diseases of
Aquatic Organisms 58, 916.
Tojo, J.L. and Santamarina, M.T. (1998) Oral pharmacological treatments for parasitic diseases of rainbow
trout Oncorhynchus mykiss. I: Hexamita salmonis. Diseases of Aquatic Organisms 33, 5156.
Tojo, J.L., Santamarina, M.T., Leiro, J., Ubeira, F.M. and Sanmartin, M.L. (1994) Pharmacological treatments
against Ichthyobodo necator (Henneguy, 1883) in rainbow trout, Oncorhynchus mykiss (Walbaum).
Journal of Fish Diseases 17, 135143.
Uldal, A. and Buchmann, K. (1996) Parasite host relations: Hexamita salmonis in rainbow trout
Oncorhynchus mykiss. Diseases of Aquatic Organisms 25, 229231.
Urawa, S. (1987) Effects of environmental stress on the mortality of chum salmon fry infected with Ichthyobodo
necator. In: Actual Problems in Fish Parasitology. Hungarian Academy of Sciences, Budapest, p. 99.
Urawa, S. (1992) Host range and geographical distribution of the ectoparasitic protozoans Ichthyobodo
necator, Trichodina trutae and Chilodonella piscicola on hatchery-reared salmonids in northern Japan.
Scientific Report of Hokkaido Salmon Hatchery 46, 175203.
Urawa, S. (1993) Effects of Ichthyobodo necator infection on seawater survival of juvenile chum salmon
(Oncorhynchus keta). Aquaculture 110, 101110.
Urawa, S. (1995) Effects of rearing conditions on growth and mortality of juvenile chum salmon
(Oncorhynchus keta) infected with Ichthyobodo necator. Canadian Journal of Fisheries and Aquatic
Science 52 (suppl. 1), 1823.
Urawa, S. (1996) Improvement in the marine survival of chum salmon by the control of protozoan infections.
Bulletin of National Research Institute Aquaculture 2, 14.
Urawa, S. and Kusakari, M. (1990) The survivability of the ectoparasitic flagellate Ichthyobodo necator on
chum salmon fry (Oncorhynchus keta) in seawater and comparison to Ichthyobodo sp. on Japanese
flounder (Paralichthys olivaceus). Journal of Parasitology 76, 3340.
Urawa, S., Ueki, N., Nakai, T. and Yamasaki, H. (1991) High mortality of cultured juvenile Japanese flounder,
Paralichthys olivaceus (Temminck and Schlegel), caused by the parasite flagellate, Ichthyobodo sp.
Journal of Fish Diseases 14, 489494.
113
Urawa, S., Ueki, N. and Karlsbakk, E. (1998) A review of Ichthyobodo infection in marine fishes. Fish Pathology
33, 311320.
Uzmann J.R. and Hayduk, S.H. (1963) In vitro culture of the flagellate protozoan Hexamita salmonis. Science
140, 290292.
Uzmann, J.R., Paulik, G.J. and Hayduk, S.H. (1965) Experimental hexamitiasis in juvenile coho salmon
(Oncorhynchus kisutch) and steelhead trout (Salmo gairdneri). Transactions of the American Fisheries
Society 94, 5361.
van Duijin, C., Jr (1973) Diseases of Fishes, 3rd edn. Thomas, Springfield, Illinois.
Verity, C.K. and Woo, P.T.K. (1996) Characterization of a monoclonal antibody against the 47 kDa antigen of
Cryptobia salmositica Katz and its use in an antigen-capture enzyme-linked immunosorbent assay for
detection of parasite antigen in infected rainbow trout, Oncorhynchus mykiss (Walbaum). Journal of Fish
Diseases 19, 91109.
Vickerman, K. (1971) Morphological and physiological considerations of extracellular blood protozoa.
In: Fallis, A.M. (ed.) Physiology and Ecology of Parasites. Toronto University Press, Toronto, Canada,
pp. 5991.
Vickerman, K. (1976a) The diversity of the kinetoplastid flagellates. In: Lumsden, W.H.R. and Evans, D.A.
(eds) Biology of the Kinetoplastida, Vol. 1. Academic Press, London, pp. 134.
Vickerman, K. (1976b) Comparative cell biology of the kinetoplastid flagellates. In: Lumsden, W.H.R. and
Evans, D.A. (eds) Biology of the Kinetoplastida, Vol. 1. Academic Press, London, pp. 35100.
Vickerman, K. (1977) DNA throughout the single mitochondrion of a kinetoplastid flagellate: observations of the ultrastructure of Cryptobia vaginalis (Hesse, 1910). Journal of Protozoology 24, 221233.
Vickerman, K. (1990) Phylum Zoomastigina Class Diplomonadida. In: Margulis, L., Corliss, J.O.,
Melkanian, M. and Chapman, D. (eds) Handbook of Protoctista. Jones and Bartlett, Boston,
Massachusetts, pp. 200210.
Vommaro, R.C., Attias, M., Silva Filho, F.C., Woo, P.T.K. and De Souza, W. (1997) Surface charge and surface
carbohydrates of Cryptobia salmositica virulent and avirulent forms and of C. bullocki (Kinetoplastida:
Cryptobiidae). Parasitology Research 83, 698705.
Wales, J.H. and Wolf, H. (1955) Three protozoan diseases of trout in California. California Fish and Game 41,
183187.
Wang, R. and Belosevic, M. (1994a) Cultivation of Trypanosoma danilewskyi (Laveran and Mesnil 1904) in
serum-free medium and assessment of the course of infection in goldfish, Carassius auratus. Journal of
Fish Diseases 17, 4756.
Wang, R. and Belosevic, M. (1994b) Estradiol increases susceptibility of goldfish to Trypanosoma danilewskyi.
Developmental and Comparative Immunology 18, 377387.
Wehnert, S.D. and Woo, P.T.K. (1980) In vivo and in vitro studies on the host specificity of Trypanoplasma
salmositica. Journal of Wildlife Diseases 16, 183187.
Wehnert, S.D. and Woo, P.T.K. (1981) The immune responses of Salmo gairdneri during Trypanoplasma
salmositica infection. Bulletin, Canadian Society of Zoologists 11, 100 (abstract).
Wiegertjes. G.F., Groeneveld and Van Muiswinkel, W.B. (1995) Genetic variation in susceptibility to
Trypanoplasma borreli infection in common carp (Cyprinus carpio L.). Veterinary Immunology and
Immunopathology 47, 153161.
Wolf, K. and Markiw, M.E. (1982) Ichthyophthiriasis, immersion immunization of rainbow trout (Salmo
gairdneri) using Tetrahymena thermophila as a protective immunogen. Canadian Journal of Fisheries and
Aquatic Science 39, 17221725.
Woo, P.T.K. (1969) The haematocrit centrifuge for the detection of trypanosomes in blood. Canadian Journal
of Zoology 47, 921923.
Woo, P.T.K. (1970) The haematocrit centrifuge technique for the diagnosis of African trypanosomiasis. Acta
Tropica 27, 384386.
Woo, P.T.K. (1978) The division process of Cryptobia salmositica in experimentally infected rainbow trout
(Salmo gairdneri). Canadian Journal of Zoology 56, 15141518.
Woo, P.T.K. (1979) Trypanoplasma salmositica: experimental infections in rainbow trout, Salmo gairdneri.
Experimental Parasitology 47, 3648.
Woo, P.T.K. (1981a) Trypanosoma danilewskyi: a new multiplication process for Trypanosoma (Protozoa,
Kinetoplastida). Journal of Parasitology 67, 522526.
Woo, P.T.K. (1981b) Acquired immunity against Trypanosoma danilewskyi in goldfish, Carassius auratus. Parasitology 83, 343346.
Woo, P.T.K. (1987a) Cryptobia and cryptobiosis in fishes. Advances in Parasitology 26, 199237.
114
P.T.K. Woo
Woo, P.T.K. (1987b) Immune response of fish to protozoan infections. Parasitology Today 3, 186188.
Woo, P.T.K. (1990) MISET: an immunological technique for the serodiagnosis of Cryptobia salmositica
(Sarcomastigophora, Kinetoplastida) infection in Oncorhynchus mykiss. Journal of Parasitology 76, 389393.
Woo, P.T.K. (1992) Immunological responses of fish to parasitic organisms. In: Faisal, M. and Hetrick, F.M.
(eds) Annual Review of Fish Diseases, vol. 2. Pergamon Press, New York, pp. 339366.
Woo, P.T.K. (1994) Flagellate parasites of fishes. In: Kreier, J.P. (ed.) Parasitic Protozoa, vol. VIII, 2nd edn.
Academic Press, London, pp. 180.
Woo, P.T.K. (1995) Piscine cryptobiosis and immunological protective strategies: a salmonid experience. In:
Shariff, M., Arthur, J.R. and Subasinghe, R.P. (eds) Diseases of Asian Aquaculture II. Asian Fisheries
Society, Manila, pp. 381392.
Woo, P.T.K. (1998) Protection against Cryptobia (Trypanoplasma) salmositica and salmonid cryptobiosis.
Parasitology Today 14, 272277.
Woo, P.T.K. (2001) Cryptobiosis and its control in North American fishes. International Journal for Parasitology
31, 566574.
Woo, P.T.K. (2003) Cryptobia (Trypanoplasma) salmositica and salmonid cryptobiosis. Journal of Fish Diseases 26, 627646.
Woo, P.T.K. and Black, G.A. (1984) Trypanosoma danikewskyi: host specificity and hosts effects on
morphometrics. Journal of Parasitology 70, 788793.
Woo, P.T.K. and Jones, S.R.M. (1989) The piscine immune systems and the effects of parasitic protozoans on
the immune response. In: Ko, R. (ed.) Concepts in Parasitology. Hong Kong University Press, Hong Kong,
pp. 4764.
Woo, P.T.K. and Li, S. (1990) In vitro attenuation of Cryptobia salmositica and its use as a live vaccine against
cryptobiosis in Oncorhynchus mykiss. Journal of Parasitology 76, 752755.
Woo, P.T.K. and Poynton, S.L. (1995) Diplomonadida, Kinetoplastida and Amoebida (Phylum
Sarcomastigophora). In: Woo, P.T.K. (ed.) Fish Diseases and Disorders, Vol. 1: Protozoan and Metazoan
Infections. CAB International, Wallingford, UK, pp. 2796.
Woo, P.T.K. and Rogers, D.J. (1974) A statistical study of the sensitivity of the haematocrit centrifuge technique in the detection of trypanosomes in blood. Transactions of the Royal Society of Tropical Medicine
and Hygiene 68, 319326.
Woo, P.T.K. and Thomas, P.T. (1991) Polypeptide and antigen profiles of Cryptobia salmositica, C. bullocki
and C. catostomi (Kinetoplastida, Sarcomastigophora) isolated from fishes. Diseases of Aquatic Organisms
11, 201205.
Woo, P.T.K. and Thomas, P.T. (1992) Comparative in vitro studies on virulent and avirulent strains of
Cryptobia salmositica Katz, 1951 (Sarcomastigophora, Kinetoplastida). Journal of Fish Diseases 15,
261266.
Woo, P.T.K. and Wehnert, S.D. (1983) Direct transmission of a haemoflagellate, Cryptobia salmositica Katz,
1951 (Kinetoplastida, Bodonina) between rainbow trout under laboratory conditions. Journal of
Protozoology 39, 334337.
Woo, P.T.K. and Wehnert, S.D (1986) Cryptobia salmositica, susceptibility of infected trout, Salmo gairdneri,
to environmental hypoxia. Journal of Parasitology 72, 392396.
Woo, P.T.K., Wehnert, S.D. and Rodgers, D. (1983) The susceptibility of fishes to haemoflagellates at different
ambient temperatures. Parasitology 87, 385392.
Woo, P.T.K., Leatherland, J.F. and Lee, M.S. (1987) Cryptobia salmositica: cortisol increases the susceptibility
of Salmo gairdneri Richardson to experimental cryptobiosis. Journal of Fish Diseases 10, 7583.
Wood, J.W. (1979) Diseases of Pacific Salmon: Their Prevention and Treatment, 3rd edn. State of Washington
Department of Fisheries, Olympia, Washington.
Wright, A.D.G., Li, S., Feng, S., Martin, D.S. and Lynn, D.H. (1999) Phylogenetic position of the
kinetoplastids, Cryptobia bullocki, Cryptobia catostomi, and Cryptobia salmositica and monophyly of
the genus Trypanosoma inferred from small subunit ribosomal RNA sequences. Molecular and Biochemical Parasitology 99, 6976.
Yanong, P.E., Curtis, E., Russa, R., Francis-Floyd, R., Klinger, R.E., Berzins, I., Kelley, K. and Poynton, S.L.
(2004) Cryptobia iubilans infection in juvenile discus. Journal of American Veterinary Medical Association 224, 16441650.
Zuo, X. and Woo, P.T.K. (1996) Acid phosphatase in pathogenic and nonpathogenic hemoflagellates,
Cryptobia spp. of fishes. Journal of Parasitology 82, 893899.
Zuo, X. and Woo, P.T.K. (1997a) Proteases in pathogenic and nonpathogenic hemoflagellates, Cryptobia spp.
(Sarcomastigophora: Kinetoplastida) of fishes. Diseases of Aquatic Organisms 29, 5765.
115
Zuo, X. and Woo, P.T.K. (1997b) Natural antiproteases in rainbow trout, Oncorhynchus mykiss, and brook
charr, Salvelinus fontinalis, and the in vitro neutralization of fish a2-macroglobulin by the metalloprotease
from the pathogenic haemoflagellate, Cryptobia salmositica. Parasitology 114, 375382.
Zuo, X. and Woo, P.T.K. (1997c) The in vivo neutralization of proteases from Cryptobia salmositica by
2-macroglobulin in the blood of rainbow trout, Oncorhynchus mykiss and brook charr, Salvelinus
fontinalis. Diseases of Aquatic Organisms 29, 6772.
Zuo, X. and Woo, P.T.K. (1997d) Purified metallo-protease from the pathogenic haemoflagellate, Cryptobia
salmositica, and its in vitro proteolytic activities. Diseases of Aquatic Organisms 30, 177185.
Zuo, X. and Woo, P.T.K. (1998a) Characterization of purified metallo- and cysteine proteases from the
pathogenic haemoflagellate, Cryptobia salmositica Katz 1951. Parasitology Research 84, 492498.
Zuo, X. and Woo, P.T.K. (1998b) In vitro secretion of metalloprotease (200 kDa) by the pathogenic piscine
haemoflagellate, Cryptobia salmositica Katz, and stimulation of protease production by collagen. Journal
of Fish Diseases 21, 249255.
Zuo, X. and Woo, P.T.K. (2000) In vitro haemolysis of piscine erythrocytes by purified metalloprotease from
the pathogenic haemoflagellate, Cryptobia salmositica Katz. Journal of Fish Diseases 23, 227230.
Zuo, X., Feng, S. and Woo, P.T.K. (1997) The in vitro inhibition of proteases from Cryptobia salmositica Katz
by a monoclonal antibody (MAb-001) against a glycoprotein on the pathogenic haemoflagellate. Journal of
Fish Diseases 20, 419426.
Introduction
I. multifiliis, Fouquet, 1876, and C. irritans,
Brown, 1951, are pathogenic ciliates that
infect fresh- and saltwater fishes, respectively. This chapter reviews what is currently known about the pathobiology of both
these parasites. In each section I. multifiliis
is discussed first, followed by C. irritans.
I. multifiliis, also referred to as Ich, is
one of the most pathogenic protozoan parasites of fishes. There is no official record on
the annual economic loss attributed to
ichthyophthiriasis, even though it is considered to be a major problem in aquaculture (Hoffman, 1999). Epizootics were
reported in China as early as the 10th century (Hines and Spira, 1974a). The first
major outbreak in North America was
described at the end of the 19th century
(Stiles, 1894). Ich was relatively unknown
in Russia before 1940, but since then it has
become a serious disease of carp (Bauer,
1953). The significance of the problem will
increase with the growth of aquaculture.
Concomitant with the rapid development of mariculture in the last decade,
C. irritans has also become an increasingly
important problem. Sikama first reported
the parasite in Japan in 1938.
117
118
H.W. Dickerson
(Fundulus notatus) (Kozel, 1976). An epizootic that occurred in Lake Titicaca on the
PeruBolivia border primarily affected
killifish (Orestias spp.) and the majority
(93%) of dead were O. agassii (Wurtsbaugh
and Tapia, 1988). The occurrence of epizootics in only one or a few species in a mixed
fish population may not indicate genetic
variation in resistance, but rather different
physiological states that predispose certain
individuals or groups to disease. Wurtsbaugh
and Tapia (1988) observed that most of the
fishes that died in the epizootic were gravid
or spent adult O. agassii. Pickering and
Christie (1980), in a study on parasite infection of brown trout (Salmo trutta L.), found
Ich more frequently in precocious mature
pre-spawning males than in immature
fishes. They concluded that sexual maturation was associated with an increase in prevalence and severity of infestation with
ectoparasites. Reproductive stress may also
be a factor in the apparent variation in susceptibility to infection.
Nigrelli et al. (1976) proposed that
there are physiological races of I. multifiliis
related to the temperature tolerances of the
host fishes. Thus, races of I. multifiliis exist
that infect coldwater (7.210.6C) fishes,
such as salmon, and others that infect
warmwater (12.816.1C) tropical fishes.
To date, there is no experimental evidence
to substantiate or refute this idea. Fishes
with wide ranges of temperature tolerance, such as carp and catfish, may be
susceptible to both cold- and warmwater
parasites. Ich epizootics in Arctic fishes
suggest that these outbreaks occur when
the water temperature reaches a moderate
range. Valtonen and Kernen (1981)
reported on an epizootic in a salmon hatchery in central Finland in two consecutive
years when the water temperature rose to
14C or higher.
Paperna (1980) stated that I. multifiliis
in Europe and Asia is highly pathogenic for
carp, with a preference for this species.
There are no experimental data to support
this speculation. Although ichthyophthiriasis
often occurs in carp in Europe and Asia,
this could merely be due to the fact that
carp are the primary fish raised in these
119
Cryptocaryon irritans
Host range, geographical distribution,
prevalence and seasonal fluctuations
C. irritans is a parasite of marine fishes.
Sikama first described cryptocaryoniasis in
Japan in 1938. The disease is now thought
to occur worldwide (Sikama, 1961). The
parasite is a recurring problem in marine
fishes in aquaria and is becoming a concern
in commercial mariculture (Colorni, 1985).
It was suggested that the parasites incidence in fishes in the USA occurred initially through the importation of fishes from
Hawaii and the Indo-Pacific area (Nigrelli
and Ruggieri, 1966). The parasite also
occurs in marine fish populations on the
east coast of the USA.
The prevalence of the parasite in native
fishes in North America is not well documented. The parasite was found on a few
fishes in Mission Bay, California (Wilke and
Gordin, 1969). These fishes were examined
at a time when there was a concomitant outbreak of cryptocaryoniasis in aquaria at the
Scripps Institute of Oceanography. It was
unclear whether the native fishes were naturally infected or whether they acquired the
infection as a result of contamination with
tomonts and theronts released from the
Institute.
C. irritans is not fastidious in its host
selection (Colorni, 1985). The host range
does not appear to be as great as that of
I. multifiliis, however. Fishes vary in susceptibility to infection. Elasmobranchs are
generally resistant (Wilke and Gordin, 1969).
Also, there are apparent differences in
degrees of susceptibility in marine teleosts.
120
H.W. Dickerson
Systematics
Ichthyophthirius multifiliis
The first description of the etiologic agent
of white spot disease was by Hilgendorf and
Paulicki in 1869 (Stiles, 1894). They described the life cycle of the ciliate and placed
it in the genus Pantotricha. In 1876 Fouquet
published a detailed description of the
organism and its life cycle. He placed the
organism in a new genus (Heterotricha) and
proposed the name Ichthyophthirius multifiliis. At present, multifiliis is the only recognized species of Ichthyophthirius (Lee
et al., 1985). Based on differences in gross
nuclear morphology between isolates, however, it was suggested by Nigrelli et al.
(1976) that subspecies could exist. Serotypic
strains of I. multifiliis are described based
on the presence of specific surface proteins, referred to as immobilization antigens
(Dickerson et al., 1993).
Cryptocaryon irritans
Sikama described a parasitic holotrichous
ciliate as the cause of a disease outbreak in
marine fishes and suggested that the disease
was similar to ichthyophthiriasis. He recognized that this organism was different from
I. multifiliis and proposed the name Ichthyophthirius marinus (Sikama, 1961). Brown
had previously described this parasitic ciliate, and proposed the name Cryptocaryon
irritans, however (Brown, 1950). Brown
published a more detailed description of
the cycle of macronuclear development,
which clearly distinguishes C. irritans from
I. multifiliis (Brown, 1963).
Although Sikama first described cryptocaryoniasis, Kerbert may have observed
the disease much earlier (Stiles, 1894).
C. irritans is placed in class Oligohymenophora, subclass Hymenostomata, order
Hymenostomatida, suborder Ophryoglenina
and family Ichthyophthiridae. Cheung
found in a scanning electron microscopic
study that the organism does not have oral
accessory membranes (membranelles) similar to those of I. multifiliis (see below) and
hence questioned the inclusion of C. irritans in the order Hymenostomatida (Cheung
et al., 1981). Colorni and Diamant noted
that the similarities between I. multifiliis
and C. irritans are more likely to be the
result of an adaptive convergence of life histories, rather than phylogenetic proximity
(Colorni and Diamant, 1993). These authors
suggested a reassessment of the taxonomic
status of C. irritans as well. Based on
sequence analysis of the 18S ribosomal
RNA (rRNA) gene, Wright and Colorni have
proposed that the ciliate be placed in the
order Prorodontida within the class
Prostomatea. They proposed a new family
name: Cryptocaryonidae (Wright and
Colorni, 2002). Distinct biological and
pathological differences have also been
found between isolates of C. irritans taken
121
122
H.W. Dickerson
123
Fig. 4.3. Channel catfish fingerling (Ictalurus punctatus) infected with Ichthyophthirius multifiliis.
The fish was exposed to parasites for 7 days at 23C. Each white spot represents a single trophont.
124
H.W. Dickerson
Fig. 4.4. The same fish as in Fig. 4.3 seen at a higher magnification. Notice how the trophonts
within the skin are often raised above the surface of the fish.
125
Cryptocaryon irritans
C. irritans is a holotrichous ciliate that
infects the surface epithelia of marine fishes.
It goes through an obligate feeding stage and
a fish-free reproductive stage during the
course of its life history. The various forms
of the parasite reach approximately the
same sizes as their Ichthyophthirius counterparts. The infective theront (Fig. 4.5) is
pyriform in shape and 25 to 60 m in length
(Brown, 1963; Nigrelli and Ruggieri, 1966;
Cheung et al., 1979; Colorni, 1987; Colorni
126
H.W. Dickerson
127
128
H.W. Dickerson
HostParasite Relationships of
I. multifiliis
Host selection
I. multifiliis does not appear to have a predilection for any specific group of fishes,
although it is believed that the organism originated as a parasite of carp (Hoffman, 1999).
There is a linear relationship between
the number of theronts to which a host is
exposed and the resultant parasite burden
(McCallum, 1982). Theronts are positively
phototactic (Lom and Cerkasova, 1974; Wahli
and Meier, 1991). Wahli and Meier (1991)
could not demonstrate that theronts were
attracted to fish, a result in disagreement
with that of Lom and Cerkasova (1974), who
found that theronts were attracted by components of fish blood. Houghton (1987)
observed that theronts were attracted to
pieces of fish tissue in the water, suggesting
a possible short-range homing mechanism.
Epizootics of I. multifiliis appear to
occur uniformly in populations of male and
female fishes. There are reports where
infections occurred predominantly in one
sex, however. Male guppies (Lebistes
reticulatus) were reported to be more
severely infected than females (Paperna,
1972). Similarly, in brown trout (S. trutta)
mature males were more frequently infected
than females, with the most severe infections occurring on precociously mature
pre-spawning males (Pickering and Christie,
1980). In contrast, in an epizootic in Lake
Titicaca, the majority of the dead and
infected fish were gravid or spent female
killifish (O. agassii) (Wurtsbaugh and Tapia,
1988). Infection may not be a function of
predilection of the parasite for either sex,
Genetic susceptibility
In experimental I. multifiliis infections, only
a portion of the infecting theronts develop
into trophonts (McCallum, 1982). McCallum
(1982) suggested that this variability
depends on the genetic background of the
host. A major host resistance factor is the
production of surface mucus, which is
increased in response to infection (Hines
and Spira, 1974c; Ventura and Paperna,
1985). There may be genetic factors that
influence the amount and composition of
fish mucus.
Significant variation in susceptibility
to infection occurs among fish species.
Behavioural modifications
In the early stages of disease, fishes congregate near water intakes to reduce contact
with free-swimming theronts (Kabata,
1985). Fishes also flash or rub their bodies against objects in reaction to skin and
gill irritation caused by the theronts (Brown
and Gratzek, 1980). Fishes swim more rapidly than normal and often leap out of the
water. As the disease progresses, they
become less active and congregate at the
bottom of ponds or aquaria (Hines and
Spira, 1973a). Fishes also lie near the edges
of ponds, moving their gill opercula rapidly in an attempt to obtain more oxygen
(Kabata, 1985). This is related to gill damage caused by the parasite. With very
heavy infections, fishes become lethargic
and stop feeding (Hines and Spira, 1973a).
129
Clinical signs
Gross pathology I. multifiliis
In very mild I. multifiliis infections the only
detectable pathological change is the presence of a few white spots on the surface of
the fishes. In more severe cases there are
usually large numbers of spots on the skin
(see Figs 4.3 and 4.4). Occasionally, however, I. multifiliis only infects the gills, with
no obvious gross lesions on the body surface.
Ulcers develop in the skin of heavily
infected fishes and are often sites of secondary bacterial or fungal infections. The fins
become frayed due to loss of tissue between
the fin rays (Hines and Spira, 1973a).
The common clinical signs of ichthyophthiriasis are the characteristic disseminated white surface lesions (spots). Each
spot represents a developing trophont within
an epithelial capsule or vesicle (see Fig. 4.4).
Visible parasites develop several days after
the initial attachment of theronts (Hines and
Spira, 1973a; Ventura and Paperna, 1985). In
cases where the infection is restricted to the
gills, these are not visible.
An early physiological response to
infection is an increase in surface mucus
production (Hines and Spira, 1973a). Skin
penetration by theronts stimulates expanded
130
H.W. Dickerson
Histopathology I. multifiliis
The nature and severity of histopathological changes seen in I. multifiliis infections vary greatly. This variation is
influenced by such host factors as stress
and nutritional status. Nevertheless, parasite load is the major factor contributing to
the diverse tissue changes. In general, mild
infections elicit minor cellular reactions.
The extensive histopathological changes
reported to occur in I. multifiliis infections
131
Histopathology C. irritans
There is limited information on the histopathologic changes that occur with C. irritans
infections. From the analogies in the infective and feeding stages of I. multifiliis
and C. irritans, it is reasonable to assume
that the cellular changes caused by both parasites are similar. The major lesions caused
by C. irritans are vesicles within the skin.
Mucus-producing cells proliferate in the skin
and gills. Epithelia of infected gills become
hyperplastic and eroded in severe cases.
Clinical pathology
Although the total leukocyte numbers do not
change during I. multifiliis infections, there
is a differential shift in the various leukocyte
populations. Infected fishes develop a
lymphocytopenia and neutrophilia (Hines
and Spira, 1973a). The number of neutrophils in circulation early in the infection
may increase 5-fold with no concurrent rise
in total leukocyte numbers. The shift in distribution of leukocyte cell populations is
accompanied by an increase in the number
of immature blast cells. It was suggested that
the leukocyte changes in infected fishes are
non-specific stress reactions (Hines and
Spira, 1973b).
Studies on serum levels of Na+, K+, Mg+
and blood urea ammonia indicated significant osmoregulatory disturbances (Hines
and Spira, 1974b). In severe infections there
was a marked drop in serum Na+ and Mg+
levels and a rise in serum K+ levels. Blood
urea-ammonia levels also increased during
the course of the infection.
132
H.W. Dickerson
layer does not completely cover the secondary lamellae in unstressed rainbow trout
(Handy and Eddy, 1991).
In addition to acting as a physical barrier, surface mucus also contains antiparasitic factors. Hines and Spira (1974c) and
Wahli and Meier (1985) found that mucus
and serum from immune carp and rainbow
trout (Salmo gairdneri) immobilized trophonts
in vitro. It was suggested that this immobilizing activity was due to the presence of
antibodies and that these prevented the penetration of theronts through the mucus. Xu
and Dickerson, using dot-blot assays, found
that Ich-immune channel catfish have
mucus antibodies against membrane antigens of I. multifiliis (Xu, 1995). In contrast,
Cross and Matthews (1993b) were unable to
demonstrate binding of carp mucus antibodies to thin sections of fixed theronts.
The discrepancy in these findings is probably due to the fact that specific antibodies
are present in relatively low levels in
mucus (as compared with serum) and may
not have been detectable in the experiments
of Cross and Matthews. More recent work
suggests that mucosal antibodies are protective. This work is discussed further below.
A basic innate host reaction to I. multifiliis is epithelial cell proliferation. In mild
infections there is little reaction other than
the formation of an epithelial cell capsule
around the parasite itself (Ventura and
Paperna, 1985). In severe or repeated infections, however, extensive epithelial cell
proliferation occurs (Hines and Spira, 1974a;
Ventura and Paperna, 1985). This epithelial
hyperplasia could interfere with penetration of the theront. The skin of infected
fishes also becomes infiltrated with neutrophils, basophils, eosinophils, eosinophilic
granular cells, macrophages and lymphocytes (Ventura and Paperna, 1985; Cross
and Matthews, 1993b). Increases in eosinophilic granular cells were coupled to the
acquired immune response against the parasite (Cross and Matthews, 1993b). Leukocytes (granulocytes) were observed adjacent
to parasite surfaces without apparent
adherence. How these cells interact with
the trophonts in the tissue is not well
understood.
133
134
H.W. Dickerson
135
136
H.W. Dickerson
fractions (Burkart et al., 1990). The vaccination and testing were done on channel
catfish under uniform conditions. The
study confirmed that controlled infection
with live organisms afforded higher protection than either injection or immersion with
killed parasites. Vaccination by intraperitoneal or surface infection provided complete protection when fishes were
challenged 21 days later. These findings
agree with other studies where it was found
that fishes exposed to non-lethal doses of
parasites (Hines and Spira, 1974c; Houghton
and Matthews, 1990) or to lethal doses followed by treatment (Beckert and Allison,
1964; Houghton and Matthews, 1986; Clark
et al., 1987) were protected against further
infection. In contrast, vaccination with
killed cell preparations was much less
effective; in most cases, all of the vaccinated groups died following challenge (see
below). The differences in protection
between live and killed parasites suggest
either that relevant immunogens are molecules rapidly turned over on the live parasite (e.g. membrane proteins or secretory
and excretory products) or they are denatured by the procedures used to treat the
parasite in killed vaccines (freezing,
deciliation or formalin fixation).
Theront versus trophont antigens
Protective immunity is elicited in channel
catfish following exposure to live theronts
(Burkart et al., 1990; Dickerson and Clark,
1996; Maki and Dickerson, 2003; Xu et al.,
2004). Because theronts differentiate into
trophonts soon after they attach to fish, it is
difficult to determine whether protection is
elicited by stage-specific antigens. To
address this question, antigens from both
theronts and trophonts were compared
directly in vaccination trials (Burkart et al.,
1990). Channel catfish were immunized
with: (i) freeze-thawed or formalin-fixed
theronts; (ii) isolated theront cilia; and
(iii) formalin-fixed trophonts. One hundred
per cent mortality was seen in all groups
except the one injected with killed trophonts,
which had a mean mortality of 51% 38.
This protection was lower than that reported
by Areerat (1974) but suggested that formalinkilled trophonts contain protective antigens. The finding in this experiment that
fish injected with Ich cilia all died following challenge is in direct disagreement with
a previous report where vaccination with
theront cilia was purported to significantly
reduce mortality (Goven et al., 1981). Nevertheless, in all groups inoculation with both
trophont and theront antigens increased the
survival period (days to death) over that of
control fish. It thus appears that killed antigen preparations elicited some protection,
although not enough to prevent death. More
recently, Xu et al. (2004) demonstrated protection following immunization with killed
trophonts.
Immobilization antigens
Sera from immune fishes immobilize
free-swimming theronts and tomonts in vitro
(Fig. 4.7). Hines and Spira (1974c) were the
first to describe this phenomenon and
they postulated that immobilization was
elicited by the binding of antibodies to parasite cilia. Immobilization of theronts and
trophonts by immune fish sera has been
described by other researchers as well
(Beckert and Allison, 1964; Parker, 1965;
Areerat, 1974; Wahli and Meier, 1985;
137
138
H.W. Dickerson
et al., 1996). Because immobilizing antibodies are present in the skin and cutaneous
mucus of actively immune fish (Xu, 1995;
Xu and Klesius, 2003), these results strongly
suggest that protective antibodies are produced locally in the skin. These results
are entirely consistent with biochemical evidence that serum and mucus antibodies
are metabolically distinct (Lobb and Clem,
1981). Whether such antibodies arise locally
from lymphocytes within the skin or are produced elsewhere and enter the epithelium
through some, as yet, unidentified pathway
is unknown (Dickerson and Clark, 1998).
Concurrent infection and cross-immunity
Protective immunity against Ichthyophthirius is highly specific. Hines and Spira
(1974c) noted that immune carp became
infected with other ectoparasites even
though they were resistant to reinfection
with Ich. This observation was used to
argue that immunity against Ich was an
acquired specific response. It was of interest, therefore, when other researchers suggested that the ciliate Tetrahymena shared
common antigens with Ichthyophthirius
(Goven et al., 1981), and that Tetrahymena
cilia could be used to vaccinate fish against
Ich. Subsequent work indicated that trout
were also protected after bath immunization
in cultures of Tetrahymena thermophila
(Wolf and Markiw, 1982). Wolf found that
fish immunized with Tetrahymena were
resistant to both Ichthyobodo necatrix and
Ich. It was reported that goldfish (C. auratus)
vaccinated with T. pyriformis were protected against I. multifiliis as well as a number of other protozoan parasites (Ling et al.,
1993). Other labs could not repeat these
findings, however (Dickerson and Clark,
1996; Matthews, 1996). Sera from carp
immunized by intraperitoneal injection
with live Tetrahymena did not immobilize
Ich, and the fish were not protected against
infection (Houghton et al., 1992). Immobilizing sera from Ich-immune channel catfish reacted with Ich ciliary membrane
proteins but not with those of Tetrahymena
(Clark et al., 1988). A possible explanation
for the discrepancy is that the protection
139
140
H.W. Dickerson
141
Diagnosis of Infection
Fishes infected with either I. multifiliis or
C. irritans usually develop characteristic
white spots on their surface (see section on
clinical signs above). In mild infections the
parasites are not readily seen. The parasites
are more difficult to see on fishes with
lightly pigmented skin. In early stages of
infection, large numbers of theronts can
actually kill a fish before the parasite
becomes visible and death is caused by
massive damage to the gill epithelia.
As mentioned earlier (see section
above on hostparasite relationships),
infected fishes often have behavioural
changes caused by the irritation from parasites in the skin and gills. This behaviour is
non-specific, however, and can also be
associated with other bacterial, fungal and
protozoan diseases.
To make a definitive diagnosis of
ichthyophthiriasis or cryptocaryoniasis, it is
necessary to microscopically examine tissue
from a gill arch, a tail fin or the body surface.
The large (200 to 800 m) ciliated trophonts
are easily seen in unstained wet mounts
( 1040 magnification). The trophont of Ich
142
H.W. Dickerson
Chemotherapy
A variety of chemicals have been used for
treating I. multifiliis, none of which is universally successful.
Sodium chloride was one of the first to
be used (Stiles, 1894), where it was reported
that theronts were killed instantly in saturated salt solutions. Stiles (1894) proposed
creating a salt concentration gradient for use
as treatment. This can be done by placing
143
144
H.W. Dickerson
Immunization
The ideal method to prevent infection of
fishes with I. multifiliis is prophylactic
immunization. Prevention of disease is
always preferred to treatment. At the present
time, there are no practical, commercially
available vaccines against Ich. A variety of
components of I. multifiliis have been used to
experimentally induce immunity in fishes,
but, because I. multifiliis is an obligate parasite that can only be collected from live
fishes, large-scale production of antigenic
material for vaccines is extremely difficult.
Chemotherapy
Many of the same chemicals used to treat
I. multifiliis infections have been tried against
C. irritans. One chemical that appears to work
is copper sulphate. Immersion of fishes in
0.150.25 ppm copper sulphate for 310 days
is recommended (Herwig, 1978). The treatment may have to be repeated several times.
Brown and Gratzek (1980) suggested that continual exposure to copper (0.15 ppm) will
control C. irritans infections. The solubility of
copper is adversely affected by calcium carbonate in the water. It was suggested that
citric acid or glacial acetic acid be added to
chelate the copper to keep it in solution. This
is questionable since the chelated copper
may not be available for activity against the
parasite (Herwig, 1978).
A mixture of cupric acetate (0.42 ppm),
formalin (5.26 ppm) and Tris buffer (4.8 ppm)
has been an effective treatment (Nigrelli and
Ruggieri, 1966). Another variation is to use
copper sulphate (0.150.2 ppm), citric acid
and methylene blue stock (1 ml of 1% solution/2.5 gallons of water) until the water is a
clear blue colour (Nigrelli and Ruggieri, 1966).
Quinine derivatives are effective drugs
against C. irritans. Quinine hydrochloride,
quinine sulphate and quinacrine hydrochloride (atebrine or mepacrine) kill
theronts and can be used interchangeably
145
146
H.W. Dickerson
measures and treatments. There are a variety of treatments or combinations of treatments available, none of which is ideal. An
important area of research is the development of effective prophylactic control methods to prevent catastrophic outbreaks.
When available, immunization is one
of the most cost- and time-effective means
of preventing disease. There are significant
problems hindering the development of
practical vaccines against I. multifiliis and
C. irritans, however. One of the major obstacles is that these ciliates cannot be grown in
axenic culture, which precludes the largescale culture of organisms for preparation of
vaccines. Future research should address
the problem of mass production of protective antigens. One solution is the development of in vitro cultivation systems for
I. multifiliis and C. irritans, which will
require basic studies on parasite physiology
and biochemistry. The current and future
resources provided by genomic technologies in ciliates are sure to provide advances
in this area. The genome of the free-living
ciliate T. thermophila is currently available
for comparative studies (Turkewitz et al.,
2002), and an Ichthyophthirius expression
sequence tag library is under construction
(T.G. Clark, unpublished). A second solution
would be the use of genetic engineering for
the production of recombinant protective
antigens in easily cultured organisms. The
free-living ciliate T. thermophila is a promising system for the large-scale production of
heterologous genes, and has already been
successfully used to express the i-antigens of
I. multifiliis (Gaertig et al., 1999).
Further research is also necessary to
understand the immune response against both
parasites. Although it has been evident for
some time that fishes develop protective
immunity against I. multifiliis, the effector
mechanisms are only now becoming
Acknowledgements
The authors wish to thank Ms B. Velasquez
for providing the drawing depicting the life
cycle of I. multifiliis.
This work was supported by multiple
consecutive grants (19872005) from the US
Department of Agriculture, National Research
Initiative Competitive Grants Program.
References
Aihua, L. and Buchmann, K. (2001) Temperature- and salinity-dependent development of a Nordic strain of
Ichthyophthirius multifiliis from rainbow trout. Journal of Applied Ichthyology 17, 273276.
Allison, R. and Kelly, H.D. (1963) An epizootic of Ichthyophthirius multifiliis in a river fish population.
Progressive Fish Culturist 25, 149150.
147
Areerat, S. (1974) The immune response of channel catfish, Ictalurus punctatus Rafinesque, to Ichthyophthirius multifiliis. MS thesis, Auburn University, Auburn, Alabama.
Bauer, O.N. (1953) The immune response of channel catfish Ictalurus punctatus Rafinesque to
Ichthyophthirius multifiliis Fouquet. Doklady Novaia Serviia 93, 377.
Beckert, H. (1975) Observations on the biology of Ichthyophthirius multifiliis Fouquet, 1876. Its susceptibility
to ethoxyquin, and some immunological responses of channel catfish, Ictalurus punctatus, to this parasite. PhD thesis, University of Southwestern Louisiana, Lafayette, Louisiana.
Beckert, H. and Allison, R. (1964) Some host responses of white catfish to Ichthyophthirius multifiliis. Proceedings of the Southeastern Association of Game Fish Commissioners 18, 438.
Beeler, C.R. (1981) Cryopreservation of Ichthyophthirius multifiliis. Masters thesis, Kansas State University,
Manhattan, Kansas.
Berg, J.M. and Shi, Y. (1996) The galvanization of biology: a growing appreciation for the role of zinc. Science
271, 1081.
Bragg, R.R. (1991) Health status of salmonids in river systems in Natal. I. Collection of fish and parasitological
examination. Onderstepoort Journal of Veterinary Research 58, 5962.
Brown, E.E. and Gratzek, J.B. (1980) Fish Farming Handbook. Food, Bait, Tropicals and Goldfish. AVI Publishing, Westport, Connecticut.
Brown, E.M. (1951) A new parasitic protozoan, the causal organism of a white spot disease in marine
fish Cryptocaryon irritans gen. & sp. n. In: Agenda of Scientific Meetings of the Zoological Society. London, pp. 12.
Brown, E.M. (1963) Studies on Cryptocaryon irritans Brown. In: Progress in Protozoology, Proceedings of the
1st International Congress on Protozoology. Academic Press, New York, pp. 284287.
Burgess, P.J. and Matthews, R.A. (1994) A standardized method for the in vivo maintenance of Cryptocaryon
irritans (Ciliophora) using the grey mullet Chelon labrosus as an experimental host. Journal of Parasitology 80, 288292.
Burkart, M.A., Clark, T.G. and Dickerson, H.W. (1990) Immunization of channel catfish, Ictalurus punctatus
Rafinesque, against Ichthyophthirius multifiliis (Fouquet): killed versus live vaccines. Journal of Fish
Diseases 13, 401410.
Bushkiel, A.L. (1910) Beitrage zur Kenntnis des Ichthyophthirius multifiliis. Arkiv fr Protistenkinde 21,
61102.
Butcher, A.D. (1941) Outbreaks of white spot or ichthyophthiriasis (Ichthyophthirius multifiliis Fouquet, 1876)
at the hatcheries of Ballarat Fish Acclimatization Society with notes on laboratory experiments. Proceedings of the Royal Society, Victoria 53, 126.
Canella, M.F. and Rocchi-Canella, I. (1976) Biologie des Ophryoglenina (cilis hymnostermes, histophages).
Annals of the University of Ferrara (NS Section III) 3 (Suppl. 2), 1510.
Chapman, G.B. (1984) Ultrastructural aspects of the hostparasite relationship in ichthyophthiriasis. Transactions of the American Microscopical Society 103, 364375.
Chapman, G.B. and Kern, R.C. (1983) Ultrastructural aspects of the somatic cortex and contractile vacuole of
the ciliate Ichthyophthirius multifiliis, Fouquet. Journal of Protozoology 30, 481490.
Cheung, P.J., Nigrelli, R.F. and Ruggieri, G.D. (1979) Studies on cryptocaryoniasis in marine fish: effect of
temperature and salinity on reproductive cycle of Cryptocaryon irritans Brown, 1951. Journal of Fish Diseases 2, 9397.
Cheung, P.J., Nigrelli, R.F. and Ruggieri, G.D. (1981) Scanning electron microscopy on Cryptocaryon irritans
Brown 1951, a parasitic ciliate in marine fish. Journal of Aquaculture 2, 7072.
Clark, T. and Forney, J. (2003) Free-living and parasitic ciliates. In: Craig, A. and Sherf, A. (eds) Antigenic Variation. Academic Press (Elsevier Science), London, pp. 387402.
Clark, T.G., Dickerson, H.W., Gratzek, J.B. and Findly, R.C. (1987) In vitro response of Ichthyophthirius
multifiliis to sera from immune channel catfish. Journal of Fish Biology 31, 203208.
Clark, T.G., Dickerson, H.W. and Findly, R.C. (1988) Immune response of channel catfish to ciliary antigens
of Ichthyophthirius multifiliis. Developmental and Comparative Immunology 12, 581594.
Clark, T.G., McGraw, R.A. and Dickerson, H.W. (1992) Developmental expression of surface antigen genes
in the parasitic ciliate Ichthyophthirius multifiliis. Proceedings of the National Academy of Sciences, USA
89, 63636367.
Clark, T.G., Lin, T. and Dickerson, H.W. (1995) Surface immobilization antigens of Ichthyophthirius
multifiliis: their role in protective immunity. Annual Review of Fish Diseases 5, 113.
Clark, T.G., Lin, T.L. and Dickerson, H.W. (1996) Surface antigen cross-linking triggers forced exit of a protozoan parasite from its host. Proceedings of the National Academy of Sciences, USA 93, 68256829.
148
H.W. Dickerson
Clark, T.G., Lin, T.L., Jackwood, D.A., Sherrill, J., Lin, Y. and Dickerson, H.W. (1999) The gene for an abundant parasite coat protein predicts tandemly repetitive metal binding domains. Gene 229, 91100.
Clark, T.G., Gao, Y., Gaertig, J., Wang, X. and Cheng, G. (2001) The I-antigens of Ichthyophthirius multifiliis
are GPI-anchored proteins. Journal of Eukaryotic Microbiology 48, 332337.
Clayton, G.M. and Price, D.J. (1988) Pleiotropic effect on scale pattern genes in common carp: susceptibility
to Ichthyophthirius multifiliis infection. Heredity 60, 312.
Clayton, G.M. and Price, D.J. (1992) Interspecific and intraspecific variation in resistance to ichthyophthiriasis
among poeciliid and goodeid fishes. Journal of Fish Biology 40, 445453.
Clayton, G.M. and Price, D.J. (1994) Heterosis in response to Ichthyophthirius multifiliis infections in poeciliid
fish. Journal of Fish Biology 44, 5966.
Colorni, A. (1985) Aspects of the biology of Cryptocaryon irritans and hyposalinity as a control measure in
cultured gilt-head sea bream, Sparus aurata. Diseases of Aquatic Organisms 1, 1927.
Colorni, A. (1987) Biology of Cryptocaryon irritans and strategies for its control. Aquaculture 67, 236237.
Colorni, A. and Diamant, A. (1993) Ultrastructural features of Cryptocaryon irritans, a ciliate parasite of
marine fish. European Journal of Protistology 29, 425434.
Corliss, J. (1979) The Ciliated Protozoa: Characterization, Classification, and Guide to the Literature.
Pergamon Press, Oxford, UK, 455 pp.
Cross, D.G. (1972) A review of methods to control ichthyophthiriasis. Progressive Fish-Culturist 34,
165170.
Cross, M.L. (1993) Antibody binding following exposure of live Ichthyophthirius multifiliis (Ciliophora) to
serum from immune carp Cyprinus carpio. Diseases of Aquatic Organisms 17, 159164.
Cross, M.L. and Matthews, R.A. (1992) Ichthyophthiriasis in carp, Cyprinus carpio L.: fate of parasites in
immunized fish. Journal of Fish Diseases 15, 497505.
Cross, M.L. and Matthews, R.A. (1993a) Ichthyophthirius multifiliis Fouquet (Ciliophora): the localization of
sites immunogenic to the host Cyprinus carpio (L.). Fish and Shellfish Immunology 3, 1324.
Cross, M.L. and Matthews, R.A. (1993b) Localized leukocyte response to Ichthyophthirius multifiliis establishment in immune carp Cyprinus carpio L. Veterinary Immunology and Immunopathology 38, 341358.
Diamant, A., Issar, G., Colorni, A. and Paperna, I. (1991) A pathogenic Cryptocaryon-like ciliate from the
Mediterranean Sea. Bulletin of the European Association of Fish Pathologists 11, 122124.
Dickerson, H. and Clark, T. (1996) Immune response of fishes to ciliates. Annual Review of Fish Diseases 6,
107120.
Dickerson, H. and Clark, T. (1998) Ichthyophthirius multifiliis: a model of cutaneous infection and immunity
in fishes. Immunological Reviews: Immune Systems of Ectothermic Vertebrates 166, 377384.
Dickerson, H.W., Lohr, A.L. and Gratzek, J.B. (1985) Experimental intraperitoneal infection of channel
catfish, Ictalurus punctatus (Rafinesque) with Ichthyophthirius multifiliis (Fouquet). Journal of Fish
Diseases 8, 139.
Dickerson, H.W., Clark, T.G. and Findly, R.C. (1989) Ichthyophthirius multifiliis has membrane-associated
immobilization antigens. Journal of Protozoology 36, 159164.
Dickerson, H.W., Clark, T.G. and Leff, A.A. (1993) Serotypic variation among isolates of Ichthyophthirius
multifiliis based on immobilization. Journal of Eukaryotic Microbiology 40, 816820.
Doerder, F.P., Arslanyolu, M., Saad, Y., Kaczmarek, M., Mendoza, M. and Mita, B. (1996) Ecological genetics
of Tetrahymena thermophila: mating types, i-antigens, multiple alleles and epistasis. Journal of
Eukaryotic Microbiology 43, 95100.
Ekless, L.M. and Matthews, R.A. (1993) Ichthyophthirius multifiliis, axenic isolation and short-term maintenance in selected monophasic media. Journal of Fish Diseases 16, 437447.
Elser, H.J. (1955) An epizootic of ichthyophthiriasis among fish in a large reservoir. Progressive Fish-Culturist
17, 132133.
Everett, K.D., Knight, J.R. and Dickerson, H.W. (2002) Comparing tolerance of Ichthyophthirius multifiliis and
Tetrahymena thermophila for new cryopreservation methods. Journal of Parasitology 88, 4146.
Ewing, M.S. and Kocan, K.M. (1986) Ichthyophthirius multifiliis (Ciliophora) development in gill epithelium.
Journal of Protozoology 33, 369374.
Ewing, M.S. and Kocan, K.M. (1987) Ichthyophthirius multifiliis (Ciliophora) exit from gill epithelium. Journal
of Protozoology 34, 309312.
Ewing, M.S. and Kocan, K.M. (1992) Invasion and development strategies of Ichthyophthirius multifiliis, a
parasitic ciliate of fish. Parasitology Today 8, 204208.
Ewing, M.S., Kocan, K.M. and Ewing, S.A. (1983) Ichthyophthirius multifiliis: morphology of the cyst wall.
Transactions of the American Microscopical Society 102, 122128.
149
Ewing, M.S., Kocan, K.M. and Ewing, S.A. (1985) Ichthyophthirius multifiliis (Ciliophora) invasion of gill epithelium. Journal of Protozoology 32, 305310.
Ewing, M.S., Lynn, M.E. and Ewing, S.A. (1986) Critical periods in development of Ichthyophthirius multifiliis
(Ciliophora) populations. Journal of Protozoology 33, 388391.
Ewing, M.S., Ewing, S.A. and Kocan, K.M. (1988) Ichthyophthirius (Ciliophora): population studies suggest
reproduction in host epithelium. Journal of Protozoology 35, 549552.
Gaertig, J., Gao, Y., Tishgarten, T., Clark, T. and Dickerson, H. (1999) Surface display of a parasite antigen in
the ciliate Tetrahymena thermophila. Nature Biotechnology 17, 462465.
Geisslinger, M. (1987) Observations on the caudal cilium of the tomite of Ichthyophthirius multifiliis Fouquet
1876. Journal of Protozoology 341, 180182.
Goven, B.A., Dawe, D.L. and Gratzek, J.B. (1981) In vitro demonstration of serological cross-reactivity
between Ichthyophthirius multifilis Foquet and Tetrahymena pyriformis Lwoff. Developmental and Comparative Immunology 5, 283289.
Gratzek, J.B., Gilbert, J.P., Lohr, A.L., Shotts, E.B. and Brown, J. (1983) Ultraviolet light control of
Ichthyophthirius multifiliis in a closed fish culture recirculation system. Journal of Fish Diseases 6,
145153.
Graves, S.S., Evans, D.L., Cobb, D. and Dawe, D.L. (1984) Nonspecific cytotoxic cells in fish (Ictalurus
punctatus) I. Optimum requirements for target cell lysis. Developmental and Comparative Immunology
8, 293302.
Graves, S.S., Evans, D.L. and Dawe, D.L. (1985a) Antiprotozoan activity of nonspecific cytotoxic cells (NCC)
from the channel catfish (Ictalurus punctatus). Journal of Immunology 134, 7885.
Graves, S.S., Evans, D.L. and Dawe, D.L. (1985b) Mobilization and activation of nonspecific cytotoxic cells
(NCC) in the channel catfish (Ictalurus punctatus) infected with Ichthyophthirius multifiliis. Comparative
Immunology and Microbiology of Infectious Diseases 8, 4351.
Handy, P.D. and Eddy, F.B. (1991) The absence of mucus on the secondary lamellae of unstressed rainbow
trout, Oncorhynchus mykiss (Walbaum). Journal of Fish Biology 38, 153155.
Hauser, M. (1973) Acetomyosin-like filaments in the dividing macronucleus of the ciliated protozoon
Ichthyophthirius multifiliis. Chromosoma 44, 4971.
Herwig, N. (1978) Notes on the treatment of Cryptocaryon. Drum and Croaker 18, 612.
Hildemann, W.H. (1972) Transplantation reactions of two species of Osteichthyes (Teleostei) from South
Pacific coral reefs. Transplantation 14, 261267.
Hines, R.S. and Spira, D.T. (1973a) Ichthyophthirius multifiliis (Fouquet) in the mirror carp, Cyprinus carpio L.
I. Course of infection. Journal of Fish Biology 5, 385392.
Hines, R.S. and Spira, D.T. (1973b) Ichthyophthiriasis in the mirror carp. II. Leukocyte response. Journal of
Fish Biology 5, 527534.
Hines, R.S. and Spira, D.T. (1974a) Ichthyophthiriasis in the mirror carp Cyprinus carpio L. III. Pathology. Journal of Fish Biology 6, 189196.
Hines, R.S. and Spira, D.T. (1974b) Ichthyophthiriasis in the mirror carp Cyprinus carpio (L.) IV. Physiological
dysfunction. Journal of Fish Biology 6, 365371.
Hines, R.S. and Spira, D.T. (1974c) Ichthyophthiriasis in the mirror carp Cyprinus carpio (L.). V. Acquired
immunity. Journal of Fish Biology 6, 373.
Hlond, S. (1967) [Attempt of cultivation in vitro of Ichthyophthirius multifiliis Fouquet]. Wiad Parazytol 13,
278282.
Hoffman, G. (1999) Parasites of North American Fishes. Comstock Publishing Associates, Ithaca, New York,
539 pp.
Houghton, G. (1987) The immune response in carp, Cyprinus carpio L. to Ichthyophthirius multifiliis
Fouquet 1876. PhD Dissertation, Department of Biological Sciences, Plymouth Polytechnic,
UK.
Houghton, G. and Matthews, R.A. (1986) Immunosuppression of carp (Cyprinus carpio L.) to ichthyophthiriasis using the corticosteroid triamcinolone acetonide. Veterinary Immunology and
Immunopathology 12, 413.
Houghton, G. and Matthews, R.A. (1990) Immunosuppression in juvenile carp, Cyprinus carpio L.: the effects
of the corticosteroids triamcinolone acetonide and hydrocortisone 21-hemisuccinate (cortisol) on
acquired immunity and the humoral antibody response to Ichthyophthirius multifiliis Fouquet. Journal
of Fish Diseases 13, 269280.
Houghton, G. and Matthews, R.A. (1993) Ichthyophthirius multifiliis (Fouquet): survival within immune
juvenile carp, Cyprinus carpio L. Fish and Shellfish Immunology 3, 157166.
150
H.W. Dickerson
Houghton, G., Healey, L.J. and Matthews, R.A. (1992) The cellular proliferative response, humoral
antibody response, and cross reactivity studies of Tetrahymena pyriformis with Ichthyophthirius
multifiliis in juvenile carp (Cyprinus carpio L.). Developmental and Comparative Immunology 16,
301312.
Huff, J.A. and Burns, C.D. (1981) Hypersaline and chemical control of Cryptocaryon irritans in red snapper,
Lutjanus campechanus, monoculture. Aquaculture 22, 181184.
Hughes, G.M. (1970) A comparative approach to fish respiration. Experientia 26, 113122.
Jarrett, L.C. (1997) The immune response of channel catfish against different immobilization serotypes of
Ichthyophthirius multifiliis. MS thesis, University of Georgia, Athens, Georgia.
Kabata, Z. (1985) Parasites and Diseases of Fish Cultured in the Tropics. Taylor and Francis, Philadelphia,
Pennsylvania.
Kesintepe, M. (1995) Light and electron microscopic observations on the ciliate Cryptocaryon irritans (Brown
1951) throughout the life cycle. PhD thesis, University of Georgia, Athens, Georgia.
Kikuchi, S. and Egami, N. (1983) Effects of -irradiation on the rejection of transplanted scale melanophores
in the teleost, Oryzias latipes. Developmental and Comparative Immunology 7, 5158.
Kozel, T.R. (1976) The occurrence of Ichthyophthirius multifiliis (Ciliata: Hymenostomatida) in Kentucky
waters. Transactions of the Kentucky Academy of Science 37, 4143.
Kozel, T.R. (1986) Scanning electron microscopy of theronts of Ichthyophthirius multifiliis: their penetration
into host tissue. Transactions of the American Microscopical Society 105, 357364.
Lee, J.J., Hunter, S.H. and Bovee, E.C. (1985) An Illustrated Guide to the Protozoa. Society of Protozoologists,
Lawrence, Kansas.
Leff, A.A., Yoshinaga, T. and Dickerson, H.W. (1994) Cross immunity in channel catfish against two immobilization serotypes of Ichthyophthirius multifiliis. Journal of Fish Diseases 17, 429432.
Lin, T.L. and Dickerson, H.W. (1992) Purification and partial characterization of immobilization antigens
from Ichthyophthirius multifiliis. Journal of Protozoology 39, 457463.
Lin, T.L., Clark, T.G. and Dickerson, H. (1996) Passive immunization of channel catfish (Ictalurus punctatus)
against the ciliated protozoan parasite Ichthyophthirius multifiliis by use of murine monoclonal antibodies. Infection and Immunity 64, 40854090.
Lin, Y., Lin, T.L., Wang, C.C., Wang, X., Stieger, K., Klopfleisch, R. and Clark, T.G. (2002) Variation in primary
sequence and tandem repeat copy number among i-antigens of Ichthyophthirius multifiliis. Molecular
and Biochemical Parasitology 120, 93106.
Ling, K.H., Sin, Y.M. and Lam, T.J. (1993) Protection of goldfish against some common ectoparasitic protozoans using Ichthyophthirius multifiliis and Tetrahymena pyriformis for vaccination. Aquaculture 116,
303314.
Lobb, C.J. and Clem, L.W. (1981) The metabolic relationship of the immunoglobulins in fish serum, cutaneous mucus, and bile. Journal of Immunology 127, 1525.
Lobb, C.J. and Clem, L.W. (1982) Fish lymphocytes differ in the expression of surface immunoglobulin.
Developmental and Comparative Immunology 6, 473479.
Lobo-da-Cunha, A. and Azevedo, C. (1993) Processing of food vacuoles in the parasitic ciliate Ichthyophthirius multifiliis after exit from the host. Parasitology Research 79, 272278.
Lom, J. and Cerkasova, A. (1974) Host finding in invasive stages of Ichthyophthirius multifiliis. Journal of
Protozoology 21, 457.
Lom, J. and Dykova, I. (1992) Protozoan Parasites of Fishes. Elsever Science Publishers, Amsterdam.
Lynn, D.H., Frombach, S., Ewing, M.S. and Kocan, K.M. (1991) The organelle of Lieberkhn as a
synapomorphy for the Ophryoglenina (Ciliophora: Hymenostomatida). Transactions of the American
Microscopical Society 110, 111.
McCallum, H.I. (1982) Infection dynamics of Ichthyophthirius multifiliis. Parasitology 85, 475488.
McCallum, H.I. (1986) Acquired resistance of black mollies Poecilia latipinna to infection by Ichthyophthirius
multifiliis. Parasitology 93 (2), 251261.
McCartney, J.B., Fortner, G.W. and Hansen, M.F. (1985) Scanning electron microscopic studies of the life
cycle of Ichthyophthirius multifiliis. Journal of Parasitology 71, 218226.
MacLennon, R.F. (1935a) Dedifferentiation and redifferentiation in Ichthyophthirius. I. Archives of
Protozoology 86, 191210.
MacLennon, R.F. (1935b) Observations on the life cycle of Ichthyophthirius, a ciliate parasitic on fish. Northwestern Scientist 9, 1214.
MacLennon, R.F. (1937) Growth in the ciliate Ichthyophthirius. I. Maturity and encystment. Journal of Experimental Zoology 76, 423440.
151
MacLennon, R.F. (1942) Growth in the ciliate Ichthyophthirius. II. Volume. Journal of Experimental Zoology
91, 113.
Maetz, J. and Garcia-Romeu, F. (1964) The mechanism of sodium and chloride uptake by the gills of a
freshwater fish, Carassius auratus. II. Evidence of NH4+/Na+ and HCO/Cl exchanges. Journal of
General Physiology 47, 12091227.
Maki, J.L. and Dickerson, H.W. (2003) Systemic and cutaneous mucus antibody responses of channel catfish
immunized against the protozoan parasite Ichthyophthirius multifiliis. Clinical and Diagnostic Laboratory
Immunology 10, 876881.
Matthews, B.F., Matthews, R.A. and Burgess, P.J. (1993) Cryptocaryon irritans Brown 1951 (Ichthyophthiriidae): the ultrastructure of the somatic cortex throughout the life cycle. Journal of Fish Diseases 16,
339349.
Matthews, R.A. (1994) Ichthyophthirius multifiliis Fouquet 1876: infection and protective responses within the
fish host. In: Pike, A.W. and Lewis, J.W. (eds) Parasitic Diseases of Fish. Samara Publishing, Tresaith,
Dyfed, UK, pp. 1742.
Matthews, R.A. (1996) Ichthyophthirius: observations on the life-cycle and indications of a possible sexual
phase. Folia Parasitologica 43, 203208.
Mehlhorn, H., Schmahl, G. and Haberkorn, A. (1988) Toltrazuril effective against a broad spectrum of
protozoan parasites. Parasitology Research 75, 6466.
Nanney, D.L. (1980) Experimental Ciliatology, An Introduction to Genetic and Developmental Analysis in Ciliates. John Wiley and Sons, New York.
Nigrelli, R.F. and Ruggieri, G.D. (1966) Enzootics in the New York Aquarium caused by Cryptocaron irritans
Brown, 1951 (= Ichthyophthirius marinus Sikama, 1961), a histophagous ciliate in the skin, eyes and gills
of marine fish. Zoologica: New York Zoological Society 51, 97102.
Nigrelli, R.F., Pokorny, K.S. and Ruggieri, G.D. (1976) Notes on Ichthyophthirius multifilis, a ciliate parasitic
on freshwater fishes, with some remarks on possible physiological races and species. Transactions of the
American Microscopical Soceity 95, 607613.
Noe, J.G. and Dickerson, H.W. (1995) Sustained growth of Ichthyophthirius multifiliis at low temperature in
the laboratory. Journal of Parasitology 81, 10221024.
Paperna, I. (1972) Infection by Ichthyophthirius multifiliis of fish in Uganda. Progressive Fish-Culturist 34,
162164.
Paperna, I. (1996) Parasites, infections, and diseases of fish in Africa. An Update CIFA Technical Paper 31,
220 pp. FAO, Rome.
Parker, J.C. (1965) Studies on the Natural History of Ichthyophthirius multifiliis Fouquet 1876, an
Ectoparasitic Ciliate of Fish. University of Maryland, College Park, Maryland.
Peshkov, M.A. and Tikhomirova, L.A. (1968) [Ultra-fine structure of the nuclear apparatus of Ichthyophthirius
multifiliis at the cystal stage in protomites.] Doklady Novaia Serviia 183, 451452.
Pickering, A.D. and Christie, P. (1980) Sexual differences in the incidence and severity of ectoparasitic infestation of the brown trout, Salmo trutta L. Journal of Fish Biology 16, 669683.
Post, G. and Vesely, K.R. (1983) Administration of drugs by hyperosmotic or vacuum infiltration or surfactant
immersion ineffective for control of intradermally encysted Ichthyophthirius multifiliis. Progressive
Fish-Culturist 45, 164166.
Preer, J.R., Preer, L.B., Rudman, B. and Barnett, A. (1987) Molecular biology of the genes for immobilization
antigens in Paramecium. Journal of Protozoology 34, 418.
Pyle, S.W. (1983) Antigenic and serologic relationships between Ichthyophthirius multifiliis Fouquet and
Tetrahymena pyriformis Lwoff. PhD Dissertation. University of Georgia, Athens, Georgia.
Pyle, S.W. and Dawe, D.L. (1985) Stage-dependent protein composition in the life cycle of synchronous
Ichthyophthirius multifiliis, a ciliate fish parasite. Journal of Protozoology 32, 355359.
Roque, M., de Puytorac, P. and Lom, J. (1967) Larchitecture buccale et la stomatogense dIchthyophthirius
multifiliis Fouquet, 1876. Protistologica 3, 7989.
Schmahl, G., Ruider, S., Mehlhorn, H., Schmidt, H. and Ritter, G. (1992a) Treatment of fish parasites. 9.
Effects of a medicated food containing malachite green on Ichthyophthirius multifiliis Fouquet, 1876
(Hymenostomatida, Ciliophora) in ornamental fish. Parasitology Research 78, 183192.
Schmahl, G., Raether, W. and Mehlhorn, H. (1992b) HOE 092 V, a new triazine derivative effective against a
broad spectrum of fish and crustacean parasites. Parasitology Research 78, 702706.
Schmahl, G., Schmidt, H. and Ritter, G. (1996) The control of ichthyophthiriasis by a medicated food containing quinine: efficacy tests and ultrastructure investigations. Parasitology Research 82, 697705.
Schwabe, J.W.R. and Klug, A. (1996) Zinc mining for protein domains. Nature: Structural Biology 1, 345.
152
H.W. Dickerson
Secombes, C.J., van Groningen, J.J.M. and Egberts, E. (1982) Separation of lymphocyte subpopulation in carp
Cyprinus carpio L. by monoclonal antibodies: immunohistochemical studies. Immunology 48, 165175.
Sikama, Y. (1938) Uber die Weisspunktchendrankheit bei Seefischen. Journal of the Shanghai Institute of
Science (Section III) 4, 113128.
Sikama, Y. (1961) On a new species of Ichthyophthirius found in marine fishes. Scientific Report of Yokosuka
City Museum 6, 6670.
Smith, H.W. (1929) The excretion of ammonia and urea by the gills of fish. Journal of Biological Chemistry 81, 7173.
Stanley, J.G. and Colby, P.J. (1971) Effects of temperature on electrolyte balance and osmoregulation in the
alewife (Alosa pseudoharengus) in fresh and sea water. Transactions of the American Fisheries Society
100, 624638.
Stiles, C.W. (1894) Reports on a parasitic protozoan observed on fish in the aquarium. Bulletin of the United
States Fisheries Commission 13, 173190.
Straus, D.L. (1993) Prevention of Ichthyophthirius multifiliis infestation in channel catfish fingerlings by copper
sulphate treatment. Journal of Aquatic Animal Health 5, 152154.
Tataner, M.F. and Manning, M.J. (1983) The ontogeny of cellular immunity in the rainbow trout, Salmo
gairdneri Richardson, in relation to the stage of development of the lymphoid organs. Developmental
and Comparative Immunology 7, 6975.
Traxler, G.S., Richard, J. and McDonald, T.E. (1998) Ichthyophthirius multifiliis (Ich) epizootics in spawning
sockeye salmon in British Columbia, Canada. Journal of Aquatic Animal Health 10, 143151.
Turkewitz, A., Orias, E. and Kapler, G. (2002) Functional genomics: the coming of age for Tetrahymena
thermophila. Trends in Genetics 18, 3540.
Uspenskaya, A.V. and Ovchinnikova, L.P. (1966) Quantitative changes of DNA and RNA during the live cycle
of Ichthyophthirius multifiliis. Acta Protozoologica 4, 127141.
Valtonen, E.T. and Kernen, A. (1981) Ichthyophthiriasis of Atlantic salmon, Salmo salar L. at the Montta
Hatchery in northern Finland in 19781979. Journal of Fish Diseases 4, 405411.
Ventura, M.T. and Paperna, I. (1985) Histopathology of Ichthyophthirius multifiliis infections in fishes. Journal
of Fish Biology 27, 185203.
Wagner, G. (1960) Der entwicklungs Zyklus von Ichthyophthirius multifiliis Fouquet und der Einfluss
physikalis. Zeitschrift fr Fischerei und der Hilfswissenschaflencher und Chemischer Aussenfaktoren 9,
425433.
Wahli, T. and Matthews, R.A. (1999) Ichthyophthiriasis in carp Cyprinus carpio: infectivity of trophonts prematurely exiting both the immune and non-immune host. Diseases of Aquatic Organisms 36, 201207.
Wahli, T. and Meier, W. (1985) Ichthyophthiriasis in trout: investigation of natural defense mechanisms. In:
Ellis, A.E. (ed.) Fish and Shellfish Pathology. Academic Press, London, pp. 347352.
Wahli, T. and Meier, W. (1991) Affinity of Ichthyophthirius multifiliis theronts to light and/or fish. Journal of
Applied Ichthyology 7, 244249.
Wang, X. (2001) Biochemical and immunological characterization of the i-antigens of Ichthyophthirius
multifiliis. PhD thesis, University of Georgia, Athens, Georgia.
Wang, X. and Dickerson, H. (2002) Surface immobilization antigen of the parasitic ciliate Ichthyophthirius
multifiliis elicits protective immunity in channel catfish (Ictalurus punctatus). Clinical and Diagnostic Laboratory Immunology 9, 176181.
Wang, X., Clark, T.G., Noe, J. and Dickerson, H.W. (2002) Immunisation of channel catfish, Ictalurus
punctatus, with Ichthyophthirius multifiliis immobilisation antigens elicits serotype-specific protection.
Fish and Shellfish Immunology 13, 337350.
Wedemeyer, G. (1972) Some physiological consequences of handling stress in juvenile coho salmon
(Oncorhynchus kisutch) and steelhead trout (Salmo gairdneri). Journal of Fisheries Research Board of
Canada 29, 17801783.
Wikgren, B.J. (1953) Osmotic regulation in some aquatic animals with special reference to the influence of
temperature. Acta Zoologica Fennica 71, 1102.
Wilke, D.W. and Gordin, H. (1969) Outbreak of cryptocaryoniasis in marine aquaria at Scripps Institute of
Oceanography. California Fish and Game 55, 227236.
Wolf, K. and Markiw, M.A. (1982) Ichthyophthiriasis: immersion immunization of rainbow trout (Salmo gairdneri) using Tetrahymena thermophila as a protective immunogen. Canadian Journal of Aquatic Science
39, 17221725.
Wright, A.D. and Colorni, A. (2002) Taxonomic re-assignment of Cryptocaryon irritans, a marine fish parasite.
European Journal of Protistology 37, 375378.
153
Wurtsbaugh, W.A. and Tapia, R.A. (1988) Mass mortality of fishes in Lake Titicaca (PeruBolivia) associated
with the protozoan parasite Ichthyophthirius multifiliis. Transactions of the American Fisheries Society
117, 213217.
Xu, C. (1995) Immunity of channel catfish to the ciliated protist, Ichthyophthirius multifiliis. PhD thesis, University of Georgia, Athens, Georgia.
Xu, D.H. and Klesius, P.H. (2003) Protective effect of cutaneous antibody produced by channel catfish,
Ictalurus punctatus (Rafinesque), immune to Ichthyophthirius multifiliis Fouquet on cohabited
non-immune catfish. Journal of Fish Diseases 26, 287291.
Xu, D.H., Klesius, P.H. and Shelby, R.A. (2004) Immune responses and host protection of channel catfish,
Ictalurus punctatus (Rafinesque), against Ichthyophthirius multifiliis after immunization with live theronts
and sonicated trophonts. Journal of Fish Diseases 27, 135141.
Yocum, D., Cuchens, M. and Clem, L.W. (1975) The hapten-carrier effect in teleost fish. Journal of Immunology 114, 925927.
Yoshinaga, T. and Dickerson, H.W. (1994) Laboratory propagation of Cryptocaryon irritans Brown, 1951 on
saltwater-adapted black mollies (Poecilia latipinna). Journal of Aquatic Animal Health 6, 197201.
Yottenckar, A.B. and Uspenskaya, A.V. (1964) Reserve materials, RNA, DNA, and respiratory enzymes at
different stages of the life cycle of Ichthyophthirius multifiliis. Acta Protozoologica 2, 175194.
Introduction
In the chapter on Trichodinids and other
ciliates, Jiri Lom (1995) mentioned that
ciliophorans are amongst the most common
and widely distributed symbionts of fishes,
either as parasites or as commensals. We
now know a little more about ciliophorans
that cause disease and mortality in fish, and
also have methods to control them. He also
stated that many facets of their existence are
in urgent need of further study, and
regrettably this has not changed in the last
10 years. Trichodinids are one of the most
commonly encountered symbiont groups in
the aquatic environment; however, much of
the diversity of this and other ciliophoran
groups is virtually unknown. What is worse,
the relationship of many ciliophorans to
their hosts is based on mere speculation.
When a ciliophoran, however inoffensive it
may be, is found growing massively on a
fish, it is often automatically considered a
pathogen and an appropriate osis is then
added. Also, with the exception of Tetrahymena, none of these ciliophorans has been
cultivated in vivo and their metabolism and
nutritional requirements are unknown.
The aim of this chapter is to update
Lom (1995), as much of it is still relevant
today. We would, however, like to place our
154
stamp on the peritrichs, especially the trichodinids, as our research interest and expertise
are in this group of ciliophorans. Furthermore, we shall also provide additional information on the African ciliophorans.
The major part of this contribution is
on the trichodinids, with the focus on those
associated with fish. The rest of the chapter
deals with the other ciliophorans, separating them into those parasites commonly
associated with fish and causing pathology
(obligate fish parasites), commensals which
seldom cause pathology (obligate fish commensals) and lastly free-living ciliophorans
associated with fish which also cause disease (facultative fish parasites). Succinct
but thorough information on ciliophoran
morphology and ultrastructure may be
found in Lee et al. (1985).
Trichodinids
The order Mobilida Kahl, 1933 (class Oligohymenophorea de Puytorac et al., 1974;
subclass Peritrichia Stein, 1859) comprises
mobile ciliated organisms with conical,
cylinder-shaped bodies, of which the dominant feature is an aboral adhesive disc.
This suborder is represented by three
families, the Urceolariidae Dujardin, 1841,
Trichodinopsidae
Kent,
1881
and
Trichodinidae Raabe, 1963. The former two
are associated with invertebrates and they
have simple plate-like denticles. The
Trichodinidae all have complex structures
in the aboral adhesive disc and are epizoics
(sometimes endozoics) of a broad range of
aquatic invertebrate and vertebrate hosts,
with seven of the ten genera associated with
fish. It is both the largest family in species
numbers and the best known worldwide,
especially those associated with fish. Van
Leewenhoek in his letter in 1703 to the
Philosophical Transactions of the Royal
Society described some animalcula
155
Fig. 5.1. SEM micrographs of Trichodina heterodentata (AE). A. Aboral side with compound wreath of
cilia used for movement. B. Oral view showing adoral spiral entering infundibulum. C. Denticle ring with
radial and peripheral pins: with pellicle removed. D. Denticles after soft body has been removed, viewed
aborally. E. Daughter cell after division, with old denticle ring in the process of resorption and new denticle
ring already formed. Note the stronger old radial pins with thinner new pins in between. F. Young fingerling
of Oreochromis mossambicus with a heavy infestation of trichodinids on the body. Scale bars = 20 m
(AE), 1 mm (F). AF originals.
156
Fig. 5.2. A. Schematic drawing of denticles of Trichodina magna to illustrate the sequence and method
of the description of denticle elements, according to the method of Van As and Basson (1989).
B. Diagnostically important features in the adhesive disc of trichodinids. C. Diagnostically important
features of the nuclear apparatus. Abbreviations: ab, blade apex; abm, anterior blade margin (surface); add,
adhesive disc diameter; b, blade length; ba, blade apophysis; bc, blade connection; bm, border membrane
with striations; ca, centre of adhesive disc; ccp, central conical part; cp, central part; dbm, distal blade
margin (surface); dd, denticle ring diameter; dpc, deepest point of curve relative to apex; ira, indentation in
lower central part; ma, macronucleus; mi, micronucleus; pbm, posterior blade margin (surface); pp,
posterior projection; r, ray length; ra, ray apophysis; rc, ray connection; rp, radial pins; rpd, number of
radial pins per denticle; tp, tangent point. B, C originals.
of division in the adhesive disc is the presence of a distinct band to the distal side of
the blade, which impregnates in a different
way in silver-impregnated specimens from
the rest of the adhesive disc. This band has
been associated with the formation of a new
denticle ring and initially consists of thickened areas on each side of the radial pins
adoral to the thatched band that connects
the radial pins. Subsequently these areas on
several radial pins will fuse to form a
platelet. The adhesive disc separates into
two semicircles, which then close to form
two smaller discs in the daughter individuals. During division the number of denticles
is reduced to half the original number. At
this stage the thickened band consists of
elongated platelets, clearly overlapping,
which continue to extend in subsequent
stages, appearing plaited. Each of these
platelets will develop into a new denticle,
first the central part, then the blade and
lastly the ray, restoring more or less the
number of denticles present in the parent
individual. The old ring is gradually
resorbed (Fig. 5.1E). Along with the development of the denticles, a completely new
striated membrane is formed. The distal
development of the blades from the platelets coincides with an extension of radial
pins in this direction. In ectozoic species,
such as Trichodina heterodentata Duncan,
1977, the extension is limited only from the
central part in a distal direction, whereas in
endozoic species, such as Trichodina xenopodos Fantham, 1924, the growth is in both
directions, as the striated membrane extends
from the tip of the ray to the border membrane. In young daughter cells the radial
pins are newly formed, but are extensions of
the original radial pins. At some stage before
the complete resorption of the old denticle
ring, an additional set of radial pins, each
placed between existing pins, will develop
(Fig. 5.1E). According to Lom (1973), these
new radial pins originate from barren kinetosomes found between consecutive radial pins.
The development of the new border
membrane and the complex hinge is still
unknown. Coinciding with the denticle
development, the nuclei undergo changes
to gradually evolve into a horseshoe shape,
157
158
159
160
other marine fishes. It is also a common species on the gills of freshwater fishes, as well
as a pathogen in eel cultures. It is rather a
small ciliophoran, the adhesive disc ranging from 18 to 35 m, with 15 to 27
denticles in the denticle ring.
Trichodina maritinkae Basson and
Van As, 1991 (Fig. 5.3F) seems to be restricted to representatives of the family
Clariidae. It has been reported from Africa
and Taiwan. The adhesive disc ranges from
31 to 50 m and the denticle ring from 21 to
32 m, with 22 to 32 denticles.
Trichodina murmanica Poljanski, 1955
(Fig. 5.4A) is a marine species with a clear
centre in its adhesive disc. It is common in
161
Fig. 5.4. Silver-impregnated adhesive discs of Trichodina species. A. T. murmanica (courtesy of Dr Lom),
B. T. mutabilis, C. T. nigra, D. T. nobilis, E. T. pediculus (courtesy of Dr Lom), F. T. perforata (courtesy of
Dr Lom). Scale bars = 20 m. BD originals.
162
163
164
These
trichodinids are small and the body is shaped
in a flat hemisphere. The denticles have
well-developed rays and are wedged together
only by the central parts. The anterior projection may be present or absent. If present, the
projection is situated near the base of the
blade and is not in contact with the notch in
the blade of the preceding denticle. The
adoral spiral makes a turn of 150280.
So far 11 species have been described in
this genus, of which eight have been collected from the gills of freshwater and marine
fishes and three from the urinary tract of
fishes. Eight species occur in Eurasia, two in
the USA and one, Paratrichodina africana
Kazubski and El-Tantawy, 1986, in Africa.
Paratrichodina corlissi Lom and Haldar,
1977 (Fig. 5.6A) occurs on the gills of Gobio
species in Eurasia and has a shallow
notch in the blade. The adhesive disc diameter ranges from 19 to 25 m, with 18 to 24
denticles.
GENUS PARATRICHODINA LOM, 1963.
165
Fig. 5.6. Silver-impregnated adhesive discs of various trichodinid species. A. Paratrichodina corlissi (courtesy
of Dr Lom), B. Paratrichodina incissa (courtesy of Dr Lom), C. Tripartiella cichlidarum, D. Tripartiella
clavodonta, E. Tripartiella orthodens, F. Trichodinella epizootica. Scale bars = 10 m. CF originals.
Only five species are currently recognized as valid, and as many as nine are
probably synonymous with T. epizootica.
They are mainly parasites of freshwater
fishes, but sometimes marine fishes are also
infested, where they occur exclusively on
the gills. Representatives of this genus have
been reported from Eurasia, Africa, the
Middle East, Mexico, the USA and the
Philippines (Lom and Dykova, 1992).
Trichodinella epizootica (Raabe, 1950)
(Fig. 5.6F) is one of the most widely distributed species of freshwater trichodinids in
Eurasia, but is also found in Africa and the
Middle East on about 90 fishes from various
166
families. This parasite proliferates massively on stressed fish and becomes highly
pathogenic. The adhesive disc ranges from
14 to 47 m, with 16 to 30 denticles.
Trichodinella lawleri Lom and Haldar,
1977 is a marine species that can be pathogenic in aquarium fishes.
GENUS DIPARTIELLA SHTEIN, 1961. The denticle
ring is composed of tightly packed denticles, consisting only of well-developed
triangular blades and weakly developed
central parts, which do not extend into conical protrusions. The adoral spiral describes
an arc of about 270.
This genus comprises a single species
and it occurs on the gills of marine fishes
from Eastern Europe and Asia.
Dipartiella simplex (Raabe, 1959)
Shtein, 1961 was originally found on the
gills of Gobius niger in the Baltic Sea. Some
authors have considered this species as a
mistaken identification of a Trichodinella,
but it has been encountered recently in two
cultured marine fishes from China (Xu et al.,
1999), as well as from Egypt (L. Basson,
unpublished data).
Other Ciliophorans
OBLIGATE PARASITES
GENUS CHILODONELLA STRAND, 1926. T h e
genus Chilodonella Strand, 1926 comprises
many free-living species and two species
infesting freshwater fishes. Both the latter
species have cosmopolitan distributions,
occur in estuarine and brackish waters (e.g.
in the eastern Baltic Sea) and appear to
infest most, if not all, teleost fishes. They
cause the well-known chilodonellosis,
a disease affecting the skin and gills,
especially in fish cultures.
These ciliophorans belong to the family
Chilodonellidae Deroux, 1970, order Cyrtophorida Faur-Fremiet in Corliss, 1956 and
class Kinetophragminophorea de Puytorac
et al., 1974.
The body of Chilodonella is oval and
dorsoventrally flattened. The slightly convex dorsal side is without cilia, with just a
167
168
occur in commercial set-ups. There is, however, a report on massive mortalities due to
chilodonellosis (C. hexasticha) in free
waters. This took place among native fish
(bony bream) in Australia in the winter,
where the temperature was 813C
(Langdon et al., 1985). Unpublished information of the present authors also indicates
that chilodonellosis does occur readily in
warmer waters; we observed mortalities
among cichlids on a fish farm in the
Okavango River (Botswana) at water temperatures exceeding 25C.
Under favourable conditions (e.g. in
fish and especially fingerlings that are
debilitated in early spring or by overcrowding), chilodonellas may virtually cover the
body surface in a continuous layer. They
disintegrate the body surface using their
oral cytoskeletal apparatus and feed on cell
debris.
Clinical signs of heavy infestations
include increase of mucus, with an overall
dark, slimy, patchy or mottled grey appearance. These films of mucus and cellular
debris may become detached from the skin
surface. Moribund fish may also show signs
of hypoxia and uncoordinated swimming,
are emaciated and have opaque eyes and
abrased skin.
Pathogenesis in skin lesions has not
been studied, but has been described in
detail in gill infestations with C. hexasticha
(Paperna and Van As, 1983; Shariff, 1984;
Langdon et al., 1985). Chilodonella initially
cause localized hyperplasia of the gill epithelium, which later becomes more generalized. Proliferating epithelial cells fill the
spaces between secondary lamellae, which
may fuse together and coalesce into a single
mass. The thin respiratory epithelium is covered by the hyperplastic epithelium and this
drastically reduces the respiratory surface of
the gills. The epithelium may be infiltrated
with lymphocytes and eosinophil granulocytes, with an additional increased proliferation of mucus and chloride cells.
The hyperplastic epithelium may
undergo changes, with dilatation of capillaries, oedema, petechia and haemorrhages.
Complete destruction of the epithelium of
primary and secondary lamellae may leave
the fish with only cartilaginous rays. Pathological manifestations may vary, depending
on the intensity of infestations. Sometimes
large aggregates of melanin can also be seen
along some of the primary lamellae undergoing degeneration. Disintegration of the
gills and their necrosis render the gills
non-functional. Fish lose osmotic balance
and suffocate; this is manifested by their
increased sensitivity to oxygen deficiency.
Heavily infested fish die.
GENUS BROOKLYNELLA LOM AND NIGRELLI, 1970.
Sessilines
The sessiline peritrichs (class Oligohymenophorea de Puytorac et al., 1974;
subclass Peritrichia Stein, 1859; order
Sessilida Kahl, 1935) contain 12 families
associated with aquatic organisms, and
four of them are associated with fish. In the
first family, the Epistylididae Kahl, 1935,
there are six genera, of which two are commonly on fish, i.e. Epistylis Ehrenberg,
1830 and Apiosoma Blanchard, 1885 (syn.
Glossatella Btschli, 1889). In the case of
the latter genus, all species are associated
with fish, whilst species of Epistylis are not
restricted to fish. The second family,
Scyphidiidae Kahl, 1935, has six genera,
169
170
171
172
Fig. 5.8. A. Apiosoma piscicolum, stained with haematoxylin, showing large macronucleus and smaller
micronucleus. B. Ambiphrya neobolae with ribbon-shaped macronucleus. C. Erastophrya sp., a live
specimen from skin of Barbus attached to an apiosoma. D. Tetrahymena corlissi, silver-impregnated
specimen (courtesy of Dr Lom). Scale bars = 20 m. AC originals.
Suctoria
Suctorians (class Kinetophragminophorea
de Puytorac et al., 1974; subclass Suctoria
173
174
175
176
177
Diagnosis
Others (free-living ciliophorans
attacking the surface of fish)
There is a large group of ciliophorans that
are mostly free-living. However, when fish
are stressed by adverse environmental conditions and they are completely debilitated
and moribund, these free-living ciliophorans
become facultative parasites externally.
These freshwater ciliophorans include species of the genus Coleps Nitzsch, 1827 and
various histophagous ciliophorans, which
feed on tissues. These fishes may also be
colonized by free-living peritrichous ciliophorans (e.g. Vorticella Linnaeus, 1767,
Carchesium Ehrenberg, 1830 or Zoothamnium Bory de St Vincent, 1826).
Fish that are seriously stressed but
not moribund are also susceptible to freeliving ciliophorans, such as Chilodonella
cucullulus (O.F. Mller, 1786), Chilodonella
uncinata (Ehrenberg, 1838), Dexiostoma
campylum (Stokes, 1886) Jankovski, 1967,
Glaucoma scintillans Ehrenberg, 1830,
Colpidium colpoda (Ehrenberg, 1831) Stein,
1960, Frontonia acuminata Ehrenberg, 1833
and Frontonia leucas Ehrenberg, 1838.
They may establish transient infestations of
the skin and gills.
These ciliophorans live in highly polluted waters, and infect the body surface
and gills of pond fish under adverse conditions, e.g. in early spring after a long, severe
winter. When environmental conditions
(oxygen, temperature, food, water quality)
178
The guidelines of proper health management for fish culture are summarized as
follows:
raceways, tanks, larger water bodies or aquarium systems. The choice always depends on
their feasibility in a given situation. The
wide range of chemical concentrations
recommended by various authors can be
explained by the necessity to adjust the concentration to the ambient temperature,
oxygen contents and quality of water (pH, total
hardness, organic load) in relation to the
particular fish species and age class. Finally,
the resistance of parasite populations to these
chemicals should be taken into account.
Thus, to assess the proper concentrations
and length of exposure and to make sure that
a specific species can tolerate the chemical,
a trial should precede large-scale treatment.
For chilodonellas, trichodinids, sessiline peritrichs, facultative and opportunistic
parasites, suctorians and other ectocommensals, the following treatments are
recommended (the concentrations below are
given either in percentage or ppm):
1. Sodium chloride (not for marine or
euryhaline ciliophorans).
D: 1.5% to 3% for 5 min to 1 h (e.g. sessiline
peritrichs: 3% for 5 to 10 min, or 1.5% for
1 h; Chilodonella: in common carp fry 2%
for 15 min at temperatures above 15C, 1%
for 30 min at 2025C, in yearling carp 3%
for 1530 min at temperatures above 15C).
F: 0.10.2% for 1 to 2 days.
2. Formalin (convenient also for warmwater and for marine ciliophorans).
D: 150250 ppm for 3060 min (e.g. in common carp and salmonid yearlings, concentration depends on temperature: below 10C,
250 ppm; 1015C, 200 ppm; above 15C,
150 ppm).
F: 250 ppm for 1 h
F: 4050 ppm for 24 h.
I: 1525 ppm.
3. Acriflavin.
F: 50 ppm for one to several days.
I: 1020 ppm.
4. Malachite green.
D: 2.55 ppm for 30 s
D: 60 ppm for 1030 s at 1020C.
F: 0.150.5 ppm for 6 days (e.g. common
carp 0.5 ppm, trout fingerlings 0.15
0.2 ppm).
I: 0.1 ppm
179
180
References
Ahmed, A.T.A. (1976) Trichodiniasis of goldfish and other carps. Bangladesh Journal of Zoology 4,
1220.
Ahmed, A.T.A. (1977) Morphology and life history of Trichodina reticulata from goldfish and other carps.
Fish Pathology 12, 2131.
Arthur, J.R. and Margolis, L. (1984) Trichodina truttae Mueller, 1937 (Ciliophora: Peritricha), a common
pathogenic ectoparasite of cultured juvenile salmonid fishes in British Columbia: redescription and
examination by scanning electron microscopy. Canadian Journal of Zoology 62, 18421848.
Bassleer, G. (1983) Uronema marinum, a new and common parasite on tropical saltwater fishes. Freshwater
and Marine Aquarium 6, 7879.
Cheung, P.J., Nigrelli, R.F. and Ruggieri, G.D. (1980) Studies on the morphology of Uronema marinum
Dujardin (Ciliatea: Uronematidae) with a description of the histopathology of the infection in marine
fishes. Journal of Fish Diseases 3, 295303.
Corliss, J.O. (1960) Tetrahymena chironomi sp. nov., a ciliate from midge larvae and the current status of
facultative parasitism in the genus Tetrahymena. Parasitology 50, 111153.
Davis, H.S. (1947) Studies of the Protozoan Parasites of Freshwater Fishes. Fishery Bulletin 51, US Department
of the Interior, Washington, 129 pp.
Elliot, A.M. (ed.) (1973) Biology of Tetrahymena. Dowden, Hutchinson and Ross, Stroudsburg, Pennsylvania.
Esch, G.W., Hazen, T.C., Dimock, R.V., Jr and Gibbons, J.W. (1976) Thermal effluent and the epizootology
of the ciliate Epistylis and the bacterium Aeromonas in association with centrarchid fish. Transactions of
the American Microscopical Society 95, 687693.
Ferguson, H.W., Hicks, B.D., Lynn, D.H., Ostland, V.E. and Bailey, J. (1987) Cranial ulceration in Atlantic
salmon Salmo salar associated with Tetrahymena sp. Diseases of Aquatic Organisms 2, 191195.
Haider, G. (1964) Monographie der Familie Urceolariidae (Ciliata, Peritricha, Mobilia) mit besonderer
Bercksichtigung der im sddeutschen Raum vorkommenden Arten. Parasitologische Schriftenreihe
Heft 17, Fischer, Jena, Germany, 251 pp.
Hazen, T.C., Raker, M.L., Esch, G.W. and Fliermans, C.B. (1978) Ultrastructure of red-sore lesions on
largemouth bass (Micropterus salmoides): association of the ciliate Epistylis sp. and the bacterium
Aeromonas hydrophila. Journal of Protozoology 25, 351355.
Hoffman, G.L. and Lom, J. (1967) Observations on Tripartiella bursiformis, Trichodina nigra and a pathogenic
trichodinid, Trichodina fultoni. Bulletin of the Wildlife Disease Association 3, 156159.
Hoffman, G.L., Landholt, M., Camper, J.E., Coast, D.W., Stockey, J.L. and Burek, J.D. (1975) A disease of
freshwater fishes caused by Tetrahymena corlissi Thompson, 1955, and a key for identification of
holotrich ciliates of freshwater fishes. Journal of Parasitology 61, 217223.
Hoffman, G.L., Kazubski, S.L., Mitchell, A.J. and Smith, C.E. (1979) Chilodonella hexasticha (Kiernik, 1909)
(Protozoa, Ciliata) from North American warmwater fish. Journal of Fish Diseases 2, 153157.
Imai, S., Hatai, K. and Ogawa, M. (1985) Chilodonella hexasticha (Kiernik, 1909) found from the gills of a
discus, Symphysodon discus Heckel, 1940. Japanese Journal of Veterinary Science 47, 305308.
181
Imai, S., Tsurimaki, S., Goto, E., Wakita, K. and Hatai, K. (2000) Tetrahymena infection in guppy, Poecilia
reticulata. Fish Pathology 35, 6772.
Johnson, S.K. (1978) Tet Disease of Tropical Fishes and an Evaluation of Correction Techniques. F12, Fish Diseases Diagnostic Laboratory, Texas A & M University, College Station, Texas.
Kazubski, S.L. and Migala, K. (1968) Urceolariidae from breeding carp Cyprinus carpio L. in Zabiniec and
remarks on the seasonal variability in trichodinids. Acta Protozoologica 6, 137160.
Khan, R.A. (1972) Taxonomy, prevalence, and experimental transmission of a protozoan parasite, Trichodina
oviducti Polyanski (Ciliata: Peritricha) of the thorny skate, Raja radiata Donovan. Journal of Parasitology
58, 680686.
Khan, R.A., Barber, V.C. and McCann, S. (1974) A scanning electron microscopical study of the surface
topography of a trichodinid ciliate. Transactions of the American Microscopical Society 93, 131134.
Kruger, J., Van As, J.G. and Basson, L. (1995) Observations on the adhesive disc of Trichodina xenopodos
Fantham, 1924 and Trichodina heterodentata Duncan, 1977 (Ciliophora: Peritrichida) during binary
fission. Acta Protozoologica 34, 203209.
Langdon, J.S., Gudkovs, N., Humphrey, J.D. and Saxon, E.C. (1985) Death in Australian freshwater fishes
associated with Chilodonella hexasticha infection. Australian Veterinary Journal 62, 409413.
Lee, J.J., Hunter, S.H. and Bovee, E.C. (eds) (1985) An Illustrated Guide to the Protozoa. Society of
Protozoologists, Lawrence, Kansas, 629 pp.
Leibovitz, L. (1980) Chilodonelliasis. Journal of the American Veterinary Medical Association 177,
222223.
Li, L.X. and Desser, S.S. (1983) Trichodina algonquinensis, a new species of peritrich ciliate from Ontario
freshwater fish, and observations on its transmission. Canadian Journal of Zoology 61, 11591164.
Lom, J. (1958) A contribution to the systematics and morphology of endoparasitic trichodinids from
amphibians with a proposal of uniform specific characteristics. Journal of Protozoology 5, 251263.
Lom, J. (1964) The morphology and morphogenesis of the buccal ciliary organelles in some peritrichous
ciliates. Archiv fr Protistenkunde 107, 131162.
Lom, J. (1966) Sessiline peritrichs from the surface of some freshwater fishes. Folia Parasitologica 1, 3656.
Lom, J. (1973) The adhesive disc of Trichodinella epizootica ultrastructure and injury to the host tissue. Folia
Parasitologica (Praha) 20, 193202.
Lom, J. (1995) Trichodinidae and other ciliates (Phylum Ciliophora). In: Woo P.T.K. (ed.) Fish Diseases and
Disorders, vol. 1, Protozoan and Metazoan Infections. CAB International, Wallingford, UK, pp. 229262.
Lom, J. and Corliss, J.O. (1968) Observations on the fine structure of two species of the peritrich ciliate genus
Scyphidia and on their mode of attachment to their host. Transactions of the American Microscopical
Society 87, 493509.
Lom, J. and Corliss, J.O. (1971) Morphogenesis and cortical ultrastructure of Brooklynella hostilis, a dysteriid
ciliate ectoparasitic on marine fishes. Journal of Protozoology 18, 261281.
Lom, J. and Dykova, I. (1992) Protozoan Parasites of Fishes. Developments in Aquaculture and Fisheries Science, vol. 26, Elsevier, Amsterdam, 315 pp.
Lom, J. and Nigrelli, R.F. (1970) Brooklynella hostilis, n.g., n.sp., a pathogenic cyrtophorine ciliate in marine
fishes. Journal of Protozoology 17, 224232.
MacLennan, R.F. (1939) The morphology and locomotor activities of Cyclochaeta domerguei. Journal of
Morphology, 65, 241256.
Markiewicz, F. and Migala, K. (1980) Trichodinid invasion (Peritricha, Urceolariidae) on young eels (Anguilla
anguilla L.) grown in aquaria. Acta Hydrobiologica 22, 229236.
Migala, K. and Kazubski, S.L. (1972) Occurrence of non-specific ciliates on carps (Cyprinus carpio) in winter
ponds. Acta Protozoologica 9, 329337.
Molnr, K. and Reinhardt, M. (1978) Intestinal lesions in grass-carp Ctenopharyngodon idella (Valenciennes)
infected with Balantidium ctenopharyngodonis Chen. Journal of Fish Diseases 1, 151156.
Oldewage, W.H. and Van As, J.G. (1987) Parasites and winter mortalities of Oreochromis mossambicus.
South African Journal of Wildlife Research 17, 712.
Paperna, I. and Van As, J.G. (1983) The pathology of Chilodonella hexasticha (Kiernik). Infection in cichlid
fishes. Journal of Fish Biology 23, 441450.
Pnard, E. (1922) Etudes sur les infusoires deau douce. Georg, Geneva, Switzerland.
Precht, H. (1935) Epizoen der Kieler Bucht. Nova Acta Leopoldina, Neue Folge 3, 405474.
Prost, M. (1952) Badania nad pierwotniakami pasozytnymi skrzeli ryb. II. Chilodonella cyprini Moroff I
Chilodonella hexasticha Kiernik. Annales Universitatis M. Curie-Sklodowska, Lublin Polonia 8 (C),
113.
182
Purdom, C.E. and Howard, A.E. (1971) Ciliate infestations: a problem in marine fish farming. Journal du
Conseil International pour Exploration de la Mer 33, 511514.
Richards, C.S. (1949) Description and host relations of four new species of Trichodina from freshwater
molluscs. Abstracts of Dissertations, Stanford University 24, 9495.
Richardson, L.R. (1938) Trichodina on Salvelinus fontinalis. Transactions of the American Fishery Society 67,
228233.
Rogers, W.A. (1971) Disease in fish due to the protozoan Epistylis (Ciliata: Peritricha) in the southeastern US.
In: Proceedings of the Southeastern Association of Game Fish Commisioners, 25th Annual Conference,
Charleston, Virginia, pp. 493496.
Sanmartin Durn, M.L., Fernandez Casal, J., Tojo, J.L., Santamarina, M.T., Estevez, J. and Urbeira, F. (1991)
Trichodina sp.: effect on the growth of farmed turbot (Scophthalmus maximus). Bulletin of the European
Association of Fish Pathologists 11, 8991.
Shariff, M. (1984) Occurrence of Chilodonella hexasticha (Kiernik, 1909) (Protozoa: Ciliata) on big carp
Aristichthys nobilis (Richardson) in Malaysia. Tropical Biomedicine 1, 6975.
Shulman, S.S. and Jankovski, A.V. (1984) Phylum Ciliates Ciliophora Doflein, 1901 (in Russian). In:
Shulman, S.S. (ed.) Parasitic Protozoa, vol. 1, in Bauer, O.N. (ed.) Key to Parasites of Freshwater Fishes of
the USSR, Vol. 140 of Keys to the Fauna of the USSR. Nauka, Leningrad, Russia, pp. 252280.
Soltynska, M.S. (1971) Morphology and fine structure of Chilodonella cucullulus (O.F.M.). Cortex and
cytopharyngeal apparatus. Acta Protozoologica 9, 4982.
Stolk, A. (1960) Glaucoma sp. in the central nervous system of the carp. Nature 184, 1737.
Urawa, S. and Yamao, S. (1992) Scanning electron microscopy and pathogenicity of Chilodonella piscicola
(Ciliophora) on juvenile salmonids. Journal of Aquarium and Animal Health 4, 188197.
Van As, J.G. and Basson, L. (1987) Host specificity of trichodinid ectoparasites of freshwater fish. Parasitology
Today 3, 8890.
Van As, J.G. and Basson, L. (1988) The Incidence and Control of Fish Ectoparasitic Protozoa in South Africa.
Technical Communication No. 211, Department of Agriculture and Water Supply (South Africa),
Pretoria, 11 pp.
Van As, J.G. and Basson, L. (1989) A further contribution to the taxonomy of the Trichodinidae (Ciliophora:
Peritrichia) and a review of the taxonomic status of some fish ectoparasitic trichodinids. Systematic
Parasitology 14, 157179.
Van As, J.G. and Basson, L. (1990) An articulated internal skeleton resembling a spinal column in a ciliated
protozoan. Naturwissenschaften 77, 229231.
Van As, J.G., Basson, L. and Theron, J. (1984) An experimental evaluation of the use of formalin to control
trichodiniasis and other ectoparasitic protozoans on fry of Cyprinus carpio L. and Oreochromis
mossambicus (Peters). South African Journal of Wildlife Research 14, 4248.
Xu, K., Song, W. and Warren A. (1999) Trichodinid ectoparasites (Ciliophora: Peritrichida) from the gills of
cultured marine fishes in China, with the description of Trichodina lomi n. sp. Systematic Parasitology
42, 219227.
Zick, K. (1928) Urceolaria korschelti n. sp., eine neue marine Urceolarine, nebst einen berblick ber die
Urceolarinen. Zeitschrift fr Wissenschaftiche Zoologie, 132, 355403.
Phylum Apicomplexa
Klmn Molnr
Introduction
Apicomplexans occur in a wide variety
of animals (helminths to mammals). Apicomplexan parasites, primarily coccidia of
warm-blooded animals, belong to the most
important and harmful group of animal
pathogens. The economic importance of
apicomplexan infection in mammals and
birds is documented every year by hundreds
of reports on the development and pathogenic effect of these parasites, as well as by
dozens of drugs and technologies recommended for prevention. Contrary to this
fast-developing branch of coccidiology, the
progress in fish apicomplexan research is
rather moderate and can claim only modest
results.
Since the recent knowledge on fish apicomplexans was summarized in a chapter
of the first edition of this book (Molnr,
1996), only a limited number of related
papers has been published. These papers
concern mostly the occurrence of the known
species (Cruz and Davies, 1998; Diouf et al.,
2000; Abollo et al., 2001; Alvarez-Pellitero
et al., 2002; Tolonen and Karlsbakk, 2003)
and the description of some new species from
different continents (Diouf and Toguebaye,
1994, 1996; Lom and Dykov, 1995; SitjaBobadilla et al., 1996; Baska, 1997; Molnr
and Ogawa, 2000; Alvarez-Pellitero and
Sitja-Bobadilla, 2002; Molnr et al., 2003), and
183
184
K. Molnr
He listed 26 fish hosts for the five Babesiosoma spp. he considered valid. A similar
conclusion was drawn by Negm-Eldin
(1998, 1999), who, using the leech vector
Batracobdeloides tricarinata, could transmit Babesiosoma mariae and Cyrilia nili to
series of fishes in cross-transmission experiments. Fish coccidia seem to be less host
specific than mammalian coccidia. A fish
coccidium can infect several closely related
host species, usually of the same genus
(Belova and Krylov, 2000). However, Goussia
subepithelialis of the common carp and
Goussia sinensis of silver and bighead carp
are relatively strictly host specific. Eimeria
anguillae, which is found in eel species of
both the Atlantic and the Pacific Oceans,
and Goussia vanasi and Goussia cichlidarum
of tilapia species are good examples of group
specificity. Although Shulman (1984) listed
more than a dozen hosts for Goussia carpelli,
experimental data (K. Molnr, unpublished)
suggest that G. carpelli infects only fish of the
genera Cyprinus and Carassius and that coccidians in other cyprinids are morphologically
similar but less well-studied species.
Cryptosporidia are considered to have an
extremely broad host range. According to
Levine (1984) four species, including the
fish-parasitic Cryptosporidium nasoris, are
valid, while according to Fayer et al. (1997)
eight species should be recognized. Up to the
present time, four named Cryptosporidium
species (C. nasoris, C. reichenbachklinkei,
C. cichlidis and C. molnari), as well as five
Cryptosporidium spp., are known from fishes
(Hoover et al., 1981; Paperna and Vilenkin,
1996; Alvarez-Pellitero and Sitja-Bobadilla,
2002). Paperna and Vilenkin (1996) thought
that fish cryptosporidia differed in morphology and in their location in the host from
cryptosporidia of warm-blooded animals and
created a new genus, Piscicryptosporidium,
for them.
Phylum Apicomplexa
185
rather large; therefore Goussia and Calyptospora are tentatively included in the
family Eimeriidae as independent genera.
Phylum: Apicomplexa Levine, 1970
Class: Conoidasida Levine, 1988
Order: Eucoccidiorida Leger and Duboscq,
1910
Suborder: Adeleiorina Leger 1911
Family: Haemogregarinidae NeveuLemaire, 1901
Genus: Haemogregarina Danilewsky,
1885
Genus: Cyrilia Lainson, 1981
Genus: Desseria Siddal, 1995
Family: Dactylosomatidae Jakowska and
Nigrelli, 1955
Genus: Dactylosoma Labb, 1894
Genus: Babesiosoma Jakowska and
Nigrelli, 1956
Suborder: Eimeriorina Leger, 1911
Family: Eimeriidae Leger, 1911
Genus: Eimeria Schneider, 1875
Genus: Goussia Labb, 1896
Genus: Crystallospora Labb, 1896
Genus: Calyptospora Overstreet,
Hawkins and Fournie, 1984
Family: Cryptosporidiidae Leger, 1911
Genus: Cryptosporidium Tyzzer, 1907
Protists of uncertain taxonomic position
Genus: Haematractidium Henry, 1910
Genus: Haemohormidium Henry, 1910
186
K. Molnr
second- and third-generation meronts. Gamogony begins when the last generation of
merozoites forms macro- and microgamonts.
In the microgamonts numerous microgametes develop. After fertilization the macrogamont develops into an oocyst. During
sporulation, the zygote in the oocyst divides
and forms sporocysts, in which sporozoites
develop. Sporulation may take place within
(endogenous sporulation) or outside (exogenous sporulation) the fish.
Morphological characteristics of the
different developmental stages
MEROGONIC STAGES. Merogonic stages in naturally infected fish have been described by
Fig. 6.2. Goussia balatonica. Intracellular meront with merozoites (transmission electron microscope
(TEM), 8800).
Phylum Apicomplexa
GAMOGONIC
STAGES.
187
Fig. 6.3. Goussia balatonica. Intracellular macrogamonts (ma) and microgamont (mi) in the intestinal
epithelium (TEM, 4400).
188
K. Molnr
Fig. 6.4. Eimeria anguillae. Epicellular macrogamont (ma) in a parasitophorous vacuole (pv) surrounded
by microvilli (mv) inside a host cell (hc) (TEM, 21,800).
Phylum Apicomplexa
Fig. 6.5.
189
190
K. Molnr
reported that C. funduli required a true intermediate host, the grass shrimp (Palaemonetes
pugio), for its development. On the other
side, Steinhagen and Krting (1990) suggested that the invertebrate is a paratenic
host in which the sporozoites do not
undergo development. Fournie et al. (2000)
have demonstrated that the sporozoites of
C. funduli need to infect the shrimp for at
least 5 days before reaching infectivity. These
authors also proved that during that stage
sporozoites were located in the basal epithelial cells of the shrimps intestine. Steinhagen
(1991) observed that the sporozoites of
G. carpelli and G. subepithelialis invaded
cells of the alimentary tract, where they were
found in membrane-bound parasitophorous
vacuoles and persisted for 9 weeks for
G. carpelli and 3 weeks for G. subepithelialis.
Steinhagen et al. (1998) have shown that uninfected carp can be infected by G. carpelli both
directly and through paratenic hosts, but
reinfection occurs only in the latter way.
Vilenkin and Paperna (1997) infected
tilapia hybrids directly with the oocysts of
Eimeria vanasi, and 7 to 56 h post-exposure
(p.e.) found sporozoites in intraepithelial
lymphocyte-like or leucocyte-like cells but
never in epithelial cells. Sporozoites in these
cells divided by endodiogeny once or twice
to form daughter sporozoites. The oocysts
of fish coccidia undergo rapid sporulation
and ageing in the environment. The sporozoites die soon after the residual body of the
sporocyst is used up. In tubifex or shrimp
vectors, on the other hand, the sporozoites
are released in the gut and remain viable for
a long time in epithelial cells.
Phylum Apicomplexa
the spring. Oocysts of warm-blooded animals have resistant oocysts, which preserve
the sporocyst residuum and infectivity for
years; fish coccidians have a soft, membranaceous oocyst wall. Residual bodies in
warm-blooded animals are relatively steady;
fish coccidia consume residual bodies very
quickly and lose infectivity within a few days.
Fig. 6.8.
191
192
K. Molnr
Fig. 6.10. Haemogregarina developmental stages in Giemsa-stained blood films. a. Free gamete of
H. acipenseris in the cytoplasm. b. Intraerythrocytic gamont of H. acipenseris ( 1200). (Courtesy of
Dr F. Baska.)
Phylum Apicomplexa
In the leech crop, gamonts became associated in syzygy and fused. Negm Eldin
(1998) found three stages of merogony in
the development of B. mariae, but Smit
et al. (2003), who recovered this parasite
from the African fish Serranochromis
angusticeps, could not find these stages.
193
Pathogenicity of Apicomplexans
The majority of fish coccidians have relatively low pathogenicity. No mortality was
observed even when 8590% of the spleen
or liver was infected with Goussia spp. or
C. funduli (see Molnr, 1976; Solangi and
Overstreet, 1980). Lethal infections occur
primarily in farm ponds, but severe cases
have been reported from natural waters as
well. Bauer et al. (1981) reported fish mortality caused by G. carpelli and G. sinensis.
Molnr (1976) also recorded deaths due to
G. sinensis. Eimeria anguillae infection
caused emaciation and deaths in eels in
New Zealand (Hine, 1975). Fiebiger (1913),
as well as Odense and Logan (1976),
reported mortality in the haddock caused
by G. gadi. MacKenzie (1978) found a species of Eimeria that caused 610% reduction in body mass in blue whiting. Pinto
(1956) reported parasitic castration as a
result of E. sardinae infection. Upton et al.
(2000) supposed that a heavy infection of
the gut with Eimeria phylloptericis caused
significant morbidity and mortality in the
aquarium-cultured sea-dragon, but the role
of a joint infection with bacterial pathogens
could not be excluded.
The damage to tissues depends on the
intensity of infection. In E. anguillae infection, Hine (1975) observed partial or total
destruction of the intestinal mucosa and
submucosa. The epithelial cells became
compressed and the submucosal connective
tissue vacuolated, and mature oocysts and
free sporocysts were passed out with
necrotic tissue. Kent and Hedrick (1985)
reported high mortality in a lethargic and
emaciated 15-day-old goldfish population.
They found that G. carpelli caused chronic
enteritis, with numerous yellow bodies and
inflammatory and necrotic cells in the
lamina propria of the gut. The microvillous
structure of the intestinal epithelium was
also destroyed. Molnr (1976) studied
G. sinensis in silver carp and also found
intensive histological changes in the gut
194
K. Molnr
Fig. 6.11. Nodular coccidiosis in tench. Unsporulated oocysts just leaving the infected area of the
intestinal epithelium (haemotoxylin and eosin (H & E) 730).
Phylum Apicomplexa
195
196
K. Molnr
HostParasite Relationship
Fish coccidia and their hosts have a
well-developed hostparasite relationship.
Though Steinhager and Hespe (1997)
described an enhanced phagocytic activity
during the period of merogonic and gamogonic development at G. carpelli infection of
the common carp, the host usually takes a long
time before reacting to the developing parasite.
Infected cells are inactive and gradually
die. At this time the host response is mainly
restricted to replacing the damaged cells
(Molnr, 1984). In diffuse coccidiosis, e.g. in
G. carpelli infection, the inactive epithelial
cell that contains the developing macrogamont is gradually surrounded, grown over
and pushed to deeper layers by neighbouring
epithelial cells. The sporulated oocyst is
expelled, probably as a result of macrophage
activation and necrosis of the epithelium
above the oocyst. The oocyst or two or three
oocysts together are situated in a yellow
body. One component of the yellow body is
the necrotic host cell, but macrophages engulfing oocysts may also become yellow bodies.
According to Dykov and Lom (1981), the yellow body contains mucoid substances and ferrous ions as well as the cytoplasm of the
pathologically altered host cell. Also, the yellow body contains lipofuscin and ceroid,
which may be derived from degenerating cell
membranes (Kent and Hedrick, 1985).
Molnr (1984) suggested a new ejection
process in G. subepithelialis infection. The
merogonic and gamogonic stages develop
in the epithelial cells and, as Marincek
(1973b) pointed out, only a few unsporulated
oocysts are excreted from the parasitic nodule
(Fig. 6.11). The remaining infected epithelial cells, which contain oocysts, are
pushed downwards and grown over by proliferating intact epithelial cells. In this way
large numbers of oocysts may be situated
and may sporulate close to the submucosa.
Phylum Apicomplexa
Fig. 6.12.
E 730).
197
198
K. Molnr
and absorbed into the cytoplasm of the parasite. Epiplasmally located coccidia, such as
Cryptosporidium and some Goussia and
Eimeria, absorb nutrients only through their
attachment zone or through invaginations
of the parasitophorous vacuole (Fig. 6.3). In
Cryptosporidium, the parasitophorous vacuole is not complete and there is a special
adhesive zone between the cell and the parasite. This is where absorption takes place.
Parasite nutrition is ensured by a special
feeder organelle, which is formed by close
contact of the parasitic folds and the plasma
membrane at the base of the parasitophorous vacuole. In epicellular Goussia and
Eimeria, the parasitophorous vacuole extends
invaginations into the host cell cytoplasm
(Molnr and Baska, 1986; Daoudi, 1987;
Morrison and Poynton, 1989; Jastrzebski and
Komorowski, 1990). Paperna and Landsberg
(1987), however, reported that these
invaginations are substituted by tubular
formations in G. vanasi.
Diagnosis of Infection
The thin and fragile wall of the oocyst and
sporocyst of fish coccidia does not permit
the use of concentration procedures routinely used with coccidia of warm-blooded
animals. Fish coccidia are demonstrated
exclusively in fresh preparations or by
histological methods.
Coccidia in internal organs are detected
by examining small pieces of tissue under a
cover slip. Low-intensity infections are
detected if the organs are first digested in
0.250.5% trypsin solution. Intestinal
coccidia are demonstrated by microscopic
examination of faeces and intestinal scrapings; they are easiest to detect in the mucus
from the intestinal epithelium or surface of
the faeces (Molnr, 1977). If the fish is
fasted for 1 or 2 days before the examination, oocysts in the yellow body are easily
discernible at 400 in the gut.
Unsporulated oocysts (small size and
thin oocyst wall) (Fig. 6.6) in fresh preparations are often mistaken for granulocytes or
algae, which are common in intestinal
Phylum Apicomplexa
199
References
Abollo, E., Calvo, M. and Pascual, S. (2001) Hepatic coccidiosis of the blue whiting, Micromesistius
poutassou (Risso), and horse mackerel, Trachurus trachurus (L.), from Galician waters. Journal of Fish
Diseases 24, 335343.
Alvarez-Pellitero, P. and Sitja-Bobadilla, A. (2002) Cryptosporidium molnari n. sp. (Apicomplexa:
Cryptosporidiidae) infecting two marine fish species, Sparus aurata L. and Dicentrarchus labrax L.
International Journal for Parasitology 32, 10071021.
Alvarez-Pellitero, P., Palenzuela, O. and Sitj-Bobadilla, A. (1997) Ultrastructure and cytochemistry study of
Goussia sparis (Protozoa: Apicomplexa) stages from the intestine of the gilthead sea bream Sparus aurata L.
(Pisces: Teleostei). Parasitology Research 83, 2433.
Azevedo, C. (2001) Fine structure of sporogonic stages of Goussia clupearum (Apicomplexa: Eimeriidae) in
the liver of infected fish (Belone belone L.), using light and electron microscopy. Parasitology Research
87, 326330.
Azevedo, C., Matos, E. and Matos, P. (1995) Ultrastructural data on sporogony of the coccidian parasite
Calyptospora spinosa from the liver of the Amazonian fish, Crenicichla lepidota Heckel. Journal of Fish
Diseases 18, 475479.
Barta, J.R. (1991) The Dactylosomatidae. Advances in Parasitology 30, 137.
200
K. Molnr
Barta, J.R. and Desser, S.S. (1989) Development of Babesiosoma stableri (Dactylosomatidae; Adeleida;
Apicomplexa) in its leech vector (Bactracobdella picta) and the relationship of the dactylosomatids to the
piroplasms of higher vertebrates. Journal of Protozoology 36, 241253.
Baska, F. (1997) Epicellular and nodular coccidiosis in the intestine of barbel Barbus barbus. Diseases of
Aquatic Organisms 29, 4956.
Baska, F. and Molnr, K. (1989) Ultrastructural observations on different developmental stages of Goussia
sinensis (Chen, 1955), a parasite of the silver carp (Hypophthalmichthys molitrix Valenciennes, 1844).
Acta Veterinaria Hungarica 37, 8187.
Bauer, O.N. Musselius, V.A. and Strelkov, J.A. (1981) [Diseases of Pond Fishes], 2nd edn. Legkhaya i
pischevaya promishlennost Moscow (in Russian).
Becker, C.D. and Overstreet, R.M. (1979) Haematozoa of marine fishes from the northern Gulf of Mexico.
Journal of Fish Diseases 2, 469479.
Bksi, L. and Molnr, K. (1990) Calyptospora tucunarensis n. sp. (Apicomplexa: Sporozoea) from the liver of
tucunare (Cichla ocellaris) in Brazil. Systematic Parasitology 18, 127132.
Belova, L.M. and Krylov, M.V. (2000) Specificity of coccidian of fishes (Sporozoa, Coccidia). Trudy
Zoologicheskovo Instituta Rossiyskoi Akademii Nauk 286, 1116.
Berland, B. and Hjgaard, P. (1981) IKI-solution used for flottation of coccidia (Eimeria sp.) and precipitation
of oil from fish liver. Journal of Parasitology 67, 598599.
Cruz, C. and Davies, A.J. (1998) Some observations on Babesiosoma bettencourti (Franca, 1908) n. comb.
(syns. Haemogregarina bettencourti Franca, 1908; Desseria bettencourti Siddall, 1995) from eels,
Anguilla anguilla L. in Portugal. Journal of Fish Diseases 21, 443448.
Daoudi, F. (1987) Coccidies et coccidioses de poissons mditerranens: systematique, ultrastructure et biologie.
Doctoral thesis, Laboratoire dichthyologie et de parasitologie gnerale, VSTL Montpellier, France.
Daoudi, F., Rdujkovic, B., Marques, A. and Bouix, G. (1988) Pathogenicity of the coccidian Goussia
thelohani (Labbe, 1986), in liver and pancreatic tissues of Symphodus tinca (Linne, 1758). Bulletin of the
European Association of Fish Pathologists 8, 5558.
Davies, A.J. (1980) Some observations on Haemohormidium cotti Henry, 1910, from the marine fish Cottus
bubalis Euphrasen. Zeitschrift fr Parasitenkunde 62, 3138.
Davies, A.J. (1982) Further studies on Haemogregarina bigemina Laveran & Mesnil, the marine fish Blennius
pholis L., and the isopod Gnathia maxillaris Montagu. Journal of Protozoology 29, 576583.
Davies, A.J. (1995) The biology of fish haemogregarines. Advances in Parasitology 36, 118203.
Davies, A.J. and Johnston, M.R.L. (1976) The biology of Haemogregarina bigemina Laveran & Mesnil, a
parasite of the marine fish Blennius pholis Linnaeus. Journal of Protozoology 23, 315320.
Davies, A.J. and Johnston, M.R.L. (2000) The biology of some intraerythrocytic parasites of fishes, amphibia
and reptiles. Advances in Parasitology 45, 289.
Davies, A.J. and Smit, N.J. (2001) The life cycle of Haemogregarina bigemina (Adeleina: Haemogregarinidae)
in South African hosts. Folia Parasitologica 48, 169177.
Davies, A. and Stewart, B. (2000) Autofluorescence in the oocysts of marine and freshwater fish coccidian.
Folia Parasitologica 47, 157158.
Diniz, J.A., Silva, E.O., de Souza, W. and Lainson, R. (2002) Some observations on the fine structure of
trophozoites of the haemogregarine Cyrilia lignieresi (Adeleina: Haemogregarinidae) in erythrocytes of
the fish Synbranchus marmoratus (Synbranchidae). Parasitological Research 88, 593597.
Diouf, J.N. and Toguebaye, B.S. (1994) Study of some marine fish coccidia of the genus Eimeria Schneider,
1815 (Apicomplexa, Coccidia) from Senegal coasts. Acta Protozoologica 33, 239250.
Diouf, J.N. and Toguebaye, B.S. (1996) Eimeria spari n. sp. (Apicomplexa, Eimeriidae) parasite of Sparus
caeruleostictus (Valenciennes, 1830), (Pisces, Sparidae) from the Coast of Senegal. Parasite 3, 351355.
Diouf, M., Benajiba, M.H. and Senhaji, M. (2000) Goussia cruciata (Thelohan, 1892) a hepatic coccidian
parasite of the horse mackerel Trachurus trachurus (Linnaeus, 1758) from the Mediterranean coasts of
northern Morocco. Bulletin of the European Association of Fish Pathologists 20, 219223.
Duszynski, D.W., Upton, S.J. and Couch, L. (1999) The Coccidia of the World. www.biology.unm.edu/
biology/coccidia/table.html
Dykov, J. and Lom, J. (1981) Fish coccidia: critical notes on life cycles, classification and pathogenicity.
Journal of Fish Diseases 4, 487505.
Dykov, J. and Lom, J. (1983) Fish coccidia: an annotated list of described species. Folia Parasitologica 30,
193208.
Fatham, H.B., Porter, A. and Richardson, L.B. (1942) Some haematozoa observed in vertebrates in eastern
Canada. Parasitology 34, 199266.
Phylum Apicomplexa
201
Fayer, R., Speer, C.A. and Dubey, J.P. (1997) The general biology of Cryptosporidium. In: Fayer, R. (ed.)
Cryptosporidium and Cryptosporidiosis. CRC Press, Boca Raton, Florida, pp. 141.
Ferguson, H.W. and Roberts, R.J. (1975) Myeloid leucosis associated with sporozoan infection in cultured
turbot (Scophthalmus maximus L.). Journal of Comparative Pathology 85, 317326.
Fiebiger, J. (1913) Studien ber die Schwimmblasen-Coccidien der Gadusarten (Eimeria gadi n. sp.). Archiv
fr Parasitenkunde 31, 95137.
Fournie, J.W. and Overstreet, R.M. (1983) True intermediate hosts for Eimeria funduli (Apicomplexa) from
estuarine fishes. Journal of Protozoology 30, 672675.
Fournie, J.W., Vogelbein, V.K., Overstreet, R.M. and Hawkins, W.E. (2000) Life cycle of Calyptospora funduli
(Apicomplexa: Calyptosporidae). Journal of Parasitology 86, 501505.
Grabda, E. (1983) Eimeria jadvigae n. sp. (Apicomplexa: Eucoccidia), a parasite of swim bladder of
Coryphaenoides holotrachys (Gnther, 1887) off the Falklands. Acta Ichthyologica et Piscatoria 13,
131140.
Hawkins, W.E., Solangi, M.A. and Overstreet, R.M. (1981) Ultrastructural effects of the coccidium, Eimeria
funduli Duszynski, Solangi et Overstreet (1979) on the liver of killifishes. Journal of Fish Diseases 4,
281295.
Hawkins, W.E., Fournie, J.W. and Overstreet, R.M. (1983a) Organization of sporulated oocysts of Eimeria
funduli in the gulf killifish, Fundulus grandis. Journal of Parasitology 69, 496503.
Hawkins, W.E., Solangi, M.A. and Overstreet, R.M. (1983b) Ultrastructure of the macrogamont of Eimeria
funduli, a coccidium parasitizing killifishes. Journal of Fish Diseases 6, 3343.
Hawkins, W.E., Solangi, M.A. and Overstreet, R.M. (1983c) Ultrastructure of the microgamont and
microgamete of Eimeria funduli, a coccidium parasitizing killifishes. Journal of Fish Diseases 6, 4557.
Hawkins, W.E., Fournie, J.W. and Overstreet, R.M. (1984a) Ultrastructure of the interface between stages of
Eimeria funduli (Apicomplexa) and hepatocytes of the longnose killifish Fundulus similis. Journal of
Parasitology 70, 232238.
Hawkins, W.E., Fournie, J.W. and Overstreet, R.M. (1984b) Intrahepatic stages of Eimeria funduli (Protista:
Apicomplexa) in the longnose killifish, Fundulus similis. Transactions of the American Microscopical
Society 103, 185194.
Hemmer, N., Steinhagen, D., Drommer, W. and Krting, W. (1998) Changes of intestinal epithelial structure
and cell turnover in carp Cyprinus carpio infected with Goussia carpelli (Protozoa: Apicomplexa).
Diseases of Aquatic Organisms 34, 3944.
Hine, P.M. (1975) Eimeria anguillae Leger et Hollande, 1922 parasitic in New Zealand eels. New Zealand
Journal of Marine and Freshwater Research 9, 239243.
Hoffman, G.L. (1965) Eimeria aurati n. sp. (Protozoa: Eimeriidae) from the goldfish (Carassius auratus) in
North America. Journal of Protozoology 12, 273275.
Hoover, H.M., Hoerr, F.J., Carlton, W.W., Hinsman, E.J. and Ferguson, H.W.I. (1981) Enteric cryptosporidiosis
in a nasa tang, Naso lituratus Bloch and Schneider. Journal of Fish Diseases 4, 425428.
Jastrzebski, M. (1989) Ultrastructural study on the development of Goussia aculeati, a coccidium parasitizing
the three-spined stickleback Gasterosteus aculeatus. Diseases of Aquatic Organisms 6, 4553.
Jastrzebski, M. and Komorowski, Z. (1990) Light and electron microscopic studies on Goussia zarnowskii
(Jastrzebski, 1982): an intestinal coccidium parasitizing the three-spined stickleback, Gasterosteus
aculeatus (L.). Journal of Fish Diseases 13, 124.
Jirku, M., Modry, D., Slapeta, J.R., Koudela, B. and Lukes, J. (2002) The phylogeny of Goussia and
Choleoeimeria (Apicomplexa; Eimeriorina) and the evolution of excystation structures in coccidian.
Protistology, 153, 379390.
Kent, M.L. and Hedrick, R.P. (1985) The biology and associated pathology of Goussia carpelli (Lger and
Stankovitch) in gold fish Carassius auratus (Linnaeus). Fish Pathology 20, 485494.
Kent, M.L., Fournie, J.W., Snodgrass, R.E. and Elston, R.A. (1988) Goussia girellae n. sp. (Apicomplexa:
Eimeriorina) in the opaleye, Girella nigricans. Journal of Protozoology 35, 287290.
Khan, R.A. (1972) Developmental stages of Haemogregarina delagei Laveran and Mesnil in an elasmobranch,
Raja radiata Donovan. Canadian Journal of Zoology 50, 906907.
Khan, R.A. (1978) A new haemogregarine from marine fishes. Journal of Parasitology 64, 3544.
Khan, R.A. (1980) The leech as a vector of a fish piroplasm. Canadian Journal of Zoology 58, 16311637.
Kirmse, P. (1978) Haemogregarina sachai n. sp. from cultured turbot Scophthalmus maximus L., in Scotland.
Journal of Fish Diseases 1, 337342.
Kirmse, P. (1980) Observations on the pathogenicity of Haemogregarina sachai Kirmse, 1978, in farmed
turbot Scophthalmus maximus (L.). Journal of Fish Diseases 3, 101114.
202
K. Molnr
Kirmse, P. and Ferguson, H. (1976) Toxoplasma-like organisms as the possible causative agents of a
proliferative condition in farmed turbot (Scophthalmus maximus). In: Page, L. (ed.) Wildlife Diseases.
Plenum, New York, pp. 561564.
Kocylowski, B. and Myaczynski, T. (1963) Fish Diseases. Publishing House Mezgazdasgi, Budapest.
Kocylowski, B., Zelazny, J., Antychowicz, J. and Panczyk, J. (1976) Incidence of carp coccidiosis and its
control. Bulletin of the Veterinary Institute Pulawy 20, 1217.
Lacey, S.M. and Williams, I.C. (1983) Epieimeria anguillae (Lger & Hollande, 1922) Anguilla anguilla (L.).
Journal of Fish Biology 23, 605609.
Landau, I., Marteau, M., Golvan, Y., Chabaud, A.G. and Boulard, Y. (1975) Htroxnie chez les coccidies
intestinales de poissons. Comptes Rendus de lAcadmie des Sciences 281, 17211723.
Landsberg, J.H. and Paperna, I. (1985) Goussia cichlidarum n. sp. (Barrouxiidae, Apicomplexa), a coccidian
parasite in the swimbladder of cichlid fish. Zeitschrift fr Parasitenkunde 71, 199201.
Landsberg, J.H. and Paperna, I. (1986) Ultrastructural study of the coccidian Cryptosporidium sp. from
stomachs of juvenile cichlid fish. Diseases of Aquatic Organisms 2, 1320.
Landsberg, J.H. and Paperna, I. (1987) Intestinal infections by Eimeria (S.L.) vanasi n. sp. (Eimeriidae,
Apicomplexa, Protozoa) in cichlid fish. Annales de Parasitologie Humaine et Compare 62, 283293.
Levine, N.D. (1984) Taxonomy and review of the coccidian genus Cryptosporidium (Protozoa, Apicomplexa).
Journal of Protozoology 31, 9498.
Levine, N.D. (1988) The Protozoan Phylum Apicomplexa, 2 vols. CRC Press, Boca Raton, Florida.
Lom, J. (1971) Remarks on the spore envelopes in fish coccidia. Folia Parasitologica 18, 289293.
Lom, J. (1984) Diseases caused by protistans In: Kinne, O. (ed.) Diseases of Marine Animals, vol. 4.
Biologische Anstalt Helgoland, Hamburg, Germany, pp. 114168.
Lom, J. and Dykov, I. (1995) Studies on protozoan parasites of Australian fishes notes on coccidian
parasites with description of 3 new species. Systematic Parasitology 31, 147156.
MacKenzie, K. (1978) The effect of Eimeria sp. infection on the condition of the blue whiting Micromesistius
poutassou (Risso). Journal of Fish Diseases 4, 473486.
MacLean, S.A. and Davies, A.J. (1990) Prevalence and development of intraleucocytic haemogregarines from
Northwest and Northeast Atlantic mackerel, Scomber scombrus L. Journal of Fish Diseases 13, 5968.
Mandal, A.K., Ray, R., Sarkar, N.C. and Kahali, R. (1984) The protozoa Haemogregarina colisa sp. nov. from
the fish Colisa fasciatus and Haematractidium sp. from Arius sona. Bulletin of the Zoological Survey of
India 5, 139144.
Marincek, M. (1973a) Dvloppement dEimeria subepithelialis (Sporozoa, Coccidia), parasite de la carpe.
Acta Protozoologica 19, 197215.
Marincek, M. (1973b) Les changements dans le tube digestif chez Cyprinus carpio la suite de linfection par
Eimeria subepithelialis (Sporozoa, Coccidia). Acta Protozoologica 20, 217224.
Marincek, M. (1978) Uticaj kokcidije Eimeria subepithelialis po konstituciju sarana. Acta Parasitologica
Jugoslovenica 9, 312 (in Serbo-Croatian).
Molnr, K. (1976) Histological study of coccidiosis caused in the silver carp and the bighead by Eimeria
sinensis Chen (1956). Acta Veterinaria Academiae Scientiarium Hungariae 26, 303312.
Molnr, K. (1977) Comments on the nature and methods of collection of fish coccidia. Parasitologia
Hungarica 10, 4145.
Molnr, K. (1979) Studies on Coccidia of Hungarian pond fishes and further prospects of their control. In:
Proceeding of the International Symposium on Coccidia, Prague, pp. 173183.
Molnr, K. (1984) Some peculiarities of oocyst rejection of fish coccidia. Symposia Biologica Hungarica 23, 8797.
Molnr, K. (1986) Occurrence of two new Goussia species in the intestine of the sterlet (Acipenser ruthenus).
Acta Veterinaria Hungarica 34, 169174.
Molnr, K. (1989) Nodular and epicellular coccidiosis in the intestine of cyprinid fishes. Diseases of Aquatic
Organisms 7, 112.
Molnr, K. (1996) Phylum Apicomplexa. In: Woo, P.T.K. (ed.) Fish Diseases and Disorders Vol. 1. CAB
International, Wallingford, UK, pp. 263287.
Molnr, K. and Baska, F. (1986) Light and electron microscopic studies on Epieimeria anguillae (Lger et
Hollande, 1922), a coccidium parasitizing the European eel, Anguilla anguilla L. Journal of Fish Diseases
9, 99110.
Molnr, K. and Fernando, C.H. (1974) Some new Eimeria (Protozoa, Coccidia) from freshwater fishes in
Ontario, Canada. Canadian Journal of Zoology 52, 413419.
Molnr, K. and Hanek, G. (1974) Seven new Eimeria spp. (Protozoa, Coccidia) from freshwater fishes of
Canada. Journal of Protozoology 21, 489493.
Phylum Apicomplexa
203
Molnr, K. and Ogawa, K. (2000) A survey on coccidian infection of Lake Biwa fishes in Japan, with the
description of four new species of Goussia Labbe, 1896 (Apicomplexa). Systematic Parasitology 47,
215222.
Molnr, K. and Rohde, K. (1988) New coccidians from freshwater fishes of Australia. Journal of Fish Diseases
11, 161169.
Molnr, K., Shaharom-Harrison, F. and Szkely, C. (2003) A survey of coccidian infections of freshwater fishes
of Peninsular Malaysia, with descriptions of three species of Goussia Labbe, 1896 (Apicomplexa:
Eimeriidae). Systematic Parasitology 55, 1118.
Morrison, C.M. and Hawkins, W.E. (1984) Coccidians in the liver and testis of the herring Clupea harengus L.
Canadian Journal of Zoology 62, 480493.
Morrison, C.M. and Poynton, S.L. (1989) A new species of Goussia (Apicomplexa, Coccidia) in the kidney
tubules of the cod, Gadus morhua L. Journal of Fish Diseases 12, 533560.
Musselius, V.A., Laptev, V.I. and Ivanova, N.S. (1965) On the coccidiosis of the common carp II. Trudi
VNIIPRH 13, 6978 (in Russian).
Naumova, A.M. and Kanaev, A.I. (1962) An experiment for treating common carp diseased in coccidiosis.
Voprosy Ikhtiologii Akademii Nauk SSSR 2, 749751 (in Russian).
Negm-Eldin, M.M. (1998) Life cycle, host restriction and longevity of Babesiosoma mariae Hoare, 1930
(Apicomplexa, Dactylosomatidae). Deutsche Tierrztliche Wochenschrift 105, 367374.
Negm-Eldin, M.M. (1999) Life cycle, host restriction and longevity of Cyrilia nili (Haemogregarina nili
Wenyon, 1909) n. comb. Deutsche Tierrztliche Wochenschrift 106, 191199.
Odense, P.H. and Logan, V.H. (1976) Prevalence and morphology of Eimeria gadi in the haddock. Journal of
Protozoology 23, 564571.
Paperna, I. (1981) Dactylosoma hannesi n. sp. (Dactylosomatidae, Piroplasmia) found in the blood of grey
mullets (Mugilidae) from South Africa. Journal of Protozoology 28, 486491.
Paperna, I. (1987) Scanning electron microscopy of the coccidian parasite Cryptosporidium sp. from cichlid
fishes. Diseases of Aquatic Organisms 3, 231232.
Paperna, I. (1995) Ultrastructural and developmental affinities of piscine coccidia. Diseases of Aquatic Organisms 22, 6776.
Paperna, I. and Landsberg, J.H. (1987) Tubular formations extending from parasitophorous vacuoles in gut
epithelial cells of cichlid fish infected by Eimeria (s.I.) vanasi. Diseases of Aquatic Organisms 2, 239242.
Paperna, I. and Vilenkin, M. (1996) Cryptosporidiosis in the gourami Trichogaster leeri: description of a new
species and a proposal for a new genus, Piscicryptosporidium for species infecting fish. Diseases of
Aquatic Organisms 27, 95101.
Paterson, W.B. and Desser, S.S. (1981a) An ultrastructural study of Eimeria iroquoina Molnr and Fernando,
1974 in experimentally infected fathead minnows (Pimephales promelas, Cyprinidae). 3. Merogony.
Journal of Protozoology 28, 302308.
Paterson, W.B. and Desser, S.S. (1981b) An ultrastructural study of microgametogenesis and the microgamete
in Eimeria iroquoina Molnr and Fernando, 1974, in experimentally infected fathead minnows
(Pimephales promelas, Cyprinidae). Journal of Parasitology 67, 314324.
Paterson, W.B. and Desser, S.S. (1981c) Ultrastructure of macrogametogenesis, macrogametes and young
oocysts of Eimeria iroquoina Molnr and Fernando, 1974 in experimentally infected fathead minnows
(Pimephales promelas, Cyprinidae). Journal of Parasitology 67, 496504.
Paterson, W.B. and Desser, S.S. (1982) The biology of two Eimeria species (Protista: Apicomplexa) in their
mutual fish hosts in Ontario. Canadian Journal of Zoology 60, 164175.
Pavlasek, I. (1983) Cryptosporidium sp. in Cyprinus carpio Linn 1758 in Czechoslovakia. Folia Parasitologica
30, 248.
Pellrdy, L. and Molnr, K. (1968) Known and unknown eimerian parasites of fishes in Hungary. Folia
Parasitologica 15, 97105.
Perkins, S.L., Barta, J.R., Upton, S.J. and Peirce, M.A. (2002) Apicomplexa. In: Lee, J.J., Leadale, G.F. and
Bradbury, P. (eds) The Illustrated Guide to the Protozoa, 2nd edn, Blackwell Scientific Publishing,
Boston, Massachusetts, pp. 190369.
Pinto, J.S. (1956) Parasitic castration in males of Sardinia pilchardus (Walb.) due to testicular infestation by
the coccidia Eimeria sardinae (Thelohan). Revista de la Faculdade de Ciencias de la Universidade de
Lisboa Serie C 5, 209214.
Schperclaus, W. (1954) Fischkrankheiten. Akademie Verlag, Berlin.
Setna, S.B. and Bana, R.H. (1935) Eimeria harpodoni n. sp., a new coccidium from Harpodon nehereus.
Journal of the Royal Microscopic Society 55, 165169.
204
K. Molnr
Shulman, S.S. (1984) Parasitic protozoa. In: Bauer, O.N. (ed.) Key to Parasites of Freshwater Fish of the USSR,
vol. 1. Nauka, Leningrad (in Russian), Russia, 431 pp.
Siddall, M.E. (1995) Phylogeny of adeleid blood parasites with a partial systematic revision of the
hemogregarine complex. Journal of Eukariotic Microbiology 42, 116125.
Siddall, M.E., Desser, S.S. and Measures, L.N. (1994) Light-microscopic and electron-microscopic examination of so-called piroplasms of fishes from Atlantic Canada and systematic revision of the
Haemohormiidae (Incertae-Sedis). Journal of Parasitology 80, 10181025.
Sitja-Bobadilla, A., Palenzuela, O. and Alvarez-Pellitero, P. (1996) Light microscopic description of Eimeria
sparis sp. nov. and Goussia sparis sp. nov. (Protozoa: Apicomplexa) from Sparus aurata L. (Pisces:
Teleostei). Parasitology Research 82, 323332.
Smit N.J. and Davies, A.J. (1999) New host record of Haemogregarina bigemina from the coast of Southern
Africa. Journal of Marine Biological Association of the United Kingdom 81, 751754.
Smit, N.J., Van As, J.G. and Davies, A.J. (2003) Observations on Babesiosoma mariae (Apicomplexa:
Dactylosomatidae) from the Okavango Delta, Botswana. Folia Parasitologica 50, 8586.
Solangi, M.A. and Overstreet, R.M. (1980) Biology and pathogenesis of the coccidium Eimeria funduli
infecting killifishes. Journal of Parasitogy 66, 513526.
Steinhagen, D. (1991) Ultrastructural observations on sporozoite stages of piscine Coccidia: Goussia carpelli
and G. subepithelialis from the intestine of tubificid oligochaetes. Diseases of Aquatic Organisms 10,
121125.
Steinhagen, D. (1997) Temperature modulation of the response of Ig-positive cells to Goussia carpelli
(Protozoa: Apicomplexa) infections in carp, Cyprinus carpio L. Journal of Parasitology 83, 434439.
Steinhagen, D. and Hespe, K. (1997) Carp coccidiosis: activity of phagocytic cells from common carp infected
with Goussia carpelli. Diseases of Aquatic Organisms 31, 155159.
Steinhagen, D. and Krting, W. (1988) Experimental transmission of Goussia carpelli (Leger & Stankovitch,
1921; Protista: Apicomplexa) to common carp, Cyprinus carpio L. Bulletin of the European Association
of Fish Pathologists 8, 112113.
Steinhagen, D. and Krting, W. (1990) The role of tubificid oligochaetes in the transmission of Goussia
carpelli. Journal of Parasitology 76, 104107.
Steinhagen, D., Krting, W. and van Muiswinkel, W.B. (1989) Morphology and biology of Goussia carpelli
(Protozoa: Apicomplexa) from the intestine of experimentally infected common carp Cyprinus carpio.
Diseases of Aquatic Organisms 6, 9398.
Steinhagen, D., Oesterreich, B. and Krting W. (1997) Carp coccidiosis: clinical and haematological observations of carp infected with Goussia carpelli. Diseases of Aquatic Organisms 30, 137143.
Steinhagen, D., Hespe, K., Ellmer, B. and Krting, W. (1998) Goussia carpelli (Protozoa: Coccidia) infection in
stressed and immunosuppressed common carp Cyprinus carpio. Diseases of Aquatic Organisms 34,
199204.
Studnicka, M. and Siwicki, A. (1990) The nonspecific immunobiological response in carp (Cyprinus carpio L.)
during natural infection with Eimeria subepithelialis. Israeli Journal of Aquaculture Bamidgeh 42,
1821.
Thlohan, P. (1890) Sur deux coccidies nouvelles, parasites de lpinoche et de la sardine. Comptes Rendus
Socit Biologique (Paris) 42, 345348.
Tolonen, A. and Karlsbakk, E. (2003) The parasite fauna of the Norwegian spring spawning herring (Clupea
harengus). ICES Journal of Marine Science 60, 7784.
Upton, S.J., Stamper, M.A., Osborn, A.L., Mumford, S.L., Zwick, L., Kinsel, M.J. and Overstreet, R.M. (2000)
A new species of Eimeria (Apicomplexa, Eimeriidae) from the weedy sea dragon Phyllopterix teniolatus
(Osteichthyes: Sygnathinae). Diseases of Aquatic Organisms 43, 5559.
Vilenkin, M. and Paperna, I. (1997) Development of sporozoites of the piscine coccidium Eimeria (sensu lato)
vanasi in gut intraepithelial lymphocyte-like cells. Folia Parasitologica 44, 9198.
Zmerzlaya, E.I. (1966) Temperature effect upon the infestation of carps with coccidian Eimeria carpelli Leger
et Stankovitsch, 1921. Zoologicheskhii Zhurnal 45, 305308 (in Russian).
Phylum Microspora
Iva Dykov
Introduction
Microsporidia are unicellular organisms
living as intracellular parasites in a variety
of invertebrates and in all five classes of
vertebrate hosts. Many microsporidian species are widely distributed in teleosts in
freshwater, estuarine and marine habitats.
Some species, e.g. Heterosporis anguillarum
(Hoshina, 1951), Kabatana takedai (Awakura,
1974), Loma salmonae (Putz et al., 1965)
and Nucleospora salmonis (Hedrick et al.,
1991), are serious pathogens of cultured fishes.
Microsporidian infections can cause direct
losses due to mortalities, which in natural
conditions can be accompanied by subsequent decline of stocks, and by indirect
losses due to reduction of the marketing
value of infected fish (Shaw and Kent, 1999).
Microsporidian infections also constitute a
threat to the ornamental fish industry and
to colonies of zebrafish in research facilities
(Lom et al., 1989, 1993; Michel et al., 1989;
Matthews et al., 2001).
205
206
I. Dykov
have relied exclusively on morphological features distinguishable under light and electron
microscopes. Recent classification of fishinfecting microsporidia has also integrated
molecular data accumulated in the last
decade (Bell et al., 2001). Presenting results
of phylogenetic analyses, Lom and Nilsen
(2003) concluded that the grouping of fishinfecting species of microsporidia based on
molecular data corresponds to the morphological criteria defined by Sprague et al. (1992)
for families Pleistophoridae Doflein, 1901
(now containing the genera Pleistophora,
Heterosporis and Ovipleistophora) and
Glugeidae Thlohan, 1892 (with the only
genus Glugea), while the families Spragueidae
Weissenberg, 1976 (with the only genus
Spraguea) and Tetramicridae Matthews and
Matthews, 1980 (with the genera Microgemma
and Tetramicra) cluster together with
Kabatana spp. and Microsporidium seriolae,
forming a group which is morphologically
heterogeneous. Also the clade formed by partial small subunit ribosomal RNA (SSU-rRNA)
gene sequences of Loma embiotocia,
L. salmonae, Loma spp. and Microsporidium sp. MYX1 and by SSU-rRNA gene
sequences of Pseudoloma neurophilia and
Ichthyosporidium sp. is morphologically
heterogeneous.
Phylum Microspora
207
Fig. 7.1. Spores of fish-infecting microsporidia. A. Glugea anomala from Nothobranchius korthausae.
B, C. G. anomala from Gasterosteus aculeatus (B. Spores within a sporophorous vesicle). D. Glugea
plecoglossi from Plecoglossus altivelis. E. Glugea stephani from Parophrys vetulus. F. Glugea atherinae
from Atherina boyeri. G. Ichthyosporidium giganteum from Leiostomus xanthurus. H. Tetramicra
brevifilum from Scophthalmus maximus. I. Glugea hertwigi from Osmerus mordax. J. Glugea luciopercae
from Stizostedion lucioperca. K. Pleistophora hippoglossoides from Hippoglossoides platessoides.
L. Pleistophora hyphessobryconis from Paracheirodon innesi. M, N. Heterosporis schuberti from
Pseudocrenilabrus multicolor (inset in M. Microspores; N. Spores within a sporophorous vesicle).
O. Kabatana arthuri from Pangasius sutchi. P, Q. Ovipleistophora mirandellae from Rutilus rutilus
(P. Spores within a sporophorous vesicle). R. Pleistophora ovariae from Notemigonus crysoleucas.
S. Spraguea lophii from Lophius americanus. (The size of each species included in the plate is given in
the text.)
208
I. Dykov
Fig. 7.2. Microsporidian life cycle stages. A. Elongated meront of Glugea anomala. B. Almost completely
divided sporogonial plasmodium of G. anomala. C. Division of the sporoblast mother cell in G. anomala.
D. Sporoblasts of G. anomala (common fixation shrinkage). Scale bars for AD: 1 m. E. Ovipleistophora
mirandellae, sporogonial plasmodium in the process of segmentation. Scale bar: 2 m. F. Mature spore of
O. mirandellae. Scale bar: 1 m.
Phylum Microspora
209
Fig. 7.3. Xenoma formations. A. Young xenoma of Glugea anomala in the subepithelial connective tissue
of the intestine of Nothobranchius sp. ( 480). B. Young xenoma of Glugea plecoglossi with cylindrical
meronts embedded in the lamina muscularis of the intestine ( 360). C. Mature xenoma of G. plecoglossi in
the testis of Plecoglossus altivelis surrounded by a connective-tissue layer ( 170). D. Structure of xenoma
formation of G. anomala with presporogonic stages on the periphery and densely stained spores
accumulating inwards (semi-thin section, 890). E. Typical small xenoma of Glugea sp. with hypertrophied
centrally located unfragmented nucleus localized in the cardiac muscle of Ictalurus punctatus ( 380).
F. Xenoma of Tetramicra brevifilum in the muscle tissue of Scophthalmus maximus. Note the villosities on
the periphery of the xenoma and spores released from another xenoma between the remnants of muscle
fibres ( 250).
raised above 15C. Transfer of infected rainbow trout yearlings from the optimal 18C to
8C stops parasite development.
It is supposed that all fish-infecting
microsporidia possess a direct transmission accomplished perorally, although some
species described from invertebrates (Amblyospora spp., Parathelohania spp., Dubosquina
210
I. Dykov
HostParasite Relationships
The interactions of microsporidia with fish
hosts have been studied mostly in natural
infections (Dykov and Lom, 1980). Since
the early studies of Weissenberg (1913,
1921), there have been several attempts
to elucidate the hostparasite relationships
in experimental infections (McVicar, 1975;
Olson, 1976; Takahashi and Egusa, 1977a;
Berrebi, 1978; Dykov and Lom, 1978;
Matthews and Matthews, 1980; RodrguezTovar et al., 2002, 2003).
Site selection of microsporidians within
the hosts depends on their requirements for a
particular cell type within which they can
develop. Some species seem to be highly cell
specific (e.g. S. lophii develops in neurocytes,
O. mirandellae in oocytes, Pleistophora species in myocytes). In some species (Loma) the
infection was found to start in neutrophils.
The cell type is difficult to recognize after it
has been transformed into a xenoma. This
probably explains the usage of the ambiguous term mesenchymal cells for infected
connective-tissue cells. Progressive (hyperbiotic) changes, manifested by extensive
hypertrophy of infected cell and fragmentation of the nucleus, are set up when the
xenoma starts to develop. Cells infected
with non-xenoma-forming species are
Phylum Microspora
211
Fig. 7.4. Advanced stages of host tissue reaction to microsporidian infections. A. Inflammatory infiltration
around a Glugea plecoglossi xenoma with dystrophically changed wall (the ovary of Plecoglossus
altivelis, 240). B. The remnants of G. cf. anomala xenoma surrounded by an inflammatory reaction (the
liver of Austrolebias nigripinnis, 320). C. Remnants of Tetramicra brevifilum xenoma walled off with
connective tissue from the liver parenchyma of Scophthalmus maximus ( 220). D. Pleistophora
macrozoarcidis spores replacing all muscle fibre of Macrozoarces americanus and walled off with mature
connective tissue ( 150). E. Proliferation of granulation tissue triggered by spores released from xenoma of
Loma branchialis (s, spores; gs, gill secondary lamella) ( 900).
212
I. Dykov
Fig. 7.5. Life cycle stages of Pleistophora hyphessobryconis (AD). A, B. Early stages of the life cycle as
seen in semi-thin sections: arrowheads mark meronts, arrows mark sporogonial plasmodia ( 780).
C. Earlier stage of the life cycle surrounded by a halo of destroyed sarcoplasm (asterisk) and a group of
sporophorous vesicles with maturing spores ( 850). D. Advanced sporogonial plasmodium (top) and
sporophorous vesicle (bottom) ( 780). E. Massive infection of P. hyphessobryconis in the muscle tissue
of Paracheirodon innesi ( 200). F. Sporophorocyst of Heterosporis sp. and inflammatory reaction in the
muscle tissue of Betta splendens ( 730).
phagocytic cells, macrophages and fibroblasts, which ingest and digest spores (up to
30 spores were found in one cell)
(Fig. 7.4E).
Many of the spore-filled macrophages
in the centre of the granuloma disintegrate
and other phagocytes take up the resulting
spore-containing debris. Eventually, the
spore content and even chitinous spore
shells are completely digested.
Phylum Microspora
213
214
I. Dykov
Phylum Microspora
215
216
I. Dykov
Phylum Microspora
217
218
I. Dykov
xenoma wall or any other distinct boundary. The heart muscle cysts prevail in
chronic infection and develop at lower temperatures. In the acute disease, there is high
mortality, with enormous numbers of
cysts in the trunk musculature (up to 130
per gram of tissue). There is a strong negative correlation between the condition of
the fish and the intensity of the infection.
Mortalities were also observed in wild masu
salmon (Urawa, 1989). In experimentally
infected yearlings, host tissue reaction started
on day 11 with inflammatory infiltration.
Phagocytic cells appeared on day 17. Their
number declined to a minimum on day 30.
The phagocytic response was more pronounced in 2-year-old trout.
Kabatana arthuri (Lom, Dykov
and Shaharom, 1990) Lom, Dykov and
Tonguthai, 2000 (synonyms: Microsporidium
arthuri Lom, Dykov and Shaharom, 1990;
Kabataia arthuri Lom, Dykov and Tonguthai,
1999) was observed in the skeletal musles
of Pangasius sutchi from Thailand. Sporogony proceeds without SPV formation.
Multinucleate meronts transform into sporogonial plasmodia. Round, pyriform, uninucleate spores average 2.1 m 3.1 m
(Fig. 7.1O). In heavy infections the parasite
destroyed parts of the musculature (Fig. 7.6D).
Necrotic changes developed in muscle fibres
around presporogonic stages as well as on the
periphery of giant aggregates of mature spores
(Fig. 7.6A,D). The main feature of the host
defence reaction was the phagocytic activity
of macrophages. A host inflammatory reaction
was observed only exceptionally. Sporeladen macrophages were found in various
tissues and organs (Fig. 7.6B,C). Their infiltration in the epidermis includes its outermost layers and may effectively enhance the
spread of infection while the host still lives
(Fig. 7.6B).
Kabatana seriolae (Egusa, 1982) Lom,
Dykov and Tonguthai, 1999 (syn. Microsporidium seriolae Egusa, 1982) infects Seriola
quinqueradiata in Japanese maricultures. The
spores are ovoid or pyriform (2.2 m 3.3 m
in size) and are produced by multiple fission
of multinucleate sporogonial plasmodia. As
in the preceding species, SPVs and diplokarya are absent. Pathological changes are
Phylum Microspora
219
Fig. 7.6. Kabatana arthuri infection in Pangasius sutchi. A. Regressive changes of two myomeres (M1, M2)
adjacent to a giant aggregate of spores (S). Arrows mark thin connective-tissue envelope ( 350).
B. Macrophages replete with spores among still preserved muscle fibres. Macrophages in epidermis (E) and
alarm cells (ac) ( 870). C. Spore containing macrophages in corium ( 340). D. Longitudinal section of the
ventral muscle showing a large mass of spores ( 185).
220
I. Dykov
Fig. 7.7. A. Xenoma of Loma branchialis filled with spores in a gill filament of Melanogramus aeglefinus
( 150). B. Early (left) and more advanced (right) sporophorocyst with meronts of Heterosporis schuberti
from muscles of Ancistrus cirrhosus ( 850). C. Sporophorocyst of H. schuberti in muscles of
Pseudocrenilabrus multicolor ( 480). D. Muscle fibres replaced with masses of spores in H. schuberti
infection in P. multicolor ( 150). E, F. Ovipleistophora mirandellae infection in oocytes of Abramis bjoerkna
( 140). F. Sporophorous vesicles in an oocyte ( 640). G. Sporophorous vesicles of
O. mirandellae in the testis of Rutilus rutilus ( 220). H. Nucleospora secunda, spores developing in the
nucleus of enterocyte of Nothobranchius rubripinis. Scale bar: 1 m.
Phylum Microspora
221
222
I. Dykov
Phylum Microspora
223
Diagnosis of Infection
Clinical signs and gross lesions are observed
in fish heavily infected with microsporidia.
Multiple focal lesions due to xenoma-forming
species can be observed on the body surface
as well as in the body cavity, digestive tract
and parenchymatous organs, depending on
the number and site of the development
of xenomas. They resemble plasmodial cystlike formations due to myxosporean
infections. The lesions caused by nonxenoma-forming species are of a less defined
shape, manifesting themselves as whitish foci
in the affected tissue. The white colour
also characterizes oocytes infected with
Ovipleistophora sp. To make a general
etiological diagnosis, i.e. to recognize
microsporidian infection, mature spores
typical of this group of organisms have to be
detected in the content of lesions.
In the light microscope, spores of microsporidia can easily be recognized in fresh
tissues. The best visibility can be obtained
using Nomarski differential interference
contrast. The large posterior vacuole typical
for fish-infecting species and the uniform size
and shape of the spores differentiate them
from yeasts and other objects (in most species,
mature spores are of a uniform shape and
size, natural variation is low and spore
dimorphism is rather exceptional). When
spores sampled from lesions are available,
the polar tube can be expelled by, for example, 2% hydrogen peroxide. As an important diagnostic feature, the polar cap at the
spore apex can be stained as a red dot using
the periodic acid Schiff reaction. In tissue
sections, spores stain dark blue with Giemsa
but they can also be recognized in sections
stained routinely with haematoxylin and
eosin.
Careful ultrastructural studies following
the lines drawn, for example, by Larsson
(1986), Canning and Lom (1986) or Lom and
Dykov (1992) constitute a basic prerequisite
for generic and species determination of
the agents of lesions. A practical key for the
determination of microsporidian genera parasitic in fishes, together with a catalogue of
described genera and species, has been given
recently by Lom (2002). In total, 108 named
224
I. Dykov
Phylum Microspora
225
References
Andreadis, T.G. and Vossbrinck, C.R. (2002) Life cycle, ultrastructure and molecular phylogeny of Hyalinocysta
chapmani (Microsporidia: Thelohaniidae), a parasite of Culiseta melanura (Diptera: Culicidae) and
Orthocyclops modestus (Copepoda: Cyclopidae). Journal of Eukaryotic Microbiology 49, 350364.
Annenkova-Khlopina, N.P. (1920) Contribution to the study of parasitic diseases of Osmerus eperlanus.
Izvestiya Otdela Rybovodstva Nauchno-promyslovykh Issledovanii 1, 2 (in Russian).
Awakura, T. (1974) Studies on the microsporidian infections in salmonid fishes. Scientific Reports of the
Hokkaido Fish Hatchery 29, 196.
Awakura, T. and Kurahashi S. (1967) Studies on the Plistophora disease of salmonid fish. II. On prevention
and control of the disease. Scientific Reports of the Hokkaido Fish Hatchery 22, 5168.
Azevedo, C. and Matos, E. (2002) Fine structure of a new species Loma myrophis (Phylum Microsporidia),
parasite of the Amazonian fish Myrophis platyrhynchus (Teleostei, Ophichthidae). European Journal of
Protistology 37, 445452.
Azevedo, C. and Matos, E. (2003) Amazonspora hassar n. gen. and n. sp. (Phylum Microsporidia, fam.
Glugeidae), a parasite of the Amazonian teleost Hassar orestis (fam. Doradidae). Journal of Parasitology
89, 336341.
Barlough, J.E., McDowell, T.S., Bigornia, L., Slemenda, S.B., Peniazek, N.J. and Hedrick, R.P. (1995) Nested
polymerase chain reaction for detection of Enterocytozoon salmonis genomic DNA in chinook salmon
Oncorhynchus tschawytscha. Diseases of Aquatic Organisms 29, 1723.
Bell, A.S., Yokoyama, H., Aoki, T., Takahashi, M. and Maruyama, K. (1999) Single and nested polymerase chain reaction assays for the detection of Microsporidium seriolae (Microspora), the causative
agent of Beko disease in yellowtail Seriola quinqueradiata. Diseases of Aquatic Organisms 37,
127134.
226
I. Dykov
Bell, A.S., Aoki, T. and Yokoyama, H. (2001) Phylogenetic relationships among microsporidia based on
rDNA sequence data, with particular reference to fish-infecting Microsporidium Balbiani, 1884 species.
Journal of Eukaryotic Microbiology 48, 258265.
Berrebi, P. (1978) Contribution ltude biologique des zones saumatres du littoral mditerranen franais.
Biologie dune microsporidie: Glugea atherinae n. sp. parasite de latrine: Atherina boyeri Risso, 1810
(Poisson Teleosten) des tangs ctiers. Thesis, Universit des Sciences et Techniques du Languedoc,
Montpellier, France, 196 pp.
Bogdanova, E.A. (1957) The microsporidian Glugea hertwigi Weissenberg in the stint (Osmerus eperlanus m.
spirinchus) from the lake Ylyua-yarvi (in Russian). In: Petrushevski, G.K. (ed.) Parasites and Diseases of
Fish. Izvestiya Vsesoyuznogo Nauchno-Issledovatelskogo Instituta Ozernogo i Rechnogo Rybnogo
Khozyaistva, Leningrad, Russia, p. 328.
Brown, A.M.V. and Kent, M.L. (2002) Molecular diagnostics for Loma salmonae and Nucleospora salmonis
(Microsporidia). In: Cunningham, C.O. (ed.) Molecular Diagnosis of Salmonid Diseases. Methods
and Technologies in Fish Biology and Fisheries, vol. 3, Kluwer Academic Publishers, Dordrecht,
pp. 267283.
Cali, A. and Takvorian, P.M. (2003) Ultrastructure and development of Pleistophora ronneafiei n. sp., a
microsporidium (Protista) in the skeletal muscle of an immune-compromised individual. Journal of
Eukaryotic Microbiology 50, 7785.
Canning, E.U. and Lom, J. (1986) The Microsporidia of Vertebrates. Academic Press, New York and London,
289 pp.
Cavalier-Smith, T. (1998) A revised six-kingdom system of life. Biological Reviews 73, 203266.
Cheney, S.S., Lafranchi-Tristem, N.J. and Canning, E.U. (2001) Serological differentiation of microsporidia
with special reference to Trachipleistophora hominis. Parasite 8, 9197.
Corbel, M.J. (1975) The immune response in fish: a review. Journal of Fish Biology 7, 539563.
Delisle, C.E. (1972) Variations mensuelles de Glugea hertwigi (Sporozoa: Microsporidia) chez diffrents
tissues et organes de lperlan adulte dulcicole et consquences de cette infection sur une mortalit
massive annuelle de ce poisson. Canadian Journal of Zoology 50, 15891600.
Docker, M.F., Devlin, R.H., Richard J., Khattra, J. and Kent, M.L. (1997) Sensitive and specific polymerase
chain reaction assay for detection of Loma salmonae (Microsporea). Diseases of Aquatic Organisms 29,
4148.
Dykov, I. and Lom, J. (1978) Tissue reaction of the three-spined stickleback Gasterosteus aculeatus L. to
infection with Glugea anomala (Moniez, 1887). Journal of Fish Diseases 1, 8390.
Dykov, I. and Lom, J. (1980) Tissue reactions to microsporidian infections in fish. Journal of Fish Diseases 3,
265283.
Dykov, I. and Lom, J. (2000) Histopathology of Kabatana arthuri (Microspora) infection in sutchi catfish,
Pangasius sutchi. Folia Parasitologica 47, 161166.
Egidius, E. and Soleim, O. (1986) Pleistophora ehrenbaumi, a microsporidian parasite in wolffish, Anarhichas
lupus. Bulletin of the European Association of Fish Pathologists 6, 1314.
Elston, R.A., Kent, M.L. and Harrell, L.H. (1987) An intranuclear microsporidium associated with
acute anemia in the chinook salmon, Oncorhynchus tshawytscha. Journal of Protozoology 34,
274277.
Faye, A. (1992) Microsporidies des poissons des ctes Sngalaises: faunistique, biologie, ultrastructure.
Thesis, Universit Montpellier II, Sciences et Techniques du Languedoc, France, 241 pp.
Ferguson, H.W. (1976) Studies on the reticulo-endothelial system of fishes. PhD thesis, University of
Stirling, UK.
Figueras, A., Novoa, B., Santarem, M., Martinez, E., Alvarez, J.M., Toranzo, A.E. and Dykov, I. (1992)
Tetramicra brevifilum, a potential threat to farmed turbot Scophthalmus maximus. Diseases of Aquatic
Organisms 14, 127135.
Finn, J.P. and Nielson, N.O. (1971) The effect of temperature variation on the inflammatory response of
rainbow trout. Journal of Pathology 105, 257268.
Freeman, M.A., Yokoyama, H. and Ogawa, K. (2004) A microsporidian parasite of the genus Spraguea in the
nervous tissue of the Japanese anglerfish Lophius litulon. Folia Prasitologica 51, 167176.
Germot, A., Philippe, H. and Le Guyader, H. (1997) Evidence for loss of mitochondria in Microsporidia
from a mitochondrial-type HSP70 in Nosema locustae. Molecular and Biochemical Parasitology 87,
159168.
Gross, U. (2003) Treatment of microsporidiosis including albendazole. Parasitology Research 90 (suppl.),
S14-S18.
Phylum Microspora
227
Haley, A.J. (1952) Preliminary observations on a severe epidemic of microsporidiosis in the smelt Osmerus
mordax (Mitchill). Journal of Parasitology 38, 183185.
Haley, A.J. (1953) Observations on a protozoan infection in the freshwater smelt. In: Proceedings of the 32nd
Annual Session of the New Hampshire Academy of Science, Durham, New Hampshire, p. 7.
Haley, A.J. (1954) Microsporidian parasite, Glugea hertwigi, in American smelt from the Great Bay region,
New Hampshire. Transactions of the American Fisheries Society 83, 8490.
Hedrick, R.P., Groff, J.M. and Baxa, D.V. (1991) Experimental infections with Nucleospora salmonis n. g.,
n. sp.: an intranuclear microsporidium from chinook salmon (Oncorhynchus tshawytscha). Diseases of
Aquatic Organisms 10, 103108.
Hirt, R.P., Healy, B., Vossbrinck, C.R., Canning, E.U. and Embley, T.M. (1997) Identification of a mitochondrial HSP70 homologue in Vairomorpha necatrix: molecular evidence that microsporidia once contained mitochondria. Currents in Biology 7, 14.
Hirt, R.P., Logsdon, J.M. and Healy, B. (1999) Microsporidia are related to Fungi: evidence from the largest
subunit of RNA polymerase II and other proteins. Proceedings of the National Academy of Science of the
United States of America 96, 580585.
Hoshina, T. (1951) On a new microsporidian, Plistophora anguillarum n. sp. from the muscle of eel, Anguilla
japonica. Journal of the Tokyo University of Fisheries 38, 3546.
Kabata, Z. (1959) On two little-known microsporidia of marine fishes. Parasitology 49, 309315.
Keeling, P.J. and McFadden, G.I. (1998) Origins of microsporidia. Trends in Microbiology 6, 1923.
Keeling, P.J., Luker, M.A. and Palmer, J.D. (2000) Evidence from beta-tubulin phylogeny that microsporidia
evolved from within the fungi. Molecular Biology and Evolution 17, 2331.
Kent, M.L. and Bishop-Stewart, J.K. (2003) Transmission and tissue distribution of Pseudoloma neurophilia
(Microsporidia) of zebrafish, Danio rerio (Hamilton). Journal of Fish Diseases 26, 423426.
Larsson, J.I.R. (1986) Ultrastructure, function and classification of microsporidia. In: Corliss, J.O. and
Patterson, D.J. (eds) Progress in Protistology, vol. 1. Biopress, Bristol, UK, pp. 325390.
Lom, J. (2002) A catalogue of described genera and species of microsporidians parasitic in fish. Systematic
Parasitology 53, 8199.
Lom, J. and Dykov, I. (1992) Protozoan parasites of fish. In: Developments in Aquaculture and Fisheries
Science, vol. 26. Elsevier Science Publishers, Amsterdam, pp. 125157.
Lom, J. and Nilsen, F. (2003) Fish microsporidia: fine structural diversity and phylogeny. International Journal
for Parasitology 33, 107127.
Lom, J., Dykov, I., Krting, W. and Klinger, H. (1989) Heterosporis schuberti n. sp., a new microsporidian
parasite of aquarium fish. European Journal of Protistology 25, 129135.
Lom, J., Dykov I., Tonguthai, K. and Chinabut, S. (1993) Muscle infection due to Heterosporis sp. in the
Siamese fighting fish, Betta splendens Regan. Journal of Fish Diseases 16, 513516.
Lores, B., Rosales, M.J., Mascaro, C. and Osuna, A. (2003) In vitro culture of Glugea sp. Veterinary Parasitology
112, 185196.
Loubs, C., Maurand, J. and Ormires, R. (1979) tude ultrastructurale de Spraguea lophii (Doflein, 1898), microsporidie parasite de la baudroie: essai dinterpretation du dimorphisme sporal. Protistologica 15, 4354.
McVicar, A.H. (1975) Infection of plaice Pleuronectes platessa L. with Glugea (Nosema) stephani
(Hagenmller, 1899) (Protozoa: Microsporidia) in a fish farm and under experimental conditions. Journal
of Fish Biology 7, 611619.
Mathieu-Daude, F., Faye, A., Coste, F., Marques, A. and Bouix, G. (1992) Occurrence of microsporidiosis in
marine culture gilt-head bream from the Languedoc coast: a problem of specificity in the genus Glugea
(Protozoa, Microspora). Bulletin of the European Association of Fish Pathologists 12, 6770.
Matthews, J.L., Brown, A.M.V., Larison, K., Bishop-Stewart, J.K. and Kent, M.L. (2001) Pseudoloma
neurophilia, n. g., n. sp., a new microsporidium from the central nervous system of the zebrafish. Journal
of Eukaryotic Microbiology 48, 227233.
Matthews, R.A. and Matthews, B.F. (1980) Cell and tissue reaction of turbot Scophthalmus maximus (L.) to
Tetramicra brevifilum gen., sp. n. (Microspora). Journal of Fish Diseases 3, 495515.
Maurand, J., Loubs, C., Gasc, C., Pelletier, J. and Barral, J. (1988) Pleistophora mirandellae Vaney & Conte,
1901, a microsporidian parasite of cyprinid fish of rivers in Hrault: taxonomy and histopathology.
Journal of Fish Diseases 11, 251258.
Meyer, A. (1952) Vernderung des Fleisches beim Katfish. Fischereiwelt, 5758.
Michel, C., Maurand, J., Loubs, C., Chilmonczyk, S. and Kinkelin, P. (1989) Heterosporis finki, a microsporidian
parasite of the angel fish Pterophyllum scalare: pathology and ultrastructure. Diseases of Aquatic Organisms
7, 103109.
228
I. Dykov
Nagel, M.L. and Summerfelt, R.C. (1977) Nitrofurazone for control of the microsporidian parasite
Pleistophora ovariae in golden shiners. Progressive Fish Culturist 39, 1823.
Nepszy, S.J. and Dechtiar, A.O. (1972) Occurrence of Glugea hertwigi in Lake Erie rainbow smelt (Osmerus
mordax) and associated mortality of adult smelt. Journal of the Fisheries Research Board of Canada 29,
16391641.
Nilsen, F. (2000) Small subunit ribosomal DNA phylogeny of microsporidia with particular reference to
genera that infect fish. Journal of Parasitology 86, 128133.
Olson, R.E. (1976) Laboratory and field studies on Glugea stephani (Hagenmller), a microporidian parasite of
pleuronectid flatfishes. Journal of Protozoology 23, 158164.
Petrushevski, G.K. and Shulman, S.S. (1958) Parasitic diseases in fish in water reservoirs of the USSR (in
Russian). In: Petrushevski, G.K. and Polyanski, Y.I. (eds) Parasitology of Fishes. Leningrad University
Press, Leningrad, Russia, pp. 301320.
Priebe, K. (1971) Zur Verbreitung de Befalls des Seeteufels (Lophius piscatorius) mit Nosema lophii auf
Fischfangpltzen im stlichen Nordatlantik. Archiv fr Fischerewissenschaft 22, 98102.
Putz, R.E. (1964) Parasites of Freshwater Fish II. Protozoa. 1. Microsporidia of Fish. Fishery Leaflet 571,
US Department of the Interior, Washington, DC, 4 pp.
Putz, R.E., Hoffman, G.L. and Dunbar, C.E. (1965) Two new species of Pleistophora from North American fish
with a synopsis of Microsporidia of freshwater and euryhaline species. Journal of Protozoology 12,
228236.
Ralph, J.R. and Matthews, R.A. (1986) Hepatic microsporidiosis due to Microgemma hepaticus n. gen., n. sp.
in juvenile grey mullet Chelon labrosus. Journal of Fish Diseases 9, 225242.
Roberts, R.J. (1975) The effect of temperature on diseases and their histopathological manifestations in
fish. In: Ribelin, W.E. and Migaki, G. (eds) The Pathology of Fishes. University of Wisconsin Press,
Madison, Wisconsin, pp. 477496.
Rodrguez-Tovar, L.E., Wright, G.M., Wadowska, D.W., Speare, D.J. and Markham, J.F. (2002) Ultrastructural
study of the early development and localization of Loma salmonae in the gills of experimentally infected
rainbow trout. Journal of Parasitology 88, 244253.
Rodrguez-Tovar, L.E., Wright, G.M., Wadowska, D.W., Speare, D.J. and Markham, J.F. (2003) Ultrastructural
study of the late stages of Loma salmonae development in the gills of experimentally infected rainbow
trout. Journal of Parasitology 89, 464474.
Sanchez, J.G., Speare, D.J., Markham, R.J.F. and Jones, S.R.M. (2001a) Experimental vaccination of rainbow
trout against Loma salmonae using a live low-virulence variant of L. salmonae. Journal of Fish Biology 59,
442448.
Sanchez, J.G., Speare, D.J., Markham, R.J.F., Wright, G.M. and Kibenge, F.S.B. (2001b) Localization of the
initial developmental stages of Loma salmonae in rainbow trout (Oncorhynchus mykiss). Veterinary
Pathology 38, 540546.
Schmahl, G. and Mehlhorn, H. (1989) Treatment of fish parasites. 6. Effects of sym-triazinone (toltrazuril)
on developmental stages of Glugea anomala Moniez, 1887 (Microsporidia): a light and electron microscopic study. European Journal of Protistology 24, 252259.
Schmahl, G., El Toukhy, A. and Ghaffar, F.A. (1990) Transmission electron microscopic studies on the effects
of toltrazuril on Glugea anomala Moniez, 1887 (Microsporidia) infecting the three-spined stickleback
Gasterosteus aculeatus. Parasitology Research 76, 700706.
Schwartz, F.J. (1963) A new ichthyosporidium parasite of the spot Leiostomus xanthurus: a possible answer
to recent oyster mortalities. Progressive Fish Culturist 25, 181184.
Shaw, R.W. and Kent, M.L. (1999) Fish Microsporidia. In: Wittner, M. and Weiss, L.M. (eds) The Microsporidia
and Microsporidiosis. American Society for Microbiology, Washington, DC, pp. 418446.
Shaw, R.W., Kent, M.L. and Adamson, M.L. (1998) Modes of transmission of Loma salmonae (Microsporidia).
Diseases of Aquatic Organisms 33, 151156.
Sheehy, D.J., Sissenwine, M.P. and Saila, S.B. (1974) Ocean pout parasites. Marine Fisheries Review 36,
2933.
Sinderman, C.J. (1963) Disease in marine populations. Transactions of the North American Wildlife and
Natural Resources Conference 28, 336356.
Sprague, V. and Hussey, K.L. (1980) Observations of Ichthyosporidium giganteum (Microsporidia) with particular reference to the hostparasite relations during merogony. Journal of Protozoology 27, 169175.
Sprague, V. and Vernick, S.H. (1968) Light and electron microscope study of a new species of Glugea
(Microsporidia, Nosematidae) in the 4-spined stickleback Apeltes quadracus. Journal of Protozoology
15, 547571.
Phylum Microspora
229
Sprague, V., Becknel, J.J. and Hazard, E.I. (1992) Taxonomy of the phylum Microspora. Critical Reviews in
Microbiology 18, 285395.
Summerfelt, R.C. (1964) A new microsporidian parasite from the golden shiner, Notemigonus crysoleucas.
Transactions of the American Fisheries Society 93, 610.
Takahashi, S., Egusa, S. (1976) Studies of Glugea infection of the ayu, Plecoglossus altivelis. II. On the prevention and treatment. 1. Fumagilin efficacy as a treatment. Japanese Journal of Fisheries 11, 8388.
Takahashi, S. and Egusa, S. (1977a) Studies on Glugea infection of the ayu, Plecoglossus altivelis I. Description
of the Glugea and proposal of a new species, Glugea plecoglossi. Japanese Journal of Fisheries 11,
175182.
Takahashi, S. and Egusa, S. (1977b) Studies on Glugea infection of the ayu, Plecoglossus altivelis III. Effect of
water temperature on the development of xenoma of Glugea plecoglossi. Japanese Journal of Fisheries
11, 195200.
Takvorian, P.M. and Cali, A. (1986) The ultrastructure of spores (Protozoa: Microsporida) from Lophius
americanus, the angler fish. Journal of Protozoology 33, 570575.
Tanabe, Z., Watanabe, M.M. and Sugiyama, J. (2002) Are Microsporidia really related to Fungi? A reappraisal
based on additional gene sequences from basal fungi. Mycological Research 106, 13801391.
Tsui, W.H. and Wang, C.H. (1988) On the Pleistophora infection in eel. I. Histopathology, ultrastructure and
development of Pleistophora anguillarum in eel, Anguilla japonica. Bulletin of the Institute of Zoology,
Academia Sinica Taiwan 27, 159166.
Urawa, S. (1989) Seasonal occurrence of Microsporidium takedai (Microsporida) infection in masou salmon,
Oncorhynchus masou, from the Chitose river. Physiology and Ecology Japan Spec. Vol. 1, 587598.
Van de Peer, Y., Ben Ali, A. and Meyer, A. (2000) Microsporidia: accumulating molecular evidence that a
group of amitochondriate and suspectedly primitive eukryotes are just curious fungi. Gene 246, 18.
Wales, J. and Wolf, H. (1955) The protozoan diseases of trout in California. California Fish and Game 41,
183187.
Weissenberg, R. (1913) Beitrge zur Kenntnis der Zeugungskreises der Mikrosporidien Glugea anomala
Moniez and G. hertwigi Weissenberg. Archiv fr Mikroskopische Anatomie 82, 81163.
Weissenberg, R. (1921) Zur Wirtsgewebsableitung des Plasmakorpers des Glugea anomala Cysten. Archiv fr
Protistenkunde 42, 400421.
Weissenberg, R. (1949) Cell growth and cell transformation induced by intracellular parasites. Anatomical
Record 103, 517518.
Weissenberg, R. (1968) Intracellular development of the microsporidian Glugea anomala Moniez in hypertrophying migratory cells of the fish Gasterosteus aculeatus L., an example of the formation of xenoma
tumors. Journal of Protozoology 15, 4457.
Woese, C.R. (1987) Bacterial evolution. Microbiology Review 51, 221271.
Wongtavatchai, J., Conrad, P.A. and Hedrick, R.P. (1995) In vitro characteristics of the microsporidian:
Enterocytozoon salmonis. Journal of Eukaryotic Microbiology 42, 401405.
Phylum Myxozoa
Introduction
Myxozoans are highly specialized metazoan
parasites of aquatic hosts with a very wide
host range. This diverse group of organisms
is characterized by multicellular spores
with polar capsules containing extrudable
polar filaments. Interest in the group has
intensified along with the development of
aquaculture since many species cause serious disease outbreaks in farmed fish species,
in both freshwater and marine environments. Myxobolus cerebralis (Hofer, 1903),
Tetracapsuloides bryosalmonae (Canning,
Curry, Feist, Longshaw and Okamura, 1999)
and Ceratomyxa shasta Noble, 1950, in
salmonids are examples. The economic
impact of such parasites can be severe,
especially where prevalence rates are high.
They can also have a severe impact on wild
fish stocks. Infections with multivalvulid
myxozoans such as Kudoa spp. within the
musculature of several marine fish species
severely reduce the flesh quality and in some
cases cause extensive myoliquefaction, rendering the product unmarketable. In freshwater environments, M. cerebralis has been
shown to be a significant factor in population declines of wild stocks of Pacific
salmonids.
230
Recognition of the requirement for oligochaete and bryozoan obligatory hosts in the
life cycle of several freshwater species has
resulted in an increased interest in the biology of the group. Many new species have
been described and significant advances have
been made in the understanding of the transmission biology of several species. The development of specific diagnostic methods has
facilitated studies on the pathogenesis and
the use of molecular phylogenetic techniques has provided fundamental advances
in the taxonomy of the Myxozoa. In particular, insights into the evolution of Myxozoa
have been provided by morphological and
molecular studies of the class Malacosporea.
Current research continues to be focused on
the occurrence of disease outbreaks, pathogenesis and phylogeny of these parasites.
However, for several important and wellcharacterized diseases, including ceratomyxosis, whirling disease and proliferative
kidney disease (PKD), the emphasis is on
host immunity, prevention and control. This
chapter provides a summary of current
knowledge of the biology of the phylum
Myxozoa, with particular attention given to
those parasites as agents of disease in fish.
Sections covering diagnosis, control and
new directions for research are also provided.
Phylum Myxozoa
231
232
Phylum Myxozoa
233
234
Family
Saccosporidae
Canning,
Okamura and Curry, 1996
Seventeen
collective
groups
of
actinospores are recognized as follows:
Antonactinomyxon, Aurantiactinomyxon,
Echinactinomyxon, Endocapsa, Guyenotia,
Hexactinomyxon, Hungactinomyxon, Neoactinomyxum, Ormieractinomyxon, Pseudotriactinomyxon, Raabeia, Siedleckiella,
Sphaeractinomyxon, Synactinomyxon, Tetractinomyxon, Tetraspora and Triactinomyxon (Fig. 8.2).
Phylum Myxozoa
235
236
Phylum Myxozoa
237
Fig. 8.3. Photomicrographs of representative myxospore genera. A. Henneguya zschokkei from coho
salmon (Oncorhynchus kisutch), B. Henneguya psorospermica from pike (Esox lucius) gills,
C. Thelohanellus pyriformis from gill of tench (Tinca tinca), D. Chloromyxum sp. from P. phoxinus gall
bladder, E. Leptotheca sp. from gall bladder of tadpole fish (Raniceps raninus), F. Sphaerospora elegans from
stickleback (Gasterosteus aculeatus) kidney, G. Parvicapsula assymetrica from Cyclopterus lumpus urinary
bladder, H. Kudoa thyrsites from scabbardfish (Lepidopus caudatus) muscle, I. Myxoproteus ambiguus from
the urinary bladder of anglerfish (Lophius piscatorius), J. Myxobilatus gasterostei from the kidney of
stickleback Gasterosteus aculeatus, K. Myxidium sp. from the gall bladder of rudd (Scardinius
erythrophthalmus), L. Ceratomyxa sp. from common goby (Pomatoschistus microps), M. Myxidium gadi
from the gall bladder of whiting (Merlangius merlangus), N. Myxobolus sp. from dace (Leuciscus leuciscus)
buccal cavity cyst, O. Sphaeromyxa sp. from two-spot goby (Gobiosculus flavescens) gall bladder.
238
Fig. 8.4. Myxosporean extrasporogonic and plasmodial stages. Fresh preparations unless otherwise stated.
A. Myxobolus artus plasmodium encysted in the renal tissue of koi carp (Cyprinus carpio). B. Gill cysts of
Myxobolus macrocapsularis in juvenile chub, Leuciscus cephalus. C. Sporogonic plasmodium of
Zschokkella sp. from the gall bladder of three-bearded rockling (Gaidropsaurus vulgaris). D. MayGrnwald
Giemsa-stained smear of a Myxidium incurvatum plasmodium from the gall bladder of flounder (Platichthys
flesus). E. Sphaeromyxa sp. plasmodia contained within the gall bladder of two-spot goby (Gobiusculus
flavescens). F. Sphaerospora truttae pseudoplasmodia within renal tubule of brown trout (Salmo trutta).
G. Plasmodium of Myxobilatus gasterostei containing two mature spores from the kidney of the three-spined
stickleback (Gasterosteus aculeatus). H. Extrasporogonic stage from the rete mirabile in the eye of G.
aculeatus. I. Giemsa-stained section of the rete mirabile with the parasites located within the capillaries.
J. Phase-contrast image of a plasmodium of Myxidium lieberkuehni from the urinary bladder of pike
(Esox lucius), showing the characteristic villous projections on the surface of the plasmodium.
K. Interference-contrast image of M. lieberkuehni plasmodia showing the clear ectoplasmic layer. L. Cyst of
Myxidium rhodei from the kidney of roach (Rutilus rutilus). M. Presporogonic stages of Sphaerospora elegans
in Bowmans space of the glomerulus in the kidney of G. aculeatus. N. Numerous plasmodia attached to the
epithelium of the urinary bladder of a juvenile dace (Leuciscus leuciscus).
Phylum Myxozoa
239
Fig. 8.5. AC. Deformed myxospores; DI. Actinospores released from oligochaetes. A. Giemsa-stained
smear of Myxidium giardi spores from eel Anguilla anguilla, one of which contains three polar capsules.
B. Deformed Thelohanellus pyriformis spore from gill of tench (Tinca tinca). C. Triradiate spores of
Ceratomyxa sp. from the gall bladder of common goby (Pomatoschistus microps).
D. Aurantiactinomyxon-type actinospore. E. Echinactinomyxon-type actinospore. F. Neoactinomyxum-type
actinospore. G. Triactinomyxon-type actinospore. Note presence of large style and sporoplasm and polar
capsules at apex of spore. H. Collection of Synactinomyxon-type actinospores. I. Secondary cells released
from the sporoplasm of a Triactinomyxon-type actinospore.
been observed, whilst in salmonids a limited form of sporogony can occur (Kent
et al., 2000).
Life cycle
Until the pioneering studies by Wolf
and Markiw (1984), it was thought that
myxospores were transmitted directly from
fish to fish and that the spores needed to be
aged in mud to be infective. However,
Wolf and Markiw (1984) demonstrated that
240
Fig. 8.6. Sporogonic stages of Tetracapsuloides bryosalmonae. A. Fresh spore of T. bryosalmonae showing
the four polar capsules and two sporoplasm cells surrounded by valvogenic cells. B. Diagrams of
T. bryosalmonae spores in three-dimensional view and apical view. Note presence of four capsular cells
and eight valvular cells. C. Section through a complete spore showing the sporoplasm cells with each
containing a secondary cell. A single polar capsule can also be seen. Inset: Characteristic sporoplasmosome
within the cytoplasm of the sporoplasm cell, showing the typical bar-like invagination, also seen in the
histozoic fish stage of the parasite. D. Sacs of T. bryosalmonae released from the bryozoan host. E. Section
through the polar capsule showing the exit pore for the filament and characteristic reticulated cap. Note the
gap between the valvogenic cells at the exit pore of the polar filament. F. As E, showing the nucleus of the
capsulogenic cell and sections through the coiled polar filament.
Phylum Myxozoa
Table 8.1.
241
Myxozoan species
Fish host
Actinospore type
Invertebrate host
Reference
Ceratomyxa shasta
Tetractinomyxon
Manayunkia
speciosa
Nereis spp.
Bartholomew
et al. (1997)
Kie et al. (2004)
Enteromyxum fugu
Oncorhynchus
mykiss
Pomatoschistus
microps
Takifugu rubripes
None
Enteromyxum leei
Sparus aurata
Yasuda et al.
(2002)
Diamant (1997)
Enteromyxum
scophthalmi
Henneguya exilis1
Henneguya ictaluri
Henneguya
nuesslini
Hoferellus carassii
Scophthalmus
maximus
Ictalurus punctatus
Ictalurus punctatus
Salmo trutta,
Salvelinus fontinalis
Carassius auratus
None direct
transmission
None direct
transmission
None direct
transmission
Aurantiactinomyxon
Aurantiactinomyxon
Triactinomyxon
Aurantiactinomyxon
Hoferellus carassii
Carassius auratus
Neoactinomyxum
Hoferellus cyprini
Cyprinus carpio
Aurantiactinomyxon
Branchiura
sowerbyi
Nais sp.
Kudoa ovivora2
Thalassoma
bifasciatum
None direct
transmission?
Myxidium giardi
Anguilla anguilla
Aurantiactinomyxon
T. tubifex
Myxobolus arcticus
Triactinomyxon
Myxobolus bramae
Oncorhynchus
nerka
Oncorhynchus
masu
Abramis brama
Triactinomyxon
Stylodrilus
heringianus
Lumbriculus
variegatus
T. tubifex
Myxobolus carassii
Leuciscus idus
Triactinomyxon
T. tubifex
Myxobolus
cerebralis
Oncorhynchus
mykiss
Triactinomyxon
T. tubifex
Myxobolus cotti
Cottus gobio
Triactinomyxon
tubifex
Myxobolus cultus
Carassius auratus
Raabeia
B. sowerbyi
Myxobolus dispar
Cyprinus carpio
Raabeia
T. tubifex
Myxobolus drjagini
Hypophthalmichthys
molitrix
Triactinomyxon
Myxobolus
hungaricus
Abramis abramis
Triactinomyxon
T. tubifex
Limnodrilus
hoffmeisteri
T. tubifex,
L. hoffmeisteri
Ellipsomyxa gobii
Myxobolus arcticus
Tetractinomyxon
Triactinomyxon
None
None
Dero digitata
D. digitata
Tubifex tubifex
Redondo et al.
(2002)
Lin et al. (1999)
Pote et al. (2000)
Kallert et al.
(2005a)
Troullier et al.
(1996)
Yokoyama et al.
(1993b)
Grossheider and
Krting (1992)
Swearer and
Robertson
(1999)
Benajiba and
Marques (1993)
Kent et al. (1993)
Urawa (1994)
Eszterbauer et al.
(2000)
El-Matbouli and
Hoffmann (1993)
Wolf and Markiw
(1984);
El-Matbouli et al.
(1999b)
El-Matbouli and
Hoffmann(1989)
Yokoyama et al.
(1995b)
Molnr et al.
(1999b)
El-Mansy and
Molnr (1997a)
El-Mansy and
Molnr (1997b)
Continued
242
Table 8.1.
Myxozoan species
Fish host
Actinospore type
Invertebrate host
Reference
Myxobolus intimus
Myxobolus
macrocapsularis
Myxobolus
parviformis
Myxobolus
pavlovskii
Myxobolus
portucalensis
Myxobolus
pseudodispar
Sphaerospora
renicola
Sphaerospora
truttae
Tetracapsuloides
bryosalmonae
Rutilus rutilus
Abramis brama
Triactinomyxon
Triactinomyxon
T. tubifex
T. tubifex
Abramis brama
Triactinomyxon
L. hoffmeisteri
Hypophthalmichthys
molitrix
Anguilla anguilla
Hexactinomyxon
T. tubifex
Triactinomyxon
T. tubifex
Rutilus rutilus
Triactinomyxon
Cyprinus carpio
Neoactinomyxum
Salmo trutta
Echinactinomyxon
Oncorhynchus
mykiss
None
Thelohanellus
hovorkai
Cyprinus carpio
Aurantiactinomyxon
Thelohanellus
nikolskii
Zschokkella nova
Cyprinus carpio
Aurantiactinomyxon
Carassius
carassius
Carassius auratus
Siedleckiella
T. tubifex,
L. hoffmeisteri
B. sowerbyi,
T. tubifex
L. variegatus,
T. tubifex
Fredericella
sultana, Plumatella
repens
B. sowerbyi
Yokoyama
(1997); Szkely
et al. (1998)
T. tubifex
Szkely et al.
(1998)
T. tubifex
Uspenskaya
(1995)
B. sowerbyi
Yokoyama et al.
(1991)
Zschokkella sp.
Echinactinomyxon
1Lin et al. (1999) used sequence information to link the actinospore stage with the myxospore
stage no experimental transmission trials have confirmed this finding.
2This report needs confirming as Swearer and Robertson (1999) used fish collected from the field for
both control and challenge fish.
Phylum Myxozoa
pressures, which may account for the morphological differences (Xiao and Desser,
2000b). Understanding of the morphological
adaptations and the ecology of the actinospore stages will assist in elucidating the
reasons for the different phenotypes observed.
Although actinospores have been
recorded from a number of different oligochaete genera of Tubificidae and Nadidae,
only representatives of Stylodrilus, Tubifex,
Limnodrilus, Lumbriculus, Branchiura, Dero
and Nais have been demonstrated to be hosts.
In addition, the polychaete Manayunkia
speciosa has been shown to act as the invertebrate host for C. shasta (Bartholomew
et al., 1997), the marine polychaetes Nereis
spp. as hosts for Ellipsomyxa gobii (Kie
et al., 2004) and freshwater bryozoans as
hosts for B. plumatellae and Tetracapsuloides species, including the agent for
salmonid PKD (Anderson et al., 1999a,b;
Longshaw et al., 1999; Canning et al., 2000,
2002; Feist et al., 2001). However, life
cycles for most myxozoans have not been
elucidated and, although it is likely that a
two-host life cycle will apply to most species,
it is recognized that some can be transmitted directly between fish. Diamant (1997),
using cohabitation experiments, demonstrated that Enteromyxum (= Myxidium)
leei (Diamant, Lom and Dykov, 1994)
could be transmitted to uninfected fish and
Redondo et al. (2002) showed direct transmission with Enteromyxum scophthalmi
Palenzuela, Redondo and lvarez-Pellitero,
2002. Yasuda et al. (2002) demonstrated
that Enteromyxum (= Myxidium) fugu (Tin
Tun, Yokoyama, Ogawa and Wakabayashi,
2000) and E. leei (= Myxidium sp. TP of Tin
Tun, Yokoyama, Ogawa and Wakabayashi,
2000), parasitic in cultured tiger pufferfish,
were both capable of fish-to-fish transmission. They suggested that, although an alternate host may be available in the natural
environment, the parasites were able to
transmit from fish to fish via trophozoites
and spores passed out with the faeces.
El-Matbouli et al. (1995) and El-Matbouli
and Hoffmann (1998), described the development of M. cerebralis in the fish and
oligochaete hosts, respectively. Their findings confirmed that sexual reproduction
243
Intra-oligochaete development
Intra-oligochaete development of myxozoan
life cycles undergoes three phases schizogony, or proliferative stage, gametogamy and
sporogony (Fig. 8.7). In myxozoans with a
two-host life cycle, the oligochaete phase is
initiated by infection with myxospores from
the fish host, either over the lifetime of the
host or on death with subsequent decomposition of the host. This decomposition may
occur either naturally or, as in the case of
some Kudoa infections, more rapidly due to
the release of proteolytic enzymes (Moran
et al., 1999b).
Myxospores are ingested by oligochaetes
and, on contact with the oligochaete epithelium, polar filaments are released, which
anchor the parasite to the host. The spore
valves separate along the sutural line and
the amoeboid sporoplasms are released and
penetrate between the epithelial cells of the
gut wall. In M. cerebralis, the binucleate
sporoplasm undergoes several nuclear divisions to produce a multinucleate cell. It is
presumed that a similar pattern of development occurs in myxospores with two
uninucleate sporoplasms, each producing
a multinucleate cell, rather than fusion to
form a binucleate cell. The multinucleate
cell undergoes plasmotomy to produce
numerous uninucleate cells, which invade
other intercellular spaces. Some of these cells
may then undergo another schizogonic phase,
giving rise to more multinucleate cells and
subsequently more uninucleate cells. Fusion
by plasmogamy of uninucleate cells produces a binucleate stage.
The next phase in the development
is gametogony and is initiated by the
244
Phylum Myxozoa
245
Intra-piscine development
The actinospore stage is infective to a fish
host. On contact with a suitable host, the
polar filaments are extruded from the actinospore to anchor it to the host. The actinospore
sporoplasm penetrates the epidermis of the
host. In some cases a favoured entry point is
via mucus cells (Yokoyama and Urawa,
1997; El-Matbouli et al., 1999b). Malacospores of T. bryosalmonae released from the
bryozoan phase also enter the fish host
via the mucus cells (Morris et al., 2000b;
Longshaw et al., 2002). In the initial intercellular stage, the cell wall surrounding the
actinospore sporoplasm disintegrates and the
sporoplasm cells (infective germ cells) invade
surrounding tissues (Fig. 8.8). Endogenous
budding gives rise to an enveloping primary
cell and an internal secondary cell. At this
point, development can continue in several
ways. These range from the production of
small uninucleate pseudoplasmodia to large
complex extrasporogonic proliferative stages
prior to spore formation. The type of intrapiscine development appears to be speciesdependent and varies between genera. It is
probable that most myxozoans will undergo
at least one proliferative stage prior to spore
formation in order to maximize potential
spore production. The formation of pseudoplasmodia directly from individual actinospore sporoplasm cells appears unlikely since
only limited numbers could be produced.
Extrasporogonic cycles, which occur in
sites other than those in which sporogony
takes place, have been reported from several
genera, including Sphaerospora, Hoferellus,
Myxidium, Kudoa and Myxobolus. In the
extrasporogonic phase, the secondary cell
within the primary cell undergoes a series
of mitotic divisions to produce numerous
secondary cells. Endogenous budding of the
secondary cells gives rise to tertiary cell(s)
within each secondary cell. In M. cerebralis,
this first extrasporogonic phase takes place
intraepithelially in the dermis, and within
the blood for S. renicola. Rupture of the
246
Phylum Myxozoa
Malacospore development
The development of T. bryosalmonae does
not follow the patterns observed in the
myxosporeactinospore life cycle. The
route of entry into and the initial early
development of the parasite within the
bryozoan host have not been elucidated. In
T. bryosalmonae, the wall of the sac in
which spores develop consists of a single
layer of flattened (mural) cells. Proliferation
of these cells leads to the formation of a sac
wall and production of sporogonic cells
within the sac. These sporogonic cells take
one of two forms either sporoplasmogenic
(pale) cells or denser, stellate cells. The
sporoplasmogenic cells, containing characteristic cytoplasmic sporoplasmosomes
(Fig. 8.6), undergo a series of meiotic
247
248
Phylum Myxozoa
249
provide a route of entry for secondary infections. Pathology associated with myxozoan
infections in the gills includes fusion of lamellae, inflammation, hyperplasia, pressure
atrophy and cellular necrosis. Molnr
(2002b) proposed a system to describe the
specific site locations of myxozoans in gills.
This distinguishes between interlamellar
epithelial and intralamellar vascular types
for plasmodia in the gill lamellae, with
either chondroidal, vascular or epithelial
intrafilamental types developing in the gill
filaments.
Gill sphaerosporosis of carp, caused by
S. molnari, has been reported in C. carpio
and Carassius carassius in Europe (Dykov
and Lom, 1988a; Fig. 8.9). Additionally,
Hedrick et al. (1990) reported the presence
of S. cf. chinensis in the gills of Carassius
auratus. In both infections, moderate to
severe gill hyperplasia results and a large
proportion of the respiratory epithelium
can be replaced by sporogonic stages. In
mild S. molnari infections, local circulatory
disorders and dystrophic changes also
occur. S. molnari spores measure 10.5 m
10.3 m and those of S. chinensis measure
7.4 m 7 m. Both the parasites form
monosporic pseudoplasmodia.
Proliferative gill disease (PGD, hamburger gill disease), caused by the extrasporogonic stage of Henneguya ictaluri
Pote, Hanson and Shivaji, 2000, is a major
disease of channel catfish (Ictalurus
punctatus) and can result in high mortalities amongst juvenile farmed catfish (Pote
et al., 2000). The parasite elicits a strong
granulomatous inflammatory response in
the gills. Styer et al. (1991) demonstrated
experimentally that the life cycle alternated
between the fish host and the oligochaete
Dero digitata. Both stages in the life cycle
have been confirmed using molecular techniques (Pote et al., 2000; Hanson et al.,
2001). The spore body of the myxospore
measures 24 m 6 m and the total spore
length is 4880 m.
Another pathogenic Henneguya sp. in
the gills of I. punctatus is Henneguya exilis
Kudo, 1929. The presence of plasmodia at
the base of the secondary lamellae (epithelial filamental type of Molnr, 2002b) elicits
250
Fig. 8.9. Histological sections of gill, pseudobranch and fin infections. A. Giemsa-stained section of carp
(Cyprinus carpio) gill infected with Sphaerospora molnari (inset: mature spore in sutural view). B. Large cyst
of Myxobolus koi in gill of koi carp (C. carpio) (inset: mature spore in valvular view). C. Multiple cysts of
Henneguya psorospermica in gill of pike (Esox lucius). D. Multiple cysts of Myxobolus macrocapsularis
in gill of chub (L. cephalus) (inset: mature spore in valvular view). E. Cysts of M. macrocapsularis in
pseudobranch of dace (L. leuciscus). F. Sporogonic plasmodium of an unidentified Myxobolus sp.
in cartilage of caudal peduncle of L. cephalus. G. Longitudinal section through fin of a juvenile roach
(R. rutilus) showing Myxobolus sp. cysts within the epithelium. H. Myxobolus sp. cysts in connective tissue
of fin of barbel (Barbus barbus).
Phylum Myxozoa
The
pathology
associated
with
Henneguya creplini (Gurley, 1894) on the
gills of Stizostedion lucioperca in Lake
Balaton was described by Molnr (1998).
Plasmodia on the gills are large, reaching
900 m 750 m in size, with an average of
3060 plasmodia per fish. During cyst
development, host responses are minimal.
Following sporogenesis and rupture of
plasmodia, an intense host response, consisting of epithelial proliferation, overgrowth
of the damaged plasmodium and cell necrosis, becomes apparent. Spores are 14.3 m
5.5 m, with a total length of 43 m including caudal appendages. Infections in pike
(E. lucius) and perch (Perca fluviatilis) caused
by Henneguya psorospermica Thlohan,
1895 also give rise to multiple large plasmodia displacing the gill tissue (Fig. 8.9).
Henneguya piaractus Martins and de
Souza, 1997 in the gills of captive Piaractus
mesopotamicus can cause mortalities (Martins
and de Souza, 1997; Martins et al., 1997).
Clinical signs of infection include decreased
feeding, lethargy, erratic swimming and loss
of equilibrium. Histologically, haemorrhaging and severe inflammation occur in the
gill epithelium and larger cysts cause pressure atrophy on adjacent lamellae. Spores
measure 11.3 m 3.2 m with a total length
of 48.4 m including caudal process.
Infections with Myxobolus basilamellaris Lom and Molnr, 1983 cause a
localized pathological response to the parasite cysts within the gills of its host
(Kovcs-Gayer and Molnr, 1983). The cysts
develop in a basifilamental position on the
gill. Growth of the cyst lifts the basal part of
the gill filament and deforms adjoining
lamellae, reducing the respiratory surface.
Those cysts developing in the gill arch restrict
nerves and blood vessels passing through the
gill arch, leading to local blockages.
M. koi forms large and small-type cysts
in the gills of C. carpio (Fig. 8.9). The
smaller cysts develop in an interlamellar
position within the gills and host responses
are minimal. In contrast, large cysts produce extensive pathological changes in the
gill, including hypertrophy of the branchial
epithelium and clubbing of the gill filaments (Yokoyama et al., 1997). Spores
251
252
Muscle
There are many reports of myxozoan infections in muscle of both marine and freshwater fishes worldwide. They range from
innocuous infections with minimal host
response to intense infections leading to
mortality or spoilage of the musculature
through enzymatic degradation on the
death of the host. Typically, host responses
Phylum Myxozoa
253
254
Fig. 8.10. Histological features of muscle-invading species. A. Sporogonic plasmodia of Myxobolus artus
in the skeletal muscle of carp (C. carpio) (inset: mature spore in valvular view). B. Granulomatous host
response to a plasmodium of M. artus within the renal tissue (same fish as in Fig. 8.10A). C. A plasmodium
of Myxobolus pseudodispar within the muscle of a juvenile roach (Rutilus rutilus). D. Focal inflammatory
response to M. pseudodispar spores and sporogonic stages from a ruptured plasmodium. E. Intramyofibrillar Kudoa infection in cow-nosed ray (Rhinoptera bonasus). F. Multiple plasmodia of Kudoa sp.
in the myofibrils of common goby (Pomatoschistus microps). G. Giemsa-stained section of Kudoa thyrsites
infection in cod (Gadus morhua). H. Fibrous encapsulation of a Kudoa sp. plasmodium in viviparous blenny
(Zoarces viviparus).
Phylum Myxozoa
255
plasmodia were present within the musculature of these fish and, whilst the authors
were unable to unequivocally demonstrate
that the plasmodia causing ulceration were
early stages of K. clupeidae, strong circumstantial evidence was provided to suggest
that these invasive extrasporogonic stages
were responsible for the ulcerations.
256
Phylum Myxozoa
257
Fig. 8.11. Pathological features of cartilage infections. A. Low-power view of head cartilage of rainbow
trout (Oncorhynchus mykiss) infected with Myxobolus cerebralis, showing disintegration of cartilaginous
elements. B. High-power view showing spores and developmental stages of M. cerebralis amongst
destroyed cartilage (A and B are from Giemsa-stained sections). C and D. Vertebral deformation and
complete fusion of vertebrae in chub (L. cephalus) caused by Myxobolus buckei (C. inset: mature spore of
M. buckei in valvular view). E. Cysts of Myxobolus aeglifini in the scleral cartilage of the eye of poor cod
(Trisopterus minutus) (inset: mature spore of M. aeglifini in valvular view). F. Section through two large
cysts of M. aeglifini in the scleral cartilage of whiting (Merlangius merlangus). G. Myxobolus sp. in the
cranial cartilage of common goby (P. microps). H. Cysts of Myxobolus sp. in the cranial cartilage of roach
(R. rutilus).
Reproductive tissues
Myxozoan infections of gonadal tissue are
relatively rare and appear to be sex specific.
258
Phylum Myxozoa
259
260
Phylum Myxozoa
261
Fig. 8.12. Proliferative kidney disease, pathology and morphology of the causative agent Tetracapsuloides
bryosalmonae. A. Rainbow trout (Oncorhynchus mykiss) fingerling exhibiting renal hypertrophy. B. Giemsa
stained renal impression smear showing extrasporogonic stage of T. bryosalmonae surrounded by host
phagocytes. C. Diagrammatic representations of stages in the development of histozoic T. bryosalmonae
from rainbow trout kidney (primary cell nucleus, N; secondary cell, S; tertiary cell, T). D. Electron
micrograph of a renal interstitial stage from rainbow trout kidney. Primary cell contains a prominent nucleus
(N) with two secondary cells (S), one of which contains two tertiary cells (T). E. Fresh preparation of
T. bryosalmonae from trout kidney with characteristic cytoplasmic granules and secondary cells within the
primary cell, which is itself surrounded by phagocytic cells. F. Low-power view of a section of infected
renal tissue showing loss of excretory elements and proliferation of interstitial haemopoietic tissue (upper
left). G. Chronic granulomatous response in pike (E. lucius) spleen in response to T. bryosalmonae stages.
262
Phylum Myxozoa
263
Fig. 8.13. Pathology of renal infections. A. Intracellular and coelozoic stages of Hoferellus carassii in the
renal tubule of goldfish (Carassius auratus). B. Three-spined stickleback (G. aculeatus) kidney showing
distension of renal tubules caused by numerous sporogonic stages of Myxobilatus gasterostei. C. Large
xenoma of extrasporogonic stages of Myxidium lieberkuehni, which has replaced the glomerular tissue in
the kidney of pike (E. lucius). D. Glomerular and tubule infections of Myxobilatus platessae in the kidney of
European flounder (Platichthys flesus). E. Sporogonic stages of Myxidium minteri in the renal tubule lumen
of chinook salmon (Oncorhynchus tshawytscha). F. Parvicapsula sp. sporogonic stages within the renal
tubule epithelium and lumen of coho salmon (O. kisutch).
264
Fig. 8.14. Pathology of renal infections. A. Sphaerospora sp. in the kidney of dace (Leuciscus leuciscus)
causing dilatation of renal tubule with reduction in tubule epithelial height. B. Atrophy of the glomerular
tuft surrounded by a coelozoic plasmodium of Myxidium rhodei in the kidney of dace (L. leuciscus).
C. Fibrous encapsulation of sporogonic plasmodia of M. rhodei in the renal interstitial tissue of R. rutilus.
D. Intracellular extrasporogonic stage of an unidentified myxosporean in the renal tubule epithelium of dace
(L. leuciscus).
Phylum Myxozoa
265
266
inflammatory reaction in the interstitial tissues. Spores are infective to the oligochaete
B. sowerbyi, with Neoactinomyxum actinospores being released after 98 days of development within the oligochaete host (Molnr
et al., 1999a). However, experimental proof
that these stages are infective to nave carp
is lacking. S. renicola has two proliferative
extrasporogonic cycles. Blood stages, comprising primary cells containing a number
of secondary and tertiary cells, invade the
swim bladder, where they continue to proliferate, increase in size and induce swim
bladder inflammation (see above) (Dykov
et al., 1990). These swim bladder stages can
be transmitted experimentally but have not
been shown to give rise to the stages occurring within the renal tubule epithelium
(Molnr and Kovcs-Gayer, 1986). The
marked cellular hypertrophy and stenosis
of affected tubules are thought to be due to
extrasporogonic stages of H. cyprini rather
that S. renicola. Molnr (1988) reported that
similar intracellular tubule epithelium
stages occur in cyprinid fishes infected
with Myxobilatus legeri (Cpede, 1905).
Mass mortality among cultured cobia
(Rachycentron canadum) from Taiwan has
been caused by infections with an unidentified Sphaerospora-like species (Chen et al.,
2001). Cumulative mortality may reach
90% within 30 days of introduction to
marine cages. Affected fish exhibit pale
livers, ascites, gill pallor and marked renal
hypertrophy, with the surface having a
knobbly appearance and pale or haemorrhagic patches. Parasitic stages infect
glomeruli, renal tubules and the interstitial
tissues. Tubules become occluded with
parasites and cellular debris, with the epithelium showing hypertrophy and hyperplastic changes. Ruptured tubules invoke a
vigorous host response to the parasites,
with granuloma formation being typical.
Mature spores have not been described.
Wild and cultured groupers (Epinephelus malabaricus) from Thailand
infected with Sphaerospora epinepheli
Supamattaya, Fischer-Scherl, Hoffmann
and Boonyaratpalin, 1991 exhibit highly
vacuolated tubule epithelial cells with
pycnotic nuclei. Other changes include
Phylum Myxozoa
267
268
Fig. 8.15. Infections of the gall bladder, liver and neural tissues. A. Low-power view of papillomatous
ingrowths of the gall-bladder epithelium of saithe (Pollachius virens) infected with Myxidium gadi.
B. Semi-thin resin section from the previous specimen showing attachment of sporogonic M. gadi
plasmodia. C. Hepatobiliary fibrosis associated with invasion of the bile ductules with elongate plasmodia
of Myxidium truttae infecting brown trout (Salmo trutta). D. High-power view showing attenuation of
gall-bladder epithelium and the presence of a small plasmodium of M. truttae within the hepatic
parenchyma. E. Infection of bile ducts in Callionymus lyra with a Myxidium sp. F. Spores of Myxobolus cotti
within the brain of bullhead (Cottus gobio).
Phylum Myxozoa
trijugum Kudo, 1919 has also been reported (Mitchell et al., 1980).
Myxidium gadi Georgvitch, 1916 is a
well-known parasite of gadoid fish such as
saithe (Pollachius virens) and pollack
(Pollachius pollachius), occurring at high
prevalences in fish from the North Sea.
Infected gall bladders are atrophied and
have a pale coloration. Depending on the
intensity of infection, the bile may be
slightly discoloured and viscous, leading to
complete occlusion of the gall bladder and
bile duct with parasitic stages. Plasmodia
attach themselves to the bile duct epithelium, resulting in extensive papillomatous
ingrowths of the epithelium and necrosis
(Feist and Bucke, 1992; Fig. 8.15). Intracellular epithelial and intrahepatic stages
have not been reported.
Ceratomyxosis caused by Ceratomyxa
sparusaurati Sitj-Bobadilla, Palenzuela
and Alvarez-Pellitero, 1995 is a significant
pathogen of cultured gilthead sea bream
(S. aurata) in the Mediterranean (SitjBobadilla et al., 1995). Prevalence of infection can reach 60% in infected stocks and
low-level mortalities have been reported.
Severe infections induce abdominal distension with inflammation and ascites. Cytological damage to the bladder epithelium
includes hypertrophy and vacuolization.
Sloughing of the epithelium and inflammation of the underlying tissues can occur.
The parasite is regarded as a threat to sea
bream culture (Palenzuela et al., 1997).
269
270
Fig. 8.16. Infections of the intestine and associated tissues. A. Destruction of the intestinal mucosa of
gilthead seabream (Sparus aurata) caused by Enteromyxum leei. B. Intraepithelial stages of E. leei in the
intestinal mucosa of S. aurata. C. Section of pyloric caecae with large numbers of plasmodia and spores of
Ceratomyxa shasta (arrows) in the underlying connective tissue. Inset: developing spores of C. shasta.
D. Intraepithelial stages of C. shasta in the mucosal epithelium and submucosal tissues (arrow).
E and F. Cysts of Myxobolus sp. in the thin connective-tissue layer underlying the intestinal epithelium of
minnow (Phoxinus phoxinus) and roach (R. rutilus), respectively.
Phylum Myxozoa
271
272
Diagnosis of Infection
Diagnosis of myxozoans is still mainly reliant on morphological characteristics of
mature spore stages, using established criteria (Lom and Arthur, 1989; Lom et al., 1997).
Detection of developmental stages from fresh
material, smear preparations and histological sections is dependent on the experience of the investigator and the intensity of
the infection. However, specific identification is generally not possible. Ultrastructural
investigations using sectioned material are
rarely able to identify species, but scanning
electron microscopy provides valuable
diagnostic data on the surface morphology
of spore stages (Lom and Dykov, 1993).
Fresh or fixed spores are best visualized
using phase contrast or differential interference contrast microscopy, whilst smears
or imprints can be stained with Giemsa,
MayGrnwaldGiemsa or silver nitrate
(Wolf and Markiw, 1979; Clifton-Hadley
et al., 1983; Baska and Molnr, 1988).
Biotinylated lectins have been used to characterize the carbohydrate types within
myxozoans and have some diagnostic value
Phylum Myxozoa
273
274
Phylum Myxozoa
275
276
Phylum Myxozoa
277
With the continuing increase in aquaculture and the introduction of new species,
it is likely that myxozoan parasites will also
continue to pose health challenges to the
industry, both from previously undescribed
species and from others able to exploit a new
niche in high-density host populations. Parasites, such as E. leei, with direct transmission capabilities will pose the most serious
threats. Epidemiological approaches and the
application of risk analysis for assessment
of potential disease spread have begun to
be used for fish diseases, particularly
those listed by the Office International des
Epizooties (OIE). Similar approaches applied
to the study of myxozoan infections in wild
populations will be useful for understanding
temporal and spatial changes in infection
rates, especially where environmental data
are also considered.
Acknowledgements
We wish to thank the numerous colleagues
and friends who have provided material,
reprints and valuable discussions over the
years. We acknowledge the support from
the Department for Environment, Food and
Rural Affairs (Defra) (contracts FC1138,
FC1137, CDEP 84/5/287, CDEP 84/5/312
and AE003). We are indebted to Drs
Michael Kent and Chris Whipps (University
of Oregon), Dr Beth Okamura (University
of Reading) and Prof. Elizabeth Canning
(University of London) for allowing us
access to unpublished manuscripts.
References
Adams, A., Richards, R.H. and de Mateo, M.M. (1992) Development of monoclonal antibodies to PKX, the
causative agent of proliferative kidney disease. Journal of Fish Diseases 15, 515521.
Alderman, D.J. (1986) Whirling disease chemotherapy. Bulletin of the European Association of Fish Pathologists 6, 3840.
Alderman, D. and Clifton-Hadley, R.S. (1988) Malachite green therapy of proliferative kidney disease in rainbow trout: field trials. Veterinary Record 122, 103106.
Allen, M.B. and Bergersen, E.P. (2002) Factors influencing the distribution of Myxobolus cerebralis, the causative agent of whirling disease, in the Cache la Poudre River, Colorado. Diseases of Aquatic Organisms
49, 5160.
Alvarez-Pellitero, P. (1989) Myxidium rhodei (Protozoa: Myxozoa: Myxosporea) in cyprinid fishes from NW
Spain. Diseases of Aquatic Organisms 7, 1316.
278
Alvarez-Pellitero, P., Pereira-Bueno, J. and Gonzalez-Lanza, M.C. (1982) On the presence of Chloromyxum
truttae Leger, 1906 in Salmo trutta fario from Leon (Duero basin, NW Spain). Bulletin of the European
Association of Fish Pathologists 2, 47.
Alvarez-Pellitero, P., Molnr, K., Sitj-Bobadilla, A. and Szkely, C. (2002) Comparative ultrastructure of the
actinosporean stages of Myxobolus bramae and M. pseudodispar (Myxozoa). Parasitology Research 88,
198207.
Anderson, C.L., Canning, E.U. and Okamura, B. (1998) A triploblast origin for Myxozoa? Nature 392, 346347.
Anderson, C.L., Canning, E.U. and Okamura, B. (1999a) 18S rDNA sequences indicate that PKX organism
parasitizes Bryozoa. Bulletin of the European Association of Fish Pathologists 19, 9497.
Anderson, C.L., Canning, E.U. and Okamura, B. (1999b) Molecular data implicate bryozoans as hosts for PKX
(Phylum Myxozoa) and identify a clade of bryozoan parasites within the Myxozoa. Parasitology 119,
555561.
Andree, K.B., Gresoviac, S.J. and Hedrick R.P. (1997) Small subunit ribosomal RNA sequences unite alternate
actinosporean and myxosporean stages of Myxobolus cerebralis the causative agent of whirling disease
in salmonid fish. Journal of Eukaryotic Microbiology 44, 208215.
Andree, K.B., MacConnell, E. and Hedrick, R.P. (1998) A nested chain reaction for the detection of genomic
DNA of Myxobolus cerebralis in rainbow trout Oncorhynchus mykiss. Diseases of Aquatic Organisms
34, 145154.
Andree, K.B., El-Matbouli, M., Hoffmann, R.W. and Hedrick, R.P. (1999a) Comparison of 18S and ITS-1
rDNA sequences of selected geographic isolates of Myxobolus cerebralis. International Journal for
Parasitology 29, 771775.
Andree, K.B., Szkely, C., Molnr, K., Gresoviac, S.J. and Hedrick, R.P. (1999b) Relationships among members of the genus Myxobolus (Myxozoa: Bivalvulidae) based on small subunit ribosomal DNA
sequences. Journal of Parasitology 85, 6874.
Andrews, C. (1979) The occurrence of Henneguya psorospermica Thlohan, 1895 (Myxosporidia) on perch,
Perca fluviatilis L., from Llyn Tegid, Wales. Journal of Fish Diseases 2, 2733.
Antonio, D.B., Andree, K.B., McDowell, T.S. and Hedrick, R.P. (1998) Detection of Myxobolus cerebralis in
rainbow trout (Oncorhynchus mykiss) and oligochaete tissues using a non-radioactive in situ hybridisation protocol. Journal of Aquatic Animal Health 10, 338347.
Arthur, J.R. and Lom, J. (1985) Sphaerospora araii n. sp. (Myxosporea: Sphaerosporidae) from the kidney of a
longnose skate (Raja rhina Jordan and Gilbert) from the Pacific Ocean off Canada. Canadian Journal of
Zoology 63, 29022906.
Athanassopoulou, F. and Sommerville, C. (1993a) A comparative study of the myxosporeans Myxidium
rhodei Lger, 1905 and Myxidium pfeifferi Auerbach, 1908 in roach, Rutilus rutilus. Journal of Fish Diseases 16, 2738.
Athanassopoulou, F. and Sommerville, C. (1993b) The significance of myxosporean infections in roach,
Rutilus rutilus L., in different habitats. Journal of Fish Diseases 16, 3951.
Awakura, T. and Kimura, T. (1977) On the milky condition in smoked coho salmon (Oncorhynchus kisutch)
caused by myxosporidian parasite (in Japanese). Fish Pathology 12, 179184.
Awakura, T., Nagasawa, K. and Urawa, S. (1995) Occurrence of Myxobolus arcticus and M. neurobius
(Myxozoa: Myxosporea) in masu salmon Oncorhynchus masou from northern Japan. Scientific Reports
of the Hokkaido Salmon Hatchery 49, 3540.
Bahri, S. and Marques, A. (1996) Myxosporean parasites of the genus Myxobolus from Mugil cephalus in
Ichkeul lagoon, Tunisia: description of two new species. Diseases of Aquatic Organisms 27, 115122.
Bartholomew, J.L. (1998) Host resistance to infection by the myxosporean parasite Ceratomyxa shasta: a
review. Journal of Aquatic Animal Health 10, 112120.
Bartholomew, J.L. and Reno, P.W. (2002) The history and dissemination of whirling disease. In: Bartholomew,
J.L. and Wilson, J.C. (eds) Whirling Disease: Reviews and Current Topics. Symposium 29, American Fisheries Society, Bethesda, Maryland, pp. 324.
Bartholomew, J.L. and Wilson, J.C. (eds) (2002) Whirling Disease: Reviews and Current Topics. Symposium
29, American Fisheries Society, Bethesda, Maryland, 247 pp.
Bartholomew, J.L., Rohovec, J.S. and Fryer, J.L. (1989a) Ceratomyxa shasta, a Myxosporean Parasite of
Salmonids. Fish Disease Leaflet No. 80, US Fish and Wildlife Service, National Fisheries Research Center, Kearneysville, West Virginia, 8 pp.
Bartholomew, J.L., Smith, C.E., Rohovec, J.S. and Fryer, J.L. (1989b) Characterisation of a host response to
the myxosporean parasite, Ceratomyxa shasta (Noble), by histology, scanning electron microscopy and
immunological techniques. Journal of Fish Diseases 12, 509522.
Phylum Myxozoa
279
Bartholomew, J.L., Rohovec, J.S. and Fryer, J.L. (1989c) Development, characterization, and use of
monoclonal and polyclonal antibodies against the myxosporean, Ceratomyxa shasta. Journal of
Protozoology 36, 397401.
Bartholomew, J.L., Whipple, M.J., Stevens, D.J. and Fryer, J.L. (1997) The life cycle of Ceratomyxa shasta, a
myxosporean parasite of salmonids, requires a freshwater polychaete as an alternate host. Journal of
Parasitology 83, 859868.
Baska, F. (1987) Histological studies on the development of Myxobolus pseudodispar Gorbunova, 1936 in the
roach (Rutilus rutilus). Acta Veterinaria Hungarica 35, 251257.
Baska, F. (1990) Chloromyxum inexpectatum n. sp. and Sphaerospora colomani n. sp. (Myxozoa:
Myxosporea), parasites of the urinary system of the sterlet, Acipenser ruthenus L. Systematic Parasitology
16, 185193.
Baska, F. and Molnr, K. (1988) Blood stages of Sphaerospora spp. (Myxosporea) in cyprinid fishes. Diseases
of Aquatic Organisms 5, 2328.
Beauchamp, K.A., Kathman, R.D., McDowell, T.S. and Hedrick, R.P. (2001) Molecular phylogeny of tubificid
oligochaetes with special emphasis on Tubifex tubifex (Tubificidae). Molecular Phylogenetics and Evolution 19, 216224.
Beauchamp, K.A., Gay, M., Kelley, G.O., El-Matbouli, M., Kathman, R.D., Nehring, R.B. and Hedrick, R.P.
(2002) Prevalence and susceptibility of infection to Myxobolus cerebralis, and genetic differences among
populations of Tubifex tubifex. Diseases of Aquatic Organisms 51, 113121.
Benajiba, M.H. and Marques, A. (1993) The alternation of actinomyxidian and myxosporidian sporal forms in
the development of Myxidium giardi (parasite of Anguilla anguilla) through oligochaetes. Bulletin of the
European Association of Fish Pathologists 13, 100103.
Blazer, V.S., Waldrop, T.B., Schill, W.B., Densmore, C.L. and Smith, D. (2003) Effects of water temperature
and substrate type on spore production and release in eastern Tubifex tubifex worms infected with
Myxobolus cerebralis. Journal of Parasitology 89, 2126.
Boreham, R.E., Hendrick, S., ODonoghue, P.J. and Stenzel, D.J. (1998) Incidental finding of Myxobolus
spores (Protozoa: Myxozoa) in stool samples from patients with gastrointestinal symptoms. Journal of
Clinical Microbiology 36, 37283730.
Bosworth, B.G., Wise, D.J., Terhune, J.S. and Wolters, W.R. (2003) Family and genetic group effects for resistance to proliferative gill disease in channel catfish, blue catfish and channel catfish blue catfish
backcross hybrids. Aquaculture Research 34, 569573.
Branson, E., Riaza, A. and Alvarez-Pellitero, P. (1999) Myxosporean infection causing intestinal disease in farmed
turbot Scophthalmus maximus (L.) (Teleostei: Scophthalmidae). Journal of Fish Diseases 22, 395399.
Brummer-Korvenkontio, H., Valtonen, E.T. and Pugachev, O.N. (1991) Myxosporea parasites in roach,
Rutilus rutilus (Linnaeus), from four lakes in central Finland. Journal of Fish Biology 38, 573586.
Bucher, F., Hofer, R. and El-Matbouli, M. (1992) Prevalence and pathology of Zschokkella nova (Myxosporea)
in the liver of bullhead Cottus gobio from a polluted river. Diseases of Aquatic Organisms 14, 137143.
Bucke, D. and Andrews, C. (1985) Vertebral anomalies in chub, Leuciscus (Squalius) cephalus L. Bulletin of
the European Association of Fish Pathologists 5, 35.
Canning, E.U. and Okamura, B. (2004) Biodiversity and evolution of the Myxozoa. Advances in Parasitology
56, 43131.
Canning, E.U., Okamura, B. and Curry, A. (1996) Development of a myxozoan parasite Tetracapsula
bryozoides n. g., n. sp. in the body cavity of Cristatella mucedo (Bryozoa, Phylactolaemata). Folia
Parasitologica 43, 249261.
Canning, E.U., Curry, A., Feist, S.W., Longshaw, M. and Okamura, B. (1999) Tetracapsula bryosalmonae
n. sp. for PKX organism, the cause of PKD in salmonid fish. Bulletin of European Association of Fish
Pathologists 19, 203206.
Canning, E.U., Curry, A., Feist, S.W., Longshaw, M. and Okamura, B. (2000) A new class and order of
myxozoans to accommodate parasites of bryozoans with ultrastructural observations on Tetracapsula
bryosalmonae (PKX organism). Journal of Eukaryotic Microbiology 47, 456468.
Canning, E.U., Tops, S., Curry, A., Wood, T.S. and Okamura, B. (2002) Ecology, development and pathogenicity of Buddenbrockia plumatellae Schrder, 1910 (Myxozoa, Malacosporea) (syn. Tetracapsula
bryozoides) and establishment of Tetracapsuloides n. gen. for Tetracapsula bryosalmonae. Journal of
Eukaryotic Microbiology 49, 280295.
Castagnaro, M., Marn de Mateo, M., Ghittino, C. and Hedrick, R.P. (1991) Lectin histochemistry and
ultrastructure of rainbow trout Oncorhynchus mykiss kidneys affected by proliferative kidney disease.
Diseases of Aquatic Organisms 10, 173183.
280
Caullery, M. and Mesnil, F (1905) Recherches sur les Actinomyxidies. Archiv fr Protistenkunde 6, 272308.
Chase, J.C., Dawson-Coates, J.A., Haddow, J.D., Stewart, M.H., Haines, L.R., Whitaker, D.J., Kent, M.L.,
Olafson, R.W. and Pearson, T.W. (2001) Analysis of Kudoa thyrsites (Myxozoa: Myxosporea) spore antigens using monoclonal antibodies. Diseases of Aquatic Organisms 45, 121129.
Chen, S.-C., Kou, R.-J., Wu, C.-T., Wang, P.-C. and Su, F.-Z. (2001) Mass mortality with a Sphaerospora-like
myxosporidean infestation in juvenile cobia, Rachycentron canadum (L.), marine cage cultured in
Taiwan. Journal of Fish Diseases 24, 189195.
Cho, J.B. and Kim, K.H. (2003) Light- and electron-microscope description of Kudoa paralichthys n. sp.
(Myxozoa, Myxosporea) from the brain of cultured olive flounder Paralichthys olivaceus in Korea.
Diseases of Aquatic Organisms 55, 5963.
Clifton-Hadley, R.S. and Alderman, D.J. (1987) The effects of malachite green upon proliferative kidney
disease. Journal of Fish Diseases 10, 101107.
Clifton-Hadley, R.S., Richards, R.H. and Bucke, D. (1983) Method for the rapid diagnosis of proliferative
kidney disease in salmonids. Veterinary Record 112, 609.
Clifton-Hadley, R.S., Richards, R.H. and Bucke, D. (1986) Proliferative kidney disease (PKD) in rainbow trout,
Salmo gairdneri: further observations on the effects of water temperature. Aquaculture 55, 165171.
Clifton-Hadley, R.S., Bucke, D. and Richards, R.H. (1987) A study of the sequential clinical and pathological
changes during proliferative kidney disease in rainbow trout, Salmo gairdneri Richardson. Journal of
Fish Diseases 10, 335352.
Clouthier, S.C., Gunning, D.J., Olafson, R.W. and Kay, W.W. (1997) Antigenic characterization of
Henneguya salminicola. Molecular and Biochemical Parasitology 90, 543548.
Cone, D.K., Eurell, T., Axler, R., Rau, D. and Beasley, V. (1997) Intense infections with a variant of Myxobolus
procercus (Myxosporea) in muscle of trout-perch (Percopsis omiscomaycus) in Duluth Harbour, Lake
Superior. Folia Parasitologica 44, 711.
Conway Morris, S. (1981) Parasites and the fossil record. Parasitology 82, 489509.
Corliss, J.O. (1985) Consideration of taxonomic-nomenclatural problems posed by report of myxosporidians
with two-host life cycle. Journal of Protozoology 32, 589591.
Crawshaw, M.T. and Sweeting, R.A. (1986) Myxobolus koi Kudo, 1919: a new record for Britain. Journal of
Fish Diseases 9, 465467.
Csaba, G., Kovacs-Gayer, E., Bekesi, L., Bucsek, M., Szakolczai, J. and Molnr, K. (1984) Studies into the possible protozoan aetiology of swimbladder inflammation in carp fry. Journal of Fish Diseases 7, 3956.
Davies, J.A. (1985) Zschokkella russelli Tripathi (Myxozoa: Myxosporea) from five-bearded rockling, Ciliata
mustela L. (Teleostei: Gadidae), in Wales. Journal of Fish Diseases 8, 229308.
De Kinkelin, P. and Loriot, B. (2001) A water temperature regime which prevents the occurrence of
proliferative kidney disease (PKD) in rainbow trout, Oncorhynchus mykiss (Walbaum). Journal of Fish
Diseases 24, 489493.
De Kinkelin, P., Gay, M. and Forman, S. (2002) The persistence of infectivity of Tetracapsula bryosalmonaeinfected water for rainbow trout, Oncorhynchus mykiss (Walbaum). Journal of Fish Diseases 25,
477482.
Diamant, A. (1992) A new pathogenic histozoic Myxidium (Myxosporea) in cultured gilt-head sea bream
Sparus aurata L. Bulletin of the European Association of Fish Pathologists 12, 6466.
Diamant, A. (1997) Fish-to-fish transmission of a marine myxosporean. Diseases of Aquatic Organisms 30,
99105.
Diamant, A. (1998) Red drum Sciaenops ocellatus (Sciaenidae), a recent introduction to Mediterranean mariculture, is susceptible to Myxidium leei (Myxosporea). Aquaculture 162, 3339.
Diamant, A. and Paperna, I. (1985) The development and ultrastructure of Nosema ceratomyxae sp. nov.,
a microsporidian hyperparasite of the myxosporean Ceratomyxa sp. from Red Sea rabbitfish (Siganidae).
Protistologica 21, 249258.
Diamant, A. and Paperna, I. (1989) Cytopathology of Ceratomyxa sp. (Myxosporea) hyperparasitized with the
microsporidian Nosema ceratomyxae. Diseases of Aquatic Organisms 6, 7579.
Diamant, A. and Paperna, I. (1992) Zschokkella icterica sp. nov. (Myxozoa, Myxosporea), a pathogen of
wild rabbitfish Siganus luridus (Ruppell, 1829) from the Red Sea. European Journal of Protistology 28,
7178.
Diamant, A., Lom, J. and Dykov, I. (1994) Myxidium leei n. sp., a pathogenic myxosporean of cultured sea
bream Sparus aurata. Diseases of Aquatic Organisms 20, 137141.
Dykov, I. and Lom, J. (1988a) Review of pathogenic myxosporeans in intensive culture of carp (Cyprinus
carpio) in Europe. Folia Parasitologica 35, 289307.
Phylum Myxozoa
281
Dykov, I. and Lom, J (1988b) Chloromyxum reticulatum (Myxozoa: Myxosporea) in the liver of burbot (Lota
lota L.) and its migration to the final site of infection. European Journal of Protistology 23, 258261.
Dykov, I. and Lom, J. (1999) Nosema notabilis (Microsporidia), its ultrastructure and effect on the
myxosporean host Ortholinea polymorpha. Diseases of Aquatic Organisms 35, 6976.
Dykov, I., Lom, J. and Grupcheva, G. (1987) Pathogenicity and some structural features of Myxidium rhodei
(Myxozoa: Myxosporea) from the kidney of the roach Rutilus rutilus. Diseases of Aquatic Organisms 2,
109115.
Dykov, I., Lom, J. and Krting, W. (1990) Light and electron microscopic observations on the swimbladder
stages of Sphaerospora renicola, a parasite of carp (Cyprinus carpio). Parasitology Research 76, 228237.
Dykov, I., Fajer Avila, E.J. and Fiala, I. (2002) Kudoa dianae sp. n. (Myxosporea: Multivalvulida), a new parasite of bullseye puffer, Sphoeroides annulatus (Tetraodontiformes: Tetraodontidae). Folia Parasitologica
49, 1723.
Dzulinsky, K., Cone, D.K., Faulkner, G.T. and Cusak, R. (1994) Development of Myxobolus neurophilus
(Guilford, 1963) (Myxosporea) in the brain of yellow perch (Perca flavescens) in Vinegar Lake, Nova
Scotia. Canadian Journal of Zoology 72,11801185.
Egusa, S. (1985) Myxobolus buri sp. n. (Myxosporea: Bivalvulida) parasitic in the brain of Seriola
quinqueradiata Temminck et Schlegel. Fish Pathology 19 (4), 239244.
Eiras, J.C. (2002) Synopsis of the species of the genus Henneguya Thlohan, 1892 (Myxozoa: Myxosporea:
Myxobolidae). Systematic Parasitology 52, 4354.
El-Mansy, A. (2002) Immature stages and re-description of Henneguya suprabranchiae (Myxosporea:
Myxobolidae), an intestinal parasite of the catfish Clarias gariepinus in the River Nile, Egypt. Diseases of
Aquatic Organisms 51, 179186.
El-Mansy, A. and Molnr, K. (1997a) Extrapiscine development of Myxobolus drjagini Akhmerov, 1954
(Myxosporea: Myxobolidae) in oligochaete alternate hosts. Acta Veterinaria Hungarica 45, 427438.
El-Mansy, A. and Molnr, K. (1997b) Development of Myxobolus hungaricus (Myxosporea: Myxobolidae) in
oligochaete alternate hosts. Diseases of Aquatic Organisms 31, 227232.
El-Mansy, A. and Szekely, C. (1998) Development of Myxobolus portucalensis Saraiva & Molnr, 1990
(Myxosporea: Myxobolidae) in the oligochaete Tubifex tubifex (Mller). Systematic Parasitology 41,
95103.
El-Mansy, A., Szkely, C. and Molnr, K. (1998a) Studies on the occurrence of actinosporean stages of
fish myxosporeans in a fish farm of Hungary, with description of Triactinomyxon, Raabeia,
Aurantiactinomyxon and Neoactinomyxon types. Acta Veterinaria Hungarica 46, 259284.
El-Mansy, A., Szkely, C. and Molnr, K. (1998b) Studies on the occurrence of actinosporean stages of
myxosporeans in Lake Balaton, Hungary, with the description of Triactinomyxon, Raabeia and
Aurantiactinomyxon types. Acta Veterinaria Hungarica 46, 437450.
El-Matbouli, M. and Hoffmann, R.W. (1989) Experimental transmission of two Myxobolus spp. developing
bisporogony via tubificid worms. Parasitology Research 75, 462464.
El-Matbouli, M. and Hoffmann, R.W. (1991a) Experimental transmission of Myxobolus cerebralis and
Myxobolus pavlovskii and their development in tubificids (In German). Fischerei-Forschung, Rostock 29,
7075.
El-Matbouli, M. and Hoffmann, R.W. (1991b) Effect of freezing, ageing and passage through the alimentary
canal of predatory animals on the viability of Myxobolus cerebralis spores. Journal of Aquatic Animal
Health 3, 260262.
El-Matbouli, M. and Hoffmann, R.W. (1991c) Prevention of experimentally induced whirling disease in rainbow trout Oncorhynchus mykiss by Fumagillin. Diseases of Aquatic Organisms 10, 109113.
El-Matbouli, M. and Hoffmann, R.W. (1993) Myxobolus carassii Klokacheva, 1914 also requires an aquatic
oligochaete, Tubifex tubifex as an intermediate host in its life cycle. Bulletin of the European Association
of Fish Pathologists 13, 189192.
El-Matbouli, M. and Hoffmann, R.W. (1998) Light and electron microscopic studies on the chronological
development of Myxobolus cerebralis to the actinosporean stage in Tubifex tubifex. International Journal
for Parasitology 28, 195217.
El-Matbouli, M., Fischer-Scherl, T. and Hoffmann, R.W. (1990) Light and electron microscopic studies on
Myxobolus cotti El-Matbouli and Hoffmann, 1987 infecting the central nervous system of the bullhead
(Cottus gobio). Parasitological Research 76, 219227.
El-Matbouli, M., Fischer-Scherl, T. and Hoffmann, R.W. (1992a) Present knowledge on the life cycle, taxonomy, pathology, and therapy of some Myxosporea spp. important for freshwater fish. Annual Review of
Fish Diseases 2, 367402.
282
El-Matbouli, M., Fischer-Scherl, T. and Hoffmann, R.W. (1992b) Transmission of Hoferellus carassii
Akhmerov, 1960 to goldfish Carassius auratus via an aquatic oligochaete. Bulletin of the European Association of Fish Pathologists 12, 5456.
El-Matbouli, M., Hoffmann, R.W. and Mandok, C. (1995) Light and electron microscopic observations on the
route of the triactinomyxon-sporoplasm of Myxobolus cerebralis from the epidermis into rainbow trout
cartilage. Journal of Fish Biology 46, 919935.
El-Matbouli, M., McDowell, T.S., Antonio, D.B., Andree, K.B. and Hedrick, R.P. (1999a) Effect of water temperature on the development, release and survival of the triactinomyxon stage of Myxobolus cerebralis in
its oligochaete host. International Journal for Parasitology 29, 627641.
El-Matbouli, M., Hoffmann, R.W., Schoel, H., McDowell, T.S. and Hedrick, R.P. (1999b) Whirling disease:
host specificity and interaction between the actinosporean stage of Myxobolus cerebralis and rainbow
trout Oncorhynchus mykiss. Diseases of Aquatic Organisms 35, 112.
Eszterbauer, E. (2002) Molecular biology can differentiate morphologically indistinguishable myxosporean
species: Myxobolus elegans and M. hungaricus. Acta Veterinaria Hungarica 50, 5962.
Eszterbauer, E., Szkely, C., Molnr, K. and Baska, F. (2000) Development of Myxobolus bramae
(Myxosporea: Myxobolidae) in an oligochaete alternate host, Tubifex tubifex. Journal of Fish Diseases 23,
1925.
Eszterbauer, E., Benk, M., Dn, . and Molnr, K. (2001) Identification of fish-parasitic Myxobolus
(Myxosporea) species using a combined PCR-RFLP method. Diseases of Aquatic Organisms 44, 3539.
Feist, S.W. (1995) Ultrastructural aspects of Myxidium gadi (Georgvitch, 1916) (Myxozoa: Myxosporea)
infections in Pollack (Pollachius pollachius L.) and saithe (P. virens L.). European Journal of Protistology
31, 309317.
Feist, S.W. (1997) Pathogenicity of renal myxosporeans of fish. Bulletin of the European Association of Fish
Pathologists 17, 209214.
Feist, S.W. and Bucke, D. (1987) Ultrastructural aspects of PKX, the causative agent of proliferative kidney
disease in rainbow trout, Salmo gairdneri Richardson. Journal of Fish Diseases 10, 323327.
Feist, S.W. and Bucke, D. (1992) Myxidium gadi Georgvitch, 1916 infections in saithe Pollachius virens L.
from the North Sea. Bulletin of the European Association of Fish Pathologists 12, 211214.
Feist, S.W. and Bucke, D. (1993) Proliferative kidney disease in wild salmonids. Fisheries Research 17, 5158.
Feist, S.W. and Rintamki, P. (1994) Chloromyxum truttae Legr, 1906 infection from cultured salmonids
from Finland. Bulletin of the European Association of Fish Pathologists 14, 5154.
Feist, S.W., Chilmonczyk, S. and Pike, A.W. (1991) Structure and development of Sphaerospora elegans
Thholan 1892 (Myxozoa: Myxosporea) in the sticklebacks Gasterosteus aculeatus L. and Pungitius
pungitius L. (Gasterosteidae). European Journal of Protistology 27, 269277.
Feist, S.W., Longshaw, M., Canning, E.U. and Okamura, B. (2001) Induction of proliferative kidney disease
(PKD) in rainbow trout (Oncorhynchus mykiss) via the bryozoan Fredericella sultana, infected with
Tetracapsula bryosalmonae. Diseases of Aquatic Organisms 45, 6168.
Feist, S.W., Peeler, E.J., Gardiner, R., Smith, E. and Longshaw, M. (2002) Proliferative kidney disease and renal
myxosporidiosis in juvenile salmonids from rivers in England and Wales. Journal of Fish Diseases 25,
451458.
Ferguson, H.W., Lom, J. and Smith, I. (1985) Intra-axonal parasites in the fish Notropis cornutus (Mitchell).
Veterinary Pathology 22, 194196.
Fernndez-de-Luco, D., Peribez, M.A., Garca, L. and Castillo, J.A. (1997) Granulomatous myositis in rainbow trout Oncorhynchus mykiss affected by proliferative kidney disease (PKD). Diseases of Aquatic
Organisms 31, 4954.
Foott, J.S. and Hedrick, R.P. (1987) Seasonal occurrence of the infectious stage of proliferative kidney disease
(PKD) and resistance of rainbow trout, Salmo gairdneri Richardson, to reinfection. Journal of Fish
Biology 30, 477483.
Frasca, S., Poynton, S.L., West, A.B. and Van Kruiningen, H.J. (1998) Epizootiology, pathology, and
ultrastructure of the myxosporean associated with parasitic encephalitis of farmed Atlantic salmon Salmo
salar in Ireland. Diseases of Aquatic Organisms 32, 211225.
Frasca, S., Jr, Linfert, D.R., Tsongalis, G.J., Gorton, T.S., Garmendia, A.E., Hedrick, R.P., West, A.B. and Van
Kruiningen, H.J. (1999) Molecular characterization of the myxosporean associated with parasitic encephalitis of farmed Atlantic salmon Salmo salar in Ireland. Diseases of Aquatic Organisms 35, 221233.
Friedrich, C., Ingolic, E., Freitag, B., Kastberger, G., Hohmann, V., Skofitsch, G., Neumeister, U. and Kepka, O.
(2000) A myxozoan-like parasite causing xenomas in the brain of the mole, Talpa europaea L., 1758
(Vertebrata, Mammalia). Parasitology 121, 483492.
Phylum Myxozoa
283
Gay, M., Okamura, B. and de Kinkelin, P. (2001) Evidence that infective stages of Tetracapsula bryosalmonae
for rainbow trout Oncorhynchus mykiss are present throughout the year. Diseases of Aquatic Organisms
46, 3140.
Gbankoto, A., Pampoulie, C., Marques, A. and Sakiti, G.N. (2001) Myxobolus dahomeyensis infection in
ovaries of Tilapia species from Benin (West Africa). Journal of Fish Biology 58, 883886.
Gerundo, N., Alderman, D.J., Clifton-Hadley, R.S. and Feist, S.W. (1991) Pathological effects of repeated
doses of malachite green: a preliminary study. Journal of Fish Diseases 14, 521532.
Gonzalez-Lanza, C. and Alvarez-Pellitero, P. (1984) Myxobolus farionis n. sp. and M. ibericus n. sp. of Salmo
trutta m. fario from the Deuro basin (NW Spain). Description and population dynamics. Angewandte
Parasitologie 25, 181189.
Gonzalez-Lanza, C. and Alvarez-Pellitero, P. (1985) Myxobolus spp. of various cyprinids from the River Elsa
(Len, NW Spain). Description and population dynamics. Angewandte Parasitologie 26, 7183.
Gould, S.J. (1990) Wonderful Life. The Burgess Shale and the Nature of History. Hutchinson Radius, London,
Sydney, Auckland, Johannesburg, 347 pp.
Granath, W.O. and Gilbert, M.A. (2002) The role of Tubifex tubifex (Annelida: Oligochaeta: Tubificidae) in
the transmission of Myxobolus cerebralis (Myxozoa: Myxosporea: Myxobolidae). In: Bartholomew, J.L.
and Wilson, J.C. (eds) Whirling Disease: Reviews and Current Topics. Symposium 29, American Fisheries Society, Bethesda, Maryland, pp. 7985.
Grass, P.-P.(1970) Embranchement des Myxozoaires. In: Grass, P.-P., Poisson, R.A. and Tuzet, O. (eds)
Prcis de Zoologie I, Invertbres, 2nd edn, Masson et Cie, Paris, pp. 107112.
Griffin, B.R. and Davis, E.M. (1978) Myxosoma cerebralis: detection of circulating antibodies in infected rainbow trout (Salmo gairdneri). Journal of the Fisheries Research Board of Canada 35, 11861190.
Grossel, G.W., Dykova, I., Handlinger, J. and Munday, B.L. (2003) Pentacapsula neurophila n. sp.
(Multivalvulida) from the central nervous system of striped trumpeter, Latris lineata (Forster). Journal of
Fish Diseases 26, 315320.
Grossheider, G. and Krting, W. (1992) First evidence that Hoferellus cyprini (Doflein, 1898) is transmitted by
Nais sp. Bulletin of the European Association of Fish Pathologists 12, 1720.
Hallett, S.L. and Lester, R.J.G. (1999) Actinosporeans (Myxozoa) with four developing spores within a
pansporocyst: Tetraspora discoidea n. g. n. sp. and Tetraspora rotundum n. sp. International Journal for
Parasitology 29, 419427.
Hallett, S.L., Ersus, C. and Lester, R.J.G. (1995) An actinosporean from an Australian marine oligochaete. Bulletin of the European Association of Fish Pathologists 15, 168171.
Hallett, S.L., Ersus, C. and Lester, R.J.G. (1997) Actinosporea from Hong Kong marine Oligochaeta. In:
Morton, B. (ed.) The Marine Flora and Fauna of Hong Kong and Southern China IV. Proceedings of the
Eighth International Marine Biological Workshop: The Marine Flora and Fauna of Hong Kong and
Southern China, Hong Kong, 220 April, 1995. Hong Kong University Press, Hong Kong, pp. 17.
Hallett, S.L., ODonoghue, P.J. and Lester, R.J.G. (1998) Structure and development of a marine
actinosporean, Sphaeractinomyxon ersei n. sp. (Myxozoa). Journal of Eukaryotic Microbiology 45,
142150.
Hallett, S.L., Ersus, C. and Lester, R.J.G. (1999) Actinosporeans (Myxozoa) from marine oligochaetes of the
Great Barrier Reef. Systematic Parasitology 44, 4957.
Hallett, S.L., Ersus, C., ODonoghue, P.J. and Lester, R.J.G. (2001) Parasite fauna of Australian marine oligochaetes. Memoirs of the Queensland Museum 46, 555576.
Hallett, S.L., Atkinson, S.D. and El-Matbouli, M. (2002) Molecular characterisation of two aurantiactinomyxon
(Myxozoa) phenotypes reveals one genotype. Journal of Fish Diseases 25, 627631.
Hamilton, A.J. and Canning, E.U. (1988) The production of mouse anti-Myxosoma cerebralis antiserum from
Percoll-purified spores and its use in immunoflourescent labelling of Historesin-embedded cartilage
derived from infected rainbow trout, Salmo gairdneri Richardson. Journal of Fish Diseases 11, 185190.
Hanson, L.A., Lin, D., Pote, L.M.W. and Shivaji, R. (2001) Small subunit rRNA gene comparisons of four
actinosporean species to establish a polymerase chain reaction test for the causative agent of
proliferative gill disease in channel catfish. Journal of Aquatic Animal Health 13, 117123.
Hedrick, R.P., Kent, M.L., Toth, R.J. and Morrison, J.K. (1988a) Fish infected with Sphaerospora spp. Thlohan
(Myxosporea) from waters enzootic for proliferative kidney disease of salmonids. Journal of Protozoology
35 (1), 1318.
Hedrick, R.P., Groff, P.F. and McDowell, T. (1988b) Oral administration of Fumagillin DCH protects chinook
salmon Oncorhynchus tshawytscha from experimentally induced proliferative kidney disease. Diseases
of Aquatic Organisms 4, 165168.
284
Hedrick, R.P., Groff, J.M. and McDowell, T.S. (1990) Gill sphaerosporosis in goldfish (Carassius auratus). Journal of Wildlife Diseases 26, 558560.
Hedrick, R.P., MacConnell, E. and de Kinkelin, P. (1993) Proliferative kidney disease of salmonid fish. Annual
Review of Fish Diseases 3, 277290.
Hedrick, R.P., El-Matbouli, M., Adkison, M.A. and MacConnell, E. (1998) Whirling disease re-emergence
among wild trout. Immunological Reviews 166, 365376.
Hedrick, R.P., McDowell, T.S., Gay, M., Marty, G.D., Georgiadis, M.P. and MacConnell, E. (1999) Comparative susceptibility of rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta to Myxobolus
cerebralis, the cause of salmonid whirling disease. Diseases of Aquatic Organisms 37, 173183.
Hedrick, R.P., McDowell, T.S., Mukkatira, K., Georgiadis, M.P. and MacConnell, E. (2001a) Salmonids resistant to Ceratomyxa shasta are susceptible to experimentally induced infections with Myxobolus
cerebralis. Journal of Aquatic Animal Health 13, 3542.
Hedrick, R.P., McDowell, T.S., Mukkatira, K. and MacConnell, E. (2001b) Susceptibility of three species of
anadromous salmonids to experimentally induced infections with Myxobolus cerebralis, the causative
agent of whirling disease. Journal of Aquatic Animal Health 13, 4350.
Hedrick, R.P., Baxa, D.V., de Kinkelin, P. and Okamura, B. (2004) Malacosporean-like spores in urine of
rainbow trout react with antibody and DNA probes to Tetracapsuloides bryosalmonae. Parasitology
Research 92, 8188.
Hemmingsen, W., Lombardo, I. and MacKenzie, K. (1991) Parasites as biological tags for cod, Gadus morhua
L., in northern Norway: a pilot study. Fisheries Research 12, 365373.
Henderson, M. and Okamura, B. (2004) The phylogeography of salmonid proliferative kidney disease in
Europe and North America. Proceedings of the Royal Society of London B 271, 17291736.
Hendrickson, G.L., Carleton, A. and Manzer, D. (1989) Geographic and seasonal distribution of the infective stage of Ceratomyxa shasta (Myxozoa) in northern California. Diseases of Aquatic Organisms 7,
165169.
Hervio, D.M.L., Kent, M.L., Khattra, J., Sakanari, J., Yokoyama, H. and Devlin, R.H. (1997) Taxonomy of
Kudoa species (Myxosporea), using a small-subunit ribosomal DNA sequence. Canadian Journal of Zoology 75, 21122119.
Heupel, M.R. and Bennett, M.B. (1996) A myxosporean parasite (Myxosporea: Multivalvulida) in the skeletal
muscle of epaulette sharks, Hemiscyllium ocellatum (Bonnaterre), from the Great Barrier Reef. Journal of
Fish Diseases 19, 189191.
Higgins, M.J. and Kent, M.L. (1998) TNP-470, the analogue of fumagillin-DCH, controls PKX in naturally
infected sockeye salmon, Oncorhynchus nerka (Walbaum), underyearlings. Journal of Fish Diseases 21,
455457.
Hoffmann, G.L. (1984) Two fish pathogens, Parvicapsula sp. and Mitraspora cyprini (Myxosporea), new to
North America. Symposia Biologica Hungarica 23, 127135.
Hoffmann, R.W., El-Matbouli, M. and Fischer-Scherl, T. (1991) Myxozoa als Parasiten des Zentralnervensystems bei Fischen. Tierarztliche Praxis 19, 324330.
Holland, J.W., Gould, C.R.W., Jones, C.S., Noble, L.R. and Secombes, C.J. (2003) The expression of
immune-regulatory genes in rainbow trout, Oncorhynchus mykiss, during a natural outbreak of
proliferative kidney disease (PKD). Parasitology 126, S95S102.
Holzer, A.S. and Schachner, O. (2002) Myxobolus cycloides on the swimbladder of chub Leuciscus cephalus:
a controlled, host-specific localisation. Diseases of Aquatic Organisms 49, 179183.
Hsieh, S.R. and Chen, C.L. (1984) Septemcapsula yasunagai gen. et sp. nov., representative of a new family of
the class Myxosporea. Acta Zootaxonomie Sinica 9, 225227.
Ibarra, A.M., Gall, G.A.E. and Hedrick, R.P. (1990) Trials with Fumagillin DCH and malachite green to control
ceratomyxosis in rainbow trout (Oncorhynchus mykiss). Fish Pathology 25, 217223.
Ibarra, A.M., Gall, G.A.E. and Hedrick, R.P. (1991) Susceptibility of two strains of rainbow trout
Oncorhynchus mykiss to experimentally induced infections with the myxosporean Ceratomyxa shasta.
Diseases of Aquatic Organisms 10, 191194.
Ibarra, A.M., Hedrick, R.P. and Gall, G.A.E. (1992) Inheritance of susceptibility to Ceratomya shasta
(Myxozoa) in rainbow trout and the effect of length of exposure on the liability to develop
ceratomyxosis. Aquaculture 104, 217229.
Ibarra, A.M., Hedrick, R.P. and Gall, G.A.E. (1994) Genetic analysis of rainbow trout susceptibility to the
myxosporean, Ceratomyxa shasta. Aquaculture 120, 239262.
Ikeda, J. (1912) Studies on some sporozoan parasites of sipunculoids. I. The life history of a new
Actinomyxidian, Tetractinomyxon intermedium g. et. sp. nov. Archiv fr Protistenkunde 25, 240242.
Phylum Myxozoa
285
Janiszewska, J. (1955) Actinomyxidia. Morphology, ecology, history of investigations, systematics, development. Acta Parasitologica Polonica 2, 405437.
Janiszewska, J. (1957) Actinomyxidia. II New systematics, sexual cycle, description of new genera and
species. Zoologica Poloniae 8, 334.
Johnstone, A.K. (1984) Pathogenesis and life cycle of the myxosporean Parvicapsula sp. infecting marine
cultured coho salmon. PhD dissertation, University of Washington, Seattle, Washington.
Jones, S.R.M., Prosperi-Porta, G., Dawe, S.C. and Barnes, D.P. (2003) Distribution, prevalence and severity of
Parvicapsula minibicornis infections among anadromous salmonids in the Fraser River, British Columbia, Canada. Diseases of Aquatic Organisms 54, 4954.
Jones, S.R.M., Prosperi-Porta, G., Dawe, S., Blackbourn, J., Taylor, K., Lowe, G. and Osborn, A. (2004)
Proliferative renal myxosporidiosis in adult coho salmon (Oncorhynchus kisutch) in British Columbia
and Washington. Folia Parasitologica 51, 221227.
Kabata, Z. (1963) Parasites as biological tags. International Commission on Northwest Atlantic Fisheries,
Special Publications 4, 3137.
Kallert, D.M., Eszterbauer, E., El-Matbouli, M., Erseus, C. and Haas, W. (2005a) The life cycle of Henneguya
nuesslini Schuberg & Schroder 1905 (Myxozoa) involves a triactinomyxon-type actinospore. Journal of
Fish Diseases 28, 7179.
Kallert, D.M., Eszterbauer, E., Ersus, C., El-Matbouli, M. and Haas, W. (2005b) Life cycle studies of Myxobolus parviformis sp.n. (Myxozoa: Myxobolidae) from bream. Diseases of Aquatic Organisms 66, 233243.
Karlsbakk, E., Sther, P.A., Hstlund, C., Fjellsy, K.R. and Nylund, A. (2002) Parvicapsula pseudobranchiola
n. sp. (Myxozoa), a myxosporidian infecting the pseudobranch of cultured Atlantic salmon (Salmo salar)
in Norway. Bulletin of the European Association of Fish Pathologists 22, 381387.
Kaup, F.-J., Kuhm, E.-M. and Krting, W. (1995) Licht- und elektronenmikroskopische Untersuchungen zur
Sporogenese von Sphaerospora molnari in den Kiemenlamellan des Karpfens (Cyprinus carpio). Berliner
und Mnchener Tierrztliche Wochenschrift 108 (6), 206214.
Kelley, G.O., Adkison, M.A., Leutenegger, C.M. and Hedrick, R.P. (2003) Myxobolus cerebralis: identification
of a cathepsin Z-like protease gene (MyxCP-1) expressed during parasite development in rainbow trout,
Onchorhynchus mykiss. Experimental Parasitology 105, 201210.
Kelley, G.O. Beauchamp, K.A. and Hedrick, R.P. (2004) Phylogenetic comparison of the Myxosporea based
on an actin cDNA isolated from Myxobolus cerebralis. Journal of Eukaryotic Microbiology 51, 660663.
Kent, M.L. (2000) Marine netpen farming leads to infections with some unusual parasites. International
Journal for Parasitology 30, 321326.
Kent, M.L. and Hedrick, R.P. (1985) Transmission of the causative agent of proliferative kidney disease (PKD)
with the blood and spleen of infected fish: further evidence that the PKX parasite belongs to the phylum
Myxozoa. Bulletin of the European Association of Fish Pathologists 5, 3942.
Kent, M.L. and Hoffmann, G.L. (1984) Myxobolus inaequus sp. n. and Henneguya theca sp. n. from the brain
of South American knife fish, Eigenmannia virescens (V.). Journal of Protozoology 31 (1), 9194.
Kent, M. and Lom, J. (1999) Can a new species of Myxozoa be described based solely on their actinosporean
stage? Parasitology Today 15, 472473.
Kent, M.L., Whitaker D.J. and Margolis, L. (1993) Transmission of Myxobolus arcticus Pugachev and
Khokhlov, 1979, a myxosporean parasite of Pacific salmon, via a triactinomyxon from the aquatic
oligochaete Stylodrilus heringianus (Lumbriculidae). Canadian Journal of Zoology 71, 12071211.
Kent, M.L., Margolis, L. and Corliss, J.O. (1994) The demise of a class of protists: taxonomic and nomenclatural revisions proposed for the protist phylum Myxozoa Grass, 1970. Canadian Journal of Zoology
72, 932937.
Kent, M.L., Bagshaw, J.W., Nener, J. and Raymond, B. (1996) Myxobolus cyprini Doflein, 1898, in peamouth:
first report of this myxosporean in the western hemisphere. Journal of Aquatic Animal Health 8,
159162.
Kent, M.L., Whitaker, D.J. and Dawe, S.C. (1997) Parvicapsula minibicornis n. sp. (Myxozoa: Myxosporea)
from the kidney of sockeye salmon (Oncorhynchus nerka) from British Columbia, Canada. Journal of
Parasitology 83, 11531156.
Kent, M.L., Khattra, J., Hervio, D.M.L. and Devlin, R. (1998) Ribosomal DNA sequence analysis of the PKX
myxosporean and their relationship to members of the genus Sphaerospora. Journal of Aquatic Animal
Health 10,1221.
Kent, M.L., Khattra, J., Hedrick, R.P. and Devlin, R.H. (2000) Tetracapsula renicola n. sp. (Myxozoa:
Saccosporidae): the PKX myxozoan the cause of proliferative kidney disease of salmonid fishes. Journal
of Parasitology 86, 103111.
286
Kent, M.L., Andree, K.B., Bartholomew, J.L., El-Matbouli, M., Desser, S.S., Devlin, R.H., Feist, S.W.,
Hedrick, R.P., Hoffmann, R.W., Khattra, J., Hallett, S.L., Lester, R.J.G., Longshaw, M., Palenzuela, O.,
Siddall, M.E. and Xiao, C.X. (2001) Recent advances in our knowledge of the Myxozoa. Journal of
Eukaryotic Microbiology 48 (4), 395413.
Kim, J., Kim, W. and Cunningham, C.W. (1999) A new perspective on lower metazoan relationships from 18S
rDNA sequences. Molecular Biology and Evolution 16 (3), 423427.
Kie, M. (2000) First record of an actinosporean (Myxozoa) in a marine polychaete annelid. Journal of
Parasitology 86, 871872.
Kie, M. (2002) Spirorbid and sepulid polychaetes are candidates as invertebrate hosts for Myxozoa. Folia
Parasitologica 49, 160162.
Kie, M., Whipps, C.M. and Kent, M.L. (2004) Ellipsomyxa gobii (Myxozoa: Ceratomyxidae) in the common
goby Pomatoschistus microps (Teleostei: Gobiidae) uses Nereis spp. (Annelida: Polychaeta) as invertebrate hosts. Folia Parasitologica 51, 1418.
Koprivnikar, J. and Desser, S.S. (2002) A new form of raabeia-type actinosporean (Myxozoa) from the
oligochaete Uncinais uncinata. Folia Parasitologica 49, 8992.
Krting, W. (1982) Protozoan parasites associated with swimbladder inflammation (SBI) in young carp.
Bulletin of the European Association of Fish Pathologists 2, 2528.
Kovcs-Gayer, . and Molnr, K. (1983) Studies on the biology and pathology of the common carp parasite
Myxobolus basilamellaris Lom et Molnr, 1983 (Myxozoa: Myxosporea). Acta Veterinaria Hungarica 31,
91102.
Landsberg, J.H. (1993) Kidney myxosporean parasites in red drum Sciaenops ocellatus (Sciaenidae) from
Florida, USA, with a description of Parvicapsula renalis n. sp. Diseases of Aquatic Organisms 17, 916.
Langdon, J.S. (1987) Spinal curvatures and an encephalotrophic myxosporean, Triangula percae sp. nov.
(Myxozoa: Ortholineidae), enzootic in redfin perch, Perca fluviatilis L., in Australia. Journal of Fish
Diseases 10, 425434.
Langdon, J.S. (1990) Observations on new Myxobolus species and Kudoa species infecting the nervous
system of Australian fishes. Journal of Applied Ichthyology 6, 107116.
Larsen, G., Hemmingsen, W., MacKenzie, K. and Lysne, D.A. (1997) A population study of cod, Gadus
morhua L., in northern Norway using otolith structure and parasite tags. Fisheries Research 32, 1320.
Lebbad, M. and Wilcox, M. (1998) Spores of Henneguya salminicola in human stool specimens. Journal of
Clinical Microbiology 36, 1820.
Le Breton, A. and Marques, A. (1995) Occurrence of a histozoic Myxidium infection in two marine cultured
species: Puntazzo puntazzo and Pagurus major. Bulletin of the European Association of Fish Pathologists
15, 210212.
Le Gouvello, R., Pobel, T., Richards, R.H. and Gould, C. (1999) Field efficacy of a 10-day treatment of fumagillin against proliferative kidney disease in rainbow trout Oncorhynchus mykiss. Aquaculture 171, 2740.
Lester, R.J.G., Hallett, S.L., El-Matbouli, M. and Canning, E.U. (1998) The case for naming actinosporeans
using the zoological code. Parasitology Today 14, 476477.
Lester, R.J.G., Hallett, S.L., El-Matbouli, M. and Canning, E.U. (1999) Can a new species of Myxozoa be
described based solely on their actinosporean stage? Reply. Parasitology Today 15, 508.
Levsen, A., Alvik, T. and Grotmol, S. (2004) Neurological symptoms in tricolour sharkminnow Balantiocheilos
melanopterus associated with Myxobolus balantiocheili n. sp. infecting the central nervous system.
Diseases of Aquatic Organisms 59, 135140.
Lin, D., Hanson, L.A. and Pote, L.M. (1999) Small subunit ribosomal RNA sequence of Henneguya exilis
(Class Myxosporea) identifies the actinosporean stage from an oligochaete host. Journal of Eukaryotic
Microbiology 46, 6668.
Lom, J. and Arthur, J.R. (1989) A guideline for the preparation of species descriptions in Myxosporea. Journal
of Fish Diseases 12, 151156.
Lom, J. and Dykov, I. (1981) Pathogenicity of some protozoan parasites of cyprinid fishes. In: Olah, J.,
Molnar, K. and Jeney, Z. (eds) Fish Pathogens and Environment in European Polyculture. Proceedings of
an International Seminar on Fish, Pathogens and Environment in European Polyculture, June 2327,
1981, Szarvas, Hungary. Fisheries Research Institute, Szarvas, Hungary, pp. 146169.
Lom, J. and Dykov, I. (1992) Protozoan Parasites of Fish. Developments in Aquaculture and Fisheries
Science, Vol. 26, Elsevier Science Publishers, Amsterdam, 315 pp.
Lom, J. and Dykov, I. (1993) Scanning electron microscopic revision of common species of the genus
Chloromyxum (Myxozoa: Myxosporea) infecting European freshwater fishes. Folia Parasitologica 40,
161174.
Phylum Myxozoa
287
Lom, J. and Dykov, I. (1997) Ultrastructural features of the actinosporean phase of Myxosporea (Myxozoa): a
comparative study. Acta Protozoologica 36, 83103.
Lom, J., Krting, W. and Dykov, I. (1985) Light and electron microscope redescription of Sphaerospora
tincae Plehn, 1925 and S. galinae Evlanov, 1981 (Myxosporea) from the tench, Tinca tinca L. Protistologica
21, 487497.
Lom, J., Dykov, I. and Feist, S. (1989a) Myxosporea-induced xenoma formation in pike (Esox lucius L.) renal
corpuscles associated with Myxidium lieberkuehni infection. European Journal of Protistology 24,
271280.
Lom, J., Feist, S.W., Dykov, I. and Kepr, T. (1989b) Brain myxoboliasis of bullhead, Cottus gobio L., due to
Myxobolus jiroveci sp. nov.: light and electron microscope observations. Journal of Fish Diseases 12,
1527.
Lom, J., Pike, A.W. and Dykov, I. (1991) Myxobolus sandrae Reuss, 1906, the agent of vertebral column
deformities of perch Perca fluviatilis in northeast Scotland. Diseases of Aquatic Organisms 12, 4953.
Lom, J., McGeorge, J., Feist, S.W., Morris, D. and Adams, A. (1997) Guidelines for the uniform characterisation of the actinosporean stages of parasites of the phylum Myxozoa. Diseases of Aquatic Organisms 30,
19.
Longshaw, M., Feist, S.W., Canning, E.U. and Okamura, B. (1999) First identification of PKX in bryozoans
from the United Kingdom molecular evidence. Bulletin of European Association of Fish Pathologists 19,
146148.
Longshaw, M., LeDeuff, R.M., Harris, A.F. and Feist, S.W. (2002) Development of proliferative kidney disease
(PKD) in rainbow trout, Oncorhynchus mykiss, following short-term exposure to Tetracapsula
bryosalmonae infected bryozoans. Journal of Fish Diseases 25, 443449.
Longshaw, M., Frear, P. and Feist, S.W. (2003) Myxobolus buckei sp. n. (Myxozoa), a new pathogenic parasite
from the spinal column of three cyprinid fish species from the United Kingdom. Folia Parasitologica 50,
251262.
Longshaw, M., Frear, P.A. and Feist, S.W. (2005) Descriptions, development and pathogenicity of myxozoan
(Myxozoa: Myxosporea) parasites of juvenile cyprinids (Pisces: Cyprinidae). Journal of Fish Diseases 28,
489508.
Lowenstine, L.J., Rideout, B.A., Gardner, M., Busch, M., Mace, M., Bartholomew, J. and Gardiner, C.H.
(2002) Myxozoanosis in waterfowl: a new host record? Proceedings of the American Society of Zoo
Veterinarians 2002, 8687.
Lowers, J.M. and Bartholomew, J.L. (2003) Detection of myxozoan parasites in oligochaetes imported as food
for ornamental fish. Journal of Parasitology 89, 8491.
Lu, Y.S., Nie, P. and Sun, B.J. (2002) Detection of Myxobolus rotundus (Myxozoa: Myxosporea) in skin mucus
of crucian carp Carassius auratus auratus using a monoclonal antibody. Diseases of Aquatic Organisms
54, 171173.
Lu, Y.S., Li, M., Wu, Y.S. and Wang, J.G. (2003) Antigenic study of Myxobolus rotundus (Myxozoa:
Myxosporea) using monoclonal antibodies. Journal of Fish Diseases 25, 307310.
McClelland, R.S., Murphy, D.M. and Cone, D.K. (1997) Report of spores of Henneguya salminicola
(Myxozoa) in human stool specimens: possible source of confusion with human spermatozoa. Journal of
Clinical Microbiology 35, 28152818.
MacConnell, E., Smith, C.E., Hedrick, R.P. and Speer, C.A. (1989) Cellular inflammatory response of rainbow
trout to the protozoan parasite that causes proliferative kidney disease. Journal of Aquatic Animal Health
1, 108118.
McGeorge, J., Sommerville, C. and Wootten, R. (1994) Light and electron microscope observations on
extrasporogonic and sporogonic stages of a myxosporean parasite of the genus Sphaerospora Thholan,
1892 from Atlantic salmon, Salmo salar L., in Scotland. Journal of Fish Diseases 17, 227238.
McGeorge, J., Sommerville, C. and Wootten, R. (1996a). Epizootiology of Sphaerospora truttae (Myxozoa:
Myxosporea) infections of Atlantic salmon Salmo salar at freshwater smolt producing hatcheries in
Scotland. Diseases of Aquatic Organisms 26, 3341.
McGeorge, J., Sommerville, C. and Wootten, R. (1996b) Transmission experiments to determine the relationship between Sphaerospora sp. from Atlantic salmon, Salmo salar L. and Sphaerospora truttae FischerScherl, El-Matbouli & Hoffmann, 1986, a revised description for S. truttae. Folia Parasitologica 43,
107116.
McGeorge, J., Sommerville, C. and Wootten, R. (1997) Studies of actinosporean myxozoan stages parasitic in
oligochaetes from the sediments of a hatchery where Atlantic salmon harbour Sphaerospora truttae
infection. Diseases of Aquatic Organisms 30, 107119.
288
McMenamin, M.A.S. (1989) The origins and radiation of the early Metazoa. In: Allen, K.C. and Briggs, D.E.G.
(eds) Evolution and the Fossil Record. Belhaven Press, London, pp. 7398.
Maeno, Y., Sorimachi, M., Ogawa, K. and Egusa, S. (1990) Myxobolus spinacurvatura sp. n. (Myxosporea:
Bivalvulida) parasitic in deformed mullet, Mugil cephalus. Fish Pathology 25 (1), 3741.
Maloney, R., Cawthorn, R.J., Markiw, M. and Groman, D. (1991) The occurrence of Myxobolus neurobius
(Myxosporea) in wild young Atlantic salmon and Arctic char in Newfoundland. Journal of Aquatic
Animal Health 3, 146147.
Margolis, L. (1993) A case of forensic parasitology. Journal of Parasitology 79, 461462.
Marn de Mateo, M., McGeorge, J., Morris, D. and Kent, M.L. (1996) Comparative studies of PKX and
Sphaerospora spp. from salmonids using lectin and monoclonal antibody staining techniques. Journal of
Fish Diseases 19, 5563.
Markiw, M.E. (1989) Portals of entry for salmonid whirling disease in rainbow trout. Diseases of Aquatic
Organisms 6, 710.
Markiw, M.E. (1992) Experimentally induced whirling disease I. Dose response of fry and adults of rainbow
trout exposed to the triactinomyxon stage of Myxobolus cerebralis. Journal of Aquatic Animal Health 4,
4043.
Markiw, M.E. and Wolf, K. (1978) Myxosoma cerebralis: fluorescent antibody techniques for antigen recognition. Journal of the Fisheries Research Board of Canada 35, 828832.
Marques, A. (1984) Contribution la connaissance des Actinomyxidies: ultrastructure, cycle biologique, systmatique. PhD thesis, Universit des Sciences et Techniques du Languedoc, Montpellier,
France.
Martins, M.L. and de Souza, V.N. (1997) Henneguya piaractus n. sp. (Myxozoa: Myxobolidae), a gill parasite
of Piaractus mesopotamicus Holmberg, 1887 (Osteichthyes: Characidae), in Brazil. Revista Brasilia
Biologica 57, 239245.
Martins, M.L., Souza, V.N., Moraes, F.R., Moraes, J.R.E., Costa, A.J. and Rocha, U.F. (1997) Pathology and
behavioural effects associated with Henneguya sp. (Myxozoa: Myxobolidae) infections of captive pacu
Piaractus mesopotamicus in Brazil. Journal of the World Aquaculture Society 28, 297300.
Meglitsch, P.A. (1960) Some coelozoic Myxosporidia from New Zealand fishes. I. General, and family
Ceratomyxidae. Transactions of the Royal Society of New Zealand 88, 265356.
Mitchell, L.G. (1989) Myxobolid parasites (Myxozoa: Myxobolidae) infecting fishes of western Montana, with
notes on histopathology, seasonality, and intraspecific variation. Canadian Journal of Zoology 67,
19151922.
Mitchell, L.G., Listebarger, J.K. and Baley, W. (1980) Epizootiology and histopathology of Chloromyxum
trijugum (Myxospora: Myxosporida) in centrarchid fishes from Iowa. Journal of Wildlife Diseases 16,
233236.
Mitchell, L.G., Seymour, C.L. and Gamble, J.M. (1985) Light and electron microscopy of Myxobolus
hendricksoni sp. nov. (Myxozoa: Myxobolidae) infecting the brain of the fathead minnow, Pimephales
promelas Rafinesque. Journal of Fish Diseases 8, 7589.
Modin, J. (1998) Whirling disease in California: a review of its history, distribution, and impacts, 19651997.
Journal of Aquatic Animal Health 10, 132142.
Moles, A. and Heifetz, J. (1998) Effects of the brain parasite Myxobolus arcticus on sockeye salmon. Journal of
Fish Biology 52, 146151.
Molnr, K. (1982) Biology and histopathology of Thelohanellus nikolskii Akhmerov, 1955 (Myxosporea,
Myxozoa), a protozoan parasite of the common carp (Cyprinus carpio). Zeitschrift fr Parasitenkunde 68,
269277.
Molnr, K. (1988) Presporogonic development of Sphaerospora renicola Dykov & Lom, 1982 in the
swimbladder of common carp Cyprinus carpio L. Journal of Fish Diseases 11, 489497.
Molnr, K. (1993) Recent achievements in the chemotherapy of myxosporean infections of fish. Acta
Veterinaria Hungarica 41, 5158.
Molnr, K. (1994) Comments on the host, organ and tissue specificity of fish myxosporeans and on the types
of their intrapiscine development. Parasitologica Hungarica 27, 520.
Molnr, K. (1998) Taxonomic problems, seasonality and histopathology of Henneguya creplini (Myxosporea)
infection of the pikeperch Stizostedion lucioperca in Lake Balaton. Folia Parasitologica 45, 261269.
Molnr, K. (2002a) Site preference of myxosporean spp. on the fins of some Hungarian fish species. Diseases
of Aquatic Organisms 52, 123128.
Molnr, K. (2002b) Site preference of fish myxosporeans in the gill. Diseases of Aquatic Organisms 48,
197207.
Phylum Myxozoa
289
Molnr, K. (2002c) Differences between the European carp (Cyprinus carpio carpio) and the coloured carp
(Cyprinus carpio haematopterus) in susceptibility to Thelohanellus nikolskii (Myxosporea) infection. Acta
Veterinaria Hungarica 50, 5157.
Molnr, K. (2002d) Redescription and histopathology of Myxobolus cyprinicola Reuss, 1906, an intestinal parasite of the common carp (Cyprinus carpio L.). Acta Protozoologica 41, 279283.
Molnr, K. and Kovcs-Gayer, . (1985) The pathogenicity and development within the fish host of
Myxobolus cyprini Doflein, 1898. Parasitology 90, 549555.
Molnr, K. and Kovcs-Gayer, . (1986) Experimental induction of Sphaerospora renicola (Myxosporea) infection in common carp (Cyprinus carpio) by transmission of SB-protozoans. Journal of Applied Ichthyology
2, 8694.
Molnr, K. and Szkely, C. (1999) Myxobolus infection of the gills of common bream (Abramis brama L.) in
Lake Balaton and in the Kis-Balaton reservoir, Hungary. Acta Veterinaria Hungarica 47, 419432.
Molnr, K. and Szkely, C. (2003) Infection in the fins of the goldfish Carassius auratus caused by Myxobolus
diversus (Myxosporea). Folia Parasitologica 50, 3136.
Molnr, K., Baska, F. and Szkely, C. (1987) Fumagillin, an efficacious drug against renal sphaerosporosis of
the common carp Cyprinus carpio. Diseases of Aquatic Organisms 2, 187190.
Molnr, K., Fischer-Scherl, T., Baska, F. and Hoffmannn, R.W. (1989) Hoferellosis in goldfish Carassius
auratus and gibel carp Carassius auratus gibelio. Diseases of Aquatic Organisms 7, 8995.
Molnr, K., El-Mansy, A., Szkely, C. and Baska, F. (1999a) Experimental identification of the actinosporean
stage of Sphaerospora renicola Dykov & Lom 1982 (Myxosporea: Sphaerosporidae) in oligochaete
alternate hosts. Journal of Fish Diseases 22, 143153.
Molnr, K., El-Mansy, A., Szkely, C. and Baska, F. (1999b) Development of Myxobolus dispar (Myxosporea:
Myxobolidae) in an oligochaete alternate host, Tubifex tubifex. Folia Parasitologica 46, 1521.
Molnr, K., Eszterbauer, E., Szkely, C., Dn, . and Harrach, B. (2002) Morphological and molecular biological studies of intramuscular Myxobolus spp. of cyprinid fish. Journal of Fish Diseases 25, 643652.
Moncada, L.I., Lpez, M.C., Murcia, M.I., Nicholls, S., Len, F., Guo, O.L. and Corredor, A. (2001)
Myxobolus sp., another opportunistic parasite in immunosuppressed patients? Journal of Clinical Microbiology 39, 19381940.
Monteiro, A.S., Okamura, B. and Holland, P.W.H. (2002) Orphan worm finds a home: Buddenbrockia is a
myxozoan. Molecular Biology and Evolution 19, 968971.
Moran, J.D.W., Whitaker, D.J. and Kent, M.L. (1999a) Natural and laboratory transmission of the marine
myxozoan parasite Kudoa thyrsites to Atlantic salmon. Journal of Aquatic Animal Health 11, 110115.
Moran, J.D.W., Whitaker, D.J. and Kent, M.L. (1999b) A review of the myxosporean genus Kudoa Meglitsch,
1947, and its impact on the international aquaculture industry and commercial fisheries. Aquaculture
172, 163196.
Morris, D.C., Morris, D.J. and Adams, A. (2002) Development of improved PCR to prevent false positives and
false negatives in the detection of Tetracapsula bryosalmonae, the causative agent of proliferative kidney
disease. Journal of Fish Diseases 25, 483490.
Morris, D.J., Adams, A. and Richards, R.H. (1997) Studies of the PKX parasite in rainbow trout via
immunohistochemistry and immunogold electron microscopy. Journal of Aquatic Animal Health 9,
265273.
Morris, D.J., Adams, A. and Richards, R.H. (1999) In situ hybridization of DNA probes to PKX, the causative
organism of proliferative kidney disease (PKD). Journal of Fish Diseases 22, 161163.
Morris, D.J., Adams, A., Feist, S.W., McGeorge, J. and Richards, R.H. (2000a) Immunohistochemical and PCR
studies of wild fish for Tetracapsula bryosalmonae (PKX), the causative organism of proliferative kidney
disease. Journal of Fish Diseases 23, 129135.
Morris, D.J., Adams, A. and Richards, R.H. (2000b) In situ hybridisation identifies the gill as a portal of entry
for PKX (Phylum Myxozoa), the causative agent of proliferative kidney disease in salmonids. Parasitology
Research 86, 950956.
Morris, D.J., Morris, D.C. and Adams, A. (2002) Development and release of a malacosporean (Myxozoa)
from Plumatella repens (Bryozoa: Phylactolaemata). Folia Parasitologica 49, 2534.
Morris, D.J., Adams, A., Smith, P. and Richards, R.H. (2003) Effects of oral treatment with TNP-470 on rainbow trout (Oncorhynchus mykiss) infected with Tetracapsuloides bryosalmonae (Malacosporea), the
causative agent of proliferative kidney disease. Aquaculture 221, 5164.
Morrison, C.M., Martell, D.J., Leggiardo, C. and ONeil, D. (1996) Ceratomyxa drepanopsettae in the gall
bladder of Atlantic halibut, Hippoglossus hippoglossus, from the northwest Atlantic Ocean. Folia
Parasitologica 43, 2036.
290
Moshu, A. and Molnr, K. (1997) Thelohanellus (Myxozoa: Myxosporea) infection of the scales in the
European wild carp Cyprinus carpio carpio. Diseases of Aquatic Organisms 28, 115123.
Muoz, P., Sitj-Bobadilla, A. and lvarez-Pellitero, P. (1998) Immunohistochemical characterization of a
polyclonal antibody against Sphaerospora dicentrarchi (Myxosporea: Bivalvulida), a parasite from sea
bass (Dicentrarchus labrax L.) (Teleostei: Serranidae). Parasitology Research 84, 733740.
Muoz, P., Palenzuela, O., lvarez-Pellitero, P. and Sitj-Bobadilla, A. (1999a) Comparative studies on carbohydrates of several myxosporean parasites of fish using lectin histochemical techniques. Folia
Parasitologica 46, 241247.
Muoz, P., Palenzuela, O., Sitj-Bobadilla, A. and lvarez-Pellitero, P. (1999b) Immunohistochemical reactivity of polyclonal antibodies against Sphaerospora testicularis and Ceratomyxa labracis (Myxosporea:
Bivalvulida), with other myxosporean parasites. International Journal for Parasitology 29, 521525.
Muoz, P., Sitj-Bobadilla, A. and lvarez-Pellitero, P. (2000) Ultrastructural localisation of carbohydrates in
four myxosporean parasites. Parasite 7, 185191.
Murakami, Y. (1979) [Studies on Myxosporidia parasitic in the nervous tissues of yamame and amago. Occurrence of the sleeping disease and detection of the cause.] Annual Reports of Freshwater Fisheries Experimental Station, Hiroshima Prefecture, Fiscal 1978, p. 14 (in Japanese).
Murakami, Y. (1980) Studies on a sleeping disease (provisional name) of cultured yamame and amago. VIII.
Timing of treatment, the dose of administration and efficacy of Fumagillin (in Japanese). In: Annual
Report of the Freshwater Fisheries Experimental Station Hiroshima Prefecture Fiscal 1979, pp. 3335.
Narasimhamurti, C.C. and Kalavati, C. (1979) Kudoa tetraspora n. sp. (Myxosporidea: Protozoa) parasitic in
the brain tissue of Mugil cephalus. Proceedings of the Indian Academy of Science 88B, 8589.
Naville, A. (1930) Le cycle chromosomique dune nouvelle actinomyxidie: Guyenotia sphaerulosa n. gen., n.
sp. Quarterly Journal of Microscopical Science 73, 547575.
Nehring, R.B., Thompson, K.G., Taurman, K.A. and Shuler, D.L. (2002) Laboratory studies indicating that living brown trout Salmo trutta expel viable Myxobolus cerebralis myxospores. In: Bartholomew, J.L. and
Wilson, J.C. (eds) Whirling Disease: Reviews and Current Topics. Symposium 29, American Fisheries
Society, Bethesda, Maryland, pp. 125134.
Nehring, R.B., Thompson, K.G., Taurman, K.A. and Atkinson, W. (2003) Efficacy of passive sand filtration in
reducing exposure of salmonids to the actinospore of Myxobolus cerebralis. Diseases of Aquatic Organisms 57, 7783.
Nichols, K.M., Bartholomew, J. and Thorgaard, G.H. (2003) Mapping multiple genetic loci associated with
Ceratomyxa shasta resistance in Oncorhynchus mykiss. Diseases of Aquatic Organisms 56, 145154.
Nielsen, C.V., Kie, M., Szkely, C. and Buchmann, K. (2002) Comparative analysis of 18S rRNA genes from
M. aeglefini Auerbach, 1906 isolated from cod, plaice and dab, using PCR-RFLP. Bulletin of the
European Association of Fish Pathologists 22, 201205.
Ogawa, K. and Yokoyama, H. (2001) Emaciation disease of cultured tiger puffer Takifugu rubripes. Bulletin of
the National Research Institute of Aquaculture Suppl. 5, 6570.
Ogawa, K., Delgahapitiya, K.P., Furuta, T. and Wakabayashi, H. (1992) Histological studies on the host
response to Myxobolus artus Akmerov, 1960 (Myxozoa: Myxobolidae) infection in the skeletal muscle of
carp, Cyprinus carpio L. Journal of Fish Biology 41, 363371.
Okamura, B. and Wood, T.S. (2002) Bryozoans as hosts for Tetracapsula bryosalmonae, the PKX organism.
Journal of Fish Diseases 25, 469475.
Okamura, B., Anderson, C.L., Longshaw, M., Feist, S.W. and Canning, E.U. (2001) Patterns of occurrence and
18s rDNA sequence variation of PKX (Tetracapsula bryosalmonae), the causative agent of salmonid
proliferative kidney disease. Journal of Parasitology 87 (2), 379385.
Okamura, B., Curry, A., Wood, T.S. and Canning, E.U. (2002) Ultrastructure of Buddenbrockia sp. identifies it
as a myxozoan and verifies the bilaterian origin of the Myxozoa. Parasitology 124, 215223.
Ormires, R. and Frzil, J.L. (1969) Aurantiactinomyxon eiseniellae n. sp., actinomyxidie parasite dEiseniella
tetraedra Sav., (Oligocheta, Lumbricidae). Protistologica 5, 137144.
Oumouna, M., Hallett, S.L., Hoffmann, R.W. and El-Matbouli, M. (2003) Seasonal occurrence of
actinosporeans (Myxozoa) and oligochaetes (Annelida) at a trout hatchery in Bavaria, Germany. Parasitology Research 89, 170184.
Overstreet, R.M. (1976) Fabespora vermicola sp. n., the first myxosporidian from a platyhelminth. Journal of
Parasitology 62, 680684.
zer, A. and Wootten, R.J. (2000) The life cycle of Sphaerospora truttae (Myxozoa: Myxosporea) and some
features of the biology of both the actinosporean and myxosporean stages. Diseases of Aquatic Organisms 40, 3339.
Phylum Myxozoa
291
zer, A. and Wootten, R. (2001) Release of actinosporean and myxosporean spores from their hosts, with
special reference to both stages of Sphaerospora truttae (Myxozoa, Myxosporea). Acta Parasitologica 46,
103112.
zer, A., Wootten, R. and Shinn, A.P. (2002) Survey of actinosporean types (Myxozoa) belonging to seven
collective groups found in a freshwater salmon farm in Northern Scotland. Folia Parasitologica 49,
189210.
Palenzuela, O., Sitj-Bobadillia, A. and lvarez-Pellitero, P. (1997) Ceratomyxa sparusaurati (Protozoa:
Myxosporea) infections in cultured gilthead sea bream Sparus aurata (Pisces: Teleostei) from Spain:
aspects of the hostparasite relationship. Parasitology Research 83, 539548.
Palenzuela, O., Alvarez-Pellitero, P. and Sitj-Bobadilla, A. (1999) Glomerular disease associated with
Polysporoplasma sparis (Myxozoa) infections in cultured gilthead seabream, Sparus aurata L. (Pices:
Teleostei). Parasitology 118, 245256.
Palenzuela, O., Redondo, M.J. and lvarez-Pellitero, P. (2002) Description of Enteromyxum scophthalmi gen.
nov., sp. nov. (Myxozoa), an intestinal parasite of turbot (Scophthalmus maximus L.) using morphological and ribosomal RNA sequence data. Parasitology 124, 369379.
Pampoulie, C., Marques, A., Rosecchi, E., Bouchereau, J.L. and Crivelli, A.J. (2001) Long-term monitoring on
the occurrence of a myxosporean parasite Kudoa camarguensis (Myxosporean) on the common goby
(Teleostei, Pisces) Pomatoschistus microps. Diseases of Aquatic Organisms 45, 6971.
Paperna, I. and Zwerna, D.E. (1974) Kudoa cerebralis sp. n. (Myxosporidea: Chloromyxidae) from the striped
bass, Morone saxatilis (Walbaum). Journal of Protozoology 21, 1519.
Paul, C.R.C. (1989) Patterns of evolution and extinction in invertebrates. In: Allen, K.C. and Briggs, D.E.G.
(eds) Evolution and the Fossil Record. Belhaven Press, London, pp. 99121.
Pote, L.M., Hanson, L.A. and Shivaji, R. (2000) Small subunit ribosomal RNA sequences link the cause of
proliferative gill disease in channel catfish to Henneguya n. sp. (Myxozoa: Myxosporea). Journal of
Aquatic Animal Health 12, 230240.
Pronin, N.M., Fleischer, G.W., Baldanova, D.R. and Pronina, S.V. (1997) Parasites of the recently established
round goby (Neogobius melanostomus) and tubenose goby (Proterorhinus marmoratus) (Cottidae) from
the St. Clair River and Lake St. Clair, Michigan, USA. Folia Parasitologica 44, 16.
Rcz, O.Z., Szkely, C. and Molnr, K. (2004) Intraoligochaete development of Myxobolus intimus (Myxosporea:
Myxobolidae), a gill myxosporean of the roach (Rutilus rutilus). Folia Parasitologica 51, 199207.
Ratliff, D.E. (1983) Ceratomyxa shasta: longevity, distribution, timing, and abundance of the infective stage in
central Oregon. Canadian Journal of Fisheries and Aquatic Sciences 40 (10), 16221632.
Redondo, M.J., Palenzuela, O., Riaza, A., Macas, . and lvarez-Pellitero, P. (2002) Experimental transmission of Enteromyxum scophthalmi (Myxozoa), an enteric parasite of turbot Scophthalmus maximus. Journal of Parasitology 88, 482488.
Redondo, M.J., Palenzuela, O. and lvarez-Pellitero, P. (2003) In vitro studies on viability and proliferation of
Enteromyxum scophthalmi (Myxozoa), an enteric parasite of cultured turbot Scophthalmus maximus.
Diseases of Aquatic Organisms 55, 133144.
Reimschuessel, R., Gieseker, C.M., Driscoll, C., Baya, A., Kane, A.S., Blazer, V.S., Evans, J.J., Kent, M.L.,
Moran, J.D.W. and Poynton, S.L. (2003) Myxosporean plasmodial infection associated with ulcerative
lesions in young-of-the-year Atlantic menhaden in a tributary of the Chesapeake Bay, and possible links
to Kudoa clupeidae. Diseases of Aquatic Organisms 53, 143166.
Rhee, J.K., Kim, H.C. and Park, B.K. (1993) Efficacy of fumagillin against Thelohanellus kitauei infection of
Israel carp, Cyprinus carpio nudus. Korean Journal of Parasitology 31 (1), 5763.
Rose, J.D., Marrs, G.S., Lewis, C. and Schisler, G. (2000) Whirling disease behaviour and its relation to pathology of brain stem and spinal cord in rainbow trout. Journal of Aquatic Animal Health 12, 107118.
Rothwell, J.T., Virgona, J.L., Callinan, R.B., Nicholls, P.J. and Langdon, J.S. (1997) Occurrence of cutaneous
infections of Myxobolus episquamalis (Myxozoa: Myxobolidae) in sea mullet, Mugil cephalus L. in
Australia. Australian Veterinary Journal 75, 349352.
Roubal, F.R. (1994) Histopathological and ecological aspects of Henneguya and Myxobolus (Myxosporea)
infections in Acanthopagrus australis (Gnther) (Pisces: Sparidae) from Moreton Bay, Australia. Journal
of Fish Diseases 17, 495512.
Ruidisch, S., El-Matbouli, M. and Hoffmann, R.W. (1991) The role of tubificid worms as an intermediate host
in the life cycle of Myxobolus pavlovskii (Akhmerov, 1954). Parasitology Research 77, 663667.
St-Hilaire, S., Boichuk, M., Barnes, D., Higgins, M., Withler, R., Khattra, J., Jones, S. and Kieser, D. (2002)
Epizootiology of Parvicapsula minibicornis in Fraser River sockeye salmon, Oncorhynchus nerka
(Walbaum). Journal of Fish Diseases 25, 107120.
292
Sanders, J.E. and Fryer, J.L. (1970) Occurrence of the myxosporidan parasite, Myxidium minteri, in salmonid
fish. Journal of Protozoology 17, 354357.
Saulnier, D. and de Kinkelin, P. (1996) Antigenic and biochemical study of PKX, the myxosporean causative
agent of proliferative kidney disease of salmonid fish. Diseases of Aquatic Organisms 27, 103114.
Saulnier, D. and de Kinkelin, P. (1997) Polymerase chain reaction primers for investigations on the causative
agent of proliferative kidney disease of salmonids. Journal of Fish Diseases 20, 467470.
Schlegel, M., Lom, J., Stechmann, D. Bernhard, D., Leipe, I., Dykov, I. and Sogin, M.L. (1996) Phylogenetic
analysis of complete small subunit ribosomal RNA coding region of Myxidium lieberkuehni: evidence
that Myxozoa are Metazoa related to the Bilateria. Archiv fr Protistenkunde 147, 19.
Schmahl, G., Taraschewski, H. and Mehlhorn, H. (1989) Chemotherapy of fish parasites. Parasitology
Research 75, 503513.
Schulman, S.S. (1966) Myxosporidia of the Fauna of the USSR (in Russian). Nauka, MoscowLeningrad, 504 pp.
Seagrave, C., Bucke, D. and Alderman, D. (1980a) The causative agent of proliferative kidney disease may be
a member of the Haplosporidia. In: Ahne, W. (ed.) Fish Diseases. Third COPRAQ-Session. SpringerVerlag, Berlin, Heidelberg.
Seagrave, C.P., Bucke, D. and Alderman, D.J. (1980b) Ultrastructure of a haplosporean-like organism: the
causative agent of proliferative kidney disease in rainbow trout. Journal of Fish Biology 16, 453459.
Seagrave, C.P., Bucke, D., Hudson, E.B. and McGregor, D. (1981) A survey of the prevalence and distribution
of proliferative kidney disease (PKD) in England and Wales. Journal of Fish Biology 4, 437439.
Siau, Y. (1977) Premiers stades du dveloppement exprimental, en cultures, de spores de la Myxosporidie
Myxobolus exiguus Thlohan, 1895. Zeitschrift fr Parasitenkunde 62, 16.
Siddall, M.E., Martin, D.S., Bridge, D., Desser, S.S. and Cone, D.K. (1995) The demise of a phylum of protists:
phylogeny of Myxozoa and other parasitic Cnidaria. Journal of Parasitology 8, 961967.
Sitj-Bobadilla, A. and Alvarez-Pellitero, P. (1992) Effect of fumagillin treatment on sea bass Dicentrarchus
labrax parasitized by Sphaerospora testicularis (Myxosporea: Bivalvulida). Diseases of Aquatic Organisms 14, 171178.
Sitj-Bobadilla, A. and Alvarez-Pellitero, P. (1993) Zschokkella mugilis n. sp. (Myxosporea: Bivalvulida) from
mullets (Teleostei: Mugilidae) of Mediterranean waters: light and electron microscopic description.
Journal of Eukaryotic Microbiology 40 (6), 755764.
Sitj-Bobadilla, A. and Alvarez-Pellitero, P. (1995) Light and electron microscopic description of
Polysporoplasma n. g. (Myxosporea: Bivalvulida), Polysporoplasma sparis n. sp. from Sparus aurata (L.)
and Polysporoplasma mugilis n. sp. from Liza aurata L. European Journal of Protistology 31, 7789.
Sitj-Bobadilla, A., Palenzuela, O. and Alvarez-Pellitero, P. (1995) Ceratomyxa sparusaurati n. sp.
(Myxosporea: Bivalvulida), a new parasite from cultured gilthead seabream (Sparus aurata L.) (Teleostei:
Sparidae): light and electron microscopic description. Journal of Eukaryotic Microbiology 42 (5), 529539.
Sitj-Bobadilla, A., Redondo, M.J., Macias, M.A., Ferreiro, I., Riaza, A., and Alvarez-Pellitero, P. (2004)
Development of immunohistochemistry and enzyme-linked immonosorbent assays for the detection of
circulating antibodies against Enteromyxum scophthalmi (Myxozoa) in turbot (Scophthalmus maximus
L.). Fish and Shellfish Immunology 17, 335345.
Smothers, J.F., von Dohlen, C.D., Smith, L.H. and Spall, R.D. (1994) Molecular evidence that the myxozoan
protists are metazoans. Science 265, 17191721.
Staton, L., Erdahl, D. and El-Matbouli, M. (2002) Efficacy of Fumagillin and TNP-470 to prevent experimentally induced whirling disease in rainbow trout Oncorhynchus mykiss. In: Bartholomew, J.L. and
Wilson, J.C. (eds) Whirling Disease: Reviews and Current Topics. Symposium 29, American Fisheries
Society, Bethesda, Maryland, pp. 7985.
Stensaas, L.J., Stensaas, S.S. and Sotelo, J.R. (1967) An intra-axonal protozoan in the spinal cord of the toad
Bufo bufo arenarum (Hensel). Journal of Protozoology 14, 585595.
Sterud, E., Simolin, P. and Kvellestad, A. (2003) Infection by Parvicapsula sp. (Myxozoa) is associated with
mortality in sea-caged Atlantic salmon Salmo salar in northern Norway. Diseases of Aquatic Organisms
54, 259263.
Stevens, R., Kernas, B.L., Lemmon, J.C. and Rasmussen, C. (2001) The effects of Myxobolus cerebralis
myxospore dose on triactinomyxon production and biology of Tubifex tubifex from two geographic
regions. Journal of Parasitology 87, 315321.
Stoffregen, D.A. and Anderson, W.I. (1990) A myxosporidian parasite in the skeletal muscle of a black-tip reef
shark, Carcharhinus melanopterus (Quoy and Gaimard, 1824). Journal of Fish Diseases 13, 549552.
tolc, A. (1899) Actinomyxidia, a new group of mesozoa, related to the Myxosporidia (in Czech). Rozpravy
Ceske Akademie Cisare Frantiska Josefa 2, 112.
Phylum Myxozoa
293
Styer, E.L., Harrison, L.R. and Burtle, G.J. (1991) Experimental production of proliferative gill disease in channel catfish exposed to a myxozoan-infected oligochaete, Dero digitata. Journal of Aquatic Animal Health
3, 288291.
Supamattaya, K., Fischer-Scherl, T., Hoffman, R.W. and Boonyaratpalin, S. (1993) Light and electron microscopic observations on presporogonic and sporogonic stages of Sphaeropsora epinepheli (Myxosporea)
in grouper (Epinephelus malabaricus). Journal of Eukaryotic Microbiology 40 (1), 7180.
Swearer, S.E. and Robertson, D.R. (1999) Life history, pathology, and description of Kudoa ovivora n. sp.
(Myxozoa, Myxosporea): an ovarian parasite of Caribbean labroid fishes. Journal of Parasitology 85,
337353.
Szkely, C., Molnr, K. and Baska, B. (1988) Efficacy of Fumagillin against Myxidium giardi Cpde, 1906
infection of the European eel (Anguilla anguilla): new observations on myxidiosis of imported glass eels.
Acta Veterinaria Hungarica 36, 239246.
Szkely, C., El-Mansy, A., Molnr, K. and Baska, F. (1998) Development of Thelohanellus hovorkai and
Thelohanellus nikolskii (Myxosporea: Myxozoa) in oligochaete alternate hosts. Fish Pathology 33 (3),
108114.
Szkely, C., Molnr, K., Eszterbauer, E. and Baska, F. (1999) Experimental detection of the actinospores of
Myxobolus pseudodispar (Myxosprea: Myxobolidae) in oligochaete alternate hosts. Diseases of Aquatic
Organisms 38, 219224.
Szkely, C., Sitj-Bobadilla, A. and Alvarez-Pellitero, P. (2000) First report on the occurrence of an actinosporean stage (Myxozoa) in oligochaetes from Spanish freshwater. Acta Veterinaria Hungarica 48,
433441.
Szkely, C., Molnr, K. and Rcz, O. (2001) Complete developmental cycle of Myxobolus pseudodispar
(Gorbunova) (Myxosporea: Myxobolidae). Journal of Fish Diseases 24, 461468.
Szkely, C., Rcz, O. and Eszterbauer, E. (2002) Development of Myxobolus macrocapsularis (Myxosporea:
Myxobolidae) in an oligochaete alternate host, Tubifex tubifex. Diseases of Aquatic Organisms 48,
117123.
Szkely, C., Yokoyama, H., Urawa, S., Timm, T. and Ogawa, K. (2003) Description of two new actinosporean
types from a brook of Fuji Mountain, Honshu, and from Chitose River, Hokkaido, Japan. Diseases of
Aquatic Organisms 53, 127132.
Taticchi, M.I., Gustinelli, A., Fioravanti, M.L., Caffara, M., Pieroni, G. and Prearo, M. (2004) Is the wormlike organism found in the statoblasts of Plumatella fungosa (Bryozoa, Phylactolaemata) the vermiform
phase of Tetracapsuloides bryosalmonae (Myxozoa, Malacosporea)? Italian Journal of Zoology 71,
143146.
Taylor, P.D. (1985) Bryozoa. In: Murray, J.W. (ed.) Atlas of Invertebrate Macrofossils. Longman, Harlow, UK,
pp. 4752.
Taylor, R.E.L., Coli, S.J. and Junell, D.R. (1973) Attempts to control whirling disease by continuous drug feeding. Journal of Wildlife Diseases 9, 302305.
Timofeeva, S.V. and Marasaeva, E.F. (1984) The parasite fauna of two forms of cod in the Kandalakhsh Bay,
White Sea. In: Ekologo-parazitologicheskie severnykh morei. Kolskii Filial, Academiya Nauk SSSR,
Apatity, USSR, pp. 6276 (in Russian).
Tin Tun, Yokoyama, H., Ogawa, K. and Wakabayashi, H. (2000) Myxosporeans and their hyperparasitic
microsporeans in the intestine of emaciated tiger puffer. Fish Pathology 35, 145156.
Tin Tun, Ogawa, K. and Wakabayashi, H. (2002) Pathological changes induced by three myxosporeans in the
intestine of cultured tiger puffer, Takifugu rubripes (Temminck and Schlegel). Journal of Fish Diseases 25,
6372.
Tipping, J.M. (1988) Ozone control of ceratomyxosis: survival and growth benefits to steelhead and cutthroat
trout. Progressive Fish-Culturist 50, 202210.
Tops, S. and Okamura, B. (2003) Infection of bryozoans by Tetracapsuloides bryosalmonae at sites endemic
for salmonid proliferative kidney disease. Diseases of Aquatic Organisms 57, 221226.
Tops, S., Baxa, D.V., McDowell, T.S., Hedrick, R.P. and Okamura, B. (2004) Evaluation of malacosporean life
cycles through transmission studies. Diseases of Aquatic Organisms 60, 109121.
Torres, A., Matos, E. and Azevedo, C. (1994) Fine structure of Henneguya amazonica (Myxozoa) in ovarian
follicles of Hoplosternum littorale (Teleostei) from the Amazon River. Diseases of Aquatic Organisms 19,
169172.
Troullier, A., El-Matbouli, M. and Hoffmann, R.W. (1996) A new look at the life-cycle of Hoferellus carassii in
the goldfish (Carassius auratus auratus) and its relation to kidney enlargement disease (KED). Folia
Parasitologica 43, 173187.
294
Urawa, S. (1994) Life cycle of Myxobolus arcticus, a myxosporean parasite of salmonid fishes. In: Program
and Abstracts International Symposium of Aquatic Animal Health, University of California, Davis,
September 48, 1994.
Urawa, S. and Awakura, T. (1994) Protozoan diseases of freshwater fishes in Hokkaido. Scientific Reports of
the Hokkaido Fish Hatchery 48, 4758.
Urawa, S. and Nagasawa, K. (1995) Prevalence of Myxobolus arcticus (Myxozoa: Myxosporea) in five species
of Pacific salmon in the North Pacific Ocean and Bering Sea. Scientific Reports of the Hokkaido Salmon
Hatchery 49, 1119.
Urawa, S., Nagasawa, K., Margolis, L. and Moles, A. (1998) Stock identification of chinook salmon
(Oncorhynchus tshawytscha) in the North Pacific Ocean and Bering Sea by parasite tags. North Pacific
Anadromous Fish Commision Bulletin 1, 199204.
Uspenskaya, A.V. (1995) Alternation of actinosporean and myxosporean phases in the life cycle of
Zschokkella nova (Myxozoa). Journal of Eukaryotic Microbiology 42, 665668.
Van Banning, P., Veen, J.F. and van Leeuwen, P.J. (1978) The Myxosporidian Parasite (Myxobolus aeglefini
Auerbach, 1906) and Its Use as Parasitological Tag for Plaice of the Eastern North Sea. International
Council for the Exploration of the Sea, CM 1978/6:48, 22 pp.
Voronin, V.N. (1993) PKX like organism in common carp during swim bladder inflammation: further evidence of an association with the myxosporean Sphaerospora renicola. Bulletin of the European Association of Fish Pathologists 13, 127129.
Voronin, V.N. and Chernysheva, N.B. (1993) An intracellular gill parasite as the possible agent of mortality
during swim-bladder inflammation in common carp, Cyprinus carpio L. Journal of Fish Diseases 16,
609611.
Wagner, E.J. (2002) Whirling disease prevention, control, and management: a review. In: Bartholomew, J.L.
and Wilson, J.C. (eds) Whirling Disease: Reviews and Current Topics. Symposium 29, American Fisheries Society, Bethesda, Maryland, pp. 217225.
Wagner, E.J., Smith, M., Arndt, R. and Roberts, D.W. (2003) Physical and chemical effects on viability of the
Myxobolus cerebralis triactinomyxon. Diseases of Aquatic Organisms 53, 133142.
Wahli, T., Knuesel, R., Bernet, D., Segner, H., Pugovkin, D., Burkhardt-Holm, P., Escher, M. and
Schmidt-Posthaus, H. (2002) Proliferative kidney disease in Switzerland: current state of knowledge.
Journal of Fish Diseases 25, 491500.
Walliker, D. (1968) Studies on Myxidium oviforme, a myxosporidian parasite of Irish salmon, Salmo salar. Parasitology 58, 839844.
Wang, G.T., Yao, W.J., Wang, J.G. and Lu, Y.S. (2001) Occurrence of thelohanellosis caused by
Thelohanellus wuhanensis (Myxosporea) in juvenile allogynogenetic silver crucian carp, Carrassius
auratus gibelio (Bloch), with an observation on the efficacy of fumagillin as a therapeutant. Journal of
Fish Diseases 24, 5760.
Whipps, C.M., Adlard, R.D., Bryant, M.S. and Kent, M.L. (2003) Two unusual myxozoans, Kudoa quadricornis
n. sp. (Multivalvulida) from the muscle of goldspotted trevally (Carangoides fulvoguttatus) and Kudoa
permulticapsula n. sp. (Multivalvulida) from the muscle of Spanish mackerel (Scomberomorus
commerson) from the Great Barrier Reef, Australia. Journal of Parasitology 89, 168173.
Whipps, C.M., Grossel, G., Adlard, R.D., Yokoyama, H., Bryant, M.S., Munday, B.L. and Kent, M.L. (2004a)
Phylogeny of the Multivalvulidae (Myxozoa: Myxosporea) based upon comparative rDNA sequence
analysis. Journal of Parasitology 90, 618622.
Whipps, C.M., El-Matbouli, M., Hedrick, R.P., Blazer, V. and Kent, M.L. (2004b) Myxobolus cerebralis internal transcribed spacer (ITS-1) sequences support recent spread of the parasite to North America and
within Europe. Diseases of Aquatic Organisms 60 (2), 105108.
Wishkovsky, A., Groff, J.M., Lauren, D.J., Toth, R.J. and Hedrick, R.P. (1990) Efficacy of fumagillin against
proliferative kidney disease and its toxic side effects in rainbow trout (Oncorhynchus mykiss) fingerlings.
Fish Pathology 25 (3), 141146.
Wolf, K. and Markiw, M.E. (1976) Myxosoma cerebralis: in vitro sporulation of the myxosporidian of salmonid
whirling disease. Journal of Protozoology 23, 425427.
Wolf, K. and Markiw, M.E. (1979) Myxosoma cerebralis: a method for staining spores and other stages with silver nitrate. Journal of the Fisheries Research Board of Canada 36, 8889.
Wolf, K. and Markiw, M.E. (1984) Biology contravenes taxonomy in the Myxozoa: new discoveries show
alternation of invertebrate and vertebrate hosts. Science 225, 14491452.
Wu, P.-H., Chang, Z.-H., Chang, J., Chen, Y.-S. and Huang, L.-F. (1975) Twist disease of Hypophthalmichthys
molitrix in Hangchow region of Chekiang Province. Acta Zoologica Sinica 21, 190196.
Phylum Myxozoa
295
Xiao, C. and Desser, S.S. (1997) Sphaerospora ovophila n. sp. and Myxobolus algonquinensis n. sp. (Myxozoa,
Myxosporea), ovarian parasites of fish from Algonquin Park, Ontario, Canada. Journal of Eukaryotic
Microbiology 44, 157161.
Xiao, C. and Desser, S.S. (1998a) Actinosporean stages of myxozoan parasites of oligochaetes from Lake
Sasajewun, Algonquin Park, Ontario new forms of Triactinomyxon and Raabeia. Journal of Parasitology 84 (5), 9981009.
Xiao, C. and Desser, S.S. (1998b) The oligochaetes and their actinosporean parasites in Lake Sasajewun,
Algonquin Park, Ontario. Journal of Parasitology 84 (5), 10201026.
Xiao, C. and Desser, S.S. (2000a) The longevity of actinosporean spores from oligochaetes of Lake Sasajewun,
Algonquin Park, Ontario, and their reaction to fish mucus. Journal of Parasitology 86, 193195.
Xiao, C. and Desser, S.S. (2000b) Cladistic analysis of myxozoan species with known alternating life-cycles.
Systematic Parasitology 46, 8191.
Xiao, C. and Desser, S.S. (2000c) Molecular characterization of myxozoan parasites from Lake Sasajewun,
Algonquin Park, Ontario, by riboprinting. Journal of Eukaryotic Microbiology 47, 8589.
Yasuda, H., Ooyama, T., Iwata, K., Tin Tun, Yokoyama, K. and Ogawa, K. (2002) Fish-to-fish transmission of
Myxidium spp. (Myxozoa) in cultured tiger puffer suffering from emaciation disease. Fish Pathology 37,
2933.
Yasutake, W.T. and Elliott, D.G. (2003) Epizootiology and histopathology of Parvicapsula sp. in coho salmon
Oncorhynchus kisutch. Diseases of Aquatic Organisms 56, 215221.
Yasutake, W.T. and Wood, E.M. (1957) Some myxosporidia found in Pacific northwest salmonids. Journal of
Parasitology 43, 633642.
Yokoyama, H. (1997) Transmission of Thelohanellus hovorkai Akhmerov, 1960 (Myxosporea: Myxozoa) to
common carp Cyprinus carpio through the alternate oligochaete host. Systematic Parasitology 36, 7984.
Yokoyama, H. and Masuda, K. (2001) Kudoa sp. (Myxozoa) causing a post-mortem myoliquefaction of
North-Pacific giant octopus Paroctopus dofleini (Cephalopoda: Octopodidae). Bulletin of the European
Association of Fish Pathologists 21, 266268.
Yokoyama, H. and Urawa, S. (1997) Fluorescent labelling of actinospores for determining the portals of entry
into fish. Diseases of Aquatic Organisms 30, 165169.
Yokoyama, H., and Wakabayashi, S. (2000) Myxobolus aeglefini found in the skeletal muscle of porous-head
eelpout Allolepis hollandi from the Sea of Japan. Fisheries Science 66, 963966.
Yokoyama, H., Ogawa, K. and Wakabayashi, H. (1990a) Light and electron microscopic studies on the development of Hoferellus carassii (Myxosporea), the causative organism of kidney enlargement disease of
goldfish. Fish Pathology 25 (3), 149156.
Yokoyama, H., Ogawa, K. and Wakabayashi, H. (1990b) Chemotherapy with Fumagillin and Toltrazuril
against kidney enlargement disease of goldfish caused by the myxosporean Hoferellus carassii. Fish
Pathology 25, 157163.
Yokoyama, H., Ogawa, K. and Wakabayashi, H. (1991) A new collection method of actinosporeans a probable infective stage of myxosporeans to fishes from tubificids and experimental infection of goldfish
with the actinosporean, Raabeia sp. Gyobyo Kenkyu 26, 133138.
Yokoyama, H., Ogawa, K. and Wakabayashi, H. (1993a) Some biological characteristics of actinosporeans
from the oligochaete Branchiura sowerbyi. Diseases of Aquatic Organisms 17, 223228.
Yokoyama, H., Ogawa, K. and Wakabayashi, H. (1993b) Involvement of Branchiura sowerbyi (Oligochaeta:
Annelida) in the transmission of Hoferellus carassii (Myxosporea: Myxozoa), the causative agent of
kidney enlargement disease (KED) of goldfish Carassius auratus. Gyobyo Kenkyu 28, 135139.
Yokoyama, H., Ogawa, K. and Wakabayashi, H. (1995a) Chemoresponse of actinosporean spores of
Myxobolus cultus to skin mucus of goldfish Carassius auratus. Diseases of Aquatic Organisms 21, 711.
Yokoyama, H., Ogawa, K. and Wakabayashi, H. (1995b) Myxobolus cultus n. sp. (Myxosporea: Myxobolidae)
in the goldfish Carassius auratus transformed from the actinosporean stage in the oligochaete Branchiura
sowerbyi. Journal of Parasitology 81, 446451.
Yokoyama, H., Danjo, T., Ogawa, K., Arima, T. and Wakabayashi, H. (1996) Hemorrhagic anemia of carp
associated with spore discharge of Myxobolus artus (Myxozoa: Myxosporea). Fish Pathology 31, 1923.
Yokoyama, H., Inoue, D., Kumamaru, A. and Wakabayashi, H. (1997) Myxobolus koi (Myxozoa: Myxosporea)
forms large- and small-type cysts in the gills of common carp. Fish Pathology 32 (4), 211217.
Yokoyama, H., Liyanage, Y.S., Sugai, A. and Wakabayashi, H. (1998) Hemorrhagic thelohanellosis of color
carp caused by Thelohanellus hovorkai (Myxozoa: Myxosporea). Fish Pathology 33, 8589.
Zrzav, J. (2001) The interrelationships of metazoan parasites: a review of phylum- and higher-level hypotheses from recent morphological and molecular phylogenetic analyses. Folia Parasitologica 48, 81103.
296
Zrzav, J. and Hypa, V. (2003) Myxozoa, Polypodium, and the origin of the Bilateria: the phylogenetic
position of Endocnidozoa in light of the rediscovery of Buddenbrockia. Cladistics 19, 164169.
Zrzav, J., Mihulka, S., Kepka, P., Bezdek, A. and Tietz, D. (1998) Phylogeny of the Metazoa based on
morphological and 18S DNA evidence. Cladistics 14, 249285.
GENERAL
Introduction
Monogeneans are flatworms (Platyhelminthes) with representatives in freshwater,
brackish and marine habitats. The vast
majority of species are ectoparasitic and they
all have a direct life cycle, i.e. without intermediate hosts. Although a number of species
parasitize cephalopods, amphibians, reptiles
and mammals, most of these platyhelminths
are fish parasites with a relatively high host
specificity. Thus, it is generally assumed
that many fish hosts (agnathans, cartilaginous and bony fish) harbour at least one
unique monogenean species and this presumption can be used to estimate the total
number of species present. Since there are
more than 25,000 known teleost species, it is
tempting to suggest that the total number of
monogenean species exceeds this number,
although fewer than 3000 species have been
described (Whittington, 1998). Furthermore,
it was recently suggested (Bakke et al., 2002)
that there are about 20,000 species in the
genus Gyrodactylus alone. The potential for
expansion of our knowledge about this
group of platyhelminths was further stressed
by Lim (1998), who stated that only 8% of
the South-east Asian monogenean species
are known.
297
298
299
300
marine waters, the monogenean Neoheterobothrium hirame has been found to be associated with a decline of Japanese flounders,
Paralichthys olivaceus (Ogawa, 2002). Recent
studies indicated that the pathogenicity of
N. hirame is increased by concomitant infections with marine strains of the viral haemorrhagic septicaema (VHS) virus (Shirakashi
et al., 2003).
Mariculture
Mariculture enterprises may also be hampered by severe monogenean infections. Sea
bass, Dicentrarchus labrax, production has
experienced severe problems with the gill
parasites Diplectanum aequans and Diplectanum laubieri (Oliver, 1977; GonzalesLanza et al., 1991). Related diplectanid
monogeneans have produced problems in
grouper culture in South-east Asia (Leong,
1997). Likewise representatives of the
related genus Pseudorhabdosynochus are
expected to pose problems in Brazilian culture of Epinephelus niveatus (Santos et al.,
2000). Gilthead sea bream, Sparus aurata,
cultured in the Mediterranean, is host for
problematic monogeneans, such as Furnestia echeneis (Paperna et al., 1977) and
Microcotyle chrysophrii (Oliver, 1984; Faisal
and Imam, 1990). Monogenean problems in
Japanese mariculture have been intensely
studied for many years. Thus, Japanese
yellowtail, Seriola quinqueradiata, cultures
have suffered from heavy infections by
Benedenia seriolae and Heteraxine heterocerca (Egusa, 1983). Red Sea bream, Pagrus
major, cultured in Japanese waters, suffer
from Anoplodiscus tai infections (Ogawa,
1994) and Japanese flounder, P. olivaceus,
both wild and in culture, can be severely
affected by N. hirame (Hayward et al., 2001;
Ogawa, 2002). Similarly, tiger puffer, Takifugu rubripes, suffers from infections with
Heterobothrium okamotoi (Ogawa, 2002).
Apart from food-fish production, other
aquaculture production types face similar
monogenean problems. Marine exhibition
aquaria are excellent habitats for monogenean propagation. The capsalid Neobenedenia melleni was reported to have
caused morbidity and mortality of a range
of marine teleosts in the New York aquarium well before 1930 (Jahn and Kuhn, 1932;
Nigrelli and Breder, 1934). This parasite
showed an unusually broad host spectrum
and infected several species of fishes. Also
sharks and rays may be severely affected by
301
Morphology of Monogeneans
Monogeneans comprise two very distinct
groups, the Monopisthocotylea (Figs 9.1
and 9.2) and Polyopisthocotylea (Fig. 9.3),
which differ considerably, with important
implications for pathogenicity, treatment
and host response.
General adult monogenean parasite
Opisthaptor
The most important adhesion apparatus is
the opisthaptor, which is located posteriorly
(Fig. 9.4). It is often equipped with characteristic sclerotinized structures used for attachment to the host. The attachment sclerites can
be formed as large hooks or anchors (hamuli)
(Fig. 9.5). Some may be able to penetrate
302
303
The fore part of monogeneans plays a crucial role in attachment, movement, feeding
and reproduction (Whittington et al., 2000).
It has been suggested that at least three
types of gland cells secrete products
involved in attachment of the parasite to the
substrate (host or external items) (Kritsky,
Different gland cells serving various purposes, such as adhesion or digestion, are
found in monogeneans (Smyth and Halton,
1983). Enzymes produced in association
with the gut of gyrodactylids include
alkaline and acid phosphatases, esterases
and proteases (Buchmann, 1998b). The
304
Nervous system
Most monogeneans are mobile and move actively in their microhabitat. Likewise, feeding
305
Fig. 9.10. Histochemical demonstration of the nervous system of Pseudodactylogyrus bini visualized due
to activity of cholinesterases, a. anterior part of worm with four eye spots and cerebral ganglia, b. posterior
body and opisthaptor with hamuli.
306
Parasite Identification
Classical morphological method
Sclerotinized elements hard parts
Classical descriptions of monogeneans have
been based on drawings and measurements
from slide preparations, i.e. helminths
embedded in Canada balsam or other
lipophilic mounting media or hydrophilic
media such as glycerine gelatin. Gyrodactylids are especially well suited for embedding in ammonium picrate glycerine
(Malmberg, 1970). Studies on live worms
are used for description of the excretory
systems and distribution of flame cells. The
primary characters are the shape and size of
hard sclerotinized parts, such as hamuli,
clamps and marginal hooklets, and their
arrangement on the opisthaptor. Additionally, hard reproductive organs, such as the
vagina, cirrus and accessory cirrus, are
important characters. However, body length
and width, arrangements of testes, ovary,
vitellaria, pharynx and intestinal caeca and
gland cell distribution may also supplement the description. It should be noted
that the water temperature at sampling sites
may influence the size of sclerotized structures (Mo, 1991, 1993). Following treatment
with silver nitrate and ultraviolet (UV)
exposure, various sensillae on the parasites
may be visible. The arrangement and distribution of these (chaetotaxy) represent
important taxonomic characters (Shinn
et al., 1997).
Molecular methods
Nuclear DNA encoding ribosomal RNA
from both large and small subunits of
monogenean ribosomes has been the subject of extensive studies (Mollaret et al.,
2000; Olson and Littlewood, 2002). These
genes have been shown to provide excellent
tools for phylogenetic studies and for diagnostic purposes. Further, mitochondrial
DNA has recently been shown to provide
a high degree of sensitivity in phylogenetic studies of gyrodactylids (Zietara
307
308
Fig. 9.12. Eggs of monogeneans. a. Discocotyle sagittata egg (length 300 m), kindly provided by Miguel
Rubio-Godoy, b. Pseudodactylogyrus anguillae, embryonated egg with oncomiracidium ready to hatch,
c. Dawestrema cycloancistrium egg with extended filament.
postlarval development and the adult lifespan are clearly influenced by temperature (Bauer et al., 1973; Buchmann, 1997;
Gannicott and Tinsley, 1997). A number of
species are ovoviviparous and a large group
of monogeneans, represented by most gyrodactylids, are viviparous, i.e. they give rise
to live offspring. In the genus Gyrodactylus,
most representatives are viviparous and
have a well-developed uterus in which the
HostParasite Relationships
Egg hatching
Both abiotic factors and host factors can
affect even the earliest stage of an oviparous
monogenean parasite, the egg. It has been
309
Host finding
The selection of the correct fish host in a
highly complex ecosystem is impressive.
The basic mechanisms behind this choice
are still insufficiently studied. However, due
to the high host specificity in monogenean
fish systems, it has been speculated that
host factors can be recognized by and attract
the monogenean transmitted stage. Controlled
studies were conducted by Kearn (1967)
using E. soleae on S. solea. It appeared that
there was some chemoattraction of the
infective oncomiracidia. Isolated epithelium-covered scales from various fish species were exposed to larvae and the larvae
clearly selected the sole scales and showed
low attraction to dab, plaice, solenette and
thickback sole. Dissected epithelia from
corneae in fish were presented to the parasite as well but appeared to be without the
310
311
312
Pathogenicity
The anatomy of attachment organs, physiology, gland secretions and feeding strategy
vary considerably among monogeneans,
even within the Monopisthocotylea and
Polyopisthocotylea.
Feeding
Direct blood feeding by polyopisthocotyleans can result in anaemia in the host. The
higher the infection intensity, the higher
the loss of blood. Thus, infection with a
high number of blood-feeding worms firmly
anchored in host tissue leads to severe anaemia. This was described by Eto et al. (1976)
studying Heteraxine heterocerca infections
of yellowtail, S. quinqueradiata. Erythrocyte
313
314
Fig. 9.14. Gyrodactylid effects on fins of salmonids. a. Gyrodactylus salaris on Atlantic salmon fin,
b. Gyrodactylus derjavini on rainbow trout fin, c. marginal hooklets of G. derjavini penetrating fin
epithelial cells.
Fig. 9.15. Pathological reactions of eel gills, a. Numerous specimens of Pseudodactylogyrus bini on
eels gills, b. hyperplasia and fusion of gill filaments and lamellae due to infection with P. bini, c. partly
embedded P. bini in tissue reaction of eel gills.
315
316
significant reaction at the site of attachment. In contrast, clamps need intact secondary lamellae in order to attach to the
gills and the strategy of these worms is to
focus on a minimum of damage to the host
structure, although prolonged exposure
may produce gill tissue changes. A combination of infection intensity and damage
produced by the monogenean is well illustrated in G. salaris infecting susceptible
Norwegian salmon. Fry of this vulnerable
host may have several thousand parasites.
Each worm produces with its marginal
hooklets 16 minute holes in epithelial cells
at each attachment site. Further, part of the
infrapopulation moves around on the fins
and skin of the fish. All these will probably
have a devastating impact on osmoregulation in the fish. Studies on the effect of
G. derjavini on rainbow trout showed a positive correlation between mortality of hosts
and intensity of infection (Busch et al., 2003).
317
Biological control
Some fish species are not particularly selective in their food choice and will readily
ingest both adult and larval parasites. It is
well established that labrids can be used for
keeping salmon and cod lice, Lepeophtheirus salmonis and Caligus elongatus,
respectively, at an acceptable level in
salmon net pens. Some monogeneans
attached to the surface of a fish host may
also be easily discernible by cleaner fish.
Several studies have been conducted indicating that cleaner fish can ingest considerable numbers of monogeneans. Control of
Macrogyrodactylus polypteri by tilapia
ingesting ectoparasites from the body surface of African lungfish was reported by
Khalil (1964). Likewise, Kearn (1978)
observed injuries in large monogeneans on
rays probably produced by smaller cleaner
fish. Further, N. melleni on red tilapia was
ingested by cleaner fish (Cowell et al.,
1993), and controlled experiments conducted by Grutter et al. (2002) demonstrated that another capsalid monogenean,
Benedenia lolo, parasitizing Hemigymnus
melapterus was subjected to predation by
the cleaner fish Labroides dimidiatus. Thus,
future control measures may involve the
use of cleaner fish.
Studying a recirculated eel farming system with fish tanks covered with extensive
biofilm layers, it was found that turbellarians of the genus Stenostomum were able to
ingest newly produced eggs of Pseudodactylogyrus spp. attached to the biofilm.
Copepods and other crustaceans are frequently found in fish tank systems and
they may have an impact on monogenean
populations by feeding on oncomiracidia.
Cyclopoid copepods were found to ingest
oncomiracidia of Pseudodactylogyrus spp.
(Buchmann, 1988).
Chemical control
Numerous chemicals have been used with
varying success to control monogenean
infections. The most widely used are copper
sulphate, formaldehyde, sodium chloride
318
The drug has wide application against monogeneans in both marine and freshwater fish
culture. It has high efficacy against Dactylogyrus (Schmahl and Mehlhorn, 1985) and P.
bini and P. anguillae (Buchmann, 1997) in
freshwater aquaculture. Also, under marine
conditions, praziquantel in a bath treatment
or in feed is effective. Thus, monogenicidal
action was shown against Benedeniella
posterocolpa (Thoney, 1990). Effective oral
treatment with praziquantel against M.
sebastis was reported by Kim and Cho
(2000). B. seriolae on kingfish (Ernst et al.,
2003) and Clemacotyle australis on whitespotted eagle rays (Aetobatus narinari) (Janse
and Borgsteede, 2003) can also be controlled by the drug.
Organophosphates paralyse the parasite by inhibiting cholinesterases in the
nervous system and neuromuscular transmission. The widely used representative of
this group is metrifonate, which is used in
low concentrations (0.250.5 ppm) for bath
exposure of fish infected with monogeneans (e.g. Sarig et al., 1965; Chan and
Wu, 1984). Dichlorvos is chemically related
to metrifonate and has a similar mode of
action (Buchmann, 1997).
The anthelmintic niclosamide has a
profound effect on monogeneans (Buchmann, 1997), but the effect on fish is even
stronger, which makes this compound
unsuitable.
319
320
Zoosanitary measures
Due to lack of technology to control infections at an acceptable level, it is often necessary to use more drastic measures. Thus,
some producers use excessive amounts of
anti-parasitic drugs or chemicals to achieve
a profitable production of fish. This is, of
course, problematic for the environment.
Further, the possible use of vaccination or
of immunostimulants is still not developed
for use in commercial fish farming. Thus, it
becomes necessary to implement eradication measures to obtain satisfactory control
of monogenean infections. This has been
applied both in natural systems and in
aquacultural enterprises. The pathogenic
G. salaris has been cleared from more than
16 Norwegian rivers by using rotenone on
the entire water system (Mo, 1994). In this
way, both fish and parasites were killed and
uninfected fish were subsequently stocked
in the rivers. Further, recirculated aquaculture plants have been cleared for infection by emptying, drying and subsequent
disinfection. Following these measures,
uninfected sterilized fish eggs have been
introduced for hatching and restocking to
obtain parasite-free facilities. Cage culture
of fishes suffering from monogenean infections may benefit from fallowing and movements of facilities to new uninfected sites at
regular intervals. Likewise, strategic placement of net pens and farms may take into
consideration the fact that infective stages
of parasites are spread to neighbouring
plants by water currents. Thus, spread of
B. seriolae and Z. seriolae parasites from one
kingfish facility to another is dependent on
water currents (Chambers and Ernst, 2003).
321
Monopisthocotyleans
Family Dactylogyridae
Dactylogyrus vastator
322
Dactylogyrus extensus
323
324
Family Pseudodactylogyridae
Pseudodactylogyrus anguillae and
Pseudodactylogyrus bini
Acolpenteron ureteroecetes
10C is extremely slow. These monogeneans are oviparous and each worm
may produce up to 24 eggs per day. The
eggs embyonate and hatch within 12
days and the postlarval development is
1 week at 25C. The worm may survive
more than 60 days at 25C (Buchmann,
1997).
Pathogenicity. Infected eels develop
hyperplasia of gill structures, including
fusion of gill lamellae. Direct mechanical action by hamuli, marginal hooklets
and feeding activity may elicit the
reactions.
Control. Bath treatment, using various
drugs such as mebendazole (1 ppm) (or
other benzimidazoles) or praziquantel
(10 ppm), is feasible (Buchmann, 1997).
Formaldehyde (50100 ppm) is commonly used by farmers. Trials have
shown that aluminium chloride (1
10 ppm) may have an adverse effect on
the infections (Larsen and Buchmann,
2003). Predation of parasite eggs and
oncomiracidia by turbellaria and copepods, respectively, has been observed,
which suggests alternative control
strategies (Buchmann, 1988).
Dawestrema cycloancistrium
Family Ancyrocephalidae
Ancylodiscoides vistulensis
325
326
Family Diplectanidae
Family Gyrodactylidae
Gyrodactylus anguillae
Furnestia echeneis
Host. Salmonids. Brown trout and rainbow trout are particularly susceptible,
whereas Atlantic salmon is relatively
resistant but may harbour a few
327
328
Host. Main host is common carp, Cyprinus carpio, but occurs occasionally
on other cyprinids.
Macrohabitat. Fresh water.
Geographical distribution. Originally
the parasite was in Asia and has
been introduced to Europe and North
America with the introduction of carp.
Morphology. Body length 0.61.1 mm.
Hamuli are 70112 m long. Ventral bar
with very long anterolateral processes
(1434 m). The marginal hooklet sickle
length is 810 m.
Microhabitat. The parasite selects body
skin and fins but may occur on the gills
and in the buccal cavity.
Life cycle. Viviparous reproduction as
in other gyrodactylids.
Pathogenicity. Adverse effects on hosts
are dependent on intensity of infection
and size of host. More than a million
parasites were found on an adult carp
(Solomatova and Luzin, 1988). Fry and
young fish are particularly vulnerable
to infection, with the parasite causing
morbidity and mortality (Ergens, 1983).
Probably the damage caused by the
attachment hooks and the feeding
activities is responsible for the epithelial damage.
Control. Bath treatments with formaldehyde and ammonia are partly effective (Solomatova and Luzin, 1988).
Mirror carp seems to be relatively resistant to infection compared with the
scaled form of carp (Ergens, 1983).
Gyrodactylus turnbulli and
Gyrodactylus bullatarudis
329
Family Anoplodiscidae
Anoplodiscus tai
330
Family Microbothriidae
Dermophthirius
Neobenedenia girellae
Family Capsalidae
Neobenedenia melleni
Benedenia monticelli
331
332
Neoheterobothrium hirame
(see Ogawa, 1999, 2002)
Polyopisthocotyleans
Family Diclidophoridae
Heterobothrium okamotoi (see Ogawa, 2002)
the buccal cavity wall, where oviposition starts (Anshary and Ogawa, 2001).
Life cycle. Oviposition exceeds 500 per
worm above 15C (Ogawa, 2002). Eggs
hatch in filtered sea water at 20C
within 24 h (Ogawa, 2000). Egg production occurs at the buccal cavity wall
microhabitat. To reach the adult stage
at this site takes 59 days at 15C but
only 31 days at 25C.
Pathogenicity. The parasite feeds
exclusively on host blood, eliciting
anaemia, and this may elicit mortality
(Ogawa, 2002). The strong inflammatory
reaction is associated with necrosis
(Anshary and Ogawa, 2001).
Control.
A
sodium
chloridesupplemented seawater (30 g/l sea
water) bath for 1 h is effective against
immature parasites on the gills.
Family Discocotylidae
Discocotyle sagittata
333
where the developmental rate is highest. Eggs released from the adults
embryonate and hatch within 28 days at
13C. Most embryonated worm eggs
hatch within 1 h from onset of darkness
(Gannicott and Tinsley, 1997). The
oncomiracidia have a lifespan of less
than 24 h at 13C. They attach to the
gills, shed their ciliary plates and develop
into adults. However, no transmission
occurs during cold winter months and
accumulated eggs hatch during spring
when temperatures rise above 10C
(Gannicott and Tinsley, 1998).
Pathogenicity. The worm is blood-feeding
and anaemia may develop in heavily
infected hosts. Intensities of more than
1000 parasites per host occur in trout
farms, although wild hosts normally
bear only a few parasites (Rubio-Godoy
and Tinsley, 2002).
Control. Anthelmintics such as praziquantel and benzimidazoles may have
some effect. It has been shown that
hosts produce specific antibodies against
the worm and immunization with worm
material confers some slight protection
against challenge infections (RubioGodoy et al., 2003a,b).
Family Microcotylidae
Microcotyle sebastis
334
Allobivagina sp.
Heteraxine heterocerca
335
References
Andersen, P.S. and Buchmann, K. (1998) Temperature dependent population growth of Gyrodactylus
derjavini on rainbow trout, Oncorhynchus mykiss. Journal of Helminthology 72, 914.
Anderson, J.I.W. and Conroy, D.A. (1968) The significance of disease in preliminary attempts to raise flatfish
and salmonids in sea water. Bulletin Office Internationaldes Epizootie 69, 11291137.
Anshary, H. and Ogawa, K. (2001) Microhabitats and mode of attachment of Neoheterobothrium hirame, a
monogenean parasite of Japanese flounder. Fish Pathology 36, 2126.
336
Bakke, T.A. and MacKenzie, K. (1993) Comparative susceptibility of native Scottish and Norwegian stocks of
Atlantic salmon, Salmo salar L., to Gyrodactylus salaris Malmberg: laboratory experiments. Fisheries
Research 17, 6985.
Bakke, T.A., Jansen, P.A. and Hansen, L.P. (1990) Differences in host resistance of Atlantic salmon, Salmo
salar L., stocks to the monogenean Gyrodactylus salaris Malmberg, 1957. Journal of Fish Biology 37,
577587.
Bakke, T.A., Soleng, A., Lunde, H. and Harris, P.D. (2000) Resistance mechanisms in Salmo salar stocks
infected with Gyrodactylus salaris. Acta Parasitologica 45, 272.
Bakke, T.A., Harris, P.D. and Cable, J. (2002) Host specificity dynamics: observations on gyrodactylid
monogeneans. International Journal for Parasitology 32, 281308.
Bauer, O.N., Musselius, V.A. and Strelkov, Y. (1973) Diseases of Pond Fishes. Translated from Russian. Israel
Program for Scientific Translation, Jerusalem.
Boeger, W.A. and Kritsky, D.C. (1997) Coevolution of the Monogenoidea (Platyhelminthes) based on a
revised hypothesis of parasite phylogeny. International Journal for Parasitology 27, 14951511.
Bondad-Reantaso, M.G., Ogawa, K., Fukudome, M. and Wakabayashi, H. (1995a) Reproduction and growth
of Neobenedenia girellae (Monogenea: Capsalidae), a skin parasite of cultured marine fishes of Japan.
Fish Pathology 30, 227231.
Bondad-Reantaso, M.G., Ogawa, K., Yoshinaga, T. and Wakabayashi, H. (1995b) Acquired protection against
Neobenedenia girellae in Japanese flounder. Fish Pathology 30, 233238.
Buchmann, K. (1988) Epidemiology of pseudodactylogyrosis in an intensive eel culture system. Diseases of
Aquatic Organisms 5, 8185.
Buchmann, K. (1993) A note on the humoral immune response of infected Anguilla anguilla against the gill
monogenean Pseudodactylogyrus bini. Fish and Shellfish Immunology 3, 397399.
Buchmann, K. (1997) Infection biology of gill parasitic monogeneans with special reference to the congeners
Pseudodactylogyrus bini and P. anguillae (Monogenea: Platyhelminthes) from European eel. Dissertation, Royal Veterinary and Agricultural University, Frederiksberg, Denmark.
Buchmann, K. (1998a) Binding and lethal effect of complement from Oncorhynchus mykiss on Gyrodactylus
derjavini (Platyhelminthes: Monogenea). Diseases of Aquatic Organisms 32, 195200.
Buchmann, K. (1998b) Histochemical characteristics of Gyrodactylus derjavini parasitizing the fins of rainbow
trout (Oncorhynchus mykiss). Folia Parasitologica 45, 312318.
Buchmann, K. (1999) Immune responses in fish against monogeneans a model. Folia Parasitologica 46,
19.
Buchmann, K. (2001) Lectins in fish skin: do they play a role in monogeneanfish host interactions? Journal of
Helminthology 75, 227232.
Buchmann, K. and Bjerregaard, J. (1990) Mebendazole treatment of pseudodactylogyrosis in an intensive
eel-culture system. Aquaculture 86, 139153.
Buchmann, K. and Bresciani, J. (1999) Rainbow trout leukocyte activity: influence on the ectoparasitic
monogenean Gyrodactylus derjavini. Diseases of Aquatic Organisms 35, 1322.
Buchmann, K. and Kristensson, R.T. (2003) Efficacy of sodium percarbonate and formaldehyde bath treatments against Gyrodactylus derjavini infestations of rainbow trout. North American Journal of
Aquaculture 65, 2527.
Buchmann, K. and Uldal, A. (1997) Gyrodactylus derjavini infections in four salmonids: comparative host susceptibility and site selection of parasites. Diseases of Aquatic Organisms 28, 201209.
Buchmann, K., Slotved, H.-C. and Dana, D. (1993) Epidemiology of gill parasite infections in Cyprinus carpio
in Indonesia and possible control methods. Aquaculture 118, 921.
Buchmann, K., Uldal, A. and Mellergaard, S. (1994) Mortality of captive Arapaima gigas (Osteoglossidae)
heavily infected with the gill monogenean Dawestrema cycloancistrium. Bulletin of the European Association of Fish Pathologists 14, 171173.
Buchmann, K., Lindenstrm, T. and Sigh, J. (1999) Partial cross-protection against Ichthyophthrius multifiliis infection in Gyrodactylus derjavini immunized rainbow trout. Journal of Helminthology 73,
189195.
Buchmann, K., Nielsen, C.V. and Bresciani, J. (2000) In vitro interactions between epithelial cells and
Gyrodactylus derjavini. Journal of Helminthology 74, 20032008.
Buchmann, K., Madsen, K.K. and Dalgaard, M. (2004) Homing of Gyrodactylus salaris and G. derjavini:
(Monogenea) on different hosts and response post-attachment. Folia Parasitologica 51, 263267.
Bulaev, A.I. (1982) Experimental study of elimination of cercariae by freshwater crustaceans Cyclops vicinus
(order Cyclopoida). Gelminty v presnovodnykh biotsenozakh, Moscow, USSR, Nauka I, 7381.
337
Busch, S., Dalsgaard, I. and Buchmann, K. (2003) Concomitant exposure of rainbow trout fry to Gyrodactylus
derjavini and Flavobacterium psychrophilum: effects on infection and mortality of host. Veterinary Parasitology 117, 117122.
Bychowsky, B.E. (1957) Monogenetic Trematodes, Their Systematics and Phylogeny. Izdatelstvo Akademiya
Nauk SSSR, Leningrad (English translation American Institute of Biological Sciences, 1961).
Cable, J. and Harris, P.D. (2002) Gyrodactylid developmental biology: historical review, current status and
future trends. International Journal for Parasitology 32, 255280.
Cable, J., Tinsley, R.C. and Harris, P.D. (2002) Survival, feeding and embryo development of Gyrodactylus
gasterostei (Monogenea: Gyrodactylidae). Parasitology 124, 5368.
Chambers, C. and Ernst, I. (2003) Effect of tidal current on monogenean egg dispersal and infection rates at a
kingfish farm in Australia. In: Van As, J. (ed.) Proceedings of the 6th International Symposium on Fish Parasitology, Bloemfontein, South Africa, September 2226. University of Free State, Bloemfontein, South
Africa, P.I.
Chan, B. and Wu, B. (1984) Studies on the pathogenicity, biology and treatment of Pseudodactylogyrus in fish
farms. Acta Zoologica Sinica 30, 173180.
Cheung, P.J., Nigrelli, R.F., Ruggieri, G.D. and Cilia, A. (1982) Treatment of skin lesions in captive lemon
sharks, Negaprion brevirostris (Poey), caused by monogeneans (Dermophthirius sp.). Journal of Fish
Diseases 5, 167170.
Chisholm, L.A., Whittington, I.D. and Fischer, A.B.P. (2004) A review of Dendromonocotyle (Monogenea:
Monocotylidae) from the skin of stingrays and their control in public aquaria. Folia Parasitologica 51,
123130.
Collins, C.M. and Cunningham, C.O. (2000) Characterization of the Gyrodactylus salaris Malmberg, 1957
(Platyhelminthes: Monogenea) ribosomal intergenic spacer (IGS) DNA. Parasitology 121, 555563.
Cone, D.K. and Burt, M.D.B. (1981) The invasion route of the gill parasite Urocleidus adspectus Mueller,
1936 (Monogenea: Ancyrocephalinae). Canadian Journal of Zoology 59, 21662171.
Cone, D.K. and Cusack, R. (1988) A study of Gyrodactylus colemanensis Mizelle and Kritsky, 1967 and
Gyrodactylus salmonis (Yin and Sproston, 1948) parasitizing captive salmonids in Nova Scotia. Canadian
Journal of Zoology 66, 409415.
Cone, D.K. and Cusack, R. (1989) Infrapopulation dispersal of Gyrodactylus colemanensis (Monogenea) on
fry of Salmo gairdneri. Journal of Parasitology 75, 702706.
Cone, D.K. and Odense, P.H. (1984) Pathology of five species of Gyrodactylus Nordmann, 1832
(Monogenea). Canadian Journal of Zoology 62, 10841088.
Cone, D.K. and Wiles, M. (1989) Ultrastructural study of attachment of Gyrodactylus colemanensis
(Monogenea) to fins of fry of Salmo gairdneri. Proceedings of the Helminthological Society of Washington
56, 2932.
Cone, D.K., Beverley-Burton, M., Wiles, M. and MacDonald, T.E. (1983) The taxonomy of Gyrodactylus
(Monogenea) parasitizing certain salmonid fishes of North America, with a description of Gyrodactylus
nerkae n. sp. Canadian Journal of Zoology 61, 25872597.
Cone, D.K., Gratzek, J.B. and Hoffmann, G.L. (1987) A study of Enterogyrus sp. (Monogenea) parasitizing the
foregut of captive Pomacanthus paru (Pomacanthidae) in Georgia. Canadian Journal of Zoology 65,
312316.
Cowell, L.E., Watanabe, W.O., Head, W.D., Grover, J.J. and Shenker, M.M. (1993) Use of tropical cleaner fish
to control the ectoparasite Neobenedeni melleni (Monogenea: Capsalidae) on sea-water cultured Florida
red tilapia. Aquaculture 113, 189200.
Cunningham, C.O. (1997) Species variation within the internal transcribed spacer (ITS) region of
Gyrodactylus (Monogenea, Gyrodactylidae) ribosomal RNA genes. Journal of Parasitology 83, 215219.
Cunningham, C.O. (2002) Molecular Diagnosis of Salmonid Diseases. Methods and Technologies in Fish Biology and Fisheries. Kluwer Academic Publishers, Dordrecht, The Netherlands.
Cunningham, C.O. and Mo, T.A. (1997) Random amplified polymorphic DNA (RAPD) analysis of three
Norwegian Gyrodactylus salaris populations (Monogenea, Gyrodactylidae). Journal of Parasitology 83,
311314.
Cunningham, C.O., Mo, T.A., Collins, C.M., Buchmann, K., Thiery, R., Blanc, G. and Lautraite, A.
(2001) Redescription of Gyrodactylus teuchis Lautraite, Blanc, Thiery, Daniel & Vigneulle, 1999
(Monogenea: Gyrodactylidae); a species identified by ribosomal RNA sequence. Systematic Parasitology
48, 141150.
Cusack, R. (1986) Development of infections of Gyrodactylus colemanensis Mizelle and Kritstry, 1967
(Monogenea) and the effects on fry of Salmo gairdneri Richardson. Journal of Parasitology 72, 663668.
338
Cusack, R. and Cone, D.K. (1985) A report of bacterial microcolonies on the surface of Gyrodactylus
(Monogenea). Journal of Fish Diseases 8, 125127.
Cusack, R. and Cone, D.K. (1986) A review of parasites as vectors of viral and bacterial diseases of fish.
Journal of Fish Diseases 9, 169171.
Dalgaard, M.B., Nielsen, C.V. and Buchmann, K. (2003) Comparative susceptibility of two races of Salmo
salar (Baltic Lule river and Atlantic Conon river strains) to infection with Gyrodactylus salaris. Diseases of
Aquatic Organisms 53, 173176.
Deveney, M.R., Chisholm, L.A. and Whittington, I.D. (2001) First published record of the pathogenic
monogenean parasite Neobenedenia melleni (Capsalidae) from Australia. Diseases of Aquatic Organisms
46, 7982.
Egusa, S. (1983) Disease problems in Japanese yellowtail, Seriola quinqueradiata, culture: a review. Rapports
et Procs-verbaux des Runion Conseil International pour Exploration de la Mer 182, 1018.
El-Naggar, M.M. and Kearn, G.C. (1980) Ultrastructural observations on the anterior adhesive apparatus in the
monogenean Dactylogyrus amphibothrium Wagener, 1857 and D. hemiamphibothrium Ergens, 1956.
Zeitschrift fr Parasitenkunde 61, 223241.
El-Naggar, M.M. and Kearn, G.C. (1983) The tegument of the monogenean gill parasites Dactylogyrus
amphibothrium and D. hemiamphibothrium. International Journal for Parasitology 13, 579592.
Ergens, R. (1983) A survey of results of studies on Gyrodactylus katharineri Malmberg, 1964 (Gyrodactylidae:
Monogenea). Folia Parasitologica 30, 319327.
Ernst, I., Chambers, C. and Whittington, I.D. (2003) Contrasting challenges for efficient management of
monogenean parasites infecting Seriola spp. in Australia and Japan. In: Van As, J. (ed.) Proceedings of the
6th International Symposium for Fish Parasitology, Bloemfontein, South Africa, September 2226.
University of Free State, Bloemfontein, South Africa.
Eto, A., Sakamoto, S., Fujii, M., and Yone, Y. (1976) Studies on an anemia of yellowtail parasitized by
a trematode, Axine (Heteraxine) heterocerca. Report of the Fisheries Research Laboratory. Kyushu
University 3, 4552.
Euzet, L. and Combes, C. (1998) The selection of habitats among the monogenea. International Journal for Parasitology 28, 16451652.
Faisal, M. and Imam, E.A. (1990) Microcotyle chrysophryii (Monogenea: Polyopisthocotylea), a pathogen for
cultured and wild sea bream, Sparus aurata. In: Perkins, F.O. and Cheng, T.C. (eds) Pathology in Marine
Science. Academic Press, New York, pp. 283290.
Fischthal, J.H. and Allison, L.N. (1941) Acolpenteron ureteroecetes Fischthal and Allison, 1940, a
monogenetic trematode from the ureters of the black basses, with a revision of the family
Calceostomatidae (Gyrodactyloidea). Journal of Parasitology 27, 517524.
Gannicott, A.M. and Tinsley, R.C. (1997) Egg hatching in the monogenean gill parasite Discocotyle sagittata
from the rainbow trout (Oncorhynchus mykiss). Parasitology 114, 569579.
Gannicott, A.M. and Tinsley, R.C. (1998) Environmental effects on transmission of Discocotyle sagittata
(Monogenea): egg production and development. Parasitology 117, 499504.
Gelnar, M. (1987) Experimental verification of the effect of water temperature on micropopulation growth of
Gyrodactylus katharineri Malmberg, 1964 (Monogenea) parasitizing carp fry (Cyprinus carpio L.). Folia
Parasitologica 34, 1923.
Gonzales-Lanza, C., Alvarez-Pellitero, P. and Sitja-Bobadilla, A. (1991) Diplectanidae (Monogenea) infestations of sea bass, Dicentrarchus labrax (L.) from the Spanish Mediterranean area. Parasitology Research
77, 307314.
Goven, B.A. and Amend, D.F. (1982) Mebendazole/trichlorfon combination: a new anthelmintic for removing
monogenetic trematodes from fish. Journal of Fish Biology 20, 373378.
Grutter, A.S., Deveney, M.R., Whittington, I.D. and Lester R.J.G. (2002) The effect of the cleaner fish
Labroides dimidiatus on the capsalid monogenean Benedenia lolo parasite of the labrid fish
Hemigymnus melapterus. Journal of Fish Biology 61, 10981108.
Halton, D.W. (1974) Hemoglobin absorption in the gut of a monogenetic trematode Diclidophora merlangi.
Journal of Parasitology 60, 5966.
Halton, D.W. (1978) Transtegumental absorption of L-alanine and L-leucine by a monogenean, Diclidophora
merlangi. Parasitology 76, 2937.
Halton, D.W., Maule, A.G. and Shaw, C. (1993) Neuronal mediators in monogenean parasites. Bulletin
Franais de la Pche et de la Pisciculture 328, 82104.
Halton, D.W., Maule, A.G., Mair, G.R. and Shaw, C. (1998) Monogenean neuromusculature: some structural
and functional correlates. International Journal for Parasitology 28, 16091623.
339
Hansen, H., Bachmann, L. and Bakke, T.A. (2003) Mitochondrial DNA variation of Gyrodactylus spp.
(Monogenea, Gyrodactylidae) populations infecting Atlantic salmon, grayling, and rainbow trout in
Norway and Sweden. International Journal for Parasitology 33, 14711478.
Harris, P.D. (1988) Changes in the site specificity of Gyrodactylus turnbulli Harris, 1986 (Monogenea) during
infections of individual guppies (Poecilia reticulata Peters, 1859). Canadian Journal of Zoology 66,
28542857.
Harris, P.D., Soleng, A. and Bakke, T.A. (1998) Killing of Gyrodactylus salaris (Platyhelminthes, Monogenea)
mediated by host complement. Parasitology 117, 137143.
Harris, P.D., Soleng, A. and Bakke, T.A. (2000) Increased susceptibility of salmonids to the monogenean
Gyrodactylus salaris following administration of hydrocortisone acetate. Parasitology 120, 5764.
Hayward, C.J., Kim, J.-H. and Heo, G.-J. (2001) Spread of Neoheterobothrium hirame (Monogenea), a serious
pest of olive flounder Paralichthys olivaceus, to Korea. Diseases of Aquatic Organisms 45, 209213.
Hendrix, S. (2004) Some aspects of the biology and life history of Bothitrema bothi (Monogenea:
Bothitrematidae) from the flounder, Scophthalmus aquosus (Bothidae), from New Jersey, USA. Folia
Parasitologica 51, 229237.
Hirazawa, N., Oshima, S., Mitsuboshi, T. and Yamashita, S. (2003) Mucus pH of the tiger puffer Takifugu
rubripes is an important factor for host identification by the monogenean Heterobothrium okamotoi.
Parasitology 127, 225230.
Hoshina, T. (1968) On the monogenetic trematode, Benedenia seriolae, parasitic on yellowtail, Seriola
quinqueradiata. Bulletin Office International Epizootie 69, 11791191.
Jahn, T.L. and Kuhn, L.R. (1932) The life history of Epibdella melleni Maccallum 1927, a monogenetic trematode
parasitic on marine fishes. Biological Bulletin, Marine Biological Laboratory, Woods Hole 62, 89111.
Janse, M. and Borgsteede, F.H.M. (2003) Praziquantel treatment of captive white-spotted eagle rays
(Aetobatus narinari) infested with monogenean trematodes. Bulletin of the European Association of Fish
Pathologists 23, 152156.
Jansen, P.A. and Bakke, T.A. (1991) Temperature-dependent reproduction and survival of Gyrodactylus salaris
Malmberg, 1957 (Platyhelminthes: Monogenea) on Atlantic salmon Salmo salar. Parasitology 102,
105112.
Johnsen, B.O. and Jensen, A.J. (1986) Infestation of Atlantic salmon, Salmo salar, by Gyrodactylus salaris in
Norway. Journal of Fish Biology 29, 233241.
Justine, J.L. (1993) Phylogeny of the Monogenea based upon a parsimony analysis of characters of
spermiogenesis and spermatozoon ultrastructure including recent results. Bulletin Franais de la Pche et
de la Pisciculture 328, 137155.
Justine, J.L. (1998) Non-monophyly of the monogeneans? International Journal for Parasitology 28,
16531657.
Justine, J.L. and Bonami, J.R. (1993) Virus-like particles in a monogenean (Platyhelminthes) parasitic in a
marine fish. International Journal for Parasitology 23, 6975.
Kaneko, I.J., Yamada, R., Brock, J.A. and Nakamura, R.N. (1988) Infection of tilapia, Oreochromis
mossambicus (Trewavas), by a marine monogenean, Neobenedenia melleni (MacCallum, 1927)
Yamaguti, 1963 in Kaneohe Bay, Hawai, USA, and its treatment. Journal of Fish Diseases 11, 295300.
Kearn, G.C. (1963) The egg, oncomiracidium and larval development of Entobdella soleae, a monogenean
skin parasite of the common sole. Parasitology 53, 435447.
Kearn, G. (1967) Experiments on host-finding and host-specificity in the monogenean skin parasite Entobdella
soleae. Parasitology 57, 585605.
Kearn, G.C. (1974) The effects of fish skin mucus on hatching in the monogenean parasite Entobdella soleae
from the skin of the common sole, Solea solea. Parasitology 68, 173188.
Kearn, G.C. (1978) Predation on a skin-parasitic monogenean by a fish. Journal of Parasitology 64,
11291130.
Kearn, G.C. (1994) Evolutionary expansion of the Monogenea. International Journal for Parasitology 24,
12271271.
Kearn, G.C. (2002) Entobdella soleae pointers to the future. International Journal for Parasitology 32,
367372.
Kearn, G.C. and Evans-Gowing, R. (1998) Attachment and detachment of the anterior adhesive pads of the
monogenean (platyhelminth) parasite Entobdella soleae from the skin of the common sole (Solea solea).
International Journal for Parasitology 28, 15831593.
Khalil, L.F. (1964) On the biology of Macrogyrodactylus polypteri Malmberg, 1956, a monogenetic trematode
on Polypterus senegalus in Sudan. Journal of Helminthology 38, 219222.
340
Kim, K.H. and Cho, J.B. (2000) Treatment of Microcotyle sebastis (Monogenea: Polyopisthocotylea)
infestation with praziquantel in an experimental cage simulating commercial rockfish Sebastes
schlegeli culture conditions. Diseases of Aquatic Organisms 40, 229231.
Kim, K.H., Hwang, Y.J., Cho, J.B. and Park, S.I. (2000) Immunization of cultured rockfish Sebastes schlegeli
against Microcotyle sebastis (Monogenea). Diseases of Aquatic Organisms 40, 2932.
Kritsky, D.C. (1978) The cephalic glands and associated structures in Gyrodactylus eucaliae Ikezaki and
Hoffmann, 1957 (Monogenea: Gyrodactylidae). Proceedings of the Helminthological Society of
Washington 45, 3749.
Kritsky, D.C. and Heckmann, R. (2002) Species of Dactylogyrus (Monogenoidea: Dactylogyridae) and
Trichodina mutabilis (Ciliata) infesting koi carp, Cyprinus carpio, during mass mortality at a commercial
rearing facility in Utah, USA. Comparative Parasitology 69, 217218.
Kritsky, D.C., Boeger, W. and Thatcher, V.E. (1985) Neotropical Monogenea. 7. Parasites of the pirarucu, Arapaima gigas (Cuvier), with description of two new species and redescription of Dawestrema
cycloancistrium Price and Nowlin, 1967 (Dactylogyridae: Ancyrocephalinae). Proceedings of the
Biological Society of Washington 98, 321331.
Kritsky, D.C., Bourget, D. and Spall, R. (1994) Fine structure of the gastrodermis of two species of
Gyrodactylus (Monogenoidea: Polyonchoinea, Gyrodactylidae). Transactions of the American Microscopical Society 113, 4351.
Larsen, A.H., Bresciani, J. and Buchmann, K. (2002) Interactions between ecto- and endoparasites in trout
Salmo trutta. Veterinary Parasitology 103, 167173.
Larsen, T.B. and Buchmann, K. (2003) Effects of aqueous aluminium chloride and zinc chloride on survival of
the gill parasitizing monogenean Pseudodactylogyrus anguillae from European eel Anguilla anguilla. Bulletin of the European Association of Fish Pathologists 23, 123127.
Leong, T.S. (1997) Control of parasites in cultured marine finfishes in Southeast Asia an overview. International Journal for Parasitology 27, 11771184.
Lester, R.J.G. (1972) Attachment of Gyrodactylus to Gasterosteus and host response. Journal of Parasitology
58, 717722.
Lester, R.J.G. and Adams, J.R. (1974) A simple model of a Gyrodactylus population. International Journal for
Parasitology 4, 497506.
Lim, L.H.S. (1998) Diversity of monogeneans in Southeast Asia. International Journal for Parasitology 28,
14951515.
Lindenstrm, T. and Buchmann, K. (2000) Acquired resistance in rainbow trout against Gyrodactylus
derjavini. Journal of Helminthology 74, 155160.
Lindenstrm, T., Buchmann, K. and Secombes, C.J. (2003) Gyrodactylus derjavini infection elicits IL-1beta
expression in rainbow trout skin. Fish and Shellfish Immunology 15, 107115.
Lindenstrm, T., Secombes, C.J. and Buchmann, K. (2004) Expression of immune response genes in rainbow
trout skin induced by Gyrodactylus derjavini infections. Veterinary Immunology and Immunopathology
97, 137148.
Llewellyn, J. (1960) Amphibdellid (monogenean) parasites of electric rays (Torpedinidae). Journal of the
Marine Biological Association UK 39, 561589.
Llewellyn, J. (1982) Host specificity and corresponding evolution in monogenean flatworms and vertebrates.
Mmoires de Musum National dHistoire Naturelle 123, 289293.
Llewellyn, J. and Simmons, J.E. (1984) The attachment of the monogenean parasite Callorhyncicola
multitesticulatus to the gills of its holocephalan host Callorhynchus millii. International Journal for
Parasitology 14, 191196.
Lutta, A.S. (1941) [Infection of Aral sturgeon (Acipenser nudiventris) with the gill trematode Nitzschia
sturionis.] Trudy Leningrad Obbschchest Estetsvoispyt 68, 4060 (in Russian).
Lyons, K.M. (1969) Sense organs of monogenean skin parasites ending in a typical cilium. Parasitology 59,
625636.
Lyons, K.M. (1970) Fine structure of the outer epidermis of the viviparous monogenean Gyrodactylus sp. from
the skin of Gasterosteus aculeatus. Journal of Parasitology 56, 11101117.
MacDonald, S. (1974) Host skin mucus as a hatching stimulant in Acanthocotyle lobianchi, a monogenean
from the skin of Raja spp. Parasitology 68, 331338.
MacDonald, S. and Llewellyn, J. (1980) Reproduction in Acanthocotyle greeni n. sp. (Monogenea) from the
skin of Raia spp. at Plymouth. Journal of the Marine Biological Association UK 60, 8188.
Madhavi, M. and Anderson, R.M. (1985) Variability in the susceptibility of the fish host Poecilia reticulata, to
infection with Gyrodactylus bullatarudis (Monogenea). Parasitology 91, 531544.
341
Malmberg, G. (1970) The excretory system and the marginal hooks as a basis for the systematics of
Gyrodactylus (Trematoda: Monogenea). Arkiv fr Zoologi 23, 1235.
Martins, M.L., Onaka, E.M., Moraes, F.R. and Fujimoto, R.Y. (2001) Mebendazole treatment against Anacanthorus penilabiatus (Monogenea, Dactylogyridae) gill parasite of cultivated Piaractus mesopotamicus
(Osteichthyes, Characidae) in Brazil. Efficacy and hematology. Acta Parasitologica 46, 332336.
Mazzanti, C., Monni, G. and Varriale, A.M.C. (1999) Observations on antigenic activity of Pseudodactylogyrus anguillae (Monogenea) on the European eel (Anguilla anguilla). Bulletin of the European
Association of Fish Pathologists 19, 5759.
Mo, T.A. (1991) Seasonal variations of opisthaptoral hard parts of Gyrodactylus salaris Malmberg, 1957
(Monogenea: Gyrodactylidae) on parr of Atlantic salmon Salmo salar L. in laboratory experiments.
Systematic Parasitology 20, 1120.
Mo, T.A. (1993) Seasonal variations of opisthaptoral hard parts of Gyrodactylus derjavini Mikailov, 1975
(Monogenea: Gyrodactylidae) on brown trout Salmo trutta L. parr and of Atlantic salmon Salmo salar L.
parr in the river Sandvikselva, Norway. Systematic Parasitology 26, 225231.
Mo, T.A. (1994) Status of Gyrodactylus salaris: problems and research in Norway. In: Pike, A.W. and
Lewis, J.W. (eds) Parasitic Diseases of Fish. Samara Publishing, Tresaith, UK, pp. 4356.
Mo, T.A. and MacKenzie, K.A. (1991) Occurrence of Gyrodactyloides bychowskii Albova, 1948 on
gills of sea-caged Atlantic salmon. Bulletin of the European Association of Fish Pathologists 11,
156158.
Mollaret, I., Jamieson, B.G.M. and Justine, J.-L. (2000) Phylogeny of the Monopisthocotylea and
Polyopisthocotylea (Platyhelminthes) inferred from 28S rDNA sequences. International Journal for Parasitology 30, 171185.
Molnar, K. (1968) Die Wurmkrankheit (Ancylodiscoidose) des Welses (Silurus glanis). Zeitschrift fr Fischerei
16, 2141.
Molnar, K. (1972) Studies on gill parasitosis of grass-carp (Ctenopharyngodon idella) caused by Dactylogyrus
lamellatus Achmerow, 1952. IV. Histopathological changes. Acta Veterinaria Academiae Scientiarum
Hungariae 22, 924.
Molnar, K. (1994) Effects of decreased water oxygen content on common carp fry with Dactylogyrus vastator
(Monogenea) infection of varying severity. Diseases of Aquatic Organisms 20, 153157.
Morris, G.P. and Halton, D.W. (1975) The occurrence of bacteria and mycoplasma-like organisms in a
monogenean parasite Diclidophora merlangi. International Journal for Parasitology 5, 495498.
Nigrelli, R.F. and Breder, C.M. (1934) The susceptibility and immunity of certain fishes to Epibdella melleni, a
monogenetic trematode. Journal of Parasitology 20, 259269.
Obiekezie, A.I. and Taege, M. (1991) Mortalities in hatchery-reared fry of the African catfish, Clarias
gariepinus (Burchell) caused by Gyrodactylus groschafti Ergens, 1973. Bulletin of the European Association of Fish Pathologists 11, 8285.
Ogawa, K. (1994) Anoplodiscus tai sp. nov. (Monogenea: Anoplodiscidae) from cultured red sea bream
Pagrus major. Fish Pathology 29, 510.
Ogawa, K. (1999) Neoheterobothrium hirame sp. n. (Monogenea: Diclidophoridae) from the buccal cavity of
Japanese flounder Paralichthys olivaceus. Fish Pathology 34, 195201.
Ogawa, K. (2000) The oncomiracidium of Neoheterobothrium hirame, a monogenean parasite of Japanese
flounder Paralichthys olivaceus. Fish Pathology 35, 299230.
Ogawa, K. (2002) Impacts of diclidophorid monogenean infections on fisheries in Japan. International Journal
for Parasitology 32, 373380.
Ogawa, K. and Egusa, S. (1976) Studies on eel pseudodactylogyrosis I. Morphology and classification of
three eel dactylogyrids with a proposal of a new species Pseudodactylogyrus microrchis. Bulletin of the
Japanese Society of Scientific Fisheries 51, 381385.
Ogawa, K. and Egusa, S. (1980) Gyrodactylus infections of cultured eels (Anguilla japonica and A. anguilla) in
Japan. Fish Pathology 15, 9599.
Ogawa, K. and Egusa, S. (1985) Tetraonchus infections of masou salmon, Oncorhynchus masou. Fish Pathology
19, 215223.
Ogawa, K. and Hioki, M. (1986) Two new species of Gyrodactylus (Monogenea: Gyrodactylidae) of eel,
Anguilla japonica, with some data on the occurrence of gyrodactylids in greenhouse culture at Yoshida,
Shizuoka prefecture, Japan. Fish Pathology 21, 8994.
Olafsdottir, S.H., Lassen, H.P.. and Buchmann, K. (2003) Labile resistance of Atlantic salmon, Salmo salar
L., to infections with Gyrodactylus derjavini Mikailov, 1975: implications for host specificity. Journal of
Fish Diseases 26, 5154.
342
Oliver, G. (1977) Effet pathogne de la fixation de Diplectanum aequans (Wagener, 1857) Diesing, 1858
(Monogenea, Monopisthocotylea, Diplectanidae) sur les branchies de Dicentrarchus labrax (Linnaeus,
1758, Pisces, Serranidae). Zeitschrift fr Parasitenkunde 53, 711.
Oliver, G. (1984) Microcotyle chrysophryii Van Beneden and Hesse, 1863 (Monogenea, Polyopisthocotylea,
Microcotylidae) a gill parasite of Sparus aurata Linnaeus, 1758 (Teleostei, Sparidae) in some coastal
ponds of Languedoc-Roussillon. Bulletin de la Socit Zoologique de France Evolution et Zoologie 109,
113118.
Olson, P.D. and Littlewood, D.T.J. (2002) Phylogenetics of the monogenea evidence from a medley of molecules. International Journal for Parasitology 32, 233244.
Paperna, I. (1963) Some observations on the biology and ecology of Dactylogyrus vastator in Israel. Bamidgeh
Israel 15, 828.
Paperna, I. (1964) Competitive exclusion of Dactylogyrus extensus by Dactylogyrus vastator (Trematoda,
Monogenea) on the gills of reared carp. Journal of Parasitology 50, 9498.
Paperna, I. and Laurencin, B.F. (1979) Parasitic infections of sea bass, Dicentrarchus labrax, and gilthead sea
bream, Sparus aurata, in mariculture facilities in France. Aquaculture 16, 173175.
Paperna, I. And Overstreet, R.M. (1981) Parasites and diseases of mullets (Mugilidae). In: Oren, O.H. (ed.)
Aquaculture of Grey Mullets. International Programme 26. Cambridge University Press, Cambridge, UK,
pp. 411493.
Paperna, I., Colorni, A., Gordin, H. and Kissil, G.W. (1977) Diseases of Sparus aurata in marine culture at Elat.
Aquaculture 10, 195213.
Paperna, I., Diamant, A. and Overstreet, R.M. (1984) Monogenean infestations and mortality in wild and
cultured red sea fishes. Helgolnder Meeres-Untersuchungen 37, 445462.
Petrie-Hanson, L. (2001) First reported mortality and associated pathology attributed to Acolpenteron
ureteroecetes in largemouth bass. Journal of Aquatic Animal Health 13, 364367.
Petrushevski, G.K. and Shulman, S.S. (1961) The parasitic diseases of fishes in the natural waters of the USSR.
In: Dogiel, V.A., Petrushevski, G.K. and Polyanski, Y.I. (eds) Parasitology of Fishes. Oliver & Boyd,
Edingburgh, UK, pp. 299319.
Prost, M. (1963) Investigations on the development and pathogenicity of Dactylogyrus anchoratus (Duj. 1845)
and D. extensus Mueller et van Cleave, 1932 for breeding carps. Acta Parasitologica Polonica 11, 1748.
Rand, T.G., Wiles, M. and Odense, P. (1986) Attachment of Dermophthirius carcharini (Monogenea:
Microbothriidae) to the Galapagos shark Carcharhinus galapagensis. Transactions of the American
Microscopical Society 105, 158169.
Richards, G.R. and Chubb, J.C. (1996) Host responses to initial and challenge infections, following treatment
of Gyrodactylus bullatarudis and G. turnbulli (Monogenea) on the guppy (Poecilia reticulata). Parasitology Research 82, 242247.
Rohde, K. (1977) Habitat partitioning in Monogenea of marine fishes. Zeitschrift fr Parasitenkunde 53,
171182.
Rohde, K. (1993) Ultrastructure of protonephridia in the Monogenea. Implications for the phylogeny of the
group. Bulletin Franais de la Pche et de la Pisciculture 328, 115119.
Roubal, F.R. (1995) Microhabitats, attachment of eggs and histopathology by the monogenean
Allomurraytrema robustum on Acanthopagrus australis (Pisces: Sparidae). International Journal for Parasitology 25, 293298.
Rubio-Godoy, M. and Tinsley, R. (2002) Trickle and single infection with Discocotyle sagittata (Monogenea:
Polyopisthocotylea): effect of exposure mode on parasite abundance and development. Folia
Parasitologica 49, 269278.
Rubio-Godoy, M. and Tinsley, R. (2004) Comparative susceptibility of brown and rainbow trout to
Discocotyle sagittata (Monogenea). Journal of Parasitology 90, 900901.
Rubio-Godoy, M., Sigh, J., Buchmann, K. and Tinsley, R. (2003a) Immunization of rainbow trout
Oncorhynchus mykiss against Discocotyle sagittata (Monogenea). Diseases of Aquatic Organisms 55,
2330.
Rubio-Godoy, M., Sigh, J., Buchmann, K. and Tinsley, R.C. (2003b) Antibodies against Discocotyle sagittata
(Monogenea) in farmed trout. Diseases of Aquatic Organisms 56, 181184.
Rubio-Godoy, M., Porter, R. and Tinsley, R. (2004) Evidence of complement-mediated killing of Discocotyle
sagittata (Platyhelminthes, Monogenea) oncomiracidia. Fish and Shellfish Immunology 17, 95103.
Santamarina, M.T., Tojo, J., Ubeira, F.M., Quinteiro, P. and Sanmartin, M.L. (1991) Anthelmintic treatment
against Gyrodactylus sp. infecting rainbow trout Oncorhynchus mykiss. Diseases of Aquatic Organisms
10, 3943.
343
Santos, C.P., Buchmann, K. and Gibson, D.I. (2000) Pseudorhabdosynochus spp. (Monogenea: Diplectanidae)
from the gills of Epinephelus spp. in Brazilian waters. Systematic Parasitology 45, 145153.
Sarig, S., Lahav, M. and Shilo, M. (1965) Control of Dactylogyrus vastator on carp fingerlings with dipterex.
Bamidgeh, Israel 17, 4752.
Schmahl, G. and Mehlhorn, H. (1985) Treatment of fish parasites. I. Praziquantel effective against Monogenea
(Dactylogyrus vastator, Dactylogyrus extensus, Diplozoon paradoxum). Zeitschrift fr Parasitenkunde
71, 727737.
Scott, M.E. (1985) Dynamics of challenge infections of Gyrodactylus bullatarudis (Monogenea) on guppies,
Poecilia reticulata (Peters). Journal of Fish Diseases 8, 495503.
Scott, M.E. and Robinson, M.A. (1984) Challenge infections of Gyrodactylus bullatarudis (Monogenea) on
guppies (Poecilia reticulata) following treatment. Journal of Fish Biology 24, 581586.
Shinn, A.P., Sommerville, C. and Gibson, D.I. (1995) Distribution and characterization of species of
Gyrodactylus Nordmann, 1832 (Monogenea) parasitizing salmonids in the UK, and their discrimination
from G. salaris Malmberg, 1957. Journal of Natural History 29, 13831402.
Shinn, A.P., Sommerville, C. and Gibson, D.I. (1997) Argentophilic structures as a diagnostic criterion for
the discrimination of species of the genus Gyrodactylus von Nordmann (Monogenea). Systematic Parasitology 37, 4757.
Shirakashi, S., Mori, K., Sugaya, T. and Ogawa, K. (2003) Effects of Neoheterobothrium hirame on predation
and viral hemorrhagic septicemia infection of olive flounder, Paralichthys olivaceus. In: Van As, J. (ed.)
Proceedings of the 6th International Symposium on Fish Parasitology, Bloemfontein, South Africa,
September 2226. University of Free State, Bloemfontein, South Africa, p. 1.
Slotved, H.C. and Buchmann, K. (1993) Acquired resistance of the eel Anguilla anguilla L. to challenge infections with gill monogeneans. Journal of Fish Diseases 16, 585591.
Smyth, J.D. and Halton, D.W. (1983) The Physiology of Trematodes, 2nd edn. Cambridge University Press,
Cambridge.
Soleng, A., Poleo, A.B.S., Alstad, N.E.W. and Bakke, T.A. (1999) Aqueous aluminium eliminates Gyrodactylus salaris (Platyhelminthes, Monogenea) infections in Atlantic salmon. Parasitology 119, 1925.
Solomatova, V.P. and Luzin, A.V. (1988) Gyrodactylosis of carps in fish tanks located on discharged waters
of the Kostromsk electric power plant and some problems of the biology of Gyrodactylus katharineri.
In: Skarlato, O.A. (ed.) Investigations of Monogeneans in the USSR. Russian translation series 62,
A.A. Balkema, Rotterdam, The Netherlands, pp. 162168.
Sterud, E., Harris, P.H. and Bakke, T.A. (1998) The influence of Gyrodactylus salaris Malmberg, 1957
(Monogenea) on the epidermis of Atlantic salmon, Salmo salar L., and brook trout, Salvelinus fontinalis
(Mitchill), experimental studies. Journal of Fish Diseases 21, 257263.
Szekely, C. and Molnar, K. (1987) Mebendazole is an efficaceous drug against pseudodactylogyrosis in the
European eel Anguilla anguilla L. Journal of Applied Ichthyology 3, 183186.
Szekely, C. and Molnar, K. (1990) Treatment of Ancylodiscoides vistulensis monogenean infestations of the
European catfish (Silurus glanis). Bulletin of the European Association of Fish Pathologists 10, 7477.
Thoney, D.A. (1990) The effects of trichlorfon, praziquantel and copper sulphate on various stages of the
monogenean Benedeniella posterocolpa, a skin parasite of the cownose ray, Rhinoptera bonasus
(Mitchill). Journal of Fish Diseases 13, 385389.
Thoney, D.A. and Burreson, E.M. (1988) Lack of specific humoral antibody reponse in Leiostomus
xanthurus (Pisces: Serranidae) to parasitic copepods and monogeneans. Journal of Parasitology 74,
191194.
Thoney, D.A. and Hargis, W.J. (1991) Monogenea (Platyhelminthes) as hazards for fish in confinement.
Annual Review of Fish Diseases 2, 133153.
Tojo, J. and Santamarina, M.T. (1998) Oral pharmacological treatments for parasitic diseases of rainbow trout
Oncorhynchus mykiss. II. Gyrodactylus sp. Diseases of Aquatic Organisms 33, 187193.
Tojo, J., Santamarina, M.T., Ubeira, F.M., Estevez, J. and Sanmartin, M.L. (1992) Anthelmintic activity of
benzimidazoles against Gyrodactylus sp. infecting rainbow trout Oncorhynchus mykiss. Diseases of
Aquatic Organisms 12, 185189.
Vladimirov, V.L. (1971) The immunity of fishes in the case of dactylogyrosis. Parasitologiya 5, 5158 (in
Russian). English translation: Parasitology, Riverdale 1, 5868.
Wang, G., Kim, J.-H., Sameshima, M. and Ogawa, K. (1997) Detection of antibodies against the monogenean
Heterobothrium okamotoi in tiger puffer. Fish Pathology 32, 179180.
Watson, N.A. and Rohde, K. (1994) Two new sensory receptors in Gyrodactylus sp. (Platyhelminthes,
Monogenea, Monopisthocotylea). Parasitology Research 80, 442445.
344
Wells, P.R. and Cone, D.K. (1990) Experimental studies on the effect of Gyrodactylus colemanensis and
G. salmonis on density of mucus cells in the epidermis of fry of Oncorhynchus mykiss. Journal of Fish
Biology 37, 599603.
Whittington, I.D. (1998) Diversity down under: monogeneans in the antipodes Australia with a prediction of
monogenean biodiversity worldwide. International Journal for Parasitology 28, 14811493.
Whittington, I.D. (2004) The Capsalidae (Monogenea: Monopisthocotylea): a review of diversity, classification and phylogeny with a note about species complexes. Folia Parasitologica 51, 109122.
Whittington, I.D., Cribb, B.W., Hamwood, T.E. and Halliday, J.A. (2000) Host-specificity of monogenean
(platyhelminth) parasites: a role for anterior adhesive areas? International Journal for Parasitology 30,
305320.
Wilde, J. (1935) Der Schleiendactylogyrus (Dactylogyrus macracanthus) und die Schdigung der
Schleienkieme diesen Parasiten. Fischerei-Zeitung 38, 661663.
Wunder, W. (1929) Die Dactylogyrus-krankheit der Karpfenbrut, ihre Ursache und ihre Bekmpfung.
Zeitchrift fr Fischerei 27, 511545.
Xia, X., Nie, P. and Yao, W. (1996) Effects of light, temperature and host mucus on the egg hatching of
Ancyrocephalus mogurndae (Monogenea). Acta Hydrobiologica Sinica 20, 195196.
Yamamoto, K., Takagi, S. and Matsuoka, S. (1984) Mass mortality of the Japanese anchovy (Engraulis
japonica) caused by a gill monogenean Pseudanthocotyloides sp. (Mazocraeidae) in the sea of Iyo
(Iyo-nada), Ehime prefecture. Fish Pathology 19, 119123.
Yoshinaga, T., Nagakura, T., Ogawa, K. and Wakabayashi, H. (2000) Attachment-inducing capacities of fish
tissue extract on oncomiracidia of Neobenedenia girellae (Monogenea, Capsalidae). Journal of
Parasitology 86, 214219.
Yoshinaga, T., Nagakura, T., Ogawa, K., Fukuda, Y. and Wakabayashi, H. (2002) Attachment-inducing
capacities of fish skin epithelial extracts on oncomiracidia of Benedenia seriolae (Monogenea:
Capsalidae). International Journal for Parasitology 32, 381384.
Zietara, M. and Lumme, J. (2002) Speciation by host switch and adaptive radiation in a fish parasite genus
Gyrodactylus (Monogenea, Gyrodactylidae). Evolution 56, 24452458.
10
Introduction
The Digenea (previously termed digenetic
trematodes) are one of the three major taxa
of parasitic Platyhelminthes, the other
two being the Cestoda and the Monogenea.
Digeneans are heteroxenous (i.e. they
require more than one host to complete
their life cycle), and their adult stage is
parasitic in vertebrates. All major groups of
vertebrates serve as hosts for adult digeneans. Apart from being hosts to adult
digeneans, fish may also be infected by the
metacercarial larval stage. With one exception, digeneans undergo part or all of their
larval development in molluscs. Members
of the genus Aporocotyle complete their
larval development in polychaete annelids
(Koie, 1982).
Very few adult-stage digeneans are
known to cause significant harm to the
fish host. Notable exceptions are the extraintestinal parasites, such as sanguinicoliid
blood flukes, the cyst-forming didymozoids
and the skin-inhabiting Transversotrema spp.
Metacercarial infection in fish is the
main source of disease, with subsequent
economic loss. Metacercariae may affect
growth and survival, or disfigure fish so
that they lose their market value as a food or
ornamental product (Paperna, 1991, 1996).
345
346
molluscs and piscivorous birds; hence infections by skin, gill and visceral metacercariae
are high. The high natural infections of
young-of-the-year plaice with Cryptocotyle
lingua and Stephanostomum baccatum in
the north-east Atlantic littoral zones are well
documented (MacKenzie, 1968; MacKenzie
and Liversidge, 1975). There are also heavy
heterophyid muscle infections in grey mullets and in juveniles of other fishes in
lagoons and inshore marshes and estuaries
in the eastern Mediterranean Sea. These
areas are inhabited by high populations
of the intermediate host Pirenella conica
(Fig. 10.1A; Paperna, 1975; Paperna and
Overstreet, 1981; Taraschewski and Paperna,
1981; Taraschewski, 1984). The Syrian
African rift is a major migratory route for
birds between Europe and Africa. Water
bodies from the Jordan to the East African
Great Lakes have common fishes (cichlids,
Clarias and Barbus), snails (Melanoides
tuberculata (Fig. 10.2), Bulinus (Fig. 10.1B)
and Lymnaea spp.) and metacercariae whose
definitive hosts are herons (Ardeidae), cormorants (Phalacrocorax spp.) and pelicans
(Pelecanus onochrotalus). Gill infection
Fig. 10.2.
20 mm).
347
348
349
the low winter temperatures at which activity of pulmonate snails, such as Bulinus
truncatus and Lymnaea (= Stagnicola)
palustris, is interrupted in the south-eastern
Mediterranean (Yekutiel, 1985; Farstey,
1986). The latter snails live in aquatic habitats fringing Lake Kinneret. M. tuberculata,
which inhabits the lake proper, may also be
found in deeper waters in the winter. During winter, some snails retain sporocysts
that contain xiphidiocercariae, and some
rediae may have pleurolophocercous cercariae
(Farstey, 1986). Shedding of Bolbophorus
damnificus cercariae by its snail, Planorbella trivolis, is also temperature dependent
(Terhune et al., 2002). The pulmonates
inhabiting the flood pools fringing the lake
are more susceptible to annual flooddrought
transitions in their habitat. Successive years
of drought and flooding resulted in the
elimination or reduction of pulmonate
snails and the disappearance of metacercariae of Neascus, Bolbophorus levantinus,
Clinostomum tilapiae and Euclinostomum
heterostomum from the lake-dwelling cichlids for several years (Dzikowski et al.,
2003a). However, infections transmitted by
lake-inhabiting snails (M. tuberculata transmitting Centrocestus and Haplorchis spp.,
Melanopsis costata transmitting Pygidiopsis
genata and Lymnasa (= Radix) auricularia
transmitting Clinostomum complanatum)
are not affected (Paperna, 1964a; Yekutiel,
1985; Farstey, 1986; Finkelman, 1988;
Dzikowski et al., 2003a). In north-east
Thailand, the seasonal pattern of Opistorchis
viverini occurrence in cyprinid fish fluctuates between high abundance during the
rainy season and a low during the dry season (winter). The number of metacercariae
in fish is often positively associated with
infection levels in humans (Sithithaworn
et al., 1997). Recruitment of Haplorchis
taichui in north Thailand is highest during
the dry season (Sukontason et al., 1999).
P. conica in marine lagoons fringing
the south-eastern Mediterranean and the
northern gulfs of the Red Sea continues to
shed cercariae (of Heterophyes and others)
throughout the winter months, when water
temperatures of fringing and landlocked
sites may drop to below 10C (Taraschewski
350
and Paperna, 1981, 1982). Year-round infection by larval digeneans has been reported
in Cerithidea californica from mudflats in
southern California (Martin, 1955). In the
perennial habitats of the East African lakes,
the M. tuberculata-transmitted metacercariae
(Centrocestus and Haplorchis) and a variety
of pigmented skin metacercariae (Bulinustransmitted) accumulate uninterruptedly
until the young cichlids migrate to deeper
waters (Paperna, 1996). A similar year-round
recruitment occurs in India of C. formosanus and of Postdiplostomum grayii in
Apocheilus panchax (Madhavi and Rukmini,
1991, 1992) and in China of C. formosanus
in grass carp (Zeng and Liao, 2000).
351
352
Parasite Morphology
Adult-stage morphology
Adult digeneans (Fig. 10.3) usually have
a dorsoventrally flattened oval body with
353
Fig. 10.4. Scanning electron micrographs of adult-stage Haplorchis pumilio (A) and Pygidiopsis
geneta (B) from the gut of a cormorant (Phalacrocorax carbo), scales 50 m.
Larval stages
Fig. 10.5. A. Clinostomum tilapiae eggs containing
ready-to-hatch miracidium (actual size 125 m
83 m). B. Redia of Mesorchis denticulatum (scanning
electron micrograph, scale 10 m, courtesy of M.
Kie). C. Redia of C. tilapiae (live, actual size). D.
Furcocercaria of C. tilapiae (live, actual size).
354
Ultrastructural studies
355
Fig. 10.7. Blood flukes. A. Scanning electron micrograph of Sanguinicola fontianalis (from Hoffman et al.,
1985, courtesy of the author; bar = 100 m). B. Eggs of Sanguinicola sp. in gills of Oreochromis aurea, Lake
Kinnereth. C. Egg in gill tissue of Baryanchistus sp. (Plecostomidae), Amazon, Brazil. D. Eggs in spleen of
O. aurea, Lake Kinnereth.
356
Fig. 10.8. Didymozoidae. A. Palate of Platycephalus fuscus infected with Neometadidymozoon helicis (in
life, bright yellow). From Lester, 1980, courtesy of the author. B. Lobatozoum multidacculatum on gills of
Katsumonus pelamis, New Zealand. C. Larval stages of didymozoids encysted on the surface of the intestine
of Favonigobius exquisitus. D. Section of Nematobothrium spinneri in the body wall muscle of Acanthocybium solndri, Queensland. E. N. helicis capsule in the body wall of P. fuscus. (BE courtesy of B. Lester.)
357
Fig. 10.10. Transversotrema haasi (drawn with reference to Witenberg, 1944a; for abbreviations see
legend to Fig. 10.3).
358
Fig. 10.11. A. Bolbophorus levantinum daughter sporocyst with cercariae, characteristic of strigeoid and
schistosomatid digeneans (redrawn from Paperna and Lengy, 1963). B.Young and C, mature, daughter redia
containing cercariae of Clinostomum tilapiae. Abbreviations: b = birth pore; c = cercariae; gr = germinating
stages; in = intestine; os = oral sucker.
359
Fig. 10.12. Transmission electron micrographs of Centrocestus sp. metacercariae from gills of
Oreochromis aurea. A. View of the host-produced cartilaginous cyst (c), the parasite-produced wall (pw)
enclosing the parasite (p) with the spiny tegument (s). B. Parasites wall (pw) and the syncytial tegument.
C. Enlarged view of the tegument with its spine-carrying border. Abbreviations: cl = circular muscles;
ll = longitudinal muscles; m = mitochondrion; n = nuclei of the tegument; s = spines.
360
Fig. 10.13. Scanning electron micrographs of adult-stage trematodes from cormorants gut:
A. Paryphostomum radiatum (Echinostomatidae) with perioral spines and smooth tegument, scale bar
100 m. B. Centrocestus sp. (Heterophyiidae) with perioral and tegumental spines, scale bar 10 m.
Molecular diagnosis
The molecular knowledge of Digenea is
accumulating rapidly and has great potential in resolving life histories and obtaining
new perspectives on their phylogeny (Cribb
et al., 2001; Olson et al., 2003). DNA data
provide a useful tool to define limits of
taxons and for unveiling cryptic species
(Overstreet et al., 2002). Specific determination of digenean larval stages, cercariae and
metacercariae, by morphological traits is
difficult and ambiguous, because of the lack
of morphological traits related to the reproductive system. Experimental demonstration of the life history is often unachievable
due to the lack of knowledge of the specific
intermediate or definitive host. Although
hosts and morphology change throughout
the life history of these parasites, the
genetic composition remains constant.
The use of these methodologies has
proved their great potential in creating the
genetic linkage between all stages in
digenean life history by either comparing
ribosomal gene sequences or creating specific DNA probes. Using PCR methodologies
enables the targeting of genes even from
a single cerceria without DNA extraction
(Grevelding et al., 1997). Various ribosomal
genes, along with the interspecific polymorphic regions, contain highly conserved
regions for which universal primers can be
designed in order to amplify this gene from a
newly studied species (Hillis and Dixon,
1991; Littlewood and Olson, 2001).
There are already several achievements
in resolving life histories of marine fish
Digenea, where experimental studies are
particularly difficult. The metacercaria of
Indodidymozoon pearsoni was identified
using the DNA sequence of the internal
transcribed spacer 2 (ITS2) rDNA (Anderson,
1999). Cribb et al. (1998) have demonstrated
the three-host life cycle of Bivesicula
361
362
Lifespan of digeneans
Information on the lifespan of adult digeneans is scanty and has been mostly extrapolated from field data. The lifespan of an
adult digenean is highly variable, even
between members within the same family.
Some adults apparently live for one or two
seasons (spring to autumn Rhipidocotyle
septapapillata (Krull, 1934), Asymphylodora
kubanica (Evans, 1978)), whereas others,
363
Yield of cercariae
The intramolluscan infection with rediaeforming digeneans is usually considerably
longer than that with sporocyst-forming
digeneans; the sporocyst elapses after
yielding rediae or cercaricae, while rediae
remain to yield daughter rediae or cercariae.
Heterophyid infections in P. conica
(H. Taraschewski and I. Paperna, unpublished) and in M. tuberculata (Farstey,
1986) last over a year, and up to 5 years in
C. lingua-infected Littorina littorea (Meyerhof
and Rothschild, 1940). C. lingua-infected
L. littorea shed about 3330 cercariae per day
at the early stage of infection, and 830
towards the end of the 5-year period. Daily
or periodic cercarial output in pulmonate
snails is often similar (Wright, 1971;
I. Paperna, unpublished) or even higher
(Paperna and Lengy, 1963), but the overall
production time is shorter for digeneans in
pulmonates, which have only sporocyst
stages (Strigeata, Sanguinicolidae, Plagiorchidae). Cercarial production has daily
364
365
Progenetic generations
Sexually mature stages containing fully
developed eggs are sometimes found in the
first intermediate molluscan host and in
other aquatic invertebrates that are hosts of
metacercariae. Eggs are released only after
disintegration of the host tissue following
366
HostParasite Relationships
Pathology
Adult trematodes
Adult intestinal trematodes are normally
considered not to cause disease even when
their numbers are high. Extra-intestinal parasites are, however, potentially pathogenic.
Blood flukes (sanguinicolids and aporocotyles) cause considerable damage to the
gills and impair respiration. Adult worms
and eggs can physically obstruct the passage of blood and cause thrombosis and
subsequent tissue necrosis (Hoffman et al.,
1985; Ogawa et al., 1989). Extensive rupture
of the gill lining by emerging miracidia and
tissue response around trapped eggs in
367
Fig. 10.15. Degenerate eggs of the sanguinicolis Pearsonellum corventum in the heart of the fish
Plectropomus leopardus. A. Encapsulated egg mass enclosed by infiltrated macrophages. B. Granulomaencased egg residue within a melanomacrophage. (From Overstreet and Thulin, 1989, courtesy of R. Overstreet.)
368
interdigitated with worm coils, which facilitates worm feeding on blood (Lester, 1980).
Only natural infections have been recorded,
and these are likely to be moderate. It is not
known whether these infections are harmful to maricultured fish. T. patialense, an
ectoparasite on the Brachydanio rerio
integument, leaves pressure and feeding
indentations on the body surface. Tissue
regeneration occurs soon after the worm
changes position (Mills, 1979). Kidney
damage induced by heavy infection of
the urethra with Phyllodistomum umblae
(= conostomum) adversely affects survival
of charr migrating from fresh water to sea
water (Berland, 1987). A. kubanica are
pathogenic to R. rutilus heckeli in the Sea of
Azov when they infect the kidneys rather
than the intestine (Bauer, 1958).
Metacercariae
Clinical effects of infection are often not
obvious. Metacercariae in supposedly sensitive organs, such as the brain, cranial nerves
or spinal cord, e.g. B. gracilescens in cod,
G. morhua (Matthews, 1974), Diplostomum
mashonense and Diplostomum tregenna in
Clarias spp. (Beverly-Burton, 1963; Khalil,
1963) and Ornithodiplostomum ptychocheilus in P. promelas (Hoffman, 1958; So
and Wittrock, 1982), do not necessarily have
obvious debilitating effects on fish even
when the number of parasites is relatively
high and despite visible structural damage to
the organs.
A sudden massive outbreak of infection is often fatal. Exposure to massive
numbers of cercariae will kill fry within a
few hours (Sommerville, 1982), but such
exposures do not normally occur in nature.
Cercariae penetrate and encyst deeper in
the tissues of small fishes and the relatively larger cysts may interfere with organ
function (Fig. 10.16). The effects of cercarial
infestation are most severe in 0-year-class
plaice and minimal in the 1+-year class
(Sommerville, 1981). Hoffmann et al. (1990)
reported a massive Bucephalus polymorphus infestation and mortality of cyprinid
fishes after the water temperature was
suddenly increased from 1214 to 20C.
369
Fig. 10.16. Metacercariae in fish tissues. A. Cartilaginous cyst around Centrocestus sp. metacercariae in
gills of Oreochromis aurea, Lake Kinnereth. B. Ascocotyle coelostoma (live) in the truncus arteriosus of Liza
ramada. C. Encysted Phagicola nana in the gut wall of Micropterus salmoides. D. Pigmented Neascus
(black spot) encysted on fins of young Oreochromis hybrids.
370
Fig. 10.17. Diplostomatid metacercariae: A. Diplostomum sp. removed from a visceral cyst in Clarias
gariepinus, Uganda. B. Heavy Bolbophorus levantinum metacercaria in muscles of young Oreochromis
aurea from Lake Kinnereth. C. Early-stage B. levantinum metacercaria with expanded posterior half.
D. Later-stage B. levantinum metacercaria with emptied posterior end (actual size 0.60.8 mm).
371
by the host tissues. Collagen may be deposited in the liver (Mitchell, 1974) and in the
spleen (Font et al., 1984), but it is usually
absent. When crowded on the serosal surface of the pyloric caeca (Fig. 10.16C),
metacercariae of Phagicola nana evoke
intense proliferation of the connective tissues, with a considerable amount of collagen. When the parasite is in the submocosa,
the proliferation includes smooth muscle
(Font et al., 1984).
Gill infection due to Centrocestus spp.
372
373
374
375
Immune responses
Estimating the extent of mortality
in affected fish populations
Estimation of metacercaria-induced host
mortality in natural fish populations has
been attempted by extrapolating quantitative data on frequency distribution of
infection. The decline in variance was considered to result from the loss of heavily
parasitized fish. Hence a measure of
overdispersion, in comparison with negative binomial distribution or by calculating
the ratio of variance to mean, was advocated as an indirect method of estimating
fish mortality (Lester, 1977, 1984; Anderson
and Gordon, 1982; Gordon and Rau, 1982;
Kennedy, 1984). Seasonal changes in the
degree of overdispersion were related to
suggested parasite-caused mortality in
bluegill during the winter (Lemly and
Esch, 1984b). However, extrapolations from
field data have met with a variable degree
of success and at times have produced
376
In Vitro Culture
Prior to the era of molecular biology (see
above), metacercariae could not provide
morphological cues for specific identifications. In vitro studies of piscine digeneans
have been concentrated on the induction of
sexual maturation of metacercariae, rather
than on the long-term maintenance of larval
or adult stages. Stunkard (1930) was the
first to attempt cultivation of metacercariae
to adult stages and this has now been accomplished for a number of species (Kannangara
and Smyth, 1974). Metacercariae that already
possess genital primordia are more readily
cultured to the adult stage, with the production of eggs capable of hatching (Basch et al.,
1973; Mitchell et al., 1978). Moreover, some
metacercariae (Gynaecotyle adunca, Pleurogenoides sitapurri, Microphallus papillorobustus) produce eggs after only minimal
stimulation, e.g. release from the cyst, exposure to light or changes in temperature
(Kannangara and Smyth, 1974). Metacercariae that do not have genital rudiments
take longer to develop and are more fastidious in their in vitro maintenance needs.
Diplostomum phoxini was first cultivated
in a medium that contained egg yolk (Bell
and Smyth, 1958), but subsequent studies
demonstrated that the egg yolk had little
or no beneficial effect. D. phoxini and
D. spathaceum reached the egg production
stage, but eggs of the latter were not viable
(Kannangara and Smyth, 1974). In a more
recent study, Leno and Holloway (1986)
reported cultivation of D. spathaceum on
chick chorioallantois. Whyte et al. (1988)
transformed D. spathaceum cercariae into
metacercariae in vitro. These were then further maintained for 72 h. Cercariae were
allowed to penetrate via trout skin using a
modified version of the Clegg and Smithers
(1972) mouse-skin technique for schistosomes. The best results for metacercarial
maintenance in vitro were obtained with
L-15 (Gibco) medium supplemented with
added fetal calf serum (Whyte et al., 1988).
377
Parasite control
Praziquantel (Droncit, Biltricide, Bayer AG,
Germany) is safe and effective against digeneans and cestodes of man and animals
(Andrews et al., 1983). It demonstrated high
efficacy over a wide range of metacercariae:
Szekely and Molnar (1991) reported on the
elimination of all D. spathaceum metacercariae from herbivorous carp that were fed a
single dose of the drug (300 mg/kg body
mass). Three sequential lower doses of
378
Conclusions
Digeneans that parasitize fish are numerous
and diverse in their morphologies and life
histories. Studies on adult digeneans and
metacercariae require different approaches.
The importance of digeneans to fish culture
has long been underestimated; also their risk
to public health has not received adequate
recognition. With the rapid development of
warmwater aquaculture, as well as mariculture, and the spread of exotic culinary practices to Western societies risks to cultured
fish and to consumers of infected fish are
likely to become significant (Ko, 1995).
Intra-intestinal adult digeneans are potentially pathogenic to maricultured fish: however, piscine digeneans are receiving less
attention now than in the past. In the last
decade, the burden due to massive infections by metacercariae has increasingly
alarmed freshwater fish farmers. Some of the
most troubling infections are of the gills by
Centrocestus spp. and of the muscles and
connective tissue by Bolbophorus spp. and
Future Studies
In the last decade the transition in parasitology from an essentially zoological to a biochemical, immunological and molecular
science has had only a marginal impact on
fish digenean research. Future studies
should include nutritional physiology,
immunology and taxonomy that make use
of DNA analysis. Temperature dependence
of the immune response, combined with the
peculiarities of the defence mechanisms
against helminthic infections, offers an
attractive and challenging research model.
The emerging methodology of DNA taxonomy is potentially the best option for
resolving taxonomic affinities and revealing
life histories of digeneans by specific
recognition of larval stages.
Acknowledgements
We wish to thank our collegues Glenn L.
Hoffman, Kearneysville, West Virginia,
USA, Johan Hoglund, National Veterinary
Institute, Uppsala, Sweden, Marianne Koie,
Marine Biology Laboratory, Helsingor,
Denmark, Omer R. Larson, University of
South Dakota, USA, Bob Lester, University
of Queensland, Australia, Paola Oreccia,
Universita degli Studi di Roma, Italy, Robin
Overstreet, Gulf Coast Research Laboratory,
Mississippi, USA, John C. Pearson, University of Queensland, Australia, and Darwin
Wittrock, University of Wisconsin, Eau
Claire, USA, for kindly providing us with
published and unpublished data and publications, drawings and photographs and their
kind permission to use their illustrations
and photographs in this review.
379
References
Aaltonen, T.M., Valtonen, E.T. and Jokinen, E.I. (1997) Humoral response of roach (Rutilus rutilus) to digenean
Rhipidocotyle fennica infection. Parasitology 114, 285291.
Abdul-Salam, J. and Sreelatha, B.N.S. (1992) The surface topography and ultrastructure of the tegument of the
ectoparasitic digenean Transversotrema licinum. Zoologischer Anzeiger 228, 248261.
Anderson, G.R. (1999) Identification and maturation of the metacercaria of Indodidymozoon pearsoni. Journal of Helminthology 73, 2126.
Anderson, G.R. and Barker, S.C. (1993) Species differentiation in the Didymozoidae (Digenea): restriction
fragment length differences in internal transcribed spacer and 5.8S ribosomal DNA. International Journal
of Parasitology 21, 113136.
Anderson, I.G. and Shaharom-Harrison, F. (1986) Sanguinicola armata infection in bighead carp (Aristichthys
nobilis) and grass carp (Ctenopharyngodon idellus) imported in Malaysia. In: Maclean, J.I., Dizon, L.B.
and Hosillos. L.V. (eds) The First Asian Fishery Forum. Asian Fisheries Society, Manila, Philippines,
pp. 247250.
Anderson, R.M. and Gordon, D.M. (1982) Processes influencing the distribution of parasite numbers within
host populations with special emphasis on parasite induced host mortalities. Parasitology 85, 373398.
Andrews, P.H., Thomas, R., Pohlke, R. and Seubert, J. (1983) Praziquantel. Medical Research Review 3,
147200.
Angel, M. (1969) Prototransversotrema steeri gen. nov. sp. nov. (Digenea: Transversotrematidae) from a South
Australian fish. Parasitology 59, 719724.
Armitage, M.H. (2000) Ultrastructure of metacercarial cysts of six heterophyid trematodes from fish. Parasitology
Research 86, 10031007.
Avtalion, R.R., Wajdani, Z., Malik, Z., Shahrabani, R. and Duczyminer, M. (1973) Influence of environmental
temperatures on the immune response in fish. Current Topics in Microbiology and Immunology 61,
135.
Awachie, J.B.E. (1968) On the bionomics of Crepidostomum metoecus (Braun, 1900) and Crepidostomum
farionis (Muller, 1784) (Trematoda: Allocreadiidae). Parasitology 58, 307324.
Barber, I. and Crompton, D.W.T. (1997) The ecology of Diplostomum phoxini infections in two minnow
(Phoxinus phoxinus) populations in Scotland. Journal of Helminthology 71, 189196.
Bartoli, P., Jousson, O. and Russell-Pinto, F. (2000) The life cycle of Monorchis parvus (Digenea:
Monorchiidae) demonstrated by developmental and molecular data. Journal of Parasitology 86 (3),
479489.
Barton, C.L., Halton, D.W., Shaw, C., Maule, A.G. and Johnston, C.F. (1993) An immunocytochemical study
of putative neurotransmitters in the metacercariae of two strigeoid trematodes from rainbow trout
(Onchorhynchus mykiss). Parasitology Research 79, 389396.
Basch, P.E., Dicozla, J.J. and Johnson, B.E. (1973) Strieid trematode (Cotylurus lutzi) cultured in vitro: production of normal eggs with continuance of life cycle. Journal of Parasitology 59, 319322.
Bauer, O.N. (1958) Relationships between the parasites and their hosts (fishes). In: Dogiel, V.A.,
Petrushevski, C.K. and Polyanski, Y.I. (eds) Fundamental Problems of the Parasitology of Fishes.
Izdatelstvo Leningradskovo Universiteta, Leningrad, pp. 90108 (in Russian, English translation: Kabata,
Z., 1961, Parasitology of Fishes. Oliver and Boyd, Edinburgh, pp. 84103).
Bauer, O.N. (1959) The influence of environmental factors on reproduction of fish parasites. Voprosy Ecologii
3, 132141 (in Russian, English translation: Fisheries Research Board of Canada, Translation No. 1099).
Becker, C.D. and Brunson, W.D. (1966) Transmission of Diplostomum flexicaudatum to trout by ingestion of
precocious metacercariae in molluscs. Journal of Parasitology 52, 829830.
Bell, E.J. and Smyth, J.D. (1958) Cytological and histochemical criteria for evaluating development of
trematodes and pseudophyllidean cestodes in vivo and in vitro. Parasitology 48, 131148.
Berland, B. (1987) Helminth problems in seawater aquaculture. In: Stenmark, E. and Malmberg, G. (eds)
Parasites and Diseases in Natural Waters and Aquaculture in Nordic Counries. Zoo-Tax Naturhistoriska
Riksmuseet, Stockholm, Sweden, pp. 5662.
Beverly-Burton, M. (1963) A new strigeid, Diplostomum (Tylodelphys) mashonense n. sp. (Trematoda:
Diplostomidae) from the grey heron, Ardea cinerea L, in Southern Rhodesia with an experimental
demonstration of part of the life cycle. Revue de Zoologie et Botanie Africaine 68, 291308.
Bortz, B.M., Kenny, C.P., Pauley, G.B., Garcia-Ortigosa, E. and Anderson, D.P. (1984) The immune response
in immunized and naturally infected rainbow trout (Salmo gairdneri) to Diplostomum spathaceum as
380
381
Donges, J. (1969) Entwicklung und Lebendauer von Metacercarien. Zeitschrift fr Parasitenkunde 31,
340366.
Donges, J. (1974) The life history of Euclinostomum heterostomum (Rudolphi, 1809) (Trematoda:
Clinostomidae). International Journal for Parasitology 4, 7990.
Douellou, L. (1992) Parasites of Oreochromis mortimeri (Trewavas, 1996) and Tilapia rendalli rendalli
(Boulanger, 1836) in Lake Kariba, Zimbabwe. University of Zimbabwe Lake Kariba Research Station
Bulletin, 2 (Proceedings of Seminar Series), 1431.
Dubois, G. (1953) Systmatique des Strigeida. Completement de la Monographie. Mmoires de la Socit
Neuchteloise des Sciences Naturelles 8, 141 pp.
Dzikowski, R., Diamant, A. and Paperna, I. (2003a) Trematode metacercariae of fish as sentinels for changing
limnological environment. Diseases of Aquatic Organisms 55, 145150.
Dzikowski, R., Levy, M.G., Poore, M.F., Flowers, J.R. and Paperna, I. (2003b) Genetic and morphologic differentiation of Bolbophorus confusus (Krause 1914) and Bolbophorus levantinus Dubois 1970 (Digenea:
Diplostomatidae), based on rDNA SSU polymorphism and scanning electron microscopy. Diseases of
Aquatic Organisms 57, 231235.
Dzikowski, R., Levy, M.G., Poore, M.F., Flowers, J.R. and Paperna, I. (2004a) Clinostomum complanatum and
Clinostomum marginatum (Rudolphi, 1819) (Digenea: Clinostomidae) are separate species based on
differences in rDNA. Journal of Parasitology 90, 413414.
Dzikowski, R., Levy, M.G., Poore, M.F., Flowers, J.R. and Paperna, I. (2004b) Use of rDNA polymorphism for
identification of Heterophyidae infecting freshwater fishes. Diseases of Aquatic Organisms 59, 3541.
Ellis, A.E. (1977) The leucocytes of fish: a review. Journal of Fish Biology 11, 453491.
Erasmus, D.A. (1977) The hostparasite interface of trematodes. Advances in Parasitology 15, 201242.
Euzet, L. and Raibaut, A. (1985) Les maladies parasitaires en pisciculture marine. Symbioses 17, 5168.
Evans, N.A. (1978) The occurrence and life history of Asymphylodora kubanicum (Platyhelminthes: Digenea:
Monorchidae) in the WorcesterBirmingham canal, with special references to the feeding habits of the
definitive host, Rutilus rutilus. Journal of Zoology 184, 143153.
Evans, W.A. (1974a) The histopathology of cutthroat trout experimentally infected with blood fluke
Sanguinicola klamathensis. Journal of Wildlife Diseases 10, 243248.
Evans, W.A. (1974b) Growth, mortality, and hematology of cutthroat trout experimentally infected with the
blood fluke Sanguinicola klamathensis. Journal of Wildlife Diseases 10, 341346.
Ezenwaji, H.M.G. and Inyang, N.M. (1998) Observation on the biology of Clarias agboyiensis Syndenham,
1980 (Osteichthyes: Claridae) in the floodriver system, Nigeria. Fisheries Research Amsterdam 36 (1),
4760.
Ezenwaji, H.M.G. and Llozumba, P.C.O. (1992) Helminthofauna of four West African small Clarias species
(Osteichthyes: Clariidae) from Nigeria. Journal of African Zoology 106, 391400.
Faliex, E. (1991) Ultrastructural study of the hostparasite interface after infection of two species of teleosts by
Labratrema minimus metacercariae (Trematoda, Bucephalidae). Diseases of Aquotic Organisms 10,
93101.
Fares, A. and Maillard, C. (1974) Recherches sur quelques Haploporidae (Trematoda) parasites des muges de
Mditerrane Occidentale: systmatique et cycles volutifs. Zeitschrift fr Parasitenkunde 45, 1143.
Farstey, Y. (1986) Centrocestus sp. (Hetophyidae) and other trematode infections of the snail Melanoides
tuberculala (Muller, 1774) and cichlid fish in Lake Kinneret. Unpublished MSc thesis, Hebrew University
of Jerusalem (Hebrew text, English summary).
Ferguson, M.S. and Hayford, R.A. (1941) The life history and control of eye flukes. Progressive Fish Culturist
54, 113.
Finkelman, S. (1988) Infection of Clinostomatidea in the Sea of Galilee fish. Unpublished MSc thesis, Hebrew
University of Jerusalem (Hebrew text, English summary).
Font, W.F., Overstreet, R.W. and Heard, R. (1984) Taxonomy and biology of Phagicola nana (Digenea;
Heterophyidae). Transactions of the American Microscopical Society 103, 408422.
Garcia-Luis, J., Osorio-Sarabia, D. and Constantino, F. (1993) Prevalence of parasites and their histological
lesions in tilapia from lake of Amela, Tecoma, Colima, Mexico. Veterinaria Mexico 24, 199205.
Gibson, D.I., Mackenzie, K. and Cottle, J. (1981) Halvorsenius exilis gen. nov., sp. nov, a new didymozoid
trematode from the mackarel Scomber scombrus L. Journal of Natural History 15, 917929.
Ginetsinskaya, T.A. (1958) Life cycles and biology of the larval stages of parasitic worms of fish. In:
Dogiel, V.A., Petrushevski, G.K. and Polyanski, Y.I. (eds) Fundamental Problems of the Parasitology of
Fishes. Izdatelstvo Leningradskovo Universiteta, Leningrad, pp. 144183 (in Russian, English translation:
Kabata, Z., 1961, Parasitology of Fishes, Oliver and Boyd, Edinburgh, UK, pp. 140179).
382
Gordon, D.M. and Rau, M.E. (1982) Possible evidence for mortality induced by the parasite Apatemon gracilis
in a population of brook sticklebacks (Culea inconstans). Parasitology 84, 4147.
Grevelding, C.G., Kampkotter, A. and Kuntz, W. (1997) Schistosoma mansoni: sexing cercariae by PCR
without DNA extraction. Experimental Parasitology 85, 99100.
Grizzle, J.M. and Goldsby, M.T., Jr (1996) White grub Postdiplostomum minimum centrarchi metacercariae in
the liver of largemouth bass: quantification and effects on health. Journal of Aquatic Animal Health 8,
7074.
Halton, D.W. (1997) Nutritional adaptations to parasitism within the Platyhelminthes. International Journal for
Parasitology 27, 693704.
Halton, D.W. and Johnston, B.R. (1982) Functional morphology of the metacercarial cyst of Bucepnaloides
gracilensis (Trematoda: Bucephalidae). Parasitology 85, 4452.
Hillis, D.M. and Dixon, M.T. (1991) Ribosomal DNA: molecular evolution and phylogenetic inference.
Quarterly Review of Biology 66, 411453.
Hoffman, G.L. (1958) Studies on the life-cycle of Ornithodiplostomum ptychocheilus (Faust) (Trematoda:
Strigeoidea) and the self cure of infected fish. Journal of Parasitology 44, 416421.
Hoffman, G.L. (1960) Synopsis of Strigeoidea (Trematoda) of fishes and their life cycles. Fishery Bulletin of the
Fish and Wildlife Service 60 (Fishery Bulletin 175), 436469.
Hoffman, G.L. (1967) Parasites of North American Freshwater Fish. University of California Press, Berkeley,
California.
Hoffman, G.L. (1970) Control methods for snail-borne zoonozes. Journal of Wildlife Diseases 6, 262265.
Hoffman, G.L., Fried, B. and Harvey, J.E. (1985) Sanguinicola fontinalis sp. nov. (Digenea: Sanguinicolidae): a
blood parasite of brook trout, Salvelinus fontinalis (Mitchill), and longnose dace, Rhinichthys cataractae
(Valenciennes). Journal of Fish Diseases 8, 529538.
Hoffmann, R.W., Korting, W., Fischer-Scherl, T. and Schaufer, W. (1990) An outbreak of Bucephalus
polymorphus in fish of the Main River. Angewandte Parasitologie 31, 9599.
Hoglund, J. (1991) Ultrastructural observations and radiometric assay on cercarial penetration and migration
of the digenean Diplostomum spathaceum in the rainbow trout Oncorhynchus mykiss. Parasitology
Research 77, 283289.
Hoglund, J. and Thuvander, A. (1990) Indications of non-specific protective mechanisms in rainbow trout
Oncorhynchus mykiss with diplostomosis. Diseases of Aquatic Organisms 8, 9197.
Hopkins, S.H. (1937) A new type of allocreadiid cercaria: the cercaria of Allocreadium and Microcreadium.
Journal of Parasitology 23, 9497.
Huggins, E.J. (1972) Parasites of Fishes in South Dakota. Bulletin 484, Agricultural Experimental Station, South
Dakota State University Brooking and South Dakota Department of Game Fish and Parks, Brooking,
South Dakota, 73 pp.
Hughes, S.S.R., Cribb, T.H. and Jones, M.K. (1999) Structure of the tegument and ectocommensal microorganisms of Gyliauchen nahansis (Digenea: Gyliauchenidae), an inhabitant of herbivorous fish of the
Great Barrier Reef, Australia. Journal of Parasitology 85, 10471052.
Hunninen, A. and Cable, R.M. (1943) The life history of Podocotyle atomon (Rudolphi) (Trematoda:
Opecoelidae). Transactions of the American Microscopical Society 62, 5768.
Hunter, G.W. and Hunter, W.S. (1934) The life cycle of the yellow grub of fish. Journal of Parasitology 20, 325.
Isseroff, H. and Read, C.P. (1974) Studies on membrane transport VIII. Absorption of monosaccharides by
Fasciola hepatica. Comparative Biochemistry and Physiology 47A, 141152.
Ito, J. (1964) Metagonimus and other human heterophyid trematodes. Progress of Medical Parasitology in
Japan, Meguro Parasitological Museum, Tokyo 1, 317392.
Jones-Malcolm, K., Hughes-Stamm, S.R., East-Renae, M. and Cribb, T.H. (2000) Ultrastructure of the digestive
tract of Gyliauchen nahaensis (Platyhelminthes, Digenea), an inhabitant of the hindgut of herbivorous
fishes. Journal of Morphology 246, 198211.
Jousson, O., Bartoli, P., Zaninetti, L. and Pawlowski, J. (1998) Use of the ITS rDNA for elucidation of
some life cycles of Mesometridae (Trematoda, Digenea). International Journal for Parasitology 28,
14031411.
Kabunda, M.Y. and Sommerville, C. (1984) Parasitic worms causing the rejection of tilapia (Oreochromis
species) in Zaire. British Veterinary Journal 140, 263268.
Kamo, H., Ogino, K. and Hatsushika, R. (1962) A unique infection of man with Clinostomum sp., a small
trematode causing acute laryngitis. Yonago Acta Medica 6, 3740.
Kannangara, D.W.W. and Smyth, J.D. (1974) In vitro cultivation of Diplostomum phoxini metacercariae.
International Journal for Parasitology 4, 667673.
383
Karlsbakk, E. (2001) Aspects of the morphology and ecology of Otodistomum (Digenea: Azygiidae)
metacercariae in an intermediate host, Enchelyopus cimbrius (Pisces: Phycidae). Acta Parasitologica
46 (4), 261266.
Kennedy, C.R. (1984) The use of frequency distribution in an attempt to detect host mortality induced by
infections of diplostomatid metacercariae. Parasitology 89, 209220.
Khalil, L.F. (1963) On Diplostomum tregenna, the diplostomatid stage of Diplostomum tregenna Nazmi
Gohar, 1932, with experimental demonstration of part of the life cycle. Journal of Helminthology 37,
199206.
Khalil, L.F. (1969) Studies on the helminth parasites of freshwater fishes of the Sudan. Journal of Zoology 158,
143170.
Khalil, M.B. (1937) The life history of the human trematode parasite Heterophyes heterophyes. Proceedings of
the International Congress of Zoology (Lisbon, 1935) 12, 19892002.
Ko, R.C. (1995) Fish-borne parasitic zoonoses. In: Woo, P.T.K. (ed.) Fish Diseases and Disorders, Vol. 1,
Protozoan and Metazoan Infections. CAB International, Wallingford, UK, pp. 631671.
Kie, M. (1971a) On the histochemistry and ultrastructure of the redia of Neophasis lageniformis (Lebour,
1910). Ophelia 9, 113143.
Kie, M. (1971b) On the histochemistry and ultrastructure of the daughter sporocyst of Cercaria buccni
Lebour, 1911. Ophelia 9, 145163.
Kie, M. (1971c) On the histochemistry and ultrastructure of the tegument and associated structures of the
cercaria of Zoogonoides viviparus in the first intermediate host. Ophelia 9, 165206.
Kie, M. (1973) The hostparasite interface of the cercaria and adult Neophasis lageniformis (Lebour, 1910).
Ophelia 12, 205219.
Kie, M. (1975) On the morphology and life-history of Opechona bacillaris (Molin, 1859) Looss, 1907
(Trematoda, Lepocreadiidae). Ophelia 13, 6386.
Kie, M. (1976) On the morphology and life-history of Zoogonoides viviparus (Olsson, 1868) Odhner, 1902
(Trematoda, Zoogonidae). Ophelia 15, 114.
Kie, M. (1977) Stereoscan studies of cercariae, metacercariae and adults of Cryptocotyle lingua (Creplin,
1825) Fischoeder 1903 (Trematoda: Heterophyidae). Journal of Parasitology 63, 835839.
Kie, M. (1978) On the morphology and life history of Stephanostomum caducum (Looss, 1901) Manter,
1934 (Trematoda, Acanthocolpidae). Ophelia 17, 121133.
Kie, M. (1979a) On the morphology and life-history of Derogenes varicus (Muller, 1784) Looss, 1901
(Trematoda, Hemiuridae). Zeitschrift fr Parasitenkunde 59, 6778.
Kie, M. (1979b) On the morphology and life-history of Monascus [= Haplocladus] filiformis (Rudolphi, 1819)
Looss, 1907 and Steringophorus furciger (Olsson, 1868) Odhner, 1905 (Trematoda, Fellodistomidae).
Ophelia 18, 113132.
Kie, M. (1980) On the morphology and life history of Steringotrema pagelli (Van Beneden, 1871) Odhner,
1911 and Fellodiplostomum felis (Olsson, 1868) Nicoll, 1909 (syn. S. ovacutum (Lebour, 1908)
Yamaguti, 1953) (Trematoda, Fellodistomatidae). Ophelia 19, 215236.
Kie, M. (1981) On the morphology and life-history of Podocotyle reflexa (Creplin. 1825) Odhner, 1905
(Trematoda, Opecoelidae). Ophelia 20, 1743.
Kie, M. (1982) The redia, cercaria early stages of Aporocotyie simplex Odhner, 1900 (Sanguinicolidae):
a digenetic trematode which has a polychaete annelid as the only intermediate host. Ophelia 21,
115145.
Kie, M. (1985) The surface topography and life-cycles of digenetic trematodes in Limanda limanda (L.) and
Gadus morhua L. PhD thesis, University of Copenhagen, Marine Biological Laboratory, Helsingor,
Denmark, 20 pp.
Kie, M. (1987) Scanning electron microscopy of rediae, cercariae, metacercariae and adults of
Mesorchis denticulatus (Rudolphi, 1802) (Trematoda, Echinostomatidae). Parasitology Research 73,
5056.
Kie, M. and Lester, R.J.G. (1985) Larval didymozoids (Trematoda) in fishes from Moreton Bay, Australia.
Proceedings of the Helminithological Society of Washington 52, 196203.
Krull, W.H. (1934) Studies on the life history of the trematode, Rhipidocotyle septpapillata n. sp. Transactions
of the American Microscopical Society 53, 408415.
Larson, O.R. (1965) Diplostomulum (Trematoda: Strigeoidea) associated with herniations of bullhead lenses.
Journal of Parasitology 51, 224229.
Larson, O.R., Uglem, G.L. and Kook, J.L. (1988) Fine structure and permeability of the metacercarial wall of
Clinostomum marginatum (Digenea). Parasitology Research 74, 352355.
384
Lee, P.O. and Cheng, T.C. (1970) The histochemistry of Stellantchasmus falcatus Onji and Nishio, 1915
(Trematoda: Heterophyidae) metacercarial cyst in the mullet Mugil cephalus L. and histopathological
alternations in the host. Journal of Fish Bioiology 2, 235243.
Lemly, A.D. and Esch, G.W. (1984a) Population biology and largemouth bass Micropterus salmoides. Journal
of Parasitology 70, 466474.
Lemly, A.D. and Esch, G.W. (1984b) Effect of the trematode Uvulifer ambloplites (Hughes, 1927) on juvenile
bluegill sunfish Lepomis macrochirus: ecological implications. Journal of Parasitology 70, 475492.
Leno, G.H. and Holloway, H.L., Jr (1986) The culture of Diplostomum spathaceum metacercaria on the chick
chorioallantois. Journal of Parasitology 72, 555558.
Lester, R.J.G. (1977) An estimate of the mortality in a population of Perca flavescens owing to the trematode
Diplostomum adamsi. Canadian Journol of Zoology 55, 288292.
Lester, R.J.G. (1980) Hostparasite relations in some didymozoid trematodes. Journal of Parasitology 66,
527531.
Lester, R.J.G. (1984) A review of methods for estimating mortality due to parasites in wild fish populations.
Helgolander Meeresuntersuchungen 37, 5364.
Lester, R.J.G. and Huizinga, H.W. (1977) Diplostomum adamsi sp. n.: description, life cycle, and
pathogenesis in the retina of Perca flavescens. Canadian Journal of Zoology 55, 6473.
Lester, R.J.G. and Lee, T.D.G. (1976) Infectivity of the progenetic metacercariae of Diplostomum spathaceum.
Journal of Parasitology 62, 832833.
Levy, M.G., Flowers, J.R., Poore, M.F., Khoo, L., Pote, L.M., Mullen, J.E., Paperna, I., Dzikowski, R. and
Litaker, R.W. (2002) Morphologic, pathologic, and genetic investigations of Bolbophorus spp.
(Diplostomatida, Trematoda) affecting cultured Ictalurus punctatus in the Mississippi delta. Journal of
Aquatic Animal Health 14, 235246.
Littlewood, D.T.J. and Olson, P.D. (2001) Small subunit rDNA and the Platyhelminthes: signals, noise, conflicts
and compromise. In: Littlewood, D.T.J. and Bray, R.A. (eds) Interrelationships of the Platyhelminthes.
Taylor and Francis, New York, pp. 262278.
Liu, F.G. (1979) Diseases of cultured loach (Misgurnus anguillicaudatum) in Taiwan. Chinese Aquaculture
304, 14.
Llewellyn, J. (1965) The evolution of parasitic platyhelminths. In: Taylor, A. (ed.) Third Symposium of the
British Society for Parasitology. Blackwell Scientific Publications, Oxford, UK, pp. 4778.
Llewellyn, J. (1986) Phylogenetic inference from platyhelminth life-cycle stages. In: Howell, M.J. (ed.) Parasitology Quo Vadit? Proceedings of the Sixth International Congress of Parasitology. Australian Academy
of Science, Canberra, Australia, pp. 281289.
Lo, C.F., Huber, F., Kou, G.H. and Lo, C.J. (1981) Studies on Clinostomum complanatum (Rudolphi, 1819).
Fish Pathology 15, 219227.
Lo, C.F., Wang, C.H., Haber, F. and Kou, G.H. (1982) The study of Clinostomum complanatum (Rudolphi,
1814) II. The life cycle of Clinostomum complanatum. CAPD Fisheries Series No. 8, Fish Diseases
Research 4, 2656.
Lombard, G.L. (1968) A survey of fish diseases and parasites encountered in Transvaal. Newsletter of the
Limnological Society of South Africa 11, 2329.
Lorio, W.J. (1989) Experimental control of metacercariae of the yellow grub Clinostomum marginatum in
channel catfish. Journal of Aquatic Animal Health 1, 269271.
Lucky, Z. (1964) Contribution to the pathology and pathogenicity of Sanguinicola inermis in juvenile carp. In:
Ergens, R. and Rysavy, B. (eds) Parasitic Worms and Aquatic Conditions. Czechoslovak Academy of
Sciences, Cesk Budejovic, pp. 153157.
Lumsden, D.R. (1975) Surface ultrastructure and cytochemistry of parasitic helminths. Experimental Parasitology 37, 267339.
Lysne, D.A., Hemmingsen, W. and Skorping, A. (1994) The distribution of Cryptocotyle spp. metacercariae in
Atlantic cod (Gadus morhua). Journal of Fish Biology 45 (2), 352355.
McArthur, C.P. (1978) Humoral antibody production by New Zealand eels, against the intestinal trematode
Telogaster opisthorchis Macfarlane, 1945. Journal of Fish Diseases 1, 377387.
McCullough, F.S. and Mott, K.E. (1983) The Role of Molluscicides in Schistosomiasis Control. Document
WHO/VBC/83.879, World Health Organization. Geneva, Switzerland.
McDaniel, J.C. and Coggins, J.R. (1972) Seasonal larval trematode infection dynamics in Nassarius obsoletus
(Say). Journal of the Elisha Mitchell Scientific Society 88, 5557.
MacKenzie, K. (1968) Some parasites of O-group plaice, Pleuronectes platessa L. under different environmental conditions. Journal of Marine Research 3, 123.
385
MacKenzie, K. and Liversidge, J.M. (1975) Some aspects of the biology of the cercaria and metacercaria of
Stephanostomum baccatum (Nicoll, 1907) Manter 1934 (Digenea: Acanthocolpidae). Journal of Fish
Biology 7, 247256.
McKeown, C.A. and Irwin, S.W.B. (1997) Accumulation of Diplostomum spp. (Digenea: Diplostomatidae)
metacercariae in the eyes of 0+ and 1+ roach (Rutilus rutilus). International Journal for Parasitology 27
(4), 377380.
McMichael-Phillips, D.F., Lewis, J.W. and Thorndyke, M.C. (1992) Ultrastructural studies on the miracidium
of Sanguinicola inermis (Digenea: Sanguinicolidae). Parasitology 105, 435443.
McQueen, A., MacKenue, K., Roberts, R.J. and Young, H. (1973) Studies on the skin of plaice (Pleuronectes
platessa L.) III. The effect of temperature on the inflammatory response to the metacercariae of
Cryptocotyle lingua (Creplin. 1825) (Digenea, Heterophyidae). Journal of Fish Biology 5, 241247.
Madhavi, R. (1979) Observations on the occurrence of Allocreadium fasciatusi in Apocheilus melastigma.
Journal of Fish Biology 14, 4758.
Madhavi, R. and Rukmini, C. (1991) Population biology of the metacercariae of Centrocestus formosanus
(Trematoda: Heterophyidae) on the gills of Apocheilus panchax. Journal of Zoology 223, 509520.
Madhavi, R. and Rukmini, C. (1992) Population biology of Postdiplostomum grayii in a population of the
larvivorous fish Aplocheilus panchax. Acta Parasitologica 37, 183188.
Madsen, H. (1990) Biological methods for the control of freshwater snails. Parasitology Today 6, 227241.
Maillard, C., Lambert, A. and Raibaut, A. (1980) Nouvelle forme de distomatose larvaire. Etude dun
trmatode pathologie pour les alvins de daurade (Sparus aurata L. 1758) en encloserie. Compte Rendu
delAcadmie des Sciences, Paris (sr. D) 2, 535538.
Manter, H.W. (1957) Host specificity and other host relationships among the digenetic trematodes of marine
fishes. In: Baer, J.G. (ed.) Premier Symposium sur la Spcifit Parasitaire des Parasites des Vertbres.
Series, B, No. 32, International Union of Biological Sciences, pp. 185197.
Marcogliese, D. and Compagna, S. (1999) Diplostomatid eye flukes in the young of the year and forage fishes
in the St Lawrence River, Quebec. Journal of Aquatic Animal Health 11, 275282.
Margolis, L. and Boyce, N.P. (1969) Life span, maturation, and growth of two hemiurid trematodes,
Tubulovesicula lindbergi and Lecithaster gibbosus, in pacific salmon (genus Oncorhynchus). Journal of
the Fisheries Research Board of Canada 26, 839907.
Martin, W.E. (1952) Another annelid first intermediate host of a digeneric trematode. Journal of Parasitology
38, 356359.
Martin, W.E. (1955) Seasonal infections of the snail, Cerithidea californica Halderman, with larval trematodes.
In: Essays in the Natural Sciences in Honor of Captain Allan Hancock. University of Southern California
Press, Los Angeles, California, pp. 203210.
Martin, W.E. (1969) Hawaiian helminths. IV. Paracardicola howaiensis n. gen. n. sp. (Trematoda:
Sanguinicolidae) from the balloon fish, Tetraodon hispidus L. Journal of Parasitology 48, 648650.
Mashego, S.N. (1982) A seasonal investigation of the helminth parasites of Barbus species in water bodies in
Lebowa and Venda, South Africa. PhD thesis, University of the North, South Africa.
Matthews, R.A. (1973a) The life-cycle of Prosorhynchus crucibulum (Rudolphi, 1819) Odner, 1905, and a
comparison of its cercariae with that of Prosorhynchus squamatus Odner, 1905. Parasitology 67,
133164.
Matthews, R.A. (1973b) The life-cycle of Bucephalus haimanus Lacaze-Duthiers 1845 from Cardium edule, L.
Parasitology 67, 341350.
Matthews, R.A. (1974) The life cycle of Bucephaloides gracilescense (Rudolphi 1819) Hopkins, 1954
(Digenea: Gasrerostomata). Parasitology 68, 112.
Mawdesley-Thomas, L. and Young, P.C. (1967) Cutaneous melanosis in a flounder (Platichthys flesus L).
Veterinary Record October 7, 2098.
Meade, T.G. (1967) Life history studies on Cardicola klamathensis (Wales, 1958) (Tremaroda:
Sanguinicolidae). Proceedings of the Helminthological Society of Washington 34, 210212.
Meade, T.G. and Pratt, I. (1965) Description and life-cycle of of Cordicola alseae sp. n. (Trematoda:
Sanguinicolidae). Journal of Parasitology 51, 575578.
Mercer, J.G. and Chappel, L.H. (1985) Schistosoma mansoni: effect of maintenance in vitro on the uptake and
incorporation of leucine by adult worms. Molecular and Biochemical Parasitology 15, 327337.
Meuller, G. (1995) Prevalence and abundance of two trematode parasites, Diplostomum phoxini and
Macrolechitus papilliger in European minnows (Phoxinus phoxinus) in an artificial Swiss Alpine lake.
Aquatic Science 57, 119126.
Meyerhof, E. and Rothschild, M. (1940) A prolific trematode. Nature 146, 367368.
386
Millemann, R.E. and Knapp, S. (1970) Pathogenicity of the salmon poisoning trematode Nanophyetus
salmincola to fish. In: Snieszko, S.F. (ed.) A Symposium on Diseases of Fishes and Shellfishes. American
Fisheries Society, Washington, DC, Special Publication No. 5, pp. 209217.
Mills, C.A. (1979) Attachment and feeding of the adult ectoparasitic digenean Transversotrema patialense
(Sorparkar, 1924) on the zebra fish Brachydanio rerio (Hamilton-Buchanan). Journal of Fish Diseases 2,
443447.
Mills, C.A., Anderson, R.M. and Whitfield, P.J. (1979) Density dependent survival and reproduction within
population of the ectoparasitic digenean Transversotrema patialense on the fish host. Journal of Animal
Ecology 48, 383399.
Mitchell, A.J. (1995) Importance of treatment duration for praziquantel used against larval digenetic
trematodes in sunshine bass. Journal of Aquatic Animal Health 7, 327330.
Mitchell, A.J., Smith, C.E. and Hoffman, G.L. (1982) Pathogenicity and histopathology of an unusually intense
infection of white grubs (Posthodiplostomum minimum) in the fathead minnow (Pimephallus promelas).
Journal of Wildlife Diseases 18, 5157.
Mitchell, A.J., Salmon, M.J., Huffman, D.G., Goodwin, A.F. and Brandt, T.M. (2000) Prevalence and pathogenicity of a heterophyid trematode infecting the gills of an endangered fish, the fountain darter, in the two
central Texas spring-fed rivers. Journal of Aquatic Animal Health 12, 283289.
Mitchell, A.J., Goodwin, A.E., Salmon, M.J. and Brandt, T.M. (2002) Experimental infections of an exotic
heterophyid trematode, Centrocestus formosanus, in four aquacultured fishes. North American Journal
of Aquaculture 64, 5559.
Mitchell, C.W. (1974) Ultrastrcture of the metacercarial cyst of Posthodiplostomum minimum (MacCallum,
1921). Journal of Parasitology 60, 6774.
Mitchell, J.S., Haltan, D.W. and Smyth, J.D. (1978) Observations on the in vitro culture of Cotylurus erraticus
(Trematoda: Strigeidae). International Journal for Parasitology 8, 389397.
Mohan, C.V., Shankar, K.M. and Ramesh, K.S. (1999) Mortalities of juvenile common carp, Cyprinus carpio associated with larval trematode infection: a case study. Journal of Aquaculture in the Tropics 14, 137142.
Niewiadomska, K. and Czubaj, A. (2000) Ultrastructure of the exeratory system in the metacercaria of
Diplostomum pseudospathacaeum Niew., 1984 (Digenea). Acta Parasitologica 45, 307321.
Nikolaeva, V.M. (1965) On the developmental cycle of the trematode family Didymozoidae (Monticelli,
1888) Poche, 1907. Zoologichesky Zhurnal 44, 13171327 (Russian text, English summary).
Ogawa, K., Hattori, K., Hatai, K. and Kubota, S. (1989) Histopathology of cultured marine fish, Seriola
purpurascens (Carangidae) infected with Paradeontacylis spp. (Trematoda: Sanguinicolidae) in the
vascular system. Fish Pathology 24, 7581.
Oliveira, K. and Campbell, R. (1998) The occurrence and pathological effects of Stephanostomum tenue
(Digenea: Acanthocolpidae) metacercariae in elvers of the American eel. Journal of Fish Biology 53 (3),
690692.
Olson, P.D., Cribb, T.H., Tkach, V.V., Bray, R.A. and Littlewood, D.T.J. (2003) Phylogeny and classification of
the Digenea (Platyhelminthes: Trematoda). International Journal for Parasitology 33, 733755.
Ooi, H.K., Wang, W.S., Tu, C.Y., Chang, H.Y. and Chenn, C.I. (1999) Natural mass infection by heterophyid
metacercariae in aquacultured Japanese eel in Taiwan. Diseases of Aquatic Organisms 35, 3136.
Ortlepp, R.J. (1935) On the metacercariae and adults of Clinostomum van der horsti sp. n., a trematode parasite of fishes and herons. Onderstepoort Journal of Veterinary Science and Animal Industry 5, 5157.
Overstreet, R.M. and Thulin, J. (1989) Response by Plectropomus leopardus and other serranid fishes to
Pearsonellum corventum (Digenea: Sanguinicolidae), including melanomacrophage centres in the heart.
Australian Journal of Zoology 37, 129142.
Overstreet, R.M., Curran, S.S., Pote, L.M., King, D.T., Blend, C.K. and Grater, W.D. (2002) Bolobophorus
damnificus n. sp. (Digenea: Bolobophoridae) from the channel catfish Ictalurus punctatus and the
American white pelican Pelecantus erythrorhynchos in the USA based on life cycle and molecular data.
Systematic Parasitology 52, 8196.
Palombi, A. (1937) Il ciclo biologico di Lepocreadium album Stossich sperimentalamente realizzato.
Osservazioni ecologiche e considerazioni sistematiche sulla Cercaria setifera (von Jon. Muller)
Monticelli. Revista di Parasitologia 1, 112.
Palombi, A. (1941) Cercaria dentali Pelseneer, forma larvale di Ptychogonimum megastoma (Rud.) Nota
preventive. Rivista Parasitologia 5, 127128.
Pampoulie, C., Lambert, A., Rosecchi, E., Crivelli, A.J., Bouchereau, J.L. and Morand, S. (2000) Host death a
necessary condition for the transmission of Aphalloides coelomicola Dollfus, Chabaud and Golvan,
1957 (Digenea, Cryptogonimidae). Journal of Parasitology 86, 416417.
387
Paperna, I. (1964a) The metazoan parasite fauna of Israel inland water fishes. Bamidgeh 16, 366.
Paperna, I. (1964b) Parasitic helminths from inland water fishes in Israel. Israel Journal of Zoology 13, 120.
Paperna, I. (1968a) Susceptibility of Bulinus (Physopsis) globosus and Bulinus truncates rohlfsi from different
localities in Ghana to different local strains of Schistosoma haematobium. Annals of Tropical Medicine
and Parasitology 62, 1326.
Paperna I. (1968b) Studies on the transmission of schistosomiasis in Ghana. 1. Ecology of Bulinus (Physopsis)
globosus, the snail host of Schistosoma haematobium in south east Ghana. Ghana Journal of Science 8,
3051.
Paperna, I. (1968c) Studies on the transmission of schistosomiasis in Ghana. III. Notes on the ecology and
distribution of Bulinus truncatus rohlfsi and Biomphalaria pfeifferi in the lower Volta basin, Ghana.
Ghana Medical Journal 7, 139145.
Paperna, I. (1975) Parasites and diseases of the grey mullet (Mugilidae) with special reference to the seas of
the Near East. Aquaculture 5, 6580.
Paperna, I. (1991) Diseases caused by parasites in the aquaculture of warm water fish. Annual Review of Fish
Diseases, 1, 155194.
Paperna, I. (1995) Digenea (Phylum Platyhelminthes). In: Woo, P.T.K. (ed.) Fish Diseases and Disorders,
Vol. I, Protozoan and Metazoan Infections. CAB International, Wallingford, UK, pp. 329389.
Paperna, I. (1996) Parasites, Infections and Diseases of Fishes in Africa an Update. Technical Paper 31,
Central Institute of Freshwater Aquaculture, Food and Agriculture Organization, United Nations,
Rome.
Paperna, I. and Lengy, J. (1963) Notes on a new subspecies of Bolbophorus confusus (Krause, 1914) Dubois
1935 (Trematoda, Diplostomatidae), a fish-transmitted bird parasite. Israel Journal of Zoology 12,
171182.
Paperna, I. and Overstreet, R.M. (1981) Parasites and diseases of mullets (Mugiiidae) In: Oren, O.H. (ed.)
Aquaculture of Grey Mullets. IBP 26, Cambridge University Press, Cambridge, pp. 411493.
Pappas, P.W. (1988) The relative roles of intestines and external surfaces in the nutrition of monogeneans,
digeneans and nematodes. Parasitology (Supplement) 96, S105S121.
Pappas, P.W. and Read, C.P. (1975) Membrane transport in helminth parasites: a review. Experimental Parasitology 37, 469530.
Pearson, J.C. (1968) Observations on the morphology and life-cycle of Paucivitellosus fragilis Coil, Reid and
Kuntz, 1965 (Trematoda: Bivesiculidae). Parasitology 58, 769788.
Pearson, J.C. (1972) A phylogeny of life cycle pattern of the Digenea. Advances in Parasitology 10, 153189.
Perera, K.L.M. (1992a) Light microscopic study of the pathology of a species of didymozoan,
Nematobothriinae gen. sp., from the gills of slimy mackerel Scomber australasicus. Diseases of Aquatic
Organisms 13, 103109.
Perera, K.L.M. (1992b) Ultrastructure of the primary gill lamellae of Scomber australasicus infected by a
didymozoid parasite. Diseases of Aquatic Organisms 13, 111121.
Philip, C.B. (1955) There is always something new under the parasitological run (the unique story of
helminth-borne salmon poisoning disease). Journal of Parasitology 41, 125148.
Rao, K.H. and Ganapati, P.N. (1967) Observation of Transversotrema patialensis (Soparkar, 1924)
(Trematoda) from Waltair, Andra Pradesh (India). Parasitology 57, 661664.
Ratanart-Brockelman, C. (1974) Migration of Diplostomum spathaceum (Trematoda) in the fish intermediate
host. Zeitschrift fr Parasitenkunde 43, 123134.
Reimer, L.W. (1973) Das Auftreten eines Fischtrematoden der Gattung Asymphyladora Looss, 1899, bei
Nereis diversicolor O.F. Muller als Beispiel fr einen Alternativzyklus. Zoologische Anzeiger 191,
187191.
Rogers, W.A. (1972) Southern Cooperative Fish Disease Project. Eighth Annual Report, Department of Fisheries and Allied Aquaculture, Auburn University, Alabama, 101 pp.
Sarig, S. (1971) The prevention and treatment of diseases of warm water fishes under subtropical conditions,
with special emphasis on intensive farming. In: Snieszko, S. and Axelrod, H.R. (eds) Diseases of Fishes,
vol. 3. TFH Publications, Jersey City, New Jersey.
Schell, S.C. (1970) How to Know the Trematodes. W.C. Brown, Dubuque, Iowa.
Scheuring, L. (1922) Der Lebenscklus von Sanguinicola inermis Plehn. Zoologischer Jahrbucher, Abteilung fr
Anatomie und Ontogenie der Tiere 44, 265310.
Scholtz, T. and Salgado, M.G. (2000) The introduction and dispersal of Centrocestus formosanus
(Nishigori, 1924) (Digenenea: Heterophyidae) in Mexico: a review. American Midland Naturalist
143, 185200.
388
Scholtz, T., Aguirre, M.M.L. and Salgado, M.G. (2001) Trematodes of the family Heterophyidae (Digenea) in
Mexico: a review of species and new host and geographical records. Journal of Natural History 35 (12),
17331772.
Scott, J.S. (1969) Trematode populations in the Atlantic argentine, Argentina silus, and their use as biological
indicators. Journal of the Fisheries Research Board of Canada 26, 879891.
Semenas, L. (1998) Primer registro de diplostomiasis ocular en trucha arco iris cultivada en Patagonia,
Argentina. Archivo Medico Veterinaria 30, 165170.
Shariff, M., Richards, R.H. and Sommerville, C. (1980) The histopathology of acute and chronic infections of
rainbow trout Salmo gairdneri Richardson with eye flukes, Diplostomum spp. Journal of Fish Diseases 3,
455465.
Shigin, A.A. (1964) The life span of Diplostomum spathaceum in the intermediate host. Trudy
Gelmintologicheskoi Laboratoryi Akademyii Nauk SSSR 14, 262272 (in Russian).
Shotter, R.A. (1973) Changes in the parasite fauna of whiting Odontogadus merlangus L. with age and sex of
host, season, and from different areas in the vicinity of the Isle of Man. Journal of Fish Biology 5,
559573.
Sillman, E.I. (1962) The life history of Azygia longa (Leidy, 1851) (Trematoda: Digenea), and notes on
A. acuminata Goldberger 1911. Transactions of the American Microscopical Society 81, 4365.
Sinclair, N.R. (1972) Studies on the heterophyid trematode Apopallus brevis, the sand grain grub of yellow
perch (Perca fluvescens). II The metacercaria: position, structure, and composition of the cyst: hosts; geographical distribution and variation. Canadian Journal of Zoology 50, 577584.
Sindermann, C.J. and Resenfield, A. (1954) Diseases of fishes of western North Atlantic III. Mortalities of sea
herring (Clupea harengus). Maine Department of Sea Shore Fisheries Bulletin 21, 116.
Sithithaworn, P., Pipitgool, V., Srisawangwong, T., Elkins, D.B. and Haswell-Elkins, M.R. (1997) Seasonal
variation of Opisthorchis viverini infection in cyprinoid fish in north-east Thailand: implications for
parasite control and food safty. Bulletin of the World Health Organization 72 (2), 125131.
Skinner, R. (1975) Parasites of the striped mullet, Mugil cephalus from the Biscayne Bay, Florida, with description of a new genus and three new species of trematodes. Bulletin of Marine Sciences 25, 318345.
Smith, J.W. (1972) The blood flukes (Digenea: Sanguinicolidae and Spirorchidae) of cold blooded vertebrates
and some comparison with schistosomes. Helminthological Abstracts, Series A 41, 161204.
Smith, J.W. and Williams, H.H. (1967) The occurrence of the blood fluke, Aporocotyle spinosicanalis Williams, 1958 in European hake, Merluccius merluccius (L.) caught off the British Isles. Journal of
Helminthology 41, 7188.
Smyth, J.D. and Halton, D.W. (1983) The Physiology of Trematodes, 2nd edn. Cambridge University Press,
Cambridge.
So F.W. and Wittrock, D.D. (1982) Ultrastructure of the metacercarial cyst of Ornithodiplostomum
ptychochelius (Trematoda: Diplostomatidae) from the brain of fathead minnows. Transactions of the
American Microscopical Society 101, 181185.
Sogandares-Bernal, F. and Lumsden, R.D. (1964) The heterophyid trematode Ascocotyle (A.) leigli Burton,
1956, from the hearts of certain poecilid and cyprinodont fishes. Zeitschrift fr Parasitenkunde 24,
312.
Sommerville, C. (1981) A comparative study of the tissue response to invasion and encystment by
Stephanochasmus baccarus (Nicoll, 1907) (Digenea: Acanthocolpidae) in four species of flatfish. Journal
of Fish Diseases 4, 5368.
Sommerville, C. (1982) The pathology of Haplorchis pumilio (Looss, 1896) infection in cultured tilapias. Journal
of Fish Diseases 5, 243250.
Sommerville, C. and Iqbal, N.A.M. (1991) The process of infection, migration, growth and development of
Sanguinicola inermis Plehn, 1905 (Digenea: Sanguinicolidae) in carp, Cyprinus carpio L. Journal of Fish
Diseases 14, 211219.
Sorensen, R.E., Curtis, J. and Minchella, D.J. (1998) Intraspecific variation in the rDNA ITS loci of
37-collar-spined echinostomes from North America: implications for sequence-based diagnoses and
phylogenetics. Journal of Parasitology 84 (5), 992997.
Speed, P. and Pauley. C.B. (1985) Feasibility of protecting rainbow trout, Salmo gairdneri Richardson, by
immunizing against the eye fluke Diplostomum spathaceum. Journal of Fish Biology 26, 739744.
Stables, J.N. and Chappell, L.H. (1986) The epidemiology of diplostomiasis in farmed rainbow trout from
north-east Scotland. Parasitology 92, 699710.
Stein, P.C. and Lumsden, R.D. (1971) An ultrastructural and cytochemical study of metacercarial cyst development in Ascocotyle pachycystis Schroeder and Leigh, 1965. Journal of Parasitology 57, 12311246.
389
Stunkard, H.W. (1930) The life history of Cryptoctyle lingua with notes on the physiology of the metacercaria.
Journal of Morphology 50, 143.
Stunkard, H.W. (1959) The morphology and life history of the digenetic trematode Asymphylodora omnicolae
n. sp.: the possible significance of progenesis for the phylogeny of the Digenea. Biological Bulletin 117,
562581.
Stunkard, H.W. (1980) Successive hosts and developmental stages in the life history of Neapechona cablei
sp. n. (Trematoda: Lepocreadiidae). Journal of Parasitology 66, 636641.
Sukontason, K., Piangjai, S., Muangyimpong, Y., Sukontason, K., Methanitikom, R. and Chaithoong, U.
(1999) Prevalence of trematode metacercariae in cyprinoid fish of Ban Pao district, Chiang Mai Province,
northern Thailand. Southeast Asian Journal of Tropical Medicine and Public Health 30, 365370.
Sweeting, R.A. (1974) Investigations into natural and experimental infections of freshwater fish by the common eye fluke Diplostomum spathaceum Rud. Parasitology 69, 291300.
Szekely, C. and Molnar, K. (1991) Praziquantel (Droncit) is effective against diplostomosis of grasscarp
(Crenopharyngodon idella) and silver carp (Hypophthalmichtys molitrix). Diseases of Aquatic Organisms
11, 147150.
Taraschewski, H. (1984) Heterophyasis, an intestinal fluke infection of man and vertebrates transmitted by
euryhaline gastropods and fish. Helgolander Meersuntersuchungen 37, 463478.
Taraschewski, H. and Paperna, I. (1981) Distribution of the snail Pirenella conica in Sinai and Israel and its
infection by Heterophyidae and other trematodes. Marine Ecology Progress Series 5, 193205.
Taraschewski, H. and Paperna, I. (1982) Trematode infection in Pirenella conica in three sites of a mangrove
lagoon in Sinai. Zeitschrift fr Parasitenkunde 67, 165173.
Terhune, J.S., Wise, D.J. and Khoo, L.H. (2002) Bolbophorus confusus infection in channel catfish in northwestern Mississippi and effects of water temperature on the emergence of cercariae from the infected
snails. North American Journal of Aquaculture 64, 7074.
Theron, A. (1986) Chronobiology of schistosome development in the snail host. Parasitology Today 2,
192194.
Threadgold, L.T. (1984) Parasitic platyhelminths. In: Bereiter-Hahn, J., Matoltsy, A.G. and Silvia Richards, K.
(eds) Biology of the Integument 1. Invertebrates. Springer-Verlag, Berlin, pp. 132191.
Thulin, J. (1980) Redescription of Nematobibothriodes histoldi Noble, 1974 (Digenea: Didymozoidea).
Zeitschrift fr Parasitenkunde 63, 213219.
Thurston, J.P. (1965) The pathogenicty of fish parasites in Uganda. Proceedings of the East African Academy 3,
4551.
Tort, L., Watson, J.J. and Priede, I.G. (1987) Changes in in vitro heart performance in rainbow trout Salmo
gairdneri Richardson, infected with Apatemon gracilis (Digenea). Journal of Fish Biology 30, 341347.
Uglem, G.L. and Larson, O.R. (1987) Facilitated diffusion and active transport system for glucose in
metacercariae of Clinostomum marginatum (Digenea). International Journal for Parasitology 17, 847850.
Ukoli, F.M.A. (1966) On Clinostomum tilapiae n. sp. and C. phalacrocoracis Dubois, 1931, from Ghana and a
discussion of the systematics of the genus Clinostomum Leidy, 1856. Journal of Helminthology 40,
187214.
Valtonen, E.T. and Gibson, D.I. (1997) Aspects of the biology of diplostomid metacercarial (Digenea) population occurring in fishes in different localities of northern Finland. Annals Zoologici Fennici 34, 4759.
Van Cleave, H.J. and Mueller, J.F. (1934) Parasites of Oneida lake fishes. Part III A biological and ecological
survey of the worm parasites. Roosevelt Wildlife Annual 3, 161334.
Van den Brock, E. and de Jong, N. (1979) Studies on the life cycle of Asymphylodora tincae (Modeer, 1790)
(Trematoda, Monorchiidae) in a small lake near Amsterdam Part 1. The morphology of various stages.
Journal of Helminthology 53, 7989.
Van Herwerden, L., Blair, D. and Agatsuma, T. (1999) Intra- and interindividual variation in ITS1 of
Paragonimus westermani (Trematoda: Digenea) and related species: implications for phylogenetic
studies. Molecular Phylogenetics and Evolution 12 (1), 6773.
van Muiswinkel, W.B. (1995) The piscine immune system: innate and aquired immunity. In: Woo, P.T.K. (ed.)
Fish Diseases and Disorders, Vol. 1, Protozoan and Metazoan Infections. CAB International,
Wallingford, UK, pp. 729750.
Velasquez, C.C. (1958) Transversotrema laurei, a new trematode of Philippine fish (Digenea:
Transversotrematidae). Journal of Parasitology 44, 449451.
Velez-Hernandez, E.M., Constantino-Casas, F. Garcia-Marques, L.J. and Osorio-Sarabia, D. (1998) Gill
lesions in common carp, Cyprinus carpio L., in Mexico due to metacercariae of Centrocestus
formosanus. Journal of Fish Diseases 21, 229232.
390
Wales, J.H. (1958) Two new blood fluke parasites of trout. California Fish and Game 44, 125136.
Walker, D.J. and Wittrock, D.D. (1992) Histochemistry and ultrastructure of the metacercarial cyst of
Bolbogonotylus corkumi (Trematoda: Cryptogonimidae). Journal of Parasitology 78, 725730.
Walker, D.J. and Wittrock, D.D. (1999) Histochemistry and ultrastructure of the metacercarial cyst of
Cryptogonimus chyli (Trematoda: Cryptogonimidae). Journal of the Helminthological Society of Washington 66, 8286.
Wang, G.T., Yao, W.J. and Nie, P. (2001) Seasonal occurrence of Dollfustrema vaneyi (Digenea:
Bucephalidae) metacercariae in the bullhead catfish Pseudobagrus fulvidraco in a reservoir in China.
Diseases of Aquatic Organisms 44, 127131.
Watson, J.J., Pike, A.W. and Priede, I.G. (1992) Cardiac pathology associated with the infection of
Oncorhynchus mykiss Walbaum with Apatemon gracilis Rud. 1819. Journal of Fish Biology 41,
163167.
Whyte, S.K., Allan, I.C., Secombes, C.J. and Chappell, L.H. (1987) Cercariae and diplostomes of
Diplostomum spathaceum (Digenea) elicit an immune response in rainbow trout, Salmo gairdneri
Richardson. Journal of Fish Biology 31 (suppl.), 185190.
Whyte, S.K., Chappell, L.H. and Secombes, C.J. (1988) In vitro transformation of Diplostomum spathaceum
(Digenea) cercariae and short term maintenance of post-penetration larvae in vitro. Journal of
Helminthology 62, 293302.
Witenberg, G. (1944a) Transversotrema haasi, a new fish trematode. Journal of Parasitology 30, 179180.
Witenberg G. (1944b) What is the cause of the parasitic laryngo-pharyngitis in the Near East (Halzoun)? Acta
Medicalis Orientalis 3, 191192.
Wittrock, D.D., Bruce, C.S. and Johnson, A.D. (1991) Histochemistry and ultrastructure of the metacercarial
cysts of blackspot trematodes Uvulifer ambloplitis and Neascus pyriformis. Journal of Parasitology 77,
454460.
Wood, B.P. and Matthews, R.A. (1987) The immune response of the thick-lipped mullet Chelon labrosus
(Risso, 1826), to metacercarial infection of a Cryptocotyle lingua (Creplin, 1825). Journal of Fish Biology
31 (suppl.), 175183.
Wooten, R. (1974) Observations on strigeid metacercariae in the eyes of fish from Hanningfield Reservoir,
Essex, UK. Journal of Helminthology 48, 7383.
Wright, C.A. (1971) Flukes and Snails. George Allen and Unwin, London.
Yamaguti, S. (1958) Systema Helminthum. Vol. I, The Digenetic Trematodes of Vertebrate Parts, I, II.
Interscience Publications, New York.
Yamaguti, S. (1970) Digenetic Trematodes of Hawaiian Fishes. Keiga Ku Publishing House, Tokyo.
Yanohara, Y. and Kagei, N. (1983) Studies on metacercaria of Centrocestus formosanus (Nishigori, 1924) I
Parasitism of metacercariae in gills of young rearing eels, and abnormal deaths of hosts. Fish Pathology
17, 237241 (in Japanese, English summary).
Yekutiel, D. (1985) Metacercarial infections of cichlid fry in Lake Kinnereth. Unpublished MSc thesis, Hebrew
University of Jerusalem (in Hebrew, English summary).
Zeng, B.P. and Liao, X.H. (2000) Monthly changes of the metacercarial cyst infrapopulation of Centrocestus
formosanus (Nishigori, 1924) on the gills of the grass carps Ctenopharyngodon idellus. Acta
Hydrobiologica Sinica 24, 137142.
Zhatkanbayeva, D. and Heckmann, R.A. (1990) Effectiveness of praziquantel against trematodes of fish. In
Book of Abstracts, VIIth International Congress of Parasitology, 2024 August 1990, Paris, p. 869
(No. 7046).
11
Introduction
Tapeworms have been observed in fish since
antiquity, with the best known being the
broad fish tapeworm (Diphyllobothrium) of
humans. Most conspicuous are the cysts of
tapeworms that harbour the infective stage in
fish flesh and viscera. These include cysts of
Diphyllobothrium spp. (Ando et al., 2001;
Dick et al., 2001), cysts of Triaenophorus
crassus in the flesh of coregonids and some
salmonids (Fig. 11.1) and massive infections
of Diphyllobothrium spp. along the viscera in
salmonids (Fig. 11.2). Very heavy infections
are commonly reported in the flesh or along
the viscera, but remarkably few have been
shown to cause mortality of fish. The
humanfish tapeworm Diphyllobothrium
has received the most attention, followed
by the large larval tapeworms Ligula and
Schistocephalus of birds and those of economic importance, such as Triaenophorus of
fish. On the other hand, entire orders, such as
the Tetraphyllidea and Tetrarhynchidea,
have received relatively little attention until
recently. With the exception of the
Cyclophyllidea and Aporidea, every order of
cestodes has members that infect fish. While
much has been made of the humanfish tapeworm Diphyllobothrium in textbooks and
anecdotal reports, it is Triaenophorus that
has been most extensively studied, not
391
392
Fig. 11.2. Diphyllobothrium ditremum and Diphyllobothrium dendriticum encysted in the viscera and
along the body wall of Arctic charr. Cysts in the liver (white arrow), large numbers of cysts on the caecae
and stomach wall (black arrow) and asterisks show cysts along the hypaxial muscles.
Table 11.1.
393
Distribution
Fish host
Location in host
Eurasia
N. America
Sturgeon
White sturgeon
Intestine
Intestine
Intestine
Intestine
Intestine
Intestine
Intestine
Europe, N. America
Worldwide
N. America
Eurasia, N. America
Eurasia, N. America
Eurasia, N. America
Eurasia, N. America
Salmonids
Percids
Trout, salmon
Cypriniforms
Sticklebacks
Whitefish, trout
Trout
Viscera
Muscle
Viscera
Viscera
Viscera, muscle
Muscle
Viscera, liver
N. America
Europe
Catfish
Thymallus
Intestine
Intestine
N. America
Small-mouth bass
Viscera, ovaries
Pathology caused by larval marine tapeworms has been reviewed by Sindermann (1970) and
Williams(1967).
394
395
396
397
Fig. 11.3. Diagram represents life cycles of important freshwater fish tapeworms. 1. Eggs from definitive
host enter water. 2A. Embryonated egg of Proteocephalidea infective to invertebrates. 2B. Hatched
coracidium of Pseudophyllidea, Tetraphyllidea and Tetrarhynchidea infective to invertebrate
intermediate hosts. 3. Infection of definitive host via infected invertebrates. 3A. Pseudophyllidea and
Proteocephalidea. 3B. Caryophyllidea. 4. Infection of fish intermediate hosts via infected invertebrates
(Diphyllobothrium spp., Triaenophorus spp., Proteocephalus spp., Tetraphyllidea, Tetrarhynchidea).
5. Infection of piscivorous fish definitive hosts via infected prey fish (Proteocephalus spp.,
Triaenophorus spp.). 6. Infection of homeotherm definitive host via infected prey fish (Ligula,
Schistocephalus, Diphyllobothrium spp. (D. latum of humans and D. dendriticum and D. ditremum
of gulls also utilize paratenic fish hosts)). 7. Infection of definitive cartilaginous fish hosts (sharks, rays, etc.)
by larvae of Tetrarhynchidea and Tetraphyllidea via infected prey fish. a: Embryonated egg of
Proteocephalidea, often with modifications to facilitate floating and dispersal; b: embryonated operculate
eggs of Pseudophyllidea, Tetraphyllidea, Tetrarhynchidea; c: ciliated motile coracidia released from b;
d and e: procercoids in invertebrate hosts; f: larva of Caryophyllidea in tubificids; g: fish intermediate hosts;
h: larval stages (plerocercoids and plerocerci) infective to definitive hosts; i: paratenic fish host.
and are transferred passively. These tapeworms usually release eggs that complete
embryonation in water and commonly
hatch into ciliated, motile and short-lived
larvae called coracidia. Non-motile embryos
possess egg envelopes modified to maintain
motion and position or attract invertebrate
hosts in the water column, thereby enhancing the chance of being ingested by invertebrates (Jarecka, 1961). In the haemocoel
(body cavity) of the invertebrate host, the
coracidium differentiates and develops into
a procercoid stage. Although not much is
known about the factors that affect development, we know that space and nutrients are
important (Shostak et al., 1984). The migration of the procercoid and its differentiation
into a plerocercoid in fish muscle is best
illustrated by T. crassus in coregonids
(Rosen and Dick, 1983). The magnitude of
398
definitive hosts (Mackiewicz, 1988). Transmission to the definitive host (fish, bird or
mammal) is through ingestion of the infected
intermediate host and can involve consumption of carrion (natural mortality) or offal left
by sports and commercial fishermen.
Host specificity of fish parasites is difficult to determine as few studies have adequately evaluated all possible routes of
transmission. For example, new hosts are
constantly being found for larval tapeworms
(Hoffman, 1967; Margolis and Arthur, 1979).
Some parasites, e.g. Caryophyllidea, are more
specific in their invertebrate hosts than others,
e.g. Pseudophyllidea. There can be narrow
host specificity even in species that have a
wide geographical distribution, but the distribution is usually closely tied to the distribution of the definitive hosts. For example,
Triaenophorus has a worldwide distribution
that is restricted and closely correlated to its
host, Esox (pike). T. nodulosus is the most
widely distributed species, with 78 species
of intermediate fish hosts. However,
T. crassus, with 39 reported intermediate
hosts (Kuperman, 1973; Margolis and Arthur,
1979), has two preferred hosts, whitefish
and cisco, in North America. Plerocercoids
of Ligula occur in a wide range of hosts (e.g.
catastomids, centrarchids, cyprinids, percids,
salmonids), but the definitive host is Larus
canus (common gull). Host specificity is also
evident in Diphyllobothrium plerocercoids
in fish from Quigly Lake, Canada, where
D. dendriticum occurs in whitefish and
cisco (Coregonus artedii) while D. latum
occurs in pike and walleye (Sander vitreus).
As fish are poikilotherms, the effects of
abiotic factors are pronounced on their
tapeworms, where growth and maturation
of these parasites are tied to temperature.
Most infections of fish occur during the
summer and early autumn and adult tapeworms grow and mature during late spring
and early summer. In spring and early summer, most tapeworms reach sexual maturity
and release eggs; this is the time when populations of the invertebrate hosts reach their
peak. Differentiation into procercoids is also
rapid, due to high water temperatures, and
there is sufficient time for infections of fish
to occur prior to winter. Adult tapeworms
399
HostParasite Relationships
Fish have a well-developed immune system
(Chapter 18), which is often temperaturedependent. Most insults to the fish host by a
helminth produce a strong cellular response, with non-specific inflammation,
while the main immunoglobulin (antibody)
is of the IgM class. Acute inflammation
400
401
Fig. 11.4. Pathology caused by T. crassus in experimentally infected whitefish. A. Cross-section through
posterior region showing encapsulated plerocercoid (arrow) at 90 days post-infection. B. Section through
region of small intestine showing the migrating plerocercoid at 5 days post-infection. C. Reconstruction of
the extensive migration of the plerocercoid and associated tissue changes at 63, 70 and 90 days
post-infection. I, intestine, hm, hypaxial muscle, P, plerocercoid, pc, peritoneal cavity. From Rosen and
Dick (1983), courtesy of the Canadian Journal of Zoology.
402
Immunity to cestodes
Although the antibody response in fish to
microbial pathogens is well documented,
knowledge on specific immunity in
helminth infections is sparse (Evans and
Gratzek, 1989; Sharp et al., 1992). The demonstration of precipitating antibodies in
Abramis brama (bream) to Ligula (see
Molnar and Berczi, 1965) must be viewed
with some caution. Precipitation reactions
may be confused with C-reactive protein
activity, which has been demonstrated in
turbot (Reinhardtius hippoglossoides) with
phosphorylcholine-rich extracts from its
tapeworm Bothriocephalus scorpii (see
Fletcher et al., 1980). A complement factor
and C-reactive protein have also been
implicated in leucocyte adherence to the
plerocercoid of Ligula (Hoole and Arme,
1986, 1988). Precipitins to phosphorylcholine
epitopes, which are common to a variety of
organisms, including microbial pathogens
and metazoans, have been observed in lake
sturgeon, Acipenser fulvescens (Choudhury
and Dick, 1993). Other studies have
only inferred the presence of antibodies to
tapeworms (Kennedy and Walker, 1969;
McVicar and Fletcher, 1970; Sweeting,
1977). However, recent studies using
ELISA have demonstrated unequivocally
the antibody response of rainbow trout to
Diphyllobothrium spp. (Sharp et al., 1989,
1992).
No detectable cellular response was
demonstrated in the gudgeon (Gobio gobio)
infected with Ligula (Arme et al., 1983) and
pike and walleye infected with D. latum
(Dick and Poole, l985). However, recent
information (Taylor and Hoole, 1989) indicated an increase of melano-macrophages
in the spleen of infected gudgeon, although
cell counts in the pronephros remained
unchanged. There was also evidence to suggest that plerocercoids of Ligula and
Schistocephalus adsorbed host proteins,
which helped them evade host immune
responses (Hoole and Arme, 1986). Parasite
diversity appears to be influenced by major
histocompatibility complex (MHC) class IIB
variation and this suggests a self-reactive
T-cell elimination (Wegner et al., 2003).
In Vitro Culture
The absence of a digestive tract in cestodes
has made them an interesting challenge for
culture studies (Taylor and Baker, 1987;
Smyth and McManus, 1989). Culture of
cestodes may include the hatching processes (mostly due to physical factors),
short-term culture or maintenance (which
may or may not include the following:
nutrient requirements, physicochemical
aspects of the media and long-term culture
involving differentiation of the parasite).
The present discussion will focus on the culture to mature adult stages only. The criteria
for development and maturation usually
accepted are segmentation, organogeny,
gametogenesis and eggshell formation
(Smyth and McManus, 1989). Cestodes also
pose more of a challenge because of their
long flat shape and tendency to knot up in
culture. Consequently, in early studies,
considerable effort was expended on the
physical set-up of the system, i.e. roller
tubes vs. continuous flow (Smyth, 1946,
403
404
Identification of Parasites
Identification of adult fish tapeworms is
generally done with the aid of morphological keys, and it is the larval tapeworms
(especially the pseudophyllideans) that
present the most problems. Morphological
keys are available for Diphyllobothrium
(Andersen and Gibson, 1989) and general
references (such as Hoffman, 1967) are useful. Isozymes were used to distinguish
between D. latum and D. dendriticum
405
406
Table 11.2.
Chemical
Result
Reference
Bothriocephalus
acheilognathi
Carp (China)
Effective
Carp (Europe)
Carp
Cucurbita, areca1
(ground up in feed)
Taenifugin carp2
(minimum 2% of fish wt)
Zestocarp2
Mansonil, Yomesan2
Weiroski, 1984
Par et al., 1977
Carp
Carp, grass carp
Taenifugin carp2
Niclosamide
Carp
Phenasal
100% effective
Successful, incorporated
into fish pellets
100% effective
100% eradication
Infection reduced
Infection reduced
(> 12C, day 1: 20 g/kg fish,
day 2: 10 g/kg fish) 93100%
effective
90% reduction
Bothriocephalus
gowkongensis
Bothriocephalus
opsariichthydis
Bothriocephalus sp.
Caryophyllaeus sp.
Caryophyllaeus and
Khawia
Proteocephalus
ambloplitis
1Herbal
extracts.
ingredient niclosamide.
3Active ingredient 2, 5-dichloro-4-nitrosalicylanilide. See Schaperclaus (1992) for details.
2Active
Boonyaratpalin and
Rogers, 1984
Parasite
Conclusions
Significant contributions have been made
to our understanding of the proteocephalids
as a group and the genus Proteocephalus.
More work is still needed on this group of
unrelated taxa. While it does not appear to
have much of a negative impact on fish, it
may be useful as a model to study phylogenetic and co-evolutionary associations, or
lack thereof, between fish and their parasites. Studies are needed to relate larval
stages of tetraphyllideans and tetrarhynchideans to their adult stages through
life-cycle studies, and the use of the name
Scolex pleuronectis should be discontinued. Also, there is very little known about
the intraspecific variability (i.e. morphological, biological and genetic) in the genus
Diphyllobothrium. The importance of
B. acheilognathi as a worldwide pathogen
of fish, with over 40 recorded fish hosts to
date, indicates that the biology, infectivity
and genetics of this tapeworm need further
study. Significant challenges include its
transfer across watersheds through engineered changes in water movements and its
potential impacts on endangered and
threatened fish species worldwide.
Morphological identification of larval
tapeworms still relies on the local expert,
but increased application of nucleic acid
sequences is changing this approach. The
perception of narrow host specificity in
fish tapeworms should be viewed with
caution. More needs to be known about
potential hosts in a given system and the
significance of these hosts in transmission.
Basic information is lacking for most fish
parasite systems, especially the significance of biological and genetic variability.
Manipulations of portions of the aquatic
407
ecosystem to control the spread of tapeworms in fish need more research. Parasite
numbers can be reduced without drastically altering the fish species composition
in a system, but an understanding of fish
population dynamics, as well as parasite
transmission, is essential. Knowledge of
predatorprey interactions, including sports
and commercial fishing, must be integrated
into the concept of parasite transmission.
Knowledge of food chains may help to
reduce D. latum, D. dendriticum and
D. ditremum from Arctic and north temperate systems. Little is known of the effects
on the indigenous fish parasite populations following stocking of an exotic
piscivorous fish species. Increased efforts
to use fish tapeworms and other fish parasites as natural indicators to gain new
insights into trophic strucuture and food
webs in marine and freshwater ecosystems
would give greater resolving power to current tools, such as stable isotopes.
As freshwater aquaculture operations
expand, particularly cage culture, and the
use of surface water by hatcheries becomes
more common, we can anticipate additional
problems with parasitic tapeworms. These
include mortality, decreased growth and
unsaleable products for human consumption. This is due to the difficulty of excluding copepods from the water supply and
increased susceptibility of cultured species
(cyprinids, coregonids, percids, salmonids)
to indigenous tapeworms. Careful selection
of aquaculture sites and monitoring of the
water supply will have to be done to minimize some of these problems.
Only a few tapeworm diseases of fish
have been closely monitored and carefully
documented. In general, cell-mediated
immunity appears to be the primary host
response. The pathology is progressive,
with the formation of large pustules and
eventually host encapsulation. It may result
in the destruction of the parasite, formation of
a granuloma and finally its resorption. The
humoral antibody response to tapeworm
infections is not well understood. T. crassus
is a useful model system to study the interaction of cellular and humoral responses since
the parasite produces extensive pathology in
408
Acknowledgements
The authors thank the Canadian Journal of
Zoology for permission to reproduce
Fig. 11.4a, b and c and Lu Ming Chuan for
photography. The authors also thank Colin
Gallagher for technical help with the
manuscript.
References
Albertova, L.M. and Michurin, S.M. (1984) Parasites and diseases of carp in the warn waters of Surgut hydroelectric station. Sbornik Nauchnykh Trudov Gosudarstvennogo Nauchno-Issledovatelskogo Isstituta
Ozernogo I Rechnogo Rybnogo Khozyaistva (Bolezni I parazity ryb vodoemov Zapadnoi Sibiri) 226, 315.
Andersen, K. and Gibson, D.I. (1989) A key to three species of larval Diphyllobothrium Cobbold, 1958
(Cestoda: Pseudophyllidea) occurring in European and North American freshwater species. Systematic
Parasitology 13, 39.
Andersen, K., Ching, H.L. and Vik, R. (1987) A review of the freshwater species of Diphyllobothrium with
descriptions and the distribution of D. dendriticum (Nitzsch, 1824) and D. ditremum (Creplin, 1825)
from North America. Canadian Journal of Zoology 65, 22162228.
Ando, K., Ishikura, K., Nakakugi, T., Shimono, Y., Tamai, T., Sugawa, M., Limviroj, W. and Chinzei, Y. (2001)
Five cases of Diphyllobothrium nihokaiense infection with discovery of plerocercoids from an infective
source, Oncorhynchus masou ishikawae. Journal of Parasitology 87 (1), 96100.
Anikieva, L.M. (1992a) Morphological variability of the population of Proteocephalus percae (Cestoda:
Proteocephalidae) from Lake Rindozero. Parazitologiya 26, 389395 (in Russian).
Anikieva, L.M. (1992b) Population morphology of Proteocephalus torulosus (Cestoda, Proteocephalidae) from
cryprinids of the Karelian lakes. Ecological Parasitology 1, 135149 (in Russian).
Anikieva, L.M. (1993) Morphological diversity of the populations of Proteocephalus percae (Proteocephalidae) in
water bodies of Karelia. Parazitologiya 27, 260268 (in Russian).
Anikieva, L.M. (1995) Variability of a perchs parasite Proteocephalus percae in the areal of the host.
Parazitologiya 29, 279288 (in Russian).
Arme, C. and Pappas, P.W. (eds) (1983) Biology of the Eucestoda, vol. 1. Academic Press, London, 296 pp.
Arme, C., Bridges, J.F. and Hoole, D. (1983) Pathology of cestode infections in the vertebrate host. In: Arme, C.
and Pappas, P.W. (eds) Biology of the Eucestoda, vol. 2. Academic Press, London, pp. 499538.
Bagamian, K.H., Heins, D.C. and Baker, J.A. (2004) Body conditioning and reproductive capacity of
three-spined stickleback infected with the cestode Schistocephalus solidus. Journal of Fish Biology 64,
15681576.
Balling, E. and Pfeiffer, W. (1997) Frequency distributions of fish parasites in the perch Perca fluviatilis L. from
Lake Constance. Parasitology Research 83, 370373.
Bandoni, S.M. and Brooks, D.R. (1987a) Revision and phylogenetic analysis of the Amphilinidea Poche, 1922
(Platyhelminthes: Cercomeria: Cercomeromorpha). Canadian Journal of Zoology 65, 11101128.
Bandoni, S.M. and Brooks, D.R. (1987b) Revision and phylogenetic analysis of the Gyrocotylidea Poche,
1926 (Platyhelminthes: Cercomeria: Cercomeromorpha). Canadian Journal of Zoology 65, 23692389.
Bauer, O.N. (1959) Parasites of freshwater fish and the biological basis for their control. Bulletin of the State
Scientific Research Institute of Lake and River Fisheries 69, 3115. Israel Program for Scientific Translations,
Jerusalem, 1962.
Bauer, O.N. and Hoffman, G.L. (1976) Helminth range extension by translocation of fish. In: Page, A. (ed.)
Wildlife Diseases. Plenum Press, New York and London, pp. 163172.
409
Berntzen, A.K. (1961) The in vitro cultivation of tapeworms. I. Growth of Hymenolepis diminuta (Cestoda:
Cyclophyllidea). Journal of Parasitology 47, 351355.
Berntzen, A.K. (1962) In vitro cultivation of tapeworms. II. Growth and maintenance of Hymenolepis nana
(Cestoda: Cyclophyllidea). Journal of Parasitology 48, 785797.
Berntzen, A.K. and Voge, M. (1965) In vitro hatching of oncospheres of four hymenolepidid cestodes. Journal
of Parasitology 51, 235242.
Berrada-Rkhami, O., Leducq, R., Gabrion, J. and Gabrion, C. (1990) Selective distribution of sugars on the
tegumental surface of adult Bothriocephalus gregarius (Cestoda: Pseudophyllidea). International Journal
for Parasitology 20, 285297.
Beveridge, I., Campbell, R.A. and Palm, H.W. (1999) Preliminary cladistic analysis of genera of the cestode
order Trypanorhyncha Diesing, 1863. Systematic Parasitology 42 (1), 2949.
Blend, C.K. and Dronen, N.O. (2003) Bothriocephalus gadellus n. sp. (Cestoda: Bothriocephalidae) from beardless
codling Gadella imberbis (Vaillant) (Moridae) in southwestern Gulf of Mexico, with a review of species of
Bothriocephalus Rudolphi, 1808 reported from gadiform fishes. Systematic Parasitology 54, 3342.
Boonyaratpalin, S. and Rogers, W. A. (1984) Control of the bass tapeworm, Proteocephalus ambloplitis
(Leidy), with mebendazole. Journal of Fish Diseases 7, 449456.
Boyce, N.P. (1979) Effects of Eubothrium salvelini (Cestoda: Pseudophyllidea) on the growth and vitality of
sockeye salmon, Oncorhynchus nerka. Canadian Journal of Zoology 57, 597602.
Boyce, N.P. and Yamada, S.B. (1977) Effects of a parasite, Eubothrium salvelini (Cestoda: Pseudophyllidea),
on the resistance of juvenile sockeye salmon, Oncorhynchus nerka, to zinc. Journal of the Fisheries
Research Board of Canada 34, 706709.
Brandt, F. de W., Van As, J. G., Schoonbee, H.J. and Hamilton-Atwell, V.L. (1981) The occurrence and
treatment of bothricephalosis in the common carp, Cyprinus carpio in fish ponds with notes on its
presence in the largemouth yellowfish Barbus kimberleyensis from the Vall Dam, Transval. Water SA 7,
3442.
Brooks, D.R. (1989) The phylogeny of the Cercomeria (Platyhelminthes: Rhabdocoela) and general
evolutionary principles. Journal of Parasitology 75 (4), 606616.
Brown, S.P., Loot, G., Teriokhin, A., Brunel, A., Brunel, C. and Guegan, J.-F. (2002) Host manipulation by
Ligula intestinalis: a cause or consequence of parasite aggregation? International Journal for Parasitology
32, 817824.
Brunanska, M. (1999) Ultrastructure of primary embryonic envelopes in Proteocephalus longicollis (Cestoda:
Proteocephalidea). Helminthologia 36 (2), 8389.
Brunanska, M., Gustafsson, M.K.S. and Fagerholm, H.P. (1998) Ultrastructure of presumed sensory receptors
in the scolex of adult Proteocephalus exiguus (Cestoda, Proteocephalidea). International Journal for
Parasitology 28, 667677.
Brunanska, M, Fagerholm, H.P. and Gustafsson, M.K.S. (2000) Ultrastructure studies of Proteocephalus
longicollis (Cestoda, Proteocephalidea): transmission electron microscopy of scolex glands. Parasitology
Research 86 (9), 717723.
Brunanska, M., Nebesarova, J. and Scholz, T. (2003a) Spermiogenesis in the proteocephalidean cestode
Proteocephalus torulosus (Batsch, 1786). Parasitology Research 90 (4), 318324.
Brunanska, M., Scholz, T. and Nebesarova, J. (2003b) Reinvestigation of the spermatozoon ultrastructure of
the cestode Proteocephalus longicollis (Zeder, 1800), a parasite of salmonid fish. Parasitology Research
91, 357362.
Brunanska, M., Scholz, T. and Nebesarova, J. (2004) Reinvestigation of spermiogenesis in the proteocephalidean
cestode Proteocephalus longicollis (Zeder, 1800). Journal of Parasitology 90 (1), 2329.
Buchmann, K., Uldal, A. and Lyholt, H.C.K. (1995) Parasite infections in Danish trout farms. Acta Veterinaria
Scandinavica 36 (3), 283298.
Bylund, G. (1972) Pathogenic effects of a diphyllobothriid plerocercoid on its host fishes. Commentationes
Biologicae 58, 110.
Caira, J. and Jensen, K. (2001) An investigation of the co-evolutionary relationships between onchobothriid
tapeworms and their elasmobranch hosts. Journal of Parasitology 31 (9), 960975.
Caira, J.N., Jensen, K. and Holsinger, K.E. (2003) On a new index of host specificity. In: Combes, C. and
Jourdane, J. (eds) Taxonomy, Ecology and Evolution of Metazoan Parasites. Presses Universitaires de
Perpignan, France, pp. 161201.
Caira, J., Zahner, N. and Shawn, D. (2004) Five new species of Pedibothrium (Tetraphyllidea: Onchobothriidae) from Tawny nurse shark, Nebrius ferrugineus in the Pacific Ocean. Journal of Parasitology 90
(2), 286300.
410
Carney, J.P. and Dick, T.A. (1999) Enteric parasites of perch (Perca flavescens Mitchill): stochastic or
predictable assemblages. Journal of Parasitology 83, 785795.
Carney, J.P. and Dick, T.A. (2000) The historical ecology of yellow perch (Perca flavescens (Mitchill)) and
their parasites. Journal of Biogeography 27 (6), 13371347.
Charles, G.H. (1971) The ultrastructure of the developing pseudophyllid tegument (epidermis) with
special reference to the larval stages of Schistocephalus solidus and Ligula intestinalis. Proceedings
of the Second International Congress of Parasitology, Journal of Parasitology, Special Volume 59 (4),
3839.
Choudhury, A. and Dick, T.A. (1994) Natural anti-phosphorylcholine (PC) antibodies in lake sturgeon, Acipenser
fulvescens Rafinesque, 1817 (Chondrostei: Acipenseridae). Fish and Shellfish Immunology 4, 399401.
Choudhury, A. and Dick, T.A. (1998) Patterns and determinants of helminth communities in the Acipenseridae
(Actinopterygii: Chondrostei) with special reference to the lake sturgeon, Acipenser fulvescens. Canadian
Journal of Zoology 76, 330349.
Chubb, J.C., Pool, D.W. and Veltkamp, C.J. (1987) A key to the species of cestodes (tapeworms) parasitic in
British and Irish freshwater fishes. Journal of Fish Biology 31, 517543.
Coggins, J.R. (1980a) Apical end organ structure and histochemistry in plerocercoids of Proteocephalus
ambloplitis. International Journal for Parasitology 10, 97102.
Coggins, J.R. (1980b) Tegument and apical end organ fine structure in the metacestode and adult
Proteocephalus ambloplitis. International Journal for Parasitology 10, 409418.
deChambrier, A. and Vaucher, C. (1997) Rvision des cestodes (Monticelliidae) dcrits par Woodland (1934)
chez Brachyplatystoma filamentosum avec redfinition des genres Endorchis Woodland, 1934 et
Nomimoscolex Woodland, 1934. Systematic Parasitology 37, 219233.
deChambrier, A., Zehnder, M., Vaucher, C. and Mariaux, J. (2004) The evolution of the Proteocephalidea
(Platyhelminthes, Eucestoda) based on an enlarged molecular phylogeny, with comments on their uterine development. Systematic Parasitology 57, 159171.
deVos, T. and Dick, T.A. (1989) Differentiation between Diphyllobothrium dendriticum and D. latum using
isozymes, restriction profiles and ribosomal gene probes. Systematic Parasitology 13, 161166.
deVos, T., Szalai, A.J. and Dick, T.A. (1990) Genetic and morphological variability in a population of
Diphyllobothrium dendriticum (Nitzsch, 1824). Systematic Parasitology 16, 99105.
Dick, T.A. and Belosevic, M. (1981) Parasites of Arctic charr, Salvelinus alpinus (Linnaeus) and their use in
separating sea-run and non-migrating charr. Journal of Fish Biology 18, 339347.
Dick, T.A. and Poole, B.C. (1985) Identification of Diphyllobothrium dendriticum and Diphyllobothrium latum from some freshwater fishes of central Canada. Canadian Journal of Zoology 63,
196201.
Dick, T.A., Nelson, P.A. and Choudhury, A. (2001) Diphyllobothriasis: update on human cases, foci, patterns
and sources of human infections and future considerations. Southeast Asian Journal of Tropical Medicine
and Public Health 32 (suppl. 2), 5976.
Doby, J.M. and Jarecka, L. (1966) Compltement la connaissance de la morphologie et de la biologie de
Proteocephalus macrocephalus (Creplin, 1825), cestode parasite de languille. Annales de Parasitologie
Humaine et Compare 41, 429442.
Dubinina, M.N. (1974) The development of Amphilina foliacea (Rud.) at all stages of its life cycle and the position of the Amphilinidea in the system of Platyhelminthes. Parazitologicheskii Sbornik 26, 938.
Dubinina, M.N. (1987) Class Cestoda Rudolphi. In: Baur, O.N. (ed.) Key to the Parasites of Freshwater Fishes,
vol. 3. Publishing House Nauka, Leningrad, Russia, pp. 576.
Evans, D.L. and Gratzek, J.B. (1989) Immune defense mechanisms in fish to protozoan and helminth
infections. American Zoologist 29, 409418.
Evseeva, N.V. (1996) Diapause of copepods as an element for stabilizing the parasite system of some fish
helminths. In: Alekseev, V.R. and Fryer, G. (eds) Diapause in the Crustacea. Kluwer Academic
Publishers, Belgium, pp. 229233.
Fletcher, T.C., White, A. and Baldo, B.A. (1980) Isolation of a phosphorylcholine-containing component from
the turbot tapeworm, Bothriocephalus scorpii (Mueller), and its reaction with C-reactive protein. Parasite
Immunology 2, 237248.
Freze, V.I. (1965) Essentials of Cestodology. Proteocephalata, in Fish, Amphibians and Reptiles. vol. 5, Israel
Program of Scientific Translations, Jerusalem.
Freze, V.I., Sergeeva, E.G. and Kulinich, L.I. (1983) Antigenic affinity of cestode species from the genus
Diphyllobothrium (Cestoidea: Diphyllobothriidae) recorded from the territory of Karelia. Helminthologia
20, 121129.
411
Fukumoto, S., Yazaki, S., Nagai, D., Takechi, M., Kamo, H. and Yamane, Y. (1987) Comparative studies on
soluble protein profiles and isozyme patterns in 3 related species of the genus Diphyllobothrium.
Japanese Journal of Parasitology 36, 222230.
Gil de Pertierra, A.A. (2002) Redescription of Proteocephalus bagri and P. rhamdiae (Cestoda: Proteocephalidae), parasites of Rhamdia quelen (Siluriformes: Pimelodidae) from South America, with
comments on morphological variation. Folia Parasitologica 49 (1), 5566.
Grabda, J. and Bier, J.W. (1988) Cultivation as an estimate for infectivity of larval Anisakis simplex from
processed herring. Journal of Food Protection 51 (9), 734736.
Halvorsen, O. and Andersen, K. (1984) The ecological interaction between Arctic charr, Salvelinus
alpinus (L.), and the plerocercoid stage of Diphyllobothrium ditremum. Journal of Fish Biology 25,
305316.
Hanzelova, V. and Gerdeaux, D. (2003) Seasonal occurrence of the tapeworm Proteocephalus longicollis and
its transmission from copepod intermediate host to fish. Parasitology Research 91 (2), 130136.
Hanzelova, V., Zitnan, R. and Sysoev, A.V. (1990) The seasonal dynamics of the invasion cycle of Proteocephalus
neglectus (Cestoda). Helminthologia 27, 135144.
Hanzelova, V., Scholz, T. and Fagerholm, H.P. (1995a) The synonymy of Proteocephalus neglectus La Rue,
1911 with P. exiguus La Rue, 1911, two fish cestodes from the Holarctic region. Systematic Parasitology
30, 173185.
Hanzelova, V., Snabel, V., Spakulova, M., Kralova, I. and Fagerholm, H.P. (1995b) A comparative study of
the fish parasites Proteocephalus exiguus and P. percae (Cestoda: Proteocephalidae): morphology,
isoenzymes, and karyotype. Canadian Journal of Zoology 73, 11911198.
Hanzelova, V., Snabel, V. and Spakulova, M. (1996) On the host specificity of fish tapeworm Proteocephalus
exiguus La Rue, 1911 (Cestoda). Parasite 3, 253257.
Heins, D.C., Singer, S.S. and Baker, J.A. (1999) Virulence of the cestode Schistocephalus solidus and reproduction
in infected threespine stickleback, Gasterosteus aculeatus. Canadian Journal of Zoology 77, 19671974.
Hoffman, G.L. (1967) Parasites of North American Freshwater Fishes. University of California Press, Berkeley
and Los Angeles, California, 486 pp.
Hoffman, G.L. (1975) Lesions due to internal helminths of freshwater fishes. In: Ribelin, W.E. and Migaki, G.
(eds) The Pathology of Fishes. University of Wisconsin Press, Madison, Wisconsin, pp. 151188.
Hoffman, G.L. (1999) Parasites of North American Freshwater Fishes. Comstock Publishing Associates, Cornell
University Press, Ithaca, New York, 539 pp.
Hoole D. and Arme, C. (1983) Ultrastructural studies on the cellular response of fish hosts following experimental
infection with the plerocercoid of Ligula intestinalis (Cestoda: Pseudophyllidea). Parasitology 87, 139149.
Hoole, D. and Arme, C. (1986) The role of leucocyte adherence to the plerocercoid of Ligula intestinalis
(Cestoda: Pseudophyllidea). Parasitology 92, 413424.
Hoole, D. and Arme, C. (1988) Ligula intestinalis (Cestoda: Pseudophyllidea): phosphorylcholine inhibition of
fish leucocyte adherence. Diseases of Aquatic Organisms 5, 2933.
Hopkins, C.A., Law, L.M. and Threadgold, L.T. (1981) Schistocephalus solidus: pinocytosis by the
plerocercoid tegument. Experimental Parasitology 44, 161172.
Iqbal, Z. (2003) Fine structure of spermatozoon of Proteocephalus filicollis (Cestoda, Proteocephalidea).
Pakistan Journal of Zoology 35 (1), 6971.
Iqbal, Z. and Wooten, R. (2002) Ultrastructure of the embryonic envelopes of Proteocephalus filicollis
Rudalphi (Cestode: Proteocephalidea). Pakistan Journal of Zoology 34 (1), 5763.
Jarecka, L. (1961) Morphological adaptations of tapeworm eggs and their importance in the life cycles. Acta
Parasitologica Polonica 9, 409426.
Jarecka, L. and Doby, J.M. (1965) Contribution l'tude du cycle volutif dun cestode du genre Proteocephalus
parasite de Coregonus fera en provenance du Lac Leman. Annales de Parasitologie Humaine et Compare
40, 433443.
Joy, J.E. and Madan, E. (1989) Pathology of black bass hepatic tissue infected with larvae of the tapeworm
Proteocephalus ambloplitis. Journal of Fish Biology 35, 111118.
Kassai, T. (1999) Veterinary Helminthology. Butterworth and Heinemann, Oxford, UK, 260 pp.
Kennedy, C.R. and Walker, P.J. (1969) Evidence for an immune response by dace, Leuciscus leuciscus, to
infections by the cestode Caryophyllaeus laticeps. Journal of Parasitology 55, 579582.
Kennedy, C.R., Nie, P. and Rostron, J. (1992) An insect, Sialis lutaria, as a host for larval Proteocephalus sp.
Journal of Helminthology 66, 716.
Knudsen, R., Kristoffersen, R. and Amundsen, P.A. (1997) Parasite communities in two sympatric morphs of Arctic charr, Salvelinus alpinus (L.), in northern Norway. Canadian Journal of Zoology 75 (12), 20032009.
412
Kodedova, I., Dolezel, D., Brouckova, M., Jirku, M., Hypsa, V., Lukes, J. and Scholz, T. (2000) On the phylogenetic positions of the Caryophyllidea, Pseudophyllidea and Proteocephalidea (Eucestoda) inferred
from 18S rRNA. International Journal for Parasitology 30, 11091113.
Koerting, W. and Barret, J. (1977) Carbohydrate catabolism in the plerocercoids of Schistocephalus solidus
(Cestoda: Pseudophyllidea). International Journal for Parasitology 7, 411417.
Korneva, Z.V. (2001) Ultrastructure of the female genital system in Proteocephalus torulosus and P. exiguus
(Cestoda: Proteocephalidea). Helminthologia 38 (2), 6774.
Korneva, Z.V. and Davydov, V.G. (2001) Ultrastructure of male reproductive system in three
proteocephalidean cestodes. Zoologicheskii Zhurnal 80 (8), 921928.
Kral, J., Sevick, B., Prouza, A. and Vondrka, K. (1980) [Taenifugin carp, medicated granulate for the treatment
of Bothricephalus gowkongensis infections in fish]. Biologizace e Chimizace Zivocisne Vyroby,
Veterinaria 16, 183192.
Kralova, I. (1996) A total DNA characterization in Proteocephalus exiguus and P. percae (Cestoda:
Proteocephalidae): RAPD and hybridization techniques. Parasitology Research 82, 668671.
Kralova-Hromadova, I. and Spakulova, M. (1996) Intraspecific variability of Proteocephalus exiguus La Rue,
1911 (Cestoda: Proteocephalidae) as studied by the random amplified polymorphic DNA method
(RADP). Parasitology Research 82, 542545.
Kralova-Hromadova, I., Van de Peer, Y., Jirku, M., Van Ranst, M., Scholz, T. and Lukes, J. (1997) Phylogenetic
analysis of a fish tapeworm, Proteocephalus exiguus, based on the small subunit rRNA gene. Molecular
and Biochemical Parasitology 84 (2), 263266.
Kralova-Hromadova, I., Hanzelova, V., Scholz, T., Gerdeaux, D., and Sapulova, M. (2001) A comparison of
the internal transcribed spacer for Eubothrium crassum and E. salvelini (Cestoda: Pseudophyllidea)
parasites of salmonid fish. Parasitology 31, 9396.
Kralova-Hromadova I., Scholz, T., Shinn, A.P., Cunningham, C.O., Wotten, R., Hanzelova, V. and
Sommerville, C. (2003) A molecular study of Eubothrium (Batsch, 1786) (Cestoda: Pseudophyllidea)
using ITS rDNA sequences, with notes on the distribution and intraspecific sequence variation of
Eubothrium crassum (Bloch, 1779). Parasitology Research 89, 473479.
Kuperman, B.I. (1973) Tapeworms of the Genus Triaenophorus, Parasites of Fishes. Academy of Sciences of
the USSR (Akademiya Nauk, SSSR), Institute of Biology of Inland Waters, Leningrad. (Translated from
Russian, Amerind Publishing, New Delhi, 1981.)
Kuperman, B.I. and Davydov, V.G. (1982) The fine structure of glands in oncospheres, procercoids and
plerocercoids of Pseudophyllidea (Cestoidea). International Journal for Parasitology 12, 135144.
Kurovskaya, L.Y. and Kititsyna, L.A. (1986) Physiological-biochemical features of the white amur infected
with helminths. Soviet Journal of Ecology 17, 168177.
La Rue, G.R. (1911) A revision of the cestode family Proteocephalidae. Zoologischer Anzeiger 38, 473482.
La Rue, G.R. (1914) A Revision of the Cestode Family Proteocephalidae. Illinois Biological Monographs 1,
Illinois, Iowa, 350 pp.
Lawler, G.H. (1970) Parasites of coregonid fishes. In: Lindsey, C.C. and Woods, C.S. (eds) Biology of
Coregonid Fishes. University of Manitoba Press, Winnipeg, Manitoba, pp. 279310.
Logan, F.J., Horak, A., Stefka, J., Aydogdu, A. and Scholz, T. (2004) The phylogeny of diphyllobothriid tapeworms (Cestoda: Pseudophyllidea) based on ITS-2 rDNA sequences. Parasitology Research 94 (1), 1015.
Loot, G., Brosse, S., Lek, S. and Guegan, J.-F. (2001) Behaviour of roach (Rutilus rutilus L.) altered by
Ligula intestinalis (Cestoda: Pseudophyllidea): a field demonstration. Freshwater Biology 46,
12191227.
Luo, H.Y., Nie, P., Zhang, Y.A., Yao, W.J., and Wang, G.T. (2003) Genetic differentiation in populations of
the cestode Bothriocephalus acheilognathi (Cestoda: Pseudophyllidea) as revealed by eight
microsatellite markers. Parasitology 126, 493501.
McCormick, H.J. and Stokes, G.N. (1982) Intraovarian invasion of smallmouth bass oocytes by
Proteocephalus ambloplitis (Cestoda). Journal of Parasitology 68, 975976.
MacDonald, T.E. and Margolis, L. (1995) Synopsis of the Parasites of Fishes of Canada: Supplement
(19781993). Canadian Special Publication of Fisheries and Aquatic Sciences, No. 122, 265 pp.
Mackiewicz, J.S. (1972) Caryophyllidea (Cestoidea): a review. Experimental Parasitology 31 (3), 417512.
Mackiewicz, J.S. (1981) Caryophyllidea (Cestoidea): evolution and classification. In: Lumsden, W.H.R., Muller, R.
and Baker, J.R. (eds) Advances in Parasitology 19. Academic Press, New York, pp. 139206.
Mackiewicz, J.S. (1988) Cestode transmission patterns. Journal of Parasitology 74, 6071.
Mackiewicz, J.S., Cosgrove, G.E. and Gude, W.D. (1972) Relationship of pathology to scolex morphology
among caryophyllid cestodes. Zeitschrift fr Parasitenkunde 39, 233246.
413
MacKinnon, B.M. and Burt, M.B.D. (1984) The comparative ultrastructure of the plerocercoid and adult
primary scolex of Haplobothrium globuliforme Cooper, 1914 (Cestoda: Haplobothriodea). Canadian
Journal of Zoology 63, 14881496.
McManus, D.P. (1985) Enzyme analyses of natural populations of Schistocephalus solidus and Ligula
intestinalis. Journal of Helminthology 59, 323332.
McVicar, A.H. (1972) The ultrastructure of the parasitehost interface of three tetraphyllidean tapeworms of
the elasmobranch Raja naevus. Parasitology 65, 7788.
McVicar, A.H. and Fletcher, T.C. (1970) Serum factors in Raja radiata toxic to Acathobothrium quadripartitum
(Cestoda: Tetraphyllidea), a parasite specific to R. naevus. Parasitology 61, 5563.
Malakhova, R.P. and Anikieva, L.V. (1976) On the biology of Proteocephalus exiguus in fishes from subfamily
Coregonidae. In: Parasitological Studies in Karelian ASSR and Murmansk Region, Petrozavodsk, Karelia,
pp. 168175 (in Russian).
Margolis, L. and Arthur, J.R. (1979) Synopsis of the Parasites of Fishes of Canada. Bulletin of the Fisheries
Research Board of Canada, 199, Department of Fisheries and Oceans, Ottawa, 269 pp.
Meggitt, F.J. (1914) The structure and life history of a tapeworm (Ichthyotaenia filicollis Rud.) in the stickleback. Proceedings of the Zoological Society, London 8, 113138.
Miller, R.B. (1952) A Review of the Triaenophorus Problem in Canadian Lakes. Bulletin of the Fisheries
Research Board of Canada, 95, Department of Fisheries and Oceans, Ottawa, 142 pp.
Mitchell, L.G., Ginal, J. and Bailey, W.C. (1983) Melanotic visceral fibrosis associated with larval infections of
Posthodiplostomum minimum and Proteocephalus sp. in bluegill, Lepomis macrochirus Rafinesque, in
central Iowa, USA. Journal of Fish Diseases 6, 135144.
Molnar, K. and Berczi, I. (1965) Nachweis von parasitenspezifischen Antikoerpern im Fischblut mittels der
Agar-Gel-Praezipitationsprobe. Zeitschrift fur Immunologie Allergie-Forschung 129, 263267.
Morandi, H. and Ponton, D. (1989) Cycle volutif dun cestode Proteocephalidae parasite du coregone du Lac
Leman (Coregonus lavaretus L.). Annales de Parasitologie Humaine et Compare 64, 257267.
Moravec, F. (2001) Common sculpin Cottus gobio as a natural paratenic host of Proteocephalus longicollis
(Cestoda: Proteocephalidae), a parasite of salmonids, in Europe. Diseases of Aquatic Organisms 45 (2),
155158.
Muller, R. (2002) Worms and Human Disease, 2nd edn. CAB International, Wallingford, UK, 300 pp.
Muzzall, P.M. (2000) Parasites of farm-raised trout in Michigan, USA. Comparative Parasitology 67 (2),
181189.
Nei, D.S. and Pan, J.P. (1985) Diseases of grass carp (Ctenopharygodon idellus Valenciennes, 1844) in
china, a review form 19531983. Fish Pathology 20, 323330.
Nelson, P.A. and Dick, T.A. (2002) Factors shaping the parasite communities of trout-perch, Percopsis
omiscomaycus Walbaum (Osteichthyes: Percopsidae), and the importance of scale. Canadian Journal of
Zoology 80 (11), 19861999.
Overli, O., Pall, M., Borg, B., Jobling, M. and Winberg, S. (2001) Effects of Schistocephalus solidus infection
on brain monoaminergic activity in female three-spined sticklebacks Gasterosteus aculeatus. Proceedings of the Royal Society (Biological Sciences Series B) 268 (1474), 14111415.
Palm, H.W. (2002) A revison of Microbothriorhynchus Yamaguti, 1952 (Cestoda: Trypanorhyncha), with the
redescription of M. coleorhynchi Yamanguti, 1952 and the description of M. reimeri n. sp. Systematic
Parasitology 53, 219226.
Paperna, I. (1991) Diseases caused by parasites in the aquaculture of warm water fish. Annual Review of Fish
Diseases 1, 155194.
Par, O., Parova, J. and Prouza, A. (1977) [Mansonil an effective anthelminitic for the treatment of
Bothricephalus infections in carp]. Bulletin Vyzkummy Utsav Rybarsky a Hydrobiologicky Vodnany,
CSSR 1, 1725 (in Russian).
Popova, L.B. and Davydov, V.G. (1988) Studies on localization of Amphilina spp. (Amphilinidae, Dubinina,
1974) in definitive hosts. Helminthologia 25 (2), 129138.
Poulin, R. and Mouillot, D. (2003) Parasite specialization from a phylogenetic perspective: a new index of
host specificity. Parasitology 126 (5), 473480.
Pronina, S.V. and Pronin, N.M. (1982) The effect of cestode (Triaenophorus nodulosus) infestation on the
digestive tract of pike (Esox lucius). Journal of Ichthyology 22, 105113.
Pulkkinen, K., Valtonen, E.T., Niemi, A. and Poikola, K. (1999) The influence of food competition and host
specificity on the transmission of Triaenophorus crassus (Cestoda) and Cystidicola farionis (Nematoda) to
Coregonus lavaretus and Coregonus albula (Pisces: Coregonidae) in Finland. International Journal for
Parasitology 29 (11), 17531763.
414
Rego, A.A. (1994) Order Proteocephalidea Mola, 1928. In: Khalil, L.F., Jones, A. and Bray, R.A. (eds) Keys to
the Cestode Parasites of Vertebrates. CAB International, Wallingford, UK, pp. 257293.
Rego, A.A. (1999) Scolex morphology of proteocephalid cestode parasites of Neotropical freshwater fishes.
Memorias do Instituto Oswaldo Cruz 94 (1), 3752.
Rego, A.A., Chubb, J.C. and Pavanelli, G.C. (1999) Cestodes in South American freshwater teleost fishes: keys
to genera and brief description of species. Revista Brasileira de Zoologia 16 (2), 299367.
Reimchen, T.E. (1997) Parasitism of asymmetrical pelvic phenotypes in stickleback. Canadian Journal of
Zoology 75, 20842094.
Renaud, F., Gabrion, C. and Pasteur, N. (1986) Geographical divergence in Bothriocephalus (Cestoda) of
fishes demonstrated by enzyme electrophoresis. International Journal of Parasitology 16, 553558.
Rim, H.J. (1998) Field investigations on epidemiology and control of fish-borne parasites in Korea.
International Journal of Food Science and Technology 33 (2), 157168.
Rintamaki, P. and Valtonen, E.T. (1988) Seasonal and size-bound infection of Proteocephalus exiguus in four
coregonid species in northern Finland. Folia Parasitologica 35, 317328.
Rodger, H.D. (1991) Diphyllobothrium sp. infections in freshwater reared salmon (Salmo salar L.).
Aquaculture 95, 714.
Rosen, R. and Dick, T.A. (1983) Growth and migration of plerocercoids of Triaenophorus crassus Forel and
pathology in experimentally infected whitefish. Canadian Journal of Zoology 62, 203211.
Rosen, R. and Dick, T.A. (1984) Experimental infections of rainbow trout, Salmo gairdneri Richardson, with
plerocercoids of Triaenophorus crassus Forel. Journal of Wildlife Diseases 20, 3448.
Rusinek, O.T., Bakina, M.P. and Nikolskii, A.V. (1996) Natural infection of the calanoid crustacean Epischura
baicalensis by procercoids of Proteocephalus sp. in Listvenichnyi Bay, Lake Baikal. Journal of
Helminthology 70, 237247.
Rzeczkowska, A. and Honowska, M. (1988) Biochemical effect of the plerocercoid of Ligula intestinalis (L.) on
the bream Abramis brama (L). Wiadomosci Parazitologiczne 34, 1927.
Saksvik, M., Nilsen, F., Nylund, A. and Berland, B. (2001) Effect of marine Eubothrium sp. (Cestoda:
Pseudophyllidea) on the growth of Atlantic salmon, Salmo salar L. Journal of Fish Diseases 24 (2), 111119.
Schaperclaus, W. (1992) Fish Diseases, vols 1 and 2. A.A. Balkema, Rotterdam, The Netherlands, 1398 pp.
Scheinert, P. and Hoffman, R. (1986) Enzymeserologische Untersuchungen an durch Triaenophorus
nodulosus befallenen Seesaibling (Salvelinus alpinus L.) des Koenigsees. Berlin Mnchen Tierische
Wochenschrift 99, 383386.
Scheuring, L. (1923) Studien an Fischparasiten. I. Triaenophorus nodulosus (Pall) und die durch ihn im
Fischkoerper hervorgerufenen pathologischen Veraenderungen. Zeitschrift fr Fischerei 22, 93205.
Schmahl, G. (1991) The chemotherapy of monogeneans which parasitize fish: a review. Folia Parastologica
88, 97106.
Schmahl, G. and Taraschewski, H. (1987) Treatment of fish parasites 2. Effects of paraziquantel, nilosamide,
levamisole-HCL, and metrifonate on mongenea (Gyrodactylus aculeate, Diplozoon paradoxum).
Parasitology Research 73, 341351.
Schmidt, G.D. (1986) CRC Handbook of Tapeworm Identification. CRC Press, Boca Raton, Florida, 675 pp.
Scholz, T. (1989) Amphilinida and Cestoda, parasites of fish in Czechoslovakia. Acta Scientiarum Naturalium
23 (4), 56.
Scholz, T. (1991) Studies on the development of the cestode Proteocephalus neglectus La Rue, 1911 (Cestoda:
Proteocephalidea) under experimental conditions. Folia Parasitologica 38, 133142.
Scholz, T. (1993) Development of Proteocephalus torulosus (Batsch, 1786) (Cestoda: Proteocephalidae) in the
intermediate host under experimental conditions. Journal of Helminthology 67, 316324.
Scholz, T. (1997) A revision of the species Bothriocephalus Rudolphi, 1808 (Cestoda: Pseudophyllidea)
parasitic in American freshwater fishes. Systematic Parasitology 36, 85107.
Scholz, T. (1999a) Life cycles of species of Proteocephalus, parasites of fishes in the Palearctic region: a
review. Journal of Helminthology 73 (1), 119.
Scholz, T. (1999b) Parasites in cultured and feral fish. Veterinary Parasitology 84, 317335.
Scholz, T. and deChambrier, A. (2003) Taxonomy and biology of proteocephalidean cestodes: current state
and perspectives. Helminthologia 40 (2), 6577.
Scholz, T. and Hanzelova, V. (1994) Taxonomic study of two Proteocephalus species (Cestoda:
Proteocephalidae) parasitizing coregonid fishes: the synonymy of P. fallax La Rue, 1911 with P. exiguus
La Rue, 1911. Systematic Parasitology 27, 112.
Scholz, T. and Hanzelova, V. (1998) Tapeworms of the Genus Proteocephalus Weinland, 1858 (Cestoda:
Proteocephalidae), Parasites of Fishes of Europe. Stude AC CR 1998 (2), Academia, Prague.
415
Scholz, T. and Hanzelova, V. (1999) Species of Proteocephalus Weinland, 1858 (Cestoda: Proteocephalidae)
from cyprinid fishes in North America. Journal of Parasitology 85, 150154.
Scholz, T. and Moravec, F. (1993) Finding of Proteocephalus torulosus (Cestoda: Proteocephalidae) in Sialis
lutaria (Insecta: Megloptera). Acta Societatis Zoologicae Bohemoslovacae 57, 159160.
Scholz, T., Hanzelova, V. and Snabel, V. (1995) The taxonomic status of Proteocephalus dubius La Rue, 1911
(Cestoda: Proteocephalidae), a puzzling parasite of perch (Perca fluviatilis L.). Parasite 2, 231234.
Scholz, T., Spakulova, M., Snabel, V., Kralova, I. and Hanzelova, V. (1997) A multidisciplinary approach to the
systematics of Proteocephalus microcephalus (Creplin, 1825) (Cestoda: Proteocephalidae). Systematic
Parasitology 37, 112.
Scholz, T., Hanzelova, V., Kralova, I. and Griffiths, D. (1998a) Synonymy of Proteocephalus pollanicola
Gresson, 1952 (Cestoda: Proteocephalidae), a parasite of pollan, Coregonus autumnalis pollan, with P.
exiguus La Rue, 1911. Systematic Parasitology 40 (1), 3541.
Scholz, T., Drabek, R. and Hanzelova, V. (1998b) Scolex morphology of Proteocephalus tapeworms
(Cestoda: Proteocephalidae), parasites of freshwater fish in the Palaearctic region. Folia Parasilologiya
45, 2743.
Scholz, T., Skerilova, A., Hanzelova, V., Koubkova, B. and Barus, V. (2003a) Resurrection of Proteocephalus
sagittus (Grimm, 1872) (Cestoda: Proteocephalidea) based on morphological and molecular data.
Systematic Parasitology 56, 173181.
Scholz, T., Rosas, V. R., Perez-Ponce de Leon, G., Choudhury, A. and Chambrier, A. (2003b) Taxonomic status of Choanoscloex lamothei Garcia-Prieto, 1990 (Cestoda: Proteocephalidae) using morphological and
molecular techniques. Journal of Parasitology 89, 12121219.
Scott, A.L. and Grizzle, J.M. (1979) Pathology of cyprinid fishes caused by Bothriocephalus gowkongenesis
Yea, 1955 (Cestoda: Pseudophyllidea). Journal of Fish Diseases 2, 6973.
Sharp, G.J.E., Pike, A.W. and Secombes, C.J. (1989) The immune response of wild rainbow trout, Salmo
gairdneri Richardson, to naturally acquired plerocercoid infections of Diphyllobothrium dendriticum
(Nitzsch, 1824) and D. ditremum (Creplin, 1825). Journal of Fish Biology 35, 781794.
Sharp, G.J.E., Pike, A.W. and Secombes, C.J. (1992) Sequential development of the immune response in rainbow
trout (Oncorhynchus mykiss (Walbalum, 1792)) to experimental plerocercoid infections of Diphyllobothrium
dendriticum (Nitsch, 1824). Parasitology 104, 169178.
Shostak, A.W. and Dick, T.A. (1986) Intestinal pathology in northern pike, Esox lucius l., infected with
Triaenophorus crassus Forel, 1868 (Cestoda: Pseudophyllidea). Journal of Fish Diseases 9, 3545.
Shostak, A.W., Rosen, R.B. and Dick, T.A. (1984) Orientation of procercoids of Triaenophorus crassus Forel in
Cyclops bicuspidatus thomasi Forbes: effects on growth and development. Canadian Journal of Zoology
62, 13731377.
Sindermann, C.J. (1970) Diseases caused by helminths and parasitic crustacea. In: Sindermann, C.J.
(ed.) Principal Diseases of Marine Fish and Shellfish. Academic Press, New York and London,
pp. 52105.
Skerikova, A., Hypsa, V. and Scholz, T. (2001) Phylogenetic analysis of European species of Proteocephalus
(Cestoda: Proteocephalidea): compatibility of molecular and morphological data, and parasitehost
coevolution. International Journal for Parasitology 31, 11211128.
Skrjabina, E.S. (1974) Helminths of Sturgeon (Acipenseridae Bonaparte 1831) (in Russian). Nauka, Moscow,
168 pp.
Smyth, J.D. (1946) Studies on tapeworm physiology. I. Cultivation of Schistocephalus solidus in vitro. Journal
of Experimental Biology 23, 4770.
Smyth, J.D. (1947). Studies on tapeworm physiology. II. Cultivation and development of Ligula intestinalis in
vitro. Parasitology 38, 173181.
Smyth, J.D. (1954) Studies on tapeworm physiology. VII. Fertilization of Schistocephalus solidus in vitro.
Experimental Parasitology 3, 6471.
Smyth, J.D. (1976) Introduction to Animal Parasitology, 2nd edn. Hodder and Stoughton, London, 470 pp.
Smyth, J.D. (1982) The inseminationfertilization problem in cestodes cultured in vitro. In: Meerovitch, E.
(ed.) Aspects of Parasitology. McGill University, Montreal, pp. 393406.
Smyth, J.D. and McManus, D.P. (1989) The Physiology and Biochemistry of Cestodes. Cambridge University
Press, Cambridge, 398 pp.
Snabel, V., Hanzelova, V. and Fagerholm, H.P. (1994) Morphological and genetic comparison of two
Proteocephalus species (Cestoda: Proteocephalidae). Parasitology Research 80, 141146.
Snabel, V., Hanzelova, V., Mattiucci, S., DAmelio, S. and Paggi, L. (1996) Genetic polymorphism in
Proteocephalus exiguus shown by enzyme electrophoresis. Journal of Helminthology 70, 345349.
416
Stoitsova, S., Georgiev, B., Dacheva, R. and Vinarova, M. (1995) Ultrastructural and cytochemical demonstration of two types of scolex glands in Proteocephalus osculatus (Cestoda, Proteocephalidea). Dokladi na
BIgarskata Akademiya na Naukite 48 (8), 9799.
Stunkard, H.W. (1983) Evolution and systematics. In: Arme, C. and Pappas, A.W. (eds) Biology of Eucestoda,
vol. 1. Academic Press, London, pp. 125.
Sweeting, R.A. (1977) Studies on Ligula intestinalis. Some aspects of the pathology in the second intermediate
host. Journal of Fish Biology 10, 4350.
Swiderski, Z. and Conn, D.B. (1999) Ultrastructural aspects of fertilization in Proteocephalus longicollis,
Inermicapsifer madagascariensis, and Mesocestoides lineatus (Platyhelminthes, Cestoda). Acta
Parasitologica 44 (1), 1930.
Sysoev, A.V., Freze, V.I. and Anderson, K.I. (1994) On the morphology of procercoids of the genus
Proteocephalus (Cestoda, Proteocephalidea). Parasitology Research 80, 245252.
Szalai, A.J., Yang, X. and Dick, T.A. (1989) Changes in numbers and growth of Ligula intestinalis in the spottail
shiner (Notropis hudsonius), and their roles in transmission. Journal of Parasitology 75, 571576.
Szalai, A.J. and Dick, T.A. (1991) Role of predation and parasitism of yellow perch in Dauphin Lake
Manitoba. Transactions of the American Fisheries Society 120 (6), 739751.
Taylor, A.E.R. and Baker, J.R. (1987) In vitro Methods for Parasite Cultivation. Academic Press, London, 465 pp.
Taylor, M. and Hoole, D. (1989) Ligula intestinalis (L.) (Cestoda: Pseudophyllidea): plerocercoid-induced
changes in the spleen and pronephros of the roach, Rutilus rutilus (L.), and gudgeon, Gobio gobio (L.).
Journal of Fish Biology 34, 583596.
Threadgold, L.T. (1984) Parasitic Platyhelminthes. In: Bereiter-Hahn, J., Maltoltsy, A.G. and Richards, K.S.
(eds) Biology of the Tegument. Springer-Verlag, Berlin, pp. 132191.
Turcekova, L., Hanzelova, V. and Spakulova, M. (2002) Concentrations of heavy metals in perch and its
endoparasites in the polluted water reservoir in Eastern Slovakia. Helminthologia 39 (1), 2328.
Vojtkova, L. and Koubkova, B. (1990) Helminth fauna of caddis-fly larvae (Megaloptera). Journal of the
Faculty of Science, Masaryk University, Brno, Seria Biologia 20, 494495 (in Czech).
Wagner, E.G. (1954) The life history of Proteocephalus tumidocollus Wagner, 1953 (Cestoda) in rainbow
trout. Journal of Parasitology 40, 489498.
Wardle, R.A. and McLeod, J.A. (1952) The Zoology of Tapeworms. University of Minnesota Press, Minneapolis,
780 pp.
Watson, R.A. and Dick, T.A. (1979) Metazoan parasites of whitefish, Coregonus clupeaformis (Mitchill) and
cisco, C. artedi LeSueur, from Southern Indian Lake, Manitoba. Journal of Fish Biology 15, 579587.
Wegner, K.M., Reusch, T.B.H. and Kalbe, M. (2003) Multiple parasites are driving major histocompatibility
complex polymorphism in the wild. Journal of Evolution 16, 224232.
Weiland, K.A. and Meyers, T.R. (1989) Histopathology of Diphyllobothrium ditremum plerocercoids in coho
salmon Oncorhynchus kisutch. Diseases of Aquatic Organisms 6, 175178.
Weiroski, F. (1984) Occurrence, spread and control of Bothricephalus acheilognathi, in the carp ponds of the
German Democratic Republic. In: Olah, J. (ed.) Fish, Pathogens and the Environment in European
Polyculture. Proceedings of International Seminar, 2327 June, 1981, Szarvas, Hungary. Symposia
Biologica Hungary 24, 149155.
Willemse, J.J. (1968) Proteocephalus filicollis (Rudolphi, 1802) and Proteocephalus ambiguus (Dujardin,
1845), two hitherto confused species of cestodes. Journal of Helminthology 42, 395410.
Willemse, J.J. (1969) The genus Proteocephalus in the Netherlands. Journal of Helminthology 43, 207222.
Williams, H. and Jones, A. (1994) Parasitic Worms of Fish. Taylor and Francis, London, 593 pp.
Williams, H.H. (1967) Helminth diseases of fish. Helminthological Abstracts 36, 261295.
Zaika, V.E. (1965) Fish Parasite Fauna of Lake Baikal. Nauka, Moscow and Leningrad, 106 pp (in Russian).
Zdarska, Z. and Nebesarova, J. (1999) Regional ultrastructural differences of the scolex and neck tegument of
Proteocephalus microcephalus (Eucestoda: Proteocephalidae). Folia Parasitologica 46 (4), 279283.
Zehnder, M.P. and Mariaux, J. (1999) Molecular systematic analysis of the order Proteocephalidae
(Eucestoda) based on mitochondrial and nuclear rDNA sequences. International Journal for Parasitology
29 (11), 18411852.
Zitnan, R., Hanzelova, V., Prihoda, J. and Kostan, B. (1981) [Evaluation of efficacy of Taenifugin carp in the
treatment of Bothricephalus infections in carp at low water temperature]. Biogizace e Chemizace
Zivocisne vyroby, Veterinaria 17 (23), 471477 (in Russian).
12
Phylum Nematoda
Introduction
Parasitic nematodes constitute one of the
earliest known groups of helminths in fishes.
They infect freshwater, marine and brackishwater fish species and sometimes cause
substantial damage to the host. Although
parasitic nematodes can infect almost all
organs in a fish, the majority of the currently known species have been described
from the intestine. Most nematodes infect
fish as adults, but a large proportion of them
occur as larval stages. These are usually
parasites of piscivorous birds, mammals or
reptiles, or less frequently of predatory fishes.
The majority of nematodes reach sexual maturity through a complicated developmental cycle involving an intermediate
or possibly paratenic hosts. Species living
in the temperate zone are usually characterized by seasonal occurrence, and annual
life cycles are common. Because of the complicated, multi-host life cycle, the development of fish nematodes is successful in
non-disrupted ecosystems. In fish taken
from their natural surroundings, nematode
infections are less likely to develop. For
these reasons, nematodes cause less damage
in cultured fishes than do other helminths.
At the same time, certain nematodes can
give rise to massive infections with high
fish mortality in natural waters.
417
418
K. Molnr et al.
occurrence and pathological role of fishparasitic nematodes are found in the first
edition of this publication (Dick and
Choudhury, 1995). Since the publication of
the work, relatively little new information
has been added to our existing knowledge
of fish-parasitic nematodes. The new data
concern primarily the development, pathological effect and human health implications of a few selected groups (Anguillicola,
Philometra, Skrjabillanus, Anisakis).
Economic Importance
In some cases, parasitic nematodes can produce very spectacular and massive infections in fishes. The masses of Philometra
ovata (Fig. 12.1) in the abdominal cavity of
gudgeon or the white-coloured Hysterothylacium bidentatum (Fig. 12.2) in the
stomach of sterlet (Acipenser ruthenus) definitely indicate that nematodes are important pathogens. In spite of this, Williams
(1967) rightly stated that among the
helminth parasites of fishes the pathological effect of nematodes had been studied
the least. The situation has not changed.
Although the number of known species has
gradually increased, there are still few new
data on the pathological effects of nematodes. In freshwater fish species, the new
data mostly concern Anguillicola crassus
(Fig. 12.3) infection in eel (Anguilla
anguilla). As regards marine fish parasites,
Fig. 12.1.
Philometra ovata filling the abdominal cavity of a gudgeon (Gobio gobio) ( 0.6).
Phylum Nematoda
419
Fig. 12.3. Heavy and moderate infections with Anguillicola crassus in opened swim bladders of
European eels ( 0.6).
Host Range
Nematode infection occurs in practically all
fish species and in all locations. The prevalence, intensity and economic importance
of nematode infections, however, vary by
region and by fish species.
The host range of these parasites is primarily influenced by the host specificity of
the nematode species for the final host and
for the intermediate host. Species having a
narrow host range are usually in a fish host
that is prevalent in a given habitat, while
species with a broad host range are in fish
species all over the world. These nematodes
can often cause mild disease in all members
of a fish genus and, after colonizing a new
host species, they can give rise to much more
severe disease. Such a species is A. crassus,
a nematode of Japanese eel (Anguilla
japonica), which causes a mild disease in
its original hosts. However, this nematode
is much more pathogenic in European and
American eel species (Anguilla rostrata).
The typical examples of highly specific
nematodes are the members of different
skrjabillanid genera (Skrjabillanus tincae,
Skrjabillanus cyprini, Molnaria intestinalis,
Sinoichthyonema amuri), which in most
cases infect a single fish species.
Nematodes with a broad host range are
represented by Capillaria species, which
can colonize numerous fish species of different taxonomic positions. Fish parasites
characterized by a global range include the
420
K. Molnr et al.
Fig. 12.4.
( 0.3).
Philometroides cyprini female freed from the scale pocket of common carp (Cyprinus carpio)
Phylum Nematoda
421
422
K. Molnr et al.
Branchiura (fish lice), can transmit developmental stages to fish. Both fish and invertebrates may serve as transport (paratenic)
hosts for some nematodes. A transport host
is an organism in which no development
necessary for the progress of the life cycle
takes place. A high number of larvae can
accumulate in such hosts. Although direct
development without an intermediate host
may be a possibility for some groups (e.g. for
Capillariidae), this has not been unequivocally proven experimentally. Recently it was
shown by Kie (2001c) that the marine
Capillaria gracilis, which invades the rectum of Atlantic cod, needs intermediate
hosts. Thus, chironomids and oligochaetes
ingest the larvated eggs, where hatching and
some growth of the larvae occurs. Further, the
obligate fish intermediate host allows considerable growth of the worm before infection of the final host. In the case of direct
development, host finding is often promoted
by paratenic hosts, e.g. by oligochaetes carrying the larvated eggs (Bell and BeverleyBurton, 1980; Lomakin and Trofimenko, 1982;
Moravec, 1983). Percutaneous transmission
by migrating larvae, which is common in
terrestrial animals, does not exist in fishes.
Some worms lay unsegmented eggs, and
these worms are oviparous. Ovoviviparous
worms lay eggs containing the first- or secondstage larva (Fig. 12.9a), and viviparous worms
discharge free first-stage larva (Fig. 12.9b).
Development
The majority of fish nematodes have rather
complicated development. Most are heteroxenous and have final, intermediate and
paratenic (transport) hosts. In the life cycle
of fish nematodes, there is always a single
intermediate host. In the majority of
cases, food animals such as aquatic crustaceans (Copepoda, Amphipoda, Mysidacea,
Decapoda), annelids, coelenterates, molluscs
and small fishes are intermediate hosts. Also
parasitic organisms infecting fish, such as
cyclostomes and crustaceans of the class
Phylum Nematoda
423
Fig. 12.10. Third-stage larvae of Anguillicola crassus (arrows) in the haemocoel of the intermediate host
cyclops ( 80).
424
K. Molnr et al.
the ascaridoid Raphidascaris acus oligochaetes, snails and crustaceans may serve
as paratenic hosts before non-developing
larvae get into the obligatory small fishes in
which they reach the infective third stage.
In this species the final host can also serve
as intermediate host. For A. simplex the
euphasiaceans, for Contracaecum osculatum
and P. decipiens copepods and for H. aduncum
copepods, amphipods, isopods and mysids
can be the intermediate hosts (Smith and
Wootten, 1978; Kie, 1993, 2001b; Kie
et al., 1995). It is also small fish which act
as the true intermediate host for C. cirratus
(Kie, 2000a), while polychaetes are intermediate hosts for Cucullanus heterochrous
and Dichelyne minutus (Kie, 2000b,
2001a).
In most cases, paratenic hosts (crustaceans, snails, oligochaetes, small fishes and
tadpoles) are food organisms of the final
host. The role of paratenic hosts in the
development of various nematode families
is different. In the family Philometridae, the
larvae of P. obturans from the copepod
intermediate hosts are transmitted to the
predacious pike through the prey fishes.
The role of paratenic hosts is more important with the anisakids. Hosts (in the
majority large predacious fishes, marine
mammals and fish-eating birds) get infected
with these parasites by several paratenic
hosts. When a paratenic host is consumed,
the infective third-stage larvae can survive
to infect the new organism until they get to
the final host. The process was studied in
Phylum Nematoda
425
426
K. Molnr et al.
HostParasite Relationship
Immune reactions
Nematodes elicit specific antibody production in the host. Migration of the larval
stages in host cavities and host tissue may
expose both structural and metabolic antigens to the host immune system. It has been
demonstrated by immunoblotting that the
European eel produces specific antibodies
against a number of antigens of the swim
bladder nematode A. crassus (Buchmann
et al., 1991; Hglund and Pilstrm, 1994;
Bksi et al., 1997; Nielsen and Buchmann,
1997; Knopf et al., 2000). Third-stage larvae
of A. simplex in the fish host provoke the
production of specific antibodies in naturally infected saithe (Priebe et al., 1991). In
addition, a range of Antarctic teleosts has
been shown to possess reactive antibodies
against molecules from C. osculatum (Coscia
Pathogenicity
Pathological effect
The pathological effect of nematode infection in fish is little studied, and most information is based on field observations. There
are only a few reported cases of mortality
due to nematode infections. Most authors
(Bauer et al., 1977; Moravec, 1994; Dick and
Choudhury, 1995) agree that fish nematodes damage the hosts by depriving the
fish of digested food; by feeding on host tissues, sera or blood; and by direct mechanical damage through fixing to host tissues
and developing or migrating in them
(Fig. 12.14). Nematodes generally possess a
range of enzymes, such as proteases, which
may have tissue-degrading functions (Newton
and Munn, 1999). Large-sized parasites
compress organs (Platzer and Adams, 1967),
Phylum Nematoda
427
428
K. Molnr et al.
Phylum Nematoda
429
430
K. Molnr et al.
Phylum Nematoda
431
432
K. Molnr et al.
Skin
The best-known parasites of the skin come
from the genera Philometra and Philometroides. By the time they reach full maturity, the large females of Philometra rischta
destroy the subepithelial layer of the gill
cover of bleak (Alburnus alburnus), and the
worms are separated from both the gill and
the aquatic environment by an epithelium
bordered by basement membrane. Worms
cause ulceration of the gill cover, which
becomes completely disintegrated in some
cases (Molnr, 1966a; K. Molnr, unpublished). Similar injuries may arise after colonization of the skin of sucker (Catostomus
commersonii) by P. nodulosa (Dailey, 1966;
Hoffman, 1975, 1999). The very tiny S. cyprini
Fig. 12.21. Parasitic nodules (arrows) in the skin caused by Cystoopsis acipenseris in the abdominal side of
sterlet (Acipenser ruthenus) ( 0.4). Photo by Ferenc Baska.
Phylum Nematoda
433
434
K. Molnr et al.
the parasites. In live fish, only large parasites on or close to the surface of the body
are recognized. Red-coloured Philometra
species in the opercula and the fins or
parasite nodules in the skin around
C. acipenseris can easily be observed. Large
nematodes inhabiting the gut and inner
organs are easily detected on dissection of
freshly killed, frozen or formalin-fixed animals; in the case of small nematodes, a dissecting microscope is necessary. Infection
with histozoic species, such as the small
skrjabillanid nematodes, can be diagnosed
on live material under a microscope. Scrapings of intestinal serosa can be examined
under a dissecting microscope for the delicate capillariid nematodes and larval
stages. Larval nematodes in the internal
organs are usually found in squash preparations between two glass plates. Physiological 0.6% fish saline is necessary to keep
nematodes alive. Before fixing, nematodes
are rinsed in saline. For fixation, a hot mixture of 70% ethanol and glycerine (9 : 1
part) or a hot mixture of saline and 40%
formalin can be used. For diagnosis of
Anguillicola infection in the lumen of the
swim bladder, Beregi et al. (1998) suggested
X-ray (Fig. 12.22) and Szkely et al. (2004)
used computer tomographic methods.
Male genital organs can be studied by
placing the worms in glycerine or lactophenol under a cover slip for clearing. For
staining permanent mounts, carmine staining
Fig. 12.22. X-ray as a tool for diagnosis of A. crassus infection of eel swim bladder. Note the large
convoluted worms (arrows) in the swim bladder and the ductus pneumaticus ( 1).
Phylum Nematoda
435
436
K. Molnr et al.
Phylum Nematoda
437
Acknowledgements
We would like to thank Tibor Kassai for
critically reading the text, and colleagues
Ferenc Baska, Jos Bresciani and Gyrgy
Csaba for providing Figs 12.2, 12.5, 12.6,
12.8, 12.14 and 12.21.
References
Adroher, F.J., Malagon, D., Valero, A. and Benitez, R. (2004) In vitro development of the fish parasite
Hysterothylacium aduncum from the third larval stage recovered from a host to the third larval stage
hatched from the egg. Diseases of Aquatic Organisms 58, 4145.
Anderson, R.C. (1958) Mthode pour lexamen des nmatodes en vue apicale. Annales de Parasitologie
Humaine et Compare 33, 171172.
Anderson, R.C. (1996) Why do fish have so few roundworm (nematode) parasites? Environmental Biology of
Fishes 46, 15.
Anderson, R.C. (2000) Nematode Parasites of Vertebrates. Their Development and Transmission, 2nd edn.
CAB International, Wallingford, UK, 650 pp.
Arai, H.P. (1969) Preliminary report on the parasites of certain marine fishes of British Columbia. Journal of
Fisheries Research Board of Canada 26, 23192337.
Avdeev, V.V., Bauer, O.N., Bykhovskaya-Pavlovskaya, I.E., Bainstein, V.A., Vismanis, K.O., Gusev, A.V.,
Dubinina, M.N., Kulakova, A.P., Lomakin, V.V., Roitman, V.A., Semenova, M.K., Skrjabina, E.C.,
Starobogamov, Ja.I., Trofimenko, V.Ja. and Epstein, V.M. (1987) Parasitic metazoans. In: Bauer, O.N.
(ed.) Key to Parasites of Freshwater Fish of the USSR 3. NAUKA, Leningrad 583 pp (in Russian).
Avdosev, B.C. (1978) Biological basis of carp phylometroides chemoprophylaxis. In: Fedorenko V.I. (ed.)
Parasites, Diseases and Their Prophylaxis. Pisthevaya Promishlennost, Moscow, pp. 320 (in
Russian).
Barus, V. (1995) First record of Anguillicola crassus (Nematoda) in the Morava River drainage basin.
Helminthologia (Bratislava) 32, 89.
Bauer, O.N. and Hoffman, G.L. (1976) Helminth range extension by translocation of fish. In: Page, L.A. (ed.)
Wildlife Diseases. Plenum Press, New York, pp. 163172.
Bauer, O.N. and Zmerzlaya, E.L. (1972) Raphidascaridosis of bream in lakes of the Pskov region and its control. Izvestia GOSNIIORKh 80, 114122 (in Russian).
Bauer, O.N., Musselius, V.A., Nikolaeva, V.M. and Strelkov, Y.A. (1977) Ichthyopathology. Izdatelstvo
Pishchevaya Promyshlennost, Moscow, 431 pp (in Russian).
Bauer, O.N., Musselius, V.A. and Strelkov, Y.A. (1981) Diseases of Pond Fishes. Izdatelstvo Pishchevaya
Promyshlennost, Moscow, 247 pp (in Russian).
Bksi, L., Hornok, S. and Szkely, C. (1997) Attempts to analyse Anguillicola crassus infection and the
humoral host response in eels (Anguilla anguilla) of Lake Balaton, Hungary. Acta Veterinaria Hungarica
45, 439445.
438
K. Molnr et al.
Bell, D.A. and Beverley-Burton, M. (1980) Prevalence and intensity of Capillaria catostomi (Nematoda:
Trichuroidea) in white sucker (Catostomus commersoni) in southern Lake Huron, Canada. Environmental Biology of Fish 5, 267271.
Beregi, A., Molnr, K., Bksi, L. and Szkely, C. (1998) Radiodiagnostic method for studying swimbladder
inflammation caused by Anguillicola crassus (Nematoda: Dracunculoidea). Diseases of Aquatic
Organisms 34, 155160.
Berland, B. (1970) On the morphology of the head in four species of the Cucullanidae (Nematoda). Sarsia 43,
1364.
Berland, B. (1981) Mass occurrence of Anisakis simplex larvae in stomach of cod (Gadus morhua L.). Fragen
der Physiologie, Biologie und Parasitologie von Nutzfischen (Wilhelm-Pieck-Universitaet Rostock,
Germany) 4, 125128.
Buchmann, K. (1991) Niche restriction of intestinal helminths from the Baltic flounder (Platichthys flesus). Bulletin of the European Association for Fish Pathologists 11, 8688.
Buchmann, K. and Brresen, T. (1988) The effect of different food types and rations on the liver and muscle of
cod (Gadus morhua L.). Acta Veterinaria Scandinavica 29, 5759.
Buchmann, K., Pedersen, L.. and Glamann, J. (1991) Humoral immune response of European eel Anguilla
anguilla to a major antigen in Anguillicola crassus (Nematoda). Diseases of Aquatic Organisms 12,
5557.
Bykhovskaya-Pavlovskaya, I.E. (1969) Parasitological Examination of Fish. Nauka, Leningrad, 108 pp (in
Russian).
Campana-Rouget, Y., Petter, A.J., Kremer, M., Molet, B. and Miltgen, F. (1976) Prsence du nmatode
Camallanus fotedari dans le tube digestif de poissons daquarium de diverses provenances. Bulletin de
lAcademie Vtrinaire de France 49, 205210.
Carvajal, J., Barros, C., Santander, G. and Alcade, C. (1981) In vitro culture of larval anisakid parasites of the
Chilean hake (Merluccius gayi). Journal of Parasitology 67, 958959.
Conboy, G.A. and Speare, D.J. (2002) Dermal nematodosis in commercially captured rockfish (Sebastes spp.)
from coastal British Columbia, Canada. Journal of Comparative Pathology 127, 211213.
Coscia, M.R. and Oreste, U. (1998) Presence of antibodies specific for proteins of Contracaecum osculatum
(Rudolphi, 1908) in plasma of several Antarctic teleosts. Fish and Shellfish Immunology 8, 295302.
Coscia, M.R. and Oreste, U. (2000) Plasma and bile antibodies of the teleost Trematomus bernacchii specific
for the nematode Pseudoterranova decipiens. Diseases of Aquatic Organisms 41, 3742.
Dailey, M. (1966) Biology and morphology of Philometroides nodulosa (Thomas, 1929) n. comb.
(Philometridae: Nematoda) in the western white sucker (Catostomus commersoni). PhD, Colorado State
University, University Microfilms, Ann Arbor, Michigan, 77 pp.
Deardorff, T.L. and Overstreet, R.M. (1980) Taxonomy and biology of North American species of Goezia
(Nematoda: Anisakidae) from fishes, including three new species. Proceedings of the Helminthological
Society of Washington 47, 192217.
Deardorff, T.L., Overstreet, R.M., Okihiro, M. and Tami, R. (1986) Piscine adult nematode invading an open
lesion in a human hand. American Journal of Tropical Medicine and Hygiene 35, 827830.
Dezfuli, B.S., Simoni, E., Rossi, R. and Manera, M. (2000) Rodlet cells and other inflammatory cells of
Phoxinus phoxinus infected with Raphidascaris acus (Nematoda). Diseases of Aquatic Organisms 43,
6169.
Dick, T.A. and Choudhury, A. (1995) Phylum Nematoda. In: Woo, P.T.K. (ed.) Fish Diseases and Disorders. I.
Protozoan and Metazoan Infections. CAB International, Wallingford, UK, pp. 415446.
Dogiel, V.A. and Bykhovskiy, B.E. (1939) The Parasites of Fishes of the Caspian Sea. 7. Izdatelstvo, AN SSSR,
Moscow, 151 pp (in Russian).
Dubinin, V.B. (1952) Parasite fauna of young acipenserids in the Lower Volga basin. Uchebnie Zapiski
Leningradskogo Gosudarskogo Universiteta Seriya Biologii 141, 238251 (in Russian).
Dunn, I.J., Russell, L.R. and Adams, J.R. (1983) Caecal histopathology caused by Truttaedacnitis truttae
(Nematoda: Cucullanidae) in rainbow trout, Salmo gairdneri. International Journal for Parasitology 13,
441445.
Eiras, J.C. and Rego, A.A. (1988) Histopatologia da parasitose de peixes do Rio Cuiaba (Mato Grosso) por
larvas de Eustrongylides sp. (Nematoda, Dioctophymidae). Revista Brasileira de Biologia 48, 273280.
Eiras, J.C. and Reichenbach-Klinke, H. (1982) Nematoden als Ursache von Darmknoten bei
Ssswasserfischen. Fisch und Umwelt 11, 4755.
Fagerholm, H. (1982) Parasites of fish in Finland. VI Nematodes. Acta Academiae Aboensis, Series B 40,
5128.
Phylum Nematoda
439
Fagerholm, H.P. (1988) Incubation in rats of a nematodal larva from cod to establish its specific identity:
Contracaecum osculatum (Rudolphi). Parasitology Research 75, 5763.
Fernando, C.H., Furtado, J.I., Gussev, A.V., Hanek, J. and Kakonge, S.A. (1972) Methods for the Study of
Freshwater Fish Parasites. Biological Series, No. 12, University of Waterloo, Waterloo, 76 pp.
Freitas, J.F.T. and Lent, H. (1946) Infestacao de apaiars 'Astronotus ocellatus' (Agassiz) pelo nematdeo
'Goezia spinulosa' Diesing, 1839. Revista do Brasil Biologia 6, 215222.
Gaines, J.L. and Rogers, W.A. (1972) Fish mortalities associated with Goezia sp. (Nematoda: Ascaroidea) in
central Florida. In: Proceedings of 25th Annual Conference of Southeastern Association of Game and
Fish Commission, Charleston, South Carolina, pp. 496497.
Garnick, E. and Margolis, L. (1990) Influence of four species of helminth parasites on orientation of seaward
migrating sockeye salmon (Oncorhynchus nerka) smolts. Canadian Journal of Fisheries and Aquatic
Sciences 47, 23802389.
Hartmann, F. (1989) Investigations on the effectiveness of levamisol as a medication against the eel parasite
Anguillicola crassus (Nematoda). Diseases of Aquatic Organisms 7, 185190.
Hauck, A.K. and May, E.B. (1977) Histopathologic alterations associated with Anisakis larvae in Pacific herring from Oregon. Journal of Wildlife Diseases 13, 290293.
Hemmingsen, W., Lysne, D.A., Eidnes, T. and Skorping, A. (1993) The occurrence of larval ascaridoid nematodes in wild-caught and in caged and artificially fed Atlantic cod, Gadus morhua L., in Norwegian
water. Fisheries Research 15, 379386.
Hirose, H., Sekino, T. and Egusa, S. (1976) Notes on the egg deposition, larval migration and intermediate
host of the nematode Anguillicola crassa parasitic in the swimbladder of eels. Fish Pathology 11, 2731
(in Japanese).
Hoffman, G.L. (1975) Lesions due to internal helminths of freshwater fishes. In: Ribelin, W.E. and Migaki, G.
(eds) The Pathology of Fishes. University of Wisconsin Press, Madison, Wisconsin, pp. 151187.
Hoffman, G.L. (1982) Capillaria catostomi, a new pathogenic nematode of golden shiners and other fishes.
In: Proceeding of Catfish Farmers of America, Research Workshop, pp. 4950.
Hoffman, G.L. (1999) Parasites of North American Freshwater Fishes, 2nd edn. Comstock Publishing Associates, Ithaca, New York, and London, 525 pp.
Hglund, J. and Pilstrm, L. (1994) Purification of adult Anguillicola crassus whole-worm antigens for detection of specific antibodies in serum from the European eel (Anguilla anguilla). Fish and Shellfish Immunology 4, 311319.
Iglesias, L., Valero, A. and Galvez, L. (2002) In vitro cultivation of Hysterothylacium aduncum (Nematoda:
Anisakidae) from 3rd stage larvae to egg-laying adults. Parasitology 125, 467475.
Janiszewska, J. (1939) Studien ber die Entwicklung und Lebenweise der parasitischen Wrmer in der Flounder (Pleuronectes flesus L.). Mmoires del lAcadmie Polonaise des Sciences et des Lettres. Classe des
Sciences Mathmatiques et Naturelles. Srie B: Sciences Naturelles 14, 168.
Jilek, R. and Crites, J.L. (1982) Intestinal histopathology of the common bluegill, Lepomis macrochirus
Rafinesque, infected with Spinitectus carolini Holl, 1928 (Spirurida: Nematoda). Journal of Fish Diseases
5, 7577.
Kall, S., Fagerholm, H.-P. and Sarvala, J. (2004) Pathogenicity of the gill artery worm Philometra obturans
(Nematoda) in northern pike (Esox lucius) in southwest Finland. Journal of Parasitology 90, 177181.
Kamstra, A. (1990) Anguillicola in Dutch eelfarms current state. Internationale Revue der Gesamten
Hydrobiologie 75, 867874.
Kennedy, C.R. and Lie, S.F. (1976) The distribution and pathogenicity of larvae of Eustrongylides
(Nematoda) in brown trout Salmo trutta L. in Fernworthy Reservoir, Devon. Journal of Fish Biology 8,
293302.
Kijewska, A., Rokicki, J., Sitko, J. and Wegrzyn, G. (2002) Ascaridoidea: a simple DNA assay for identification
of 11 species infecting marine and freshwater fish, mammals and fish-eating birds. Experimental Parasitology 101, 3539.
Knopf, K., Naser, K., Van der Heijden, M.H.T. and Taraschewski, H. (2000) Evaluation of an ELISA and
immunoblotting for studying the humoral immune response in Anguillicola crassus infected European
eel Anguilla anguilla. Diseases of Aquatic Organisms 43, 3948.
Ko, R.C., Morton, B. and Wong, P.S. (1975) Prevalence and histopathology of Echinocephalus sinensis
(Nematoda: Gnathostomatidae) in natural and experimental hosts. Canadian Journal of Zoology 53,
550559.
Kie, M. (1993) Aspects of the life cycle and morphology of Hysterothylacium (Rudolphi, 1802) (Nematoda,
Ascaridoidea, Anisakidae). Canadian Journal of Zoology 71, 12891296.
440
K. Molnr et al.
Kie, M. (2000a) Life cycle and seasonal dynamics of Cucullanus cirratus O.F. Muller, 1777 (Nematoda,
Ascaridida, Seuratoidea, Cucullanidae) in Atlantic cod, Gadus morhua L. Canadian Journal of Zoology
78, 182190.
Kie, M. (2000b) The life-cycle of the flatfish nematode Cucullanus heterochrous. Journal of Helminthology
74, 323328.
Kie, M. (2001a) The life cycle of Dichelyne (Cucullanellus) minutus (Nematoda: Cucullanidae). Folia
Parasitologica 48, 304310.
Kie, M. (2001b) Experimental infections of copepods and sticklebacks Gasterosteus aculeatus with small
ensheathed and large third-stage larvae of Anisakis simplex (Nematoda, Ascaridoidea, Anisakidae).
Parasitology Research 87, 3236.
Kie, M. (2001c) The life-cycle of Capillaria gracilis (Capillariidae), a nematode parasite of gadoid fish. Sarsia
86, 383387.
Kie, M. and Fagerholm, H.P. (1995) The life cycle of Contracaecum osculatum (Rudolphi, 1802) sensu
stricto (Nematoda, Ascaridoidea, Anisakidae) in view of experimental infections. Parasitology Research
81, 481489.
Kie, M., Berland, B. and Burt, M.D.B. (1995) Development to third-stage larvae occurs in the eggs of Anisakis
simplex and Pseudoterranova decipiens (Nematoda, Ascaridoidea, Anisakidae). Canadian Journal of
Fisheries and Aquatic Sciences 52, 134139.
Kutzer, E. and Otte, E. (1966) Capillaria petruschewskii (Schulman, 1948): Morphologie, Biologie und
Pathogene Bedeutung. Zeitschrift fr Parasitenkunde 28, 1630.
Larsen, A.H., Bresciani, J. and Buchmann, K. (2002) Interactions between ecto- and endoparasites in trout
Salmo trutta. Veterinary Parasitology 103, 167173.
Likely, C.G. and Burt, M.D.B. (1989) Cultivation of Pseudoterranova decipiens (sealworm) from
third stage larvae to egg-laying adults. Canadian Journal of Fisheries and Aquatic Sciences 46,
10951096.
Likely, C.G. and Burt, M.D.B. (1992) In vitro cultivation of Contracaecum osculatum (Nematoda: Anisakidae)
from third stage larvae to egg-laying adults. Canadian Journal of Fisheries and Aquatic Sciences 49,
347348.
Lo, Wing Yat (1988) The control of Capillaria infections in Symhysodon. Freshwater and Marine Aquarium 11,
6883.
Lomakin, V.V. and Trofimenko, V.Y.A. (1982) Capillariids (Nematoda: Capillariidae) of the freshwater fish
fauna of the USSR. Trudi Gelmintologicheskogo Instituta Akademii Nauk 31, 6087 (in Russian).
Lunestad, B.T. (2003) Absence of nematodes in farmed Atlantic salmon (Salmo salar L.) in Norway. Journal of
Food Protection 66, 122124.
McClelland, G. (2002) The trouble with sealworms (Pseudoterranova decipiens species complex, Nematoda):
a review. Parasitology 124, S183S203.
McMinn, H. (1990) Effects of the nematode parasite Camallanus cotti on sexual and nonsexual behaviors in
the guppy (Poecilia reticulata). American Zoologist 30, 245249.
Manley, K.M. and Embil, J.A. (1989) In vitro effect of ivermectin on Pseudoterranova decipiens survival.
Journal of Helminthology 63, 7274.
Mattiucci, S., Paggi, L., Nascetti, G., Ishikura, H., Kikuchi, K., Sato, N., Cianchi, R. and Bullini, L. (1998)
Allozyme and morphological identification of Anisakis, Contracaecum and Pseudoterranova from
Japanese waters (Nematoda, Ascaridoidea). Systematic Parasitology 40, 8192.
Mattiucci, S., Paggi, L., Nascetti, G., Santos, C.P., Costa, G., Di Beneditto, A.P., Ramos, R., Argyrou, M.,
Cianchi, R. and Bullini, L. (2002) Genetic markers in the study of Anisakis typica (Diesing, 1860): larval
identification and genetic relationships with other species of Anisakis Dujardin, 1845 (Nematoda:
Anisakidae). Systematic Parasitology 51, 159170.
Mattiucci, S., Cianchi, R., Nascetti, G., Paggi, L., Sardella, N., Timi, J., Webb, S.C., Bastida, R., Rodriguez, D.
and Bullini, L. (2003) Genetic evidence for two sibling species within Contracaecum ogmorhini
Johnston & Mawson, 1941 (Nematoda: Anisakidae) from otariid seals of boreal and austral regions.
Systematic Parasitology 54, 1323.
Measures, L. (1988) Epizootiology, pathology, and description of Eustrongylides tubifex (Nematoda:
Dioctophymatoidea) in fish. Canadian Journal of Zoology 66, 22122222.
Meguid, M.A and Eure, H.E. (1996) Pathobiology associated with the spiruroid nematodes Camallanus
oxycephalus and Spinitectus carolini in the intestine of green sunfish, Lepomis cyanellus. Journal of
Parasitology 82, 118123.
Phylum Nematoda
441
Mikailova, J.G., Prazdenkov, E.V. and Prusevich, T.O. (1964) Morphological changes in fish tissue around
the larvae of some parasitic worms. Transactions of Murmansk Sea Biological Institute 5, 251264 (in
Russian) (English translation, Fisheries Research Board of Canada, translation no. 580).
Mller, H. and Anders, K. (1986) Diseases and Parasites of Marine Fishes. Verlag Mller, Kiel, Germany.
Molnr, K. (1966a) On some little-known and new species of the genera Philometra and Skrjabillanus from
fishes in Hungary. Acta Veterinaria Academiae Scientiarum Hungaricae 16, 143153.
Molnr, K. (1966b) Life-history of Philometra ovata (Zeder, 1803) and Philometra rischta Skrjabin, 1917. Acta
Veterinaria Academiae Scientiarum Hungaricae 16, 227242.
Molnr, K. (1967) Morphology and development of Philometra abdominalis Nybelin, 1928. Acta Veterinaria
Academiae Scientiarum Hungaricae 17, 293300.
Molnr, K. (1987) Solving parasite related problems in cultured freshwater fish. International Journal of Parasitology 17, 319326.
Molnr, K. (1993) Effect of decreased oxygen content on eels (Anguilla anguilla) infected by Anguillicola
crassus (Nematoda: Dracunculoidea). Acta Veterinaria Hungarica 41, 349360.
Molnr, K. (1994) Formation of parasitic nodules in the swimbladder and intestinal walls of the eel Anguilla
anguilla due to infections with larval stages of Anguillicola crassus. Diseases of Aquatic Organisms 20,
163170.
Molnr, K., Szkely, C. and Baska, F. (1991) Mass mortality of eel in Lake Balaton due to Anguillicola crassus
infection. Bulletin of the European Association of Fish Pathologists 11, 211212.
Molnr, K., Baska, F., Csaba, Gy., Glvits, R. and Szkely, C. (1993) Pathological and histopathological
studies of the swimbladder of eels (Anguilla anguilla) infected by Anguillicola crassus (Nematoda:
Dracunculoidea). Diseases of Aquatic Organisms 15, 4150.
Moravec, F. (1970) Studies on the development of Raphidascaris acus (Bloch, 1779) (Nematoda:
Heterocheilidae). Vestnik Ceskoslovenske Spolecnosti Zoologicke 34, 3349.
Moravec, F. (1971) Some notes on the larval stages of Camallanus truncatus (Rudolphi, 1814) and
Camallanus lacustris (Zoega, 1776) (Nematoda; Camallanidae). Helminthologia 10 (Year 1969),
129135.
Moravec, F. (1975) Reconstruction of the Nematode Genus Rhabdochona Railliet, 1916 with a Review of the
Species Parasitic in Fishes of Europe and Asia. Studie CSAV, No. 8, 104 pp.
Moravec, F. (1983) Observation on the bionomy of the nematode Pseudocapillaria brevispicula (Linstow,
19873). Folia Parasitologica 30, 229241.
Moravec, F. (1994) Parasitic Nematodes of Freshwater Fishes of Europe. Academia, Prague, 473 pp.
Moravec, F. (1998) Nematodes of Freshwater Fishes of the Neotropical Region. Academia, Prague,
464 pp.
Moravec, F. and Dykov, I. (1978) On the biology of the nematode Philometra obturans (Prenant, 1886) in the
fishpond system of Mcha Lake, Czechoslovakia. Folia Parasitologica 25, 231240.
Moravec, F. and Gut, J. (1982) Morphology of the nematode Capillaria pterophylli Heinze, 1933, a pathogenic
parasite of some aquarium fishes. Folia Parasitologica 29, 227231.
Moravec, F., Ergens, R. and Repova, R. (1984) First record of the nematode Pseudocapillaria brevispicula
(Linstow, 1873) from aquarium fishes. Folia Parasitologica 31, 241245.
Moravec, F., Glamuzina, B. and Marino, G. (2003) Occurrence of Philometra lateolabracis (Nematoda:
Philometridae) in the gonads of marine perciform fishes in the Mediterranean region. Diseases of Aquatic
Organisms 53, 267269.
Nagasawa, K. (1985) Prevalence of visceral adhesions in sockeye salmon, Oncorhynchus nerca, in central
North Pacific Ocean. Fish Pathology 20, 313321.
Newton, S.E. and Munn, E.A. (1999) The development of vaccines against gastrointestinal nematode parasites, particularly Haemonchus contortus. Parasitology Today 15, 116122.
Nielsen, M.E. and Buchmann, K. (1997) Glutathione-S-transferase is an important antigen in the eel nematode
Anguillicola crassus. Journal of Helminthology 71, 319324.
Norris, D.E. and Overstreet, R.M. (1976) The public health implications of larval Thynnascaris nematodes
from sea fish. Journal of Milk and Food Technology 39, 4754.
Paggi, L., Mattiucci, S., Gibson, D.I., Berland, B., Nascetti, G., Cianchi, R. and Bullini, L. (2000)
Pseudoterranova decipiens species A and B (Nematoda, Ascaridoidea): nomenclatural designation,
morphological diagnostic characters and genetic markers. Systematic Parasitology 45, 185197.
Paperna, I. (1974) Hosts, distribution and pathology of infections with larvae of Eustrongylides
(Dioctophymidae, Nematoda) in fishes from East African lakes. Journal of Fish Biology 6, 6776.
442
K. Molnr et al.
Parukhin, A.M. (1975) Philometroides oveni sp. n. a parasite of the sea perch Paracenthopristis hepatus.
Zoologicheskiy Zhurnal 54, 312314 (in Russian).
Pena, N., Auro, A. and Sumano, H. (1988) A comparative trial of garlic, its extract, and ammonium-potassium
tartrate as anthelmintics in carp. Journal of Ethnopharmacology 24, 199203.
Petrushevski, G.K. and Shulman, S.S. (1961) The parasitic diseases of fishes in the natural waters of the USSR. In:
Dogiel, V.A., Petrushevski, G.K. and Polyanski, Y.I. (eds) Parasitology of Fishes. Oliver & Boyd, Edinburgh, UK.
Petter, A.J. and Thatcher, V.E. (1988) Observations sur la structure de la capsule buccale de Spirocamallanus
inopinatus (Nematoda) parasite de poissons brsiliens. Bulletin du Musum National dHistoire Naturelle
10, 685692.
Petter, A.J., Cassone, J. and France, B.M. (1974) Un nouveau nmatode Camallanus pathogne dans des
levages de poissons exotiques. Annales de Parasitologie Humaine et Compare 49, 677683.
Platzer, E.G. and Adams, J.R. (1967) The life history of a dracunculoid, Philonema oncorhynchi, in
Oncorhynchus nerka. Canadian Journal of Zoology 45, 3143.
Poole, B.C. and Dick, T.A. (1984) Liver pathology of yellow perch, Perca flavescens (Mitchill), infected with
larvae of the nematode Raphidascaris acus (Bloch, 1779). Journal of Wildlife Diseases 20, 303307.
Priebe, K., Huber, C., Martlbauer, E. and Terplan, G. (1991) Detection of antibodies against larvae of Anisakis
simplex in Atlantic pollock (Pollachius virens) by ELISA. Journal of Veterinary Medicine B 38, 209214.
Prusevich, T.O. (1964) On the study of the formation of capsules around Anisakis sp. larvae in the tissues of
the shorthorn sculpin Myoxocephalus scorpius. Trudi Murmanskogo Morskogo Biologicheskogo Instituta
AN SSSR 5, 265273 (in Russian) (English translation, Fisheries Research Board Canada, translation no.
580).
Ramakrishna, N.R., Burt, M.B.D. and MacKinnon, B.M. (1993) Cell-mediated immune response of rainbow
trout (Oncorhynchus mykiss) to larval Pseudoterranova decipiens (Nematoda; Ascaridoidea) following
sensitization to live sealworm extract, and non-homologous extracts. Canadian Journal for Fisheries and
Aquatic Sciences 50, 6065.
Ribu, D.L. and Lester, R.J.G. (2004) Moravecia australiensis n. g., n. sp. (Dracunculoidea: Guyanemidae) from
the gills of the green porcupine fish Tragulichthys jaculiferus (Cuvier) in Australia. Systematic Parasitology 57, 5965.
Santamarina, M.T., Tojo, J.L., Gestido, J.C., Leiro, J.L., Ubeira, F.M. and Santamarina, M.L. (1994) Experimental infection of rainbow trout (Oncorhynchus mykiss) by Anisakis simplex (Nematoda: Anisakidae). Japanese Journal for Parasitology 43, 187192.
Schperclaus, W. (1992) Fish Diseases, vol 1 and 2. A.A. Balkema, Rotterdam, The Netherlands, 1398 pp.
Sekretaryuk, K.V. (1983) Morphological and histochemical changes through Philometroides infection in carp.
Veterinariya 9, 4547 (in Russian).
Sindermann, C.J. (1990) Principal Diseases of Marine Fish and Shellfish, vol. 1, 2nd edn. Academic Press, London, 521 pp.
Sinha, A.K. and Sinha, C. (1988) Macrocytic hypochromic anaemia in Heteropneustes fossilis (BI.) infected
by the blood sucker nematode Procamallanus spiculogubernaculus (Agarwal). Indian Journal of Parasitology 12, 9394.
Smith, J.D. (1984) Development of Raphidascaris acus (Nematoda, Anisakidae) in paratenic intermediate, and
definitive hosts. Canadian Journal of Zoology 62, 13781386.
Smith, J.W. and Wootten, R. (1978) Anisakis and anisakiasis. Advances in Parasitology 16, 93163.
Sprengel, G. and Lchtenberg, H. (1991) Infections by endoparasites reduces maximum swimming speed of
European smelt Osmerus eperlanus and European eel Anguilla anguilla. Diseases of Aquatic Organisms
11, 3135.
Stumpp, M. (1975) Untersuchungen zur Morphologie und Biologie von Camallanus cotti (Fujita, 1927).
Zeitschrift fr Parasitenkunde 46, 277290.
Szkely, C. (1994) Paratenic hosts for the parasitic nematode Anguillicola crassus in Lake Balaton, Hungary.
Diseases of Aquatic Organisms 18, 1120.
Szkely, C. (1995) Dynamics of Anguillicola crassus (Nematoda: Dracunculoidea) larval infection in paratenic
host fishes of Lake Balaton, Hungary. Acta Veterinaria Hungarica 43, 401422.
Szkely, C., Molnr, K., Mller, T., Szab, A., Romvri, R., Hancz, C. and Bercsnyi, M. (2004) Comparative
study of X-ray computed tomography and conventional X-ray methods in the diagnosis of swimbladder
infection of eel caused by Anguillicola crassus. Diseases of Aquatic Organisms 58, 157164.
Szostakowska, B., Myjak, P. and Kur, J. (2002) Identification of anisakid nematodes from the southern Baltic
Sea using PCR-based methods. Molecular and Cellular Probes 16, 111118.
Phylum Nematoda
443
Taraschewski, H., Renner, C. and Melhorn, H. (1988) Treatment of fish parasites. 3. Effects of levamisole-HCl,
metrifonate, fenbendazole, mebendazole, and ivermectin on Anguillicola crassus (nematodes) pathogenic
in the air bladder of eels. Parasitology Research 74, 281289.
Thatcher, V.E. (1991) Amazon fish parasites. Amazoniana 11, 263572.
Thomas, K. and Ollevier, F. (1992) Paratenic hosts of the swimbladder nematode Anguillicola crassus.
Diseases of Aquatic Organisms 13, 165174.
Tojo, J.L., Santamarina, M.T., Leiro, J.L., Ubeira, F.M. and Sanmartin, M.L. (1994) Failure of anthelmintic
treatment to control Anisakis simplex in trout (Oncorhynchus mykiss). Japanese Journal of Parasitology
43, 301304.
Uhazy, L.S. (1978) Lesions associated with Philometroides huronensis (Nematoda: Philometridae) in the white
sucker (Catostomus commersoni). Journal of Wildlife Diseases 14, 401408.
Valtonen, E.T., Haaparanta, A. and Hoffmann, RW. (1994) Occurrence and histological response of
Raphidascaris acus (Nematoda, Ascaridoidea) in roach from 4 lakes differing in water quality. International Journal for Parasitology 24, 197206
Van Banning, P. and Haenen, O.L.M. (1990) Effects of the swimbladder nematode Anguillicola crassus in wild
and farmed eel, Anguilla anguilla. In: Perkins, F.O. and Cheng, T.C. (eds) Pathology in Marine Science.
Academic Press, New York, pp. 317330.
Vasilkov, G.V. (1967) Philometrosis of carp. Veterinariya 1, 6264 (in Russian).
Vasilkov, G.V. (1975) Pathogenicity and symptoms of philometroidosis in carp. Byulleten Vsesojuznogo
Instituta Eksperimentalnoy Veterinarii 20, 4546 (in Russian).
Vasilkov, G.V., Tiltin, B.P. and Suslov, C.F. (1974) Experience with the control of philometroidosis in pond
farms. Veterinarya 6, 7172 (in Russian).
Williams, H.H. (1967) Helminth diseases of fish. Helminthological Abstracts 36, 261295.
Williams, H.H. and Richards, D.H.H. (1968) Observations on Pseudoanisakis rotunda (Rudolphi, 1819)
Mozgovoi, 1950, a common but little known parasite of Raja radiata Donovan in the northern North Sea.
Journal of Helminthology 42, 199220.
13
Phylum Acanthocephala
Brent B. Nickol
Introduction
Acanthocephalans are endoparasitic worms
comprising approximately 1100 species
(Golvan, 1994), nearly one-half of which are
found as adults in the intestine of fishes.
Juvenile worms of many other species occur
in the viscera, especially the mesentery and
liver, of fishes that act as paratenic hosts.
Although these parasites are not usually
regarded as having significant economic
importance, epizootics are known from
hatcheries (Bullock, 1963) and they have
been linked to local extinction of natural
populations (Schmidt et al., 1974). There is
little knowledge of the more subtle effects the
parasite has on host populations, but mortality
might be significant when hosts are stressed
(Jilek, 1979; Connors and Nickol, 1991).
Seasonal Fluctuations
Host and Geographical Distribution
Freshwater and marine fishes from the Arctic
(Van Cleave, 1920) to the Antarctic
(Zdzitowiecki, 2001) and from surface
waters to the depths of the ocean (Noble,
1973; Wayland et al., 1999) harbour acanthocephalans. Fishes of most systematic
groups are parasitized. Although these parasites are rare in agnathans and elasmobranchs, a few species are known to occur
444
Phylum Acanthocephala
445
446
B.B. Nickol
and 16S rRNA) and a relatively small number of species. The unequal rate effect, or
long branch attraction, is a common
source of error in phylogenetic analyses of
molecular data that has often been ignored
(Garey and Schmidt-Rhaesa, 1998). Genetic
differentiation found among populations
of P. laevis in European fishes (KralovaHromadova et al., 2003) suggests that at
least some acanthocephalan taxa are evolving rapidly and thus are likely candidates
for inducing the long branch attraction
error. The variety of conclusions reached
from analysis of molecular data (Zrzavy,
2001) suggests that phylogenetic relationships of the group likely will remain controversial until analysis of other suitable genes
is completed and more species are studied.
As presently constituted, the phylum
Acanthocephala comprises four classes,
totalling nine orders (Table 13.1). Members
of the class Archiacanthocephala do not
occur in fish. The entire class Polyacanthocephala contains only four species, most
commonly parasites of South American caimans. However, at least two of the species
occur as larvae in the liver of fishes that
apparently act as paratenic hosts (Amin
et al., 1996; Aloo and Dezfuli, 1997). Nearly
all of the species found in fishes belong to
the classes Eoacanthocephala and Palaeacanthocephala. With the exception of nine
species found in North American turtles
(Barger and Nickol, 2004), all eoacanthocephalans are parasites of fishes. Among
the palaeacanthocephalans, all of the order
Echinorhynchida are parasites of fishes
except for a few species that occur as adults
in amphibians. Acanthocephalans in the
other palaeacanthocephalan order, Polymorphida, occur as adults in birds and mammals, but larvae of many species are found in
viscera of fishes that act as paratenic hosts.
Morphology
Acanthocephalans are bilaterally symmetrical, dioecious, pseudocoelomate worms
that lack an alimentary canal. They are
characterized by a spined proboscis that is
invaginable and retractable into a saccular
Table 13.1.
Class Polyacanthocephala
Order Echinorhynchida
Main lacunar canals dorsal and ventral; cement glands 8, elongate with
multiple large nuclei; proboscis receptacle closed sac with single muscle
layer; tegumental nuclei numerous, amitotic fragments
Only order of the class
Main lacunar canals dorsal and ventral; cement glands 8, spherical with
single nucleus; proboscis receptacle single-walled, often with ventral
cleft; tegumental nuclei few, elongate or branched, if fragmented,
fragments close together
Proboscis globular, not retractable, spineless or with rootless spines
usually not reaching surface
Proboscis conical, retractable, with distinct regions of large anterior hooks
and small posterior spines
Proboscis cylindrical, retractable, with strongly recurved hooks diminishing
in size anterior to posterior and arranged in longitudinal rows
Proboscis spherical, retractable, with few large hooks arranged in spirals
Main lacunar canals lateral; cement glands 28, with fragmented nuclei;
proboscis receptacle closed sac with 2 muscle layers; tegumental nuclei
numerous, amitotic fragments or few highly branched fragments
Palaeacanthocephala of lower vertebrates
Order Polymorphida
Order Polyacanthorhynchida
Class Archiacanthocephala
Order Apororhynchida
Order Gigantorhynchida
Order Moniliformida
Order Oligacanthorhynchida
Class Palaeacanthocephala
Class Eoacanthocephala
Order Gyracanthocephala
Order Neoechinorhynchida
1For
a complete key to classes, orders, families and subfamilies, see Amin (1987).
a complete list of known intermediate hosts, see Schmidt (1985).
Principal intermediate
hosts2
Crocodilians
Unknown
Terrestrial insects
Birds
Unknown
Orthoptera, Coleoptera
Mammals
Cockroaches
Orthoptera, Coleoptera
Crustacea
Fishes and
amphibians
Birds and mammals
Amphipods, isopods
Fishes
Amphipods, isopods,
decapods
Crustacea
Fishes
Fishes
Copepods
Ostracods
447
2For
Main lacunar canals dorsal and ventral; cement gland single syncytium
with large nuclei; proboscis receptacle closed sac with single muscle
layer; tegumental nuclei few, large
Eoacanthocephalans with trunk spines
Eoacanthocephala without trunk spines
Principal definitive
hosts
Phylum Acanthocephala
Taxon
448
B.B. Nickol
Phylum Acanthocephala
449
450
B.B. Nickol
Fig. 13.3. Transmission electron micrograph of the tegument of Leptorhynchoides thecatus from a green
sunfish (Lepomis cyanellus) showing crypts (C), fibres (F) of the felt layer and mitochondria (M).
Scale bar = 0.005 mm. (Unpublished micrograph, courtesy of J.A. Ewald.)
Intercalated hosts
In all documented cases, fully formed
cystacanths are infective to definitive hosts
directly from their invertebrate intermediate
host. When cystacanths of some species are
ingested by vertebrates that are unsuitable as
Phylum Acanthocephala
451
HostParasite Relationships
Site selection
After ingestion by the definitive host,
cystacanths are activated and attach to the
wall of the small intestine. Many species
apparently remain at the activation site and
develop to maturity. Others migrate and
localize in specific regions of the intestine
(Crompton 1975; Kennedy, 1985). Several
factors, including physiological differences
along the alimentary tract (Richardson and
Nickol, 1999), maximization of sexual congress (Richardson and Nickol, 2000) and
ageing (Taraschewski, 2000), have been
implicated in site specificity. In most cases,
Fig. 13.4. Scanning electron micrograph of an egg from Leptorhynchoides thecatus showing unwrapping
of embryonic membranes. Unwrapped membranes entangle aquatic vegetation and anchor eggs in habitats
of intermediate host feeding. Scale bar = 0.01 mm. (Unpublished micrograph courtesy of M.A. Barger.)
452
B.B. Nickol
however, it is unknown whether differences in sites occupied result from differences in sites of activation, differential
mortality or emigration by the parasites.
Course of infection
Clinical signs and gross pathology
Shortly after infection, the proboscis is surrounded by necrotic tissue, which becomes
haemorrhagic and inflamed after a few days.
During the second week after infection by
species that penetrate deeply (e.g. in fish,
Acanthocephalus anguillae, P. bulbocolli,
P. laevis), inflamed tissue around the anterior portion of the worm is dominated by
monocytes and macrophages maturing into
epithelioid cells, and an outer belt of connective tissue appears (Taraschewski, 2000).
This chronic stage often results in a fibrous
nodule visible on the outer surface of the
intestine. Species that do not penetrate
deeply (e.g. in fish, Acanthocephalus lucii,
E. truttae, N. cylindratus) move about in the
intestine and change their point of attachment before the connective-tissue response
results in nodules (Adel-Meguid et al., 1995).
Copulation in the definitive host may
occur within 24 h of infection (Muzzall and
Rabalais, 1975). In laboratory infections of
green sunfish (Lepomis cyanellus), copulation within a group of L. thecatus continued
at least 12 weeks after infection (Richardson
et al., 1997). For most species, egg production starts between 4 and 8 weeks after
infection and continues for approximately
2 months. The number of eggs produced
daily by each female acanthocephalan is
unknown for most species, but it appears to
be related to the size of the worm. At peak
production, a female Macracanthorhynchus
hirudinaceus (large worms found in pigs)
may produce about 260,000 eggs per day
(Kates, 1944), a female Moniliformis moniliformis (intermediate-sized worms in rats)
about 4800 (Reyda and Nickol, 2001) and a
female Polymorphus minutus (small worms
found in waterfowl) about 1700 (Crompton
and Whitfield, 1968).
Male worms have shorter lifespans than
do females; death of males and subsequent
loss from the host may begin shortly after
Acanthocephalans in moribund or dead animals are frequently assumed to indicate deleterious effects; worms have been observed
extending from the rectum (Schmidt et al.,
1974; Fig. 13.5) or protruding through the
trunk (Taraschewski, 2000) of infected fishes.
There are, however, numerous instances of
exceedingly heavy infections in animals that
do not show any obvious disease.
Bullock (1963) described trout of several
species infected with Acanthocephalus dirus
Phylum Acanthocephala
453
Histopathology
Acanthocephalans embed their spiny proboscis into the mucosal epithelium. Attachment is frequently between villi. At the site
of attachment, cells are destroyed and
fibroblasts, lymphocytes and macrophages
are mobilized below the lamina propria
(Dezfuli et al., 1990), where chronic fibrinous
inflammation, resulting in an increased
amount of connective tissue, causes
454
B.B. Nickol
Fig. 13.8. Section of chub (Leuciscus cephalus) intestine showing penetration of Pomphorhynchus laevis.
Note hyperplasia of the lamina propria (arrows) around the neck (cou) and bulbous proboscis (P) of the
worm, forming a nodule in the coelom. An anterior portion of the trunk (T) of the worm shows in the
intestinal lumen. Scale bar = 1 mm. (Unpublished micrograph, courtesy of I. de Buron.)
alimentary canal, or the proboscis perforates the capsule to emerge free in the
coelom or to penetrate the liver or another
visceral organ. Similar findings were
reported for P. bulbocolli in rainbow darters
(Etheostoma caeruleum) (McDonough and
Gleason, 1981) and two species of catostomids (Chaicharn and Bullock, 1967).
A. anguillae is also known to perforate the
intestine of its host and attach to the liver.
In goldfish (C. auratus), large portions
of this organ are replaced by proliferative
tissue, often with patches of pancreas,
surrounding the embedded proboscis
(Taraschewski, 1989a).
Most studies of acanthocephalaninduced lesions reveal areas along the trunk
of the worm where the mucosal surface is
compressed or desquamated (Fig. 13.7). In
these cases, mucosal folds and tips of villi
may be absent and the paramucosal lumen
contains large amounts of mucoid material
originating from goblet-cell hyperplasia. In
green sunfish infected with L. thecatus,
there is a significantly greater number of
Pathophysiology
Chronic fibrosis, destruction of intestinal
villi and necrotic and degenerative changes
in mucosal epithelium adversely affect
motility and the absorptive efficiency of the
fish intestine. This might affect the general
health and growth of the host. According to
Bristol et al. (1984), there is a negative correlation between the number of acanthocephalans and the amount of body lipid in
trout, and Buchmann (1986) demonstrated
a negative correlation between the number
of Echinorhynchus gadi present and energy
Phylum Acanthocephala
Mechanism of disease
Several biologists have suggested that acanthocephalans secrete toxic substances that
paralyse or kill their hosts or that promote
other patent pathological changes, such as
emaciation, discoloured viscera and prolapse
of the rectum (Holloway, 1966; Fig. 13.5). No
such substance has been isolated, however,
and Schmidt et al. (1974) attributed such
damage to localized toxaemia and chronic
fibrinous inflammation, which result from
laceration of cells at the site of attachment.
Action of the spined proboscis results
in destruction of mucosal cells and penetration of the intestinal wall, with an accompanying loss of absorptive capability, impaired
gut motility and sometimes perforation of
the intestinal wall. Apparently this damage
is exacerbated by biochemical reactions.
Miller and Dunagan (1971) described a
pore-like opening and groove on acanthocephalan hooks, and they postulated delivery
455
456
B.B. Nickol
within probably reduce the number of parasites that succeed in establishing (Thomas,
2002).
Apart from a proliferation of goblet cells,
increased numbers of eosinophils, neutrophils and monocytes at the attachment site
characterize histopathological effects of
acanthocephalans. Mobilization of leucocytes occurs regardless of whether the fish
species is suitable for development of the
parasite, and Hamers et al. (1992) found
interspecific differences in the response
of leucocytes in fishes parasitized by
P. ambiguus. In eels (A. anguilla), a suitable
definitive host, the response was much less
intense than in carp (Cyprinus carpio) or
rainbow trout (Oncorhynchus mykiss), both
unsuitable hosts that expel the acanthocephalans within a few days. The leucocytes damage acanthocephalan tegument
extensively in carp; hence Hamers et al.
(1992) concluded that cellular defence is a
factor in determining host specificity for
P. ambiguus.
Humoral
Plasma cells (type B cell) occur in the
inflammatory tissue around the proboscis
of P. laevis in rainbow trout (Salmo
gairdneri), and they are probably responsible for the humoral response produced by
the fish (Wanstall et al., 1986). Even though
immunoglobulins are relatively slow to
develop in fish following an infection, and
precipitins are rare (Taraschewski, 2000),
antibodies precipitating to acanthocephalan
antigens have been reported from sera (Harris,
1970; Szalai et al., 1988) and intestinal
mucus (Harris, 1972) of infected fishes. Sera
from chub (L. cephalus) held at 10C and
with no history of exposure to P. laevis do
not have anti-P. laevis precipitins, but precipitins were detected within 160 days after
infection. Parenteral injection of P. laevis
antigen also induces a similar response by
150 days after injection (Harris, 1972).
Anti-P. laevis precipitins are not found in
four other piscine species in which P. laevis
occurs but, unlike in L. cephalus, does not
reach maturity. This led Harris (1972) to
Cross immunity
Concurrent infections with more than one
species of acanthocephalan and/or with
other helminths of other phyla are frequent.
P. bulbocolli and A. dirus occur concurrently in rainbow darters (E. caeruleum),
where they occupy sites in close proximity
to one another. There appears to be no synergistic effect as both species cause damage
as if they were in single-species infections
(McDonough and Gleason, 1981). In contrast, numbers of the cestode Proteocephalus
exiguus and Neoechinorhynchus sp. show
an inverse relation in ciscos (Coregonus
artedii), although the two helminth species
occupy different intestinal sites. Cross
(1934) believed that non-specific immunity
limits either P. exiguus or the species of
Neoechinorhynchus.
Very little is known about the nature of
precipitins in serum of acanthocephalaninfected fishes, and seldom has specific
immunoglobulin been demonstrated. Szalai
et al. (1988), however, confirmed that antiNeoechinorhynchus carpiodi precipitins in
serum from infected quillback (Carpiodes
cyprinus) were not complement-reactive
protein or the alpha migrating factor. Partial
characterization of chub (L. cephalus) antibody to P. laevis indicated that it is an
immunoglobulin M (IgM) type (Harris, 1972).
Consequently, precipitating antibody occurs
in at least one acanthocephalan infection
but its role in limiting infection and the
degree of species specificity are not known.
In Vitro Cultivation
Studies on nutritional requirements, development and response to chemotherapeutic
Phylum Acanthocephala
457
Nutritional requirements
In addition to dietary protein (Crompton
et al., 1983), hydrolysis of secretory digestive proteins, degradation of moribund
mucosal cells and probably exchange
between the mucosal epithelium and intestinal lumen are sources of free amino acids
in the intestinal lumen of a vertebrate animal (Starling, 1985). Amino acids from host
tissues contribute significantly to the pool
available to acanthocephalans, which assimilate certain of these both by diffusion and
by active transport (Uglem and Read, 1973).
This exchange among host tissue, host
dietary materials and worms in vivo and the
inability to culture acanthocephalans satisfactorily in vitro have impeded attempts to
define nutritional requirements for amino
acids.
Taraschewski (2000) reached the following conclusions after reviewing lipid
metabolism for acanthocephalans. Nonemulsified lipid from necrotic host tissue at
the site of attachment is absorbed through
the tegumental surface of the proboscis and
neck of the worms. Apparently, these lipids
are stored in the lemnisci. In contrast, emulsified free fatty acids and monoacylglycerols
resulting from action of intestinal lipases in
458
B.B. Nickol
Energy metabolism
Glycogen and trehalose appear to be the
principal endogenous carbohydrates in
acanthocephalans. Their tissues are rich in
glycogen, and depleted stores are rapidly
replenished (Read and Rothman, 1958).
Glycogen synthase occurs in both dephosphorylated
and
glucose-6-phosphatedependent phosphorylated forms, which
can apparently be interconverted (Starling,
1985). Trehalose is present in pseudocoelomic fluid, reproductive tissues and the
body wall (McAlister and Fisher, 1972).
Presumably it contributes to the osmolality
of body tissues and extracellular fluids, but
the role of trehalose is largely undetermined in acanthocephalans. It is unlikely to
serve as a primary storage of carbohydrate
for energy (Laurie, 1959). Starling and
Fisher (1978) believed that trehalose may
trap glucose within the acanthocephalan
tegument after its absorption and carry glucose moieties to non-tegumental tissues.
Carbohydrate is the main source of
energy, and it is reasonably clear that glucose and glycogen are metabolized via the
conventional EmbdenMeyerhof pathway
to phosphoenol pyruvate. Further metabolism probably involves anaerobic reactions
common to other helminths, but the steps
are still uncertain (Starling, 1985). Lactate
and succinate are the main end products,
Feeding-induced pathogenesis
Deep penetration by the proboscis results in
fibrinous nodules, which may project several millimetres into the coelom (Fig. 13.6).
Szalai and Dick (1987) reported extensive
vascularization of such nodules in quillback (C. cyprinus) induced by N. carpiodi
and demonstrated increased leakage of
Phylum Acanthocephala
459
460
B.B. Nickol
References
Adel-Meguid, M., Esch, G.W. and Eure, H.E. (1995) The distribution and pathobiology of Neoechinorhynchus
cylindratus in the intestine of green sunfish, Lepomis cyanellus. Parasitology 111, 221231.
Aloo, P.A. and Dezfuli, B.S. (1997) Occurrence of cystacanths of Polyacanthorhynchus kenyensis larvae
(Acanthocephala) in four teleostean fishes from a tropical lake, Lake Naivasha, Kenya. Folia
Parasitologica 44, 233238.
Amin, O.M. (1978) Effect of host spawning on Echinorhynchus salmonis Muller, 1784 (Acanthocephala:
Echinorhynchidae) maturation and localization. Journal of Fish Diseases 1, 195197.
Amin, O.M. (1987) Key to the families and subfamilies of Acanthocephala, with the erection of a new class
(Polyacanthocephala) and a new order (Polyacanthorhynchida). Journal of Parasitology 73, 12161219.
Amin, O.M., Heckmann, R.A., Inchausty, V. and Vasquez, R. (1996) Immature Polyacanthorhynchus
rhopalorhynchus (Acanthocephala: Polyacanthorhynchidae) in venton, Hoplias malabaricus (Pisces)
from Moca Vie River, Bolivia, with notes on its apical organ and histopathology. Journal of the
Helminthological Society of Washington 63, 115119.
Awachie, J.B.E. (1965) The ecology of Echinorhynchus truttae Schrank, 1788 (Acanthocephala) in a trout
stream in north Wales. Parasitology 55, 747762.
Aznar, F.J., Bush, A.O. and Raga, J.A. (2002) Reduction and variability of trunk spines in the acanthocephalan
Corynosoma cetaceum: the role of physical constraints on attachment. Invertebrate Biology 12, 104114.
Bakker, T.C.M. and Mundwiler, B. (1999) Pectoral fin size in a fish species with paternal care: a
condition-dependent sexual trait revealing infection status. Freshwater Biology 41, 543551.
Phylum Acanthocephala
461
Bakker, T.C.M., Mazzi, D. and Zala, S. (1997) Parasite-induced changes in behavior and color make
Gammarus pulex more prone to fish predation. Ecology 78, 10981104.
Barger, M.A. and Nickol, B.B. (1998) Structure of Leptorhynchoides thecatus and Pomphorhynchus bulbocolli
(Acanthocephala) eggs in habitat partitioning and transmission. Journal of Parasitology 84, 534537.
Barger, M.A. and Nickol, B.B. (1999) Effects of coinfection with Pomphorhynchus bulbocolli on development
of Leptorhynchoides thecatus (Acanthocephala) in amphipods (Hyalella azteca). Journal of Parasitology
85, 6063.
Barger, M.A. and Nickol, B.B. (2004) A key to the species of Neoechinorhynchus (Acanthocephala:
Neoechinorhynchidae) from turtles. Comparative Parasitology 71, 48.
Beermann, I., Arai, H.P. and Costerton, J.W. (1974) The ultrastructure of the lemnisci and body wall of
Octospinifer macilentus (Acanthocephala). Canadian Journal of Zoology 52, 533555.
Boxrucker, J.C. (1979) Effects of a thermal effluent on the incidence and abundance of the gill and intestinal
metazoan parasites of the black bullhead. Parasitology 78, 195205.
Bristol, J.R., Mayberry, L.F., Huber, D. and Ehrlich, I. (1984) Endoparasite fauna of trout in the Plitvice Lakes
National Park. Veterinarski Arhiv 54, 511.
Brooks, D.R. and Amato, J.F.R. (1992) Cestode parasites in Potamotrygon motoro (Natterer) (Chondrichthyes:
Potamotrygonidae) from southwestern Brazil, including Rhinebothroides mclennanae n. sp.
(Tetraphyllidea: Phyllobothriidae), and a revised hostparasite checklist for helminths inhabiting
neotropical freshwater stingrays. Journal of Parasitology 78, 393398.
Buchmann, K. (1986) On the infection of Baltic cod (Gadus morhus L.) by the acanthocephalan
Echinorhynchus gadi (Zoega) Muller. Nordisk Veterinaermedicin 38, 308314.
Buchmann, K., Lindenstrom, T. and Bresciani, J. (2001) Defense mechanisms against parasites in fish and the
prospect for vaccines. Acta Parasitologica 46, 7181.
Bullock, W.L. (1963) Intestinal histology of some salmonid fishes with particular reference to the
histopathology of acanthocephalan infections. Journal of Morphology 112, 2344.
Byram, J.E. and Fisher, F.M. (1974) The absorptive surface of Moniliformis dubius (Acanthocephala) II. Functional aspects. Tissue and Cell 6, 2142.
Chaicharn, A. and Bullock, W.L. (1967) The histopathology of acanthocephalan infections in suckers with
observations on the intestinal histology of two species of catostomid fishes. Acta Zoologica 48, 1942.
Choudhury, A. and Dick, T.A. (1998) Patterns and determinants of helminth communities in the
Acipenseridae (Actinopterygii: Chondrostei), with special reference to the lake sturgeon, Acipenser
fulvescens. Canadian Journal of Zoology 76, 330349.
Choudhury, A. and Dick, T.A. (2001) Sturgeons (Chondrostei: Acipenseridae) and their metazoan parasites:
patterns and processes in historical biogeography. Journal of Biogeography 28, 14111439.
Chubb, J.C. (1982) Seasonal occurrence of helminths in freshwater fishes Part IV. Adult Cestoda, Nematoda
and Acanthocephala. Advances in Parasitology 20, 1292.
Connors, V.A. and Nickol, B.B. (1991) Effects of Plagiorhynchus cylindraceus (Acanthocephala) on the energy
metabolism of adult starlings, Sturnus vulgaris. Parasitology 103, 395402.
Crompton, D.W.T. (1975) Relationships between Acanthocephala and their hosts. In: Jennings, D.H. and
Lee, D.L. (eds) Symposia of the Society for Experimental Biology, 29. Cambridge University Press,
Cambridge, pp. 467504.
Crompton, D.W.T. (1991) Nutritional interactions between hosts and parasites. In: Toft, C.A., Aeschlimann, A.
and Bolis, L. (eds) ParasiteHost Associations. Oxford Science Publications, Oxford, UK, pp. 228257.
Crompton, D.W.T. and Lassiere, O.L. (1987) Acanthocephala. In: Taylor, A.E.R. and Baker, R.R. (eds) In Vitro
Methods for Parasite Cultivation. Academic Press, London, pp. 394406.
Crompton, D.W.T. and Lockwood, A.P.M. (1968) Studies on the absorption and metbolism of D-(u-14C)
glucose by Polymorphus minutus (Acanthocephala) in vitro. Journal of Experimental Biology 48,
411425.
Crompton, D.W.T. and Ward, P.F.V. (1967) Production of ethanol and succinate by Moniliformis dubius
(Acanthocephala). Nature 215, 964965.
Crompton, D.W.T. and Whitfield, P.J. (1968) The course of infection and egg production of Polymorphus
minutus (Acanthocephala) in domestic ducks. Parasitology 58, 231246.
Crompton, D.W.T., Keymer, A., Singhvi, A. and Nesheim, M.C. (1983) Rat dietary fructose and the intestinal
distribution and growth of Moniliformis (Acanthocephala). Parasitology 86, 5781.
Cross, S.X. (1934) A probable case of non-specific immunity between two parasites of ciscoes of the Trout
Lake region of northern Wisconsin. Journal of Parasitology 20, 244245.
462
B.B. Nickol
de Buron, I. and Nickol, B.B. (1994) Histopathological effects of the acanthocephalan Leptorhynchoides
thecatus in the ceca of the green sunfish, Lepomis cyanellus. Transactions of the American Microscopical Society 113, 161168.
DeGiusti, D.L. (1949) The life cycle of Leptorhynchoides thecatus (Linton), an acanthocephalan of fish.
Journal of Parasitology 35, 437460.
Dezfuli, B.S., Grandi, G., Franzoi, P. and Rossi, R. (1990) Histopathology in Atherina boyeri (Pisces:
Atherinidae) resulting from infection by Telosentis exiguus (Acanthocephala). Parassitologia 32,
283291.
Dezfuli, B.S., Giari, L., Simoni, E., Bosi, G. and Manera, M. (2002a) Histopathology, immunohistochemistry
and ultrastructure of the intestine of Leuciscus cephalus (L.) naturally infected with Pomphorhynchus
laevis (Acanthocephala). Journal of Fish Diseases 25, 714.
Dezfuli, B.S., Pironi, F., Giari, L., Domeneghini, C. and Bosi, G. (2002b) Effect of Pomphorhynchus laevis
(Acanthocephala) on putative neuromodulators in the intestine of naturally infected Salmo trutta.
Diseases of Aquatic Organisms 51, 2735.
Dunagan, T.T. and Bozzola, J.J. (1992) Morphology of the apical organ in Macracanthorhynchus hirudinaceus
(Acanthocephala). Journal of Parasitology 78, 899903.
Edmonds, S.J. (1965) Some experiments on the nutrition of Moniliformis dubius Meyer (Acanthocephala).
Parasitology 55, 337344.
Eure, H. (1976) Seasonal abundance of Neoechinorhynchus cylindratus taken from largemouth bass
(Micropterus salmoides) in a heated reservoir. Parasitology 73, 355370.
Filipponi, C., Taraschewski, H. and Weber, N. (1994) Metabolism of long-chain fatty acids, alcohols and
alkylglycerols in the fish parasite Paratenuisentis ambiguus (Acanthocephala). Lipids 29, 583588.
Fried, B. and Stableford, L.T. (1991) Cultivation of helminths in chick embryos. Advances in Parasitology 30,
107165.
Garcia-Varela, M., Perez-Ponce de Leon, G., de la Torre, P., Cummings, M.P., Sarma, S.S.S. and Laclette, J.P.
(2000) Phylogenetic relationships of Acanthocephala based on analysis of 18 S ribosomal RNA gene
sequences. Journal of Molecular Evolution 50, 532540.
Garey, J.R. and Schmidt-Rhaesa, A. (1998) The essential role of minor phyla in molecular studies of animal
evolution. American Zoologist 38, 907917.
Garey, J.R., Schmidt-Rhaesa, A., Near, T.J. and Nadler, S.A. (1998) The evolutionary relationships of rotifers
and acanthocephalans. Hydrobiologia 387/388, 8391.
Golvan, Y.J. (1994) Nomenclature of the Acanthocephala. Research and Reviews in Parasitology 54, 135205.
Golvan, Y.J. and de Buron, I. (1988) Les htes des acanthocephales. II Les htes dfinitifs. 1. Poissons.
Annales de Parasitologie 63, 394375.
Hamers, R., Taraschewski, H., Lehmann, J. and Mock, D. (1991) In vitro study of the impact of fish sera on
the survival and fine structure of the eel-pathogenic acanthocephalan Paratenuisentis ambiguus. Parasitology Research 77, 703708.
Hamers, R., Lehmann, J., Sturenberg, F. and Taraschewski, H. (1992) In vitro study of the migratory and
adherent responses of fish leucocytes to the eel-pathogenic acanthocephalan Paratenuisentis ambiguus
(Van Cleave, 1921) Bullock et Samuel, 1975 (Eoacanthocephala: Tenuisentidae). Fish and Shellfish
Immunology 2, 4351.
Harris, J.E. (1970) Precipitin production by chub (Leuciscus cephalus) to an intestinal helminth. Journal of
Parasitology 56, 1035.
Harris, J.E. (1972) The immune response of a cyprinid fish to infections of the acanthocephalan
Pomphorhynchus laevis. International Journal for Parasitology 2, 459469.
Herlyn, H. (2001) First description of an apical epidermis cone in Paratenuisentis ambiguus (Acanthocephala:
Eoacanthocephala) and its phylogenetic implications. Parasitology Research 87, 306310.
Herlyn, H., Piskurek, O., Schmitz, J., Ehlers, U. and Zischler, H. (2003) The syndermatan phylogeny and the
evolution of acanthocephalan endoparasitism as inferred from 18S rDNA sequences. Molecular
Phylogenetics and Evolution 26, 155164.
Hoffman, G.L. (1999) Parasites of North American Freshwater Fishes, 2nd edn. Comstock Publishing Associates,
Ithaca, New York.
Holloway, H.L., Jr (1966) Prosthorhynchus formosum (Van Cleave, 1918) in songbirds, with notes on acanthocephalans as potential parasites of poultry in Virginia. Virginia Journal of Science, New Series 17,
149154.
Jilek, R. (1979) Histopathology due to the presence of Gracilisentis gracilisentis in Dorosoma cepedianum
(Le Sueur). Journal of Fish Biology 14, 593595.
Phylum Acanthocephala
463
Kates, K.C. (1944) Some observations on experimental infections of pigs with the thorn-headed worm
Macracanthorhynchus hirudinaceus. American Journal of Veterinary Research 5, 166172.
Kennedy, C.R. (1970) The population biology of helminths of British freshwater fish. Symposia of the British
Society for Parasitology 9, 145159.
Kennedy, C.R. (1972) The effects of temperature and other factors upon the establishment and survival of
Pomphorhynchus laevis (Acanthocephala) in goldfish, Carassius auratus. Parasitology 65, 283294.
Kennedy, C.R. (1985) Site segregation by species of Acanthocephala in fish, with special reference to eels,
Anguilla anguilla. Parasitology 90, 375390.
Kennedy, C.R. (1993) Introductions, spread and colonization of new localities by fish helminth and crustacean parasites in the British Isles: a perspective and appraisal. Journal of Fish Biology 43, 287301.
Knoff, M., de Sao Clemente, S.C., Pinto, R.M. and Gomes, D.C. (2001) Digenea and Acanthocephala of
elasmobranch fishes from the southern coast of Brazil. Memorias do Instituto Oswaldo Cruz 96,
10951101.
Kralova-Hromadova, I., Tietz, D.F., Shinn, A.P. and Spakulova, M. (2003) ITS rDNA sequences of
Pomphorhynchus laevis (Zoega in Muller, 1776) and P. lucyi Williams & Rogers, 1984 (Acanthocephala:
Palaeacanthocephala). Systematic Parasitology 56, 141145.
Laurie, J.S. (1959) Aerobic metabolism of Moniliformis dubius (Acanthocephala). Experimental Parasitology 8,
188197.
McAlister, R.O. and Fisher, F.M. (1972) The biosynthesis of trehalose in Moniliformis dubius (Acanthocephala).
Journal of Parasitology 58, 5162.
McDonough, J.M. and Gleason, L.N. (1981) Histopathology in the rainbow darter, Etheostoma caeruleum,
resulting from infections with the acanthocephalans, Pomphorhynchus bulbocolli and Acanthocephalus
dirus. Journal of Parasitology 67, 403409.
Malta, J.C. de O., Gomes, A.L.S., de Andrade, M.S. and Varella, A.M.B. (2001) Infestacoes macicas por
acantocefalos, Neoechinorhynchus buttnerae Golvan, 1956 (Eoacanthocephala: Neoechinorhynchidae)
em tambaquis jovens, Colossoma macropomum (Cuvier, 1818) cultivados na Amazonia central. Acta
Amazonica 31, 133143.
Mazzi, D. and Bakker, T.C.M. (2003) A predators dilemma: prey choice and parasite susceptibility in
three-spined sticklebacks. Parasitology 126, 339347.
Meyer, A. (1933) Acanthocephala. In: Dr. Bronns Klassen und Ordnungen des Tier-reichs, vol. 4.
Akademische Verlagsgesellschaft, Leipzig, pp. 333582.
Miller, D.M. and Dunagan, T.T. (1971) Studies on the rostellar hooks of Macracanthorhynchus hirudinaceus
(Acanthocephala) from swine. Transactions of the American Microscopical Society 90, 329335.
Miller, D.M. and Dunagan, T.T. (1985) Functional morphology. In: Crompton, D.W.T. and Nickol, B.B. (eds)
Biology of the Acanthocephala. Cambridge University Press, Cambridge, pp. 73123.
Moore, J. (2002) Parasites and the Behavior of Animals. Oxford University Press, Oxford, UK.
Moravec, F. and Scholz, T. (1991) Observations on the biology of Pomphorhynchus laevis (Zoega in Muller,
1776) (Acanthocephala) in the Rokytna River, Czech and Slovak Federative Republic. Helminthologia
28, 2329.
Morris, S.C. and Crompton, D.W.T. (1982) The origins and evolution of the Acanthocephala. Biological
Reviews of the Cambridge Philosophical Society 57, 85115.
Muzzall, P.M. (1978) The hostparasite relationships and seasonal occurrence of Fessisentis friedi
(Acanthocephala: Fessisentidae) in the isopod (Caecidotea communis). Proceedings of the Helminthological Society of Washington 45, 7782.
Muzzall, P.M. (1980) Ecology and seasonal abundance of three acanthocephalan species infecting white
suckers in SE New Hampshire. Journal of Parasitology 66, 127133.
Muzzall, P.M. and Rabalais, F.C. (1975) Studies on Acanthocephalus jacksoni Bullock, 1962
(Acanthocephala: Echinorhynchidae). I. Seasonal periodicity and new host records. Proceedings of the
Helminthological Society of Washington 42, 3134.
Nickol, B.B. (1972) Two species of Acanthocephala from Australian fishes with description of
Arhythmacanthus paraplagusiarum sp. n. Journal of Parasitology 58, 778780.
Nickol, B.B. (2003) Is postcyclic transmission underestimated as an epizootiological factor for acanthocephalans? Helminthologia 40, 9395.
Noble, E.R. (1973) Parasites and fishes in a deep-sea environment. Advances in Marine Biology 11, 121195.
Olson, P.D. and Nickol, B.B. (1995) Effects of low temperature on the development of Leptorhynchoides
thecatus (Acanthocephala) in Lepomis cyanellus (Centrarchidae). Journal of the Helminthological Society of Washington 62, 4447.
464
B.B. Nickol
ONeill, G. and Whelan, J. (2002) The occurrence of Corynosoma strumosum in the grey seal, Halichoerus
grypus, caught off the Atlantic coast of Ireland. Journal of Helminthology 76, 231234.
Parshad, V.R., Crompton, D.W.T. and Nesheim, M.C. (1980) The growth of Moniliformis (Acanthocephala) in
rats fed on various monosaccharides and disaccharides. Proceedings of the Royal Society of London
B209, 299315.
Polzer, M. and Taraschewski, H. (1994) Proteolytic enzymes of Pomphorhynchus laevis and in three other
acanthocephalan species. Journal of Parasitology 80, 4549.
Read, C.P. and Rothman, A.H. (1958) The carbohydrate requirement of Moniliformis (Acanthocephala).
Experimental Parasitology 7, 191197.
Reyda, F.B. and Nickol, B.B. (2001) A comparison of biological performances among a laboratory-isolated
population and two wild populations of Moniliformis moniliformis. Journal of Parasitology 87,
330338.
Richardson, D.J. and Nickol, B.B. (1999) Physiological attributes of the pyloric caeca and anterior intestine of
green sunfish (Lepomis cyanellus) potentially influencing microhabitat specificity of Leptorhynchoides
thecatus (Acanthocephala). Comparative Biochemistry and Physiology Part A 122, 375384.
Richardson, D.J. and Nickol, B.B. (2000) Experimental investigation of physiological factors that may influence microhabitat specificity exhibited by Leptorhynchoides thecatus (Acanthocephala) in green sunfish
(Lepomis cyanellus). Journal of Parasitology 86, 685690.
Richardson, D.J., Martens, J.K. and Nickol, B.B. (1997) Copulation and sexual congress of Leptorhynchoides
thecatus (Acanthocephala). Journal of Parasitology 83, 542543.
Sanmartin, M.L., Alvarez, M.F., Peris, D., Iglesias, R. and Leiro, J. (2000) Parasite community study of the
undulate ray Raja undulata in the Ria of Muros (Galicia, northwest Spain). Aquaculture 184, 189201.
Sasal, P., Faliex, E., de Buron, I. and Morand, S. (2001) Sex discriminatory effect of the acanthocephalan
Acanthocephaloides propinquus on a gobiid fish Gobius bucchichii. Parasite 8, 231236.
Schmidt, G.D. (1985) Development and life cycles. In: Crompton, D.W.T. and Nickol, B.B. (eds) Biology of
the Acanthocephala. Cambridge University Press, Cambridge, pp. 273305.
Schmidt, G.D., Walley, H.D. and Wijek, D.S. (1974) Unusual pathology in a fish due to the acanthocephalan
Acanthocephalus jacksoni Bullock, 1962. Journal of Parasitology 60, 730731.
Starling, J.A. (1985) Feeding, nutrition and metabolish. In: Crompton, D.W.T. and Nickol, B.B. (eds) Biology
of the Acanthocephala. Cambridge University Press, Cambridge, pp. 125212.
Starling, J.A. and Fisher, F.M. (1978) Carbohydrate transport in Moniliformis dubius (Acanthocephala).
II. Post-absorptive phosphorylation of glucose and the role of trehalose in the accumulation of endogenous glucose reserves. Journal of Comparative Physiology 126, 223231.
Stranack, F.R., Woodhouse, M.A. and Griffin, R.L. (1966) Preliminary observations on the ultrastructure of the
body wall of Pomphorhynchus laevis (Acanthocephala). Journal of Helminthology 40, 395402.
Sures, B. (2001) The use of fish parasites as bioindicators of heavy metals in aquatic ecosystems: a review.
Aquatic Ecology 35, 245255.
Sures, B. (2002) Competition for minerals between Acanthocephalus lucii and its definitive host perch (Perca
fluviatilis). International Journal for Parasitology 32, 11171122.
Sures, B. and Siddall, R. (2003) Pomphorhynchus laevis (Palaeacanthocephala) in the intestine of chub
(Leuciscus cephalus) as an indicator of metal pollution. International Journal for Parasitology 33, 6570.
Sures, B., Traschewski, H. and Jackwerth, E. (1994) Lead content of Paratenuisentis ambiguus
(Acanthocephala), Anguillicola crassus (Nematodes) and their host Anguilla anguilla. Diseases of Aquatic
Organisms 19, 105107.
Sures, B., Steiner, W., Rydlo, M. and Taraschewski, H. (1999) Concentrations of 17 elements in the zebra
mussel (Dreissena polymorpha), in different tissues of perch (Perca fluviatilis), and in perch intestinal
parasites (Acanthocephalus lucii) from the subalpine Lake Mondsee, Austria. Environmental Toxicology
and Chemistry 18, 25742579.
Szalai, A.J. and Dick, T.A. (1987) Intestinal pathology and the site specificity of the acanthocephalan
Neoechinorhynchus carpiodi Dechtiar, 1968, in quillback, Carpiodes cyprinus (Lesueur). Journal of
Parasitology 73, 467475.
Szalai, A.J., Danell, G.V. and Dick, T.A. (1988) Intestinal leakage and precipitating antibodies in the serum of
quillback, Carpiodes cyprinus (Lesueur), infected with Neoechinorhynchus carpiodi Dechtiar, 1968
(Acanthocephala: Neoechinorhynchidae). Journal of Parasitology 74, 415420.
Taraschewski, H. (1989a) Acanthocephalus anguillae in intra- and extrainestinal positions in experimentally
infected juveniles of goldfish and carp and in sticklebacks. Journal of Parasitology 75, 108118.
Phylum Acanthocephala
465
Taraschewski, H. (1989b) Hostparasite interface of Paratenuisentis ambiguus (Eoacanthocephala) in naturally infected eel and in laboratory-infected sticklebacks and juvenile carp and rainbow trout. Journal of
Parasitology 75, 911919.
Taraschewski, H. (2000) Hostparasite interactions in Acanthocephala: a morphological approach. Advances
in Parasitology 46, 1179.
Taraschewski, H., Mehlhorn, H. and Raether, W. (1990) Loperamid, an efficacious drug against fish-pathogenic
acanthocephalans. Parasitology Research 76, 619623.
Tedla, S. and Fernando, C.H. (1970) Some remarks on the ecology of Echinorhynchus salmonis (Muller,
1784). Canadian Journal of Zoology 48, 317321.
Thomas, J.D. (2002) The ecology of fish parasites with particular reference to helminth parasites and their
salmonid fish hosts in Welsh rivers: a review of some of the central questions. Advances in Parasitology
52, 1154.
Uglem, G.L. and Read, C.P. (1973) Moniliformis dubius: uptake of leucine and alanine by adults. Experimental Parasitology 34, 148153.
Valtonen, E.T. and Koskivaara, M. (1994) Relationships between the parasites of some wild and cultured
fishes in two lakes and a fish farm in central Finland. International Journal for Parasitology 24, 109118.
Valtonen, E.T., Pulkkinen, K., Poulin, R. and Julkunen, M. (2001) The structure of parasite component communities in brackish water fishes of the northeastern Baltic Sea. Parasitology 122, 471481.
Van Cleave, H.J. (1920) Acanthocephala. Report of the Canadian Arctic Expedition 191318 9, 1E11E.
Van Cleave, H.J. (1941) Relationships of the Acanthocephala. American Naturalist 75, 3147.
Van Cleave, H.J. (1947) Analysis of distinctions between the acanthocephalan genera Filicollis and
Polymorphus, with description of a new species of Polymorphus. Transactions of the American Microscopical Society 66, 302313.
von Brand, T. (1939) The glycogen distribution in the body of Acanthocephala. Journal of Parasitology 25, 22S.
Wanstall, P.W., Robotham, P.W.J. and Thomas, J.S. (1982) Changes in the energy reserves of two species of
freshwater fish during infection by Pomphorhynchus laevis. Parasitology 85, xxvii.
Wanstall, P.W., Robotham, P.W.J. and Thomas, J.S. (1986) Pathological changes induced by Pomphorhynchus
laevis Muller (Acanthocephala) in the gut of rainbow trout, Salmo gairdneri Richardson. Zeitschrift fr
Parasitenkunde 72, 105114.
Ward, H.L. (1940) Studies on the life history of Neoechinorhynchus cylindratus (Van Cleave, 1913)
(Acanthocephala). Transactions of the American Microscopical Society 59, 327347.
Watson, R.A. and Dick, T.A. (1979) Metazoan parasites of whitefish, Coregonus clupeaformis (Mitchill) and
cisco C. artedii Lesueur from Southern Indian Lake, Manitoba. Journal of Fish Biology 15, 579587.
Wayland, M.T., Sommerville, C. and Gibson, D.I. (1999) Echinorhynchus brayi n. sp. (Acanthocephala:
Echinorhynchidae) from Pachycara crassiceps (Roule) (Zoarcidae), a deep-sea fish. Systematic Parasitology 43, 93101.
Weber, N., Taraschewski, H. and Aitzetmuller, K. (1995) Chain elongation of fatty acids in the fish parasite
Paratenuisentis ambiguus (Acanthocephala). Journal of Parasitology 81, 501504.
Welch, D.B.M. (2000) Evidence from a protein-coding gene that acanthocephalans are rotifers. Invertebrate
Biology 119, 1726.
Yamaguti, S. (1961) Systema Helminthum, vol. 5. Acanthocephala. Interscience Publishers, New York.
Yasumoto, S. and Nagasawa, K. (1996) Possible life cycle of Longicollum pagrosomi, an acanthocephalan parasite of cultured Red Sea bream. Fish Pathology 31, 235236.
Young, B.W. and Lewis, P.D., Jr (1977) Growth of an acanthocephalan on the chick chorioallantois. Proceedings of the Montana Academy of Sciences 37, 88.
Zdzitowiecki, K. (2001) New data on the occurrence of fish endoparasitic worms off Adelie Land, Antarctica.
Polish Polar Research 22, 159165.
Zrzavy, J. (2001) The interrelationships of metazoan parasites: a review of phylum- and higher-level
hypotheses from recent morphological and molecular phylogenetic analyses. Folia Parasitologica 48,
81103.
14
Phylum Arthropoda
Introduction
Arthropod parasites of fish have been
recorded since the time of Aristotle (300 BC).
He noted that parasitic isopods (almost certainly cymothoids) were common on the
fins of fishes, and that lice (probably
ergasilids) occurred under the gills of
chalkis (possibly bleak) in such numbers
that the fish were killed. He also mentioned
a scorpion-like parasite, possibly a pennellid,
from the body of tuna and swordfish.
About 2000 species of parasitic arthropods have been described, the majority of
which belong to the class Copepoda. Many
others await description. Thatcher (1998)
estimated that there were 9000 undescribed
parasitic copepod species in the Amazon
alone.
Some of the arthropods that affect
wild fish are of commercial significance
as they affect host survival or cause
unsightly changes in the flesh. Others (e.g.
the anchor worm, Lernaea cyprinacea)
cause ongoing problems in aquaculture.
The biology of pests in freshwater aquaculture is reasonably well known. Parasites
in the sea, especially sea lice (Lepeophtheirus
salmonis) and more recently cymothoid
isopods, have come under intense scrutiny
with the development of rearing fish in sea
cages.
466
In this chapter, we discuss those arthropods for which pathological changes in fish
have been described.
Copepoda: Ergasilidae
Introduction
Ergasilid copepods damage the gills and
cause commercially significant epizootics
in cultured and wild populations of fishes.
Ergasilus sieboldi is widespread in temperate parts of Europe and Asia, Ergasilus
lizae is important in mullet culture in the
Mediterranean and Middle East, and
Pseudergasilus zacconis infects cultured
ayu, Plecoglossus altivelis, in Japan. In
North America, Kelly and Allison (1962)
implicated E. lizae in the death of largemouth bass (Micropterus salmoides) in a
brackish lake and Hogans (1989) reported
that Ergasilus labracis killed large numbers
of Atlantic salmon (Salmo salar) parr
(85125 mm long) over a 4-day period in
New Brunswick, Canada.
Phylum Arthropoda
467
468
Phylum Arthropoda
469
Fig. 14.2. Therodamas tamarae adult female, a long-necked ergasilid. Bar = 100 m (after Amado
and Rocha, 1996.)
470
Phylum Arthropoda
471
Effects on host
Heavy infections cause death. Sublethal
infections result in decreased condition
(Grabda, 1991; Schaperclaus et al., 1991).
Infections of T. tinca and Coregonus peled
with E. sieboldi were associated with reduced
weight, reduced length, reduced condition,
reduced fat and increased water content
(Abrosov and Bauer, 1959; Dogiel et al., 1961;
Kabata, 1970).
Concurrent infection
Concurrent infections are rare. No secondary bacterial infections were found in the
gills of cyprinid fishes in Alabama infected
with E. cyprinaceus (see Rogers, 1969). However, Reichenbach-Klinke and Landolt (1973)
reported that wounds in pond-cultured
T. tinca caused by E. sieboldi became secondarily infected with Saprolegnia sp.
Parasite nutrition and physiology
Halisch (1940) suggested that attached
ergasilid copepods fed by external digestion
and showed that female copepods confined
in small volumes of water released factors
that dissolved gelatin. The diet of E. sieboldi
was shown by Einszporn (1964, 1965a,b) to
consist of mucus, epithelium and blood.
She proposed that blood was a major component of the diet. However, extrabuccal
digestion is now considered a major part of
feeding by ergasilids (Kabata, 1984). Donoghue
(1989) found mucus to be the principal diet
of Thersitina gasterostei.
Little is known about the nutrition and
physiology of the planktonic free-living
stages. They often contain bright pigments,
particularly blue and also red and orange,
which may help to protect tissues from
photo-oxidation (Alston et al., 1996). The
colours are lost from most species as the
females mature.
Diagnosis
The parasites are readily seen with the
naked eye or under a dissecting microscope.
472
Copepoda: Sarcotaces
Introduction
These bizarre copepods cause cysts several
centimetres long in the muscle under the
skin (Fig. 14.5). The cysts are exposed when
fish are filleted and cut cysts release copious black fluid over the fillets.
Sarcotaces verrucosus Olsson 1872,
the type species, has a worldwide distribution, from abyssal depths to tropical reefs
(Heegaard, 1947a; Kuitunen-Ekbaum, 1949;
Moser et al., 1985). Hosts include members
of the families Moridae, Macrouridae, Scorpaenidae, Antennariidae, Triglidae, Acanthuridae, Serranidae and Pinguipedidae. Two
other species, Sarcotaces japonicus and
Sarcotaces shiinoi, were described from
Japanese fish by Izawa (1974). The genus is
usually included in the family Phylichthyidae; these are small copepods that parasitize
the lateral line and other sensory canals of
teleosts.
Morphology and life cycle
The female is up to 45 mm long in cold
temperate waters, smaller in the tropics, the
body broadly oval and the surface verrucose
in bands corresponding to segments, with a
double rosette around minute mouthparts
and the tail pointed with a spine (Fig. 14.5).
Most of the bulk of the body is formed from
the gut, which typically contains a thick
black fluid. The male is up to 3 mm, with 0
to 26 in a capsule with each female (Gonzalez and Tanzola, 2000). For further details
see Lester and Roubal (1995).
Copepoda: Lernaea
Introduction
Lernaeids or anchor worms are common
pests in freshwater aquaculture of cyprinids
Phylum Arthropoda
473
Fig. 14.5. Sarcotaces verrucosus female, ventral view, alongside host capsule (from Mora moro,
Tasmania). Scale: units 1 mm.
Cyprinodontiformes
(Cyprinodontidae,
Poecillidae), Gadiformes (Gadidae), Gasterosteiformes (Gasterosteidae), Perciformes
(Anabantidae, Apogonidae, Centrarchidae,
Cichlidae, Gobiidae, Mastacembalidae,
Osphronemidae, Percidae), Salmoniformes
(Esocidae, Plecoglossidae, Salmonidae,
Umbridae) and Siluriformes (Bagridae,
Ictaluridae, Siluridae) (Kabata, 1979). In
a tropical display aquarium in Malaysia,
23 out of 58 species of fish became infected
(Shariff et al., 1986). In North America, the
parasite has also been reported on tadpoles
(Tidd and Shields, 1963).
Distribution of the parasite is partly
dictated by water temperature. Its optimum
temperature is 2628C (Shields and Tidd,
1968). Thus, in temperate climates the parasite is most common in late summer. It is
more prevalent in still or slowly flowing
water than in fast-flowing streams
(Hoffman, 1976; Bulow et al., 1979) and
less common during floods than in
474
Fig. 14.6. Lernaea spp. morphology of female. A and B. L. cyrinacea. C. L. polymorpha. D. L. cruciata.
a, anterior process of dorsal horn; l, 3rd pair of legs; m, mouth; p, posterior process of dorsal horn;
v, ventral horn. Scale bars 1 mm. (A redrawn from Kabata, 1979; B and C redrawn from Shariff and
Sommerville, 1986a; D redrawn from Kabata, 1988.)
Systematics
There are at least 110 species of lernaeids,
all in fresh water. They belong to two
subfamilies: the Lamprogleninae, which are
confined to Africa and Asia, and the
Lernaeinae, which are widespread (Ho,
1996). Kabata (1983) and Boxshall (2004)
give keys to genera. Ho and Kim (1997)
Phylum Arthropoda
475
Fig. 14.7. Lernaea cyprinacea. Diagram of adult female in situ. b, blood seepage; c, stratum compactum
of dermis; d, stratum spongiosum of dermis; e, epithelial collar; f, fibrous collar; h, area of muscle
disorganization, fibrous granulation tissue and haemorrhage; m, muscle; s, scale.
476
Hostparasite relationships
Site and host selection, course of infection
Larval lernaeids occur typically on the gills.
Adult females usually attach on the body
surface and lodge in the superficial layers of
the body musculature. Those of L. cyprinacea
attach all over the body of cyprinids in still
water, whereas in moving water they are
principally near the bases of fins. On rainbow trout, a third of them may attach to
gills or the wall of buccal cavities (McNeil,
1961). On Tilapia sp. and Anguilla anguilla,
they are found principally in the buccal
cavity (Fryer, 1966; Ghittino, 1987).
Clinical signs and histopathology
Copepodids of L. cyprinacea on small
cyprinids cause disruption and necrosis of
the gill epithelium. Khalifa and Post (1976)
reported that large numbers of larvae on the
gills caused the death of fish. Fingerlings
with more than six adult females became
moribund (Daskalov et al., 1999). In polyculture ponds, the grazing of large numbers
of copepodids on the surface of each gill
filament of channel catfish, I. punctatus,
Phylum Arthropoda
477
trauma and melanin deposition were evident at the attachment site. A thick fibrous
capsule formed around parasites in some
fish. In others, muscle was eroded down to
the vertebral column and the fish became
lethargic and died (Tamuli and Shanbhogue,
1996b).
Host immune response
Shields (1978) suspected that goldfish
acquired immunity to L. cyprinacea because
he was unable to reinfect fish that had once
had a heavy infestation. Shields and Goode
(1978) observed that half of the parasites on
experimentally infected goldfish were
rejected by the host 1 week after maturation
of the first egg sacs. Wounds left by rejected
females healed rapidly.
Shariff et al. (1986) found that, after an
epizootic of L. cyprinacea in a display
aquarium, 18 out of 23 fish species had
apparently acquired resistance by the time
of a second outbreak 6 months later. Few
new infections developed in experimentally infected Helostoma temmincki that
had recovered from an earlier infection.
Fish that became infected lost their infections rapidly. Parasites on recovered fish
produced fewer eggs and the resultant larvae
were less infective than those from females
on nave fish (Woo and Shariff, 1990).
A similar phenomenon occurs in some
other lernaeids. In an experimental infection of L. polymorpha on bighead carp,
the prevalence first increased and then
declined to zero after 4 months (Shariff and
Sommerville, 1986c). Degenerating females
were found in haemorrhagic ulcers of resistant fish (Shariff and Roberts, 1989).
Fingerlings of Indian carp (C. catla) from
which L. bhadraensis had been removed
were re-exposed to the parasites and examined 30 and 45 days later. Fish that had had
heavy infections (20+ per fish) had few new
infections, whereas those that had been
lightly infected (three per fish) were heavily
parasitized (Tamuli and Shanbhogue, 1996c).
No immunity was acquired by Javanese
carp, Puntius gonionotus, against subsequent infection by L. minuta, possibly
because the parasite does not penetrate far
478
In vitro culture
Egg sacs, either separate or still attached to
excised females, develop normally in
dishes in non-aerated water. Nauplii hatch
and moult three times to the infective first
copepodid in the dish (Grabda, 1963;
Shields, 1978).
Phylum Arthropoda
Diagnosis of infection
Adult females can be seen macroscopically;
copepodids require the use of a dissecting
microscope.
479
480
Copepoda: Caligidae
Introduction
Sea lice (family Caligidae) are among the
most notorious pests affecting cultured
marine fishes. The best-known representatives of this group are those infesting caged
salmonids. Sea lice infestations in salmon
farms in Norway and Scotland are estimated to have cost over 70 million ecu in
1997 (Costello and Boxshall, 2000). In 1995
in Canada, they are estimated to have cost
Phylum Arthropoda
Fig. 14.8.
481
Adult salmon lice, Lepeophtheirus salmonis (redrawn from Kim, 1998; photo C. Orr).
482
Table 14.1.
Caligids reported to have caused mortalities among non-salmonid fishes in Asia (from Ho, 2000).
Caligid species
Country
Hosts
Source
Caligus acanthopagri
Taiwan
Caligus epidemicus
Taiwan
Caligus orientalis
Caligus patulus
Caligus punctatus
China and
Taiwan
Philippines
Taiwan
Caligus rotundigenitalis
Taiwan
Caligus spinosus
Lepeophtheirus
longiventris
Lepeophtherius
paralichthydis
Japan
Japan
Japan
Phylum Arthropoda
483
484
Phylum Arthropoda
485
486
L. salmonis has the typical caligid complement of two free-living naupliar stages (N1
and N2), an infective copepodid stage (C),
four attached chalimus stages (Ch1Ch4),
two free-living, pre-adult stages (PA1, PA2)
and one adult (A) stage (Johnson and
Albright, 1991a, b; Fig. 14.10). The natural
lifespan of adult L. salmonis has not been
determined (Pike and Wadsworth, 1999).
Descriptions of the whole or part of the life
cycle of Lepeophtheirus spp. can be found
in White (1942), Lewis (1963), Boxshall
(1974a), Johannessen (1978) and Schram
(1993). Studies of varying completeness
on the life cycles of Caligus spp. include
Wilson (1905b), Heegaard (1947b), Hwa
(1965), Izawa (1969), Hewitt (1971) and
Jones (1980). However, nine stages (two N,
one C, four Ch, one PA, one A) have been
recorded for most Caligus spp., with 11
stages (six Ch) for C. epidemicus (see Lin
and Ho, 1993) and eight (four Ch, no PA)
for C. punctatus (see Kim, 1993) and
C. rogercresseyi (see Gonzlez and Carvajal,
2003).
Hostparasite relationships
Site/host selection and course of infection
Lepcophtheirus salmonis nauplii and copepodids are positively phototactic and
exhibit a daily vertical migration, rising
from the deeper waters to the surface during
the day and sinking at night. Heuch et al.
(1995) conclude that crossing over, as
copepodids migrate upwards and salmon
move downwards during daylight, allows
transmission to take place. Nauplii and
copepods also swim upwards in response
to pressure, but they do not respond to
chemical cues. A change in water flow or a
mechanical vibration produces a burst in
Phylum Arthropoda
487
488
Phylum Arthropoda
489
Fig. 14.12. Lepeophtheirus salmonis on Atlantic salmon Salmo salar showing severe erosion of the
epidermal and deeper tissues of the head and operculum (photo courtesy of T. Hastein).
490
Mechanism of disease
The primary cause of pathology associated
with adult caligid copepods results from
parasite feeding; the extent of damage
depends on the number of parasites. Five
adult L. salmonis cause skin erosion on
salmon smelts, but up to 2000 parasites have
Phylum Arthropoda
In vitro culture
Pike and Wadsworth (1999) decribe how
egg sacs can be removed from mature gravid
females, hatched in clean, filtered sea water
and the nauplii allowed to moult to infective copepodids. Experimental hosts are
exposed to copepodids in static, aerated
water for several hours. Successful establishment is indicated by black pigment
spots at the sites of infection.
491
posterior lip of the mouth tube. The mandibles aid the passage of food into the mouth
tube (Kabata, 1974). Naupliar stages lack a
gut and anus, whereas the copepodid has a
mouth cone but lacks the strigil (Johnson
and Albright, 1991b). The first chalimus
stage of L. salmonis has well-developed
mouthparts and a functional alimentary
canal and is the first feeding stage in the life
cycle (Jones et al., 1990; Bron et al., 1991).
Mucus and epidermis appear to be the
main diet (Boxshall, 1977; Wootten et al.,
1982). Blood was found in the gut of adult
Lepeophtheirus spp. when blood vessels or
haemorrhaging tissue occurred near the surface (Brandal et al., 1976). C. elongatus has
higher levels and a greater diversity of proteases in the gut than does L. salmonis, a
difference attributed to the wider host range
of the former (Ellis et al., 1990). Lipase was
found in the gut of L. salmonis by Grayson
et al. (1991).
Kvamme et al. (2004) characterized five
trypsin-like peptidase transcripts from
L. salmonis, and found that their levels
increased from planktonic to early hostattached stages and also from pre-adult to
sexually mature stages. These authors also
noted that the digestive functions of these
five peptidases are indicated by their finding that they are all transcribed throughout
the undifferentiated midgut.
The genetic population structure of
L. salmonis has been investigated in some
detail to evaluate the claim that individuals
originating from farmed salmonids are
responsible for the decline of populations
of sea trout (S. trutta) since 1989 on the
west coasts of both Scotland and Ireland.
However, populations show varying degrees
of polymorphism and hence there is currently no consensus as to whether sea lice
from farms are reducing numbers of sea
trout. Todd et al. (1997) predicted that the
inclusion of a planktonic larval phase in
the life cycle of L. salmonis, in addition to
the high mobility of salmon, would
enhance gene flow and preclude genetic
differentiation of populations as a result of
random drift alone. This was confirmed in
their analysis of allozyme variation in two
polymorphic loci of female sea lice from
492
Diagnosis of infection
Large female caligoids, though semitransparent and often cryptically coloured,
are usually visible to the discerning eye on
the gills, fins or body of fish or in the buccal
and opercular cavities, particularly when
mobile. Copepodids and chalimus larvae
are generally small (less than 4 mm long)
and detection requires at least the use of a
magnifying glass (Johnson, 1998). Sea lice
still attached to the skin of freshly killed
fish may also be detected by running a wet
hand along the flanks of the body, and will
be felt as a minor lump.
Phylum Arthropoda
493
494
Phylum Arthropoda
495
1990; Costello and Bjordal, 1990). The number of mobile lice, and not chalimi, was
lower on salmon in cages with wrasse (211
lice per fish) than in cages without wrasse
(< 50 lice per fish) (Treasurer, 1993). Cages
in which wrasse have been introduced
require little or no chemical treatment to
control sea lice. The wrasse were not hosts
to L. salmonis and Caligus centrodonti
found on wrasse were not found on salmon,
indicating that copepod transfer between
wrasse and salmon did not pose a problem
(Bron and Treasurer, 1992). Wrasse were
not carriers of the typical strain of
A. salmonicida (see Treasurer, 1993), and
the atypical strain found in some wrasse
was non-pathogenic to salmon (Frerichs
et al., 1992).
Udonellid monogeneans, which are
found on a number of sea lice, have been
suggested as candidates for biological control, but they are probably unsuitable as
they are ectocommensals that feed on the
fish, not the lice.
Copepoda: Pennellidae
Introduction
Pennellids are widespread and highly visible parasites of marine fishes. Most cause
localized changes in adjacent tissues and
some result in loss of condition or reduced
gonad development.
Lernaeocera branchialis (Fig. 14.14)
has been estimated to cause reductions of
more than 1000 t/year in the gadoid catch
around Scotland through loss of condition
(Kabata, 1970). In mariculture, infected cod
(Gadus morhua) farmed in sea cages in
Newfoundland show poor weight gain and
increased mortality (Khan et al., 1990).
Lernaeocera lusci has caused mortality in
cultured sole (Solea solea) in Britain (Slinn,
1970; Kirmse, 1987).
Dark muscle lesions caused by Pennella
hawaiiensis delayed the marketing of
169,000 t of boarfish (Pentaceros richardsoni) until the source of the lesion was
identified (Kurochkin, 1985).
496
Phylum Arthropoda
Systematics
A key to genera of pennellids based on
adult females is in Boxshall (2004). Outlines of common genera are given in
Figs 14.1414.16. The two species of
Lernaeocera, L. branchialis and L. lusci, are
distinguished by the shape of the holdfast
of adult females (Van Damme and Ollevier,
1995). L. branchialis (Fig. 14.14) has one
dorsal and two lateral thoracic lobes,
whereas the holdfast of L. lusci incorporates
two additional lobes, the antennary processes, which arise on the dorsal side
between the mouth and the holdfast proper
(Fig. 14.15). A key to Cardiodectes is
given by Bellwood (1981) and to pennellid
species of India by Pillai (1985).
Males and copepodids can be recognized as members of the family Pennellidae
from the characteristic second antennae,
which are typically subchelate with a
strong opposable claw. The chalimus stage
497
498
Phylum Arthropoda
499
Fig. 14.17. Cardiodectes medusaeus. A. Adult female attached to myctophid (after Perkins, 1983).
B. Entire parasite, scale bar 1 mm (after Shiino, 1958). C. Section though heart of myctophid with parasite
embedded in the bulbus arteriosus. a, atrium; ba, bulbus arteriosus; bw, body wall; c, copepod; m, mouth;
r, rhizoid holdfast processes; v, ventricle. (After Kabata, 1981.)
500
Hostparasite relationships
Site and host selection, course of infection
Phylum Arthropoda
501
502
Mechanism of disease
The disease caused by L. branchialis is primarily the result of anorexia, stress and
blood loss. Sudden mortality occurs when
part of the holdfast enters the vessel lumen,
resulting in thrombi and blockage of major
blood vessels (Khan, 1988). C. medusaeus, a
parasite that lies within a blood vessel, does
not cause such thrombi, perhaps because it
Phylum Arthropoda
503
504
Phylum Arthropoda
505
Copepoda: Lernaeopodidae
Introduction
Lernaeopodids are highly modified copepods
chiefly parasitic on marine teleosts. Adult
females are attached permanently by a
unique structure, the bulla, which is
implanted in the host tissue. Dwarf, shortlived, adult males attach to the female.
Members of the freshwater genus
Salmincola, especially S. californiensis
506
in the sea. Friend (1941) found that S. salmonea could survive for several months,
and possibly up to 2 years, on Atlantic
salmon at sea. The parasite was able to grow
but not reproduce. New infection occurred
only when the salmon returned to fresh
water to spawn. The parasites that survived
at sea were able to produce viable eggs and
infect other salmon. Most S. californiensis
died within 2 months following the transfer
of its host, O. nerka, from fresh to sea water,
but some survived for up to 1 year (Bailey
et al., 1989).
Alella macrotrachelus (Fig. 14.24)
infect the gills of sparids in the Mediterranean, Japan and Australia, particularly in
the summer, and apparently overwinter on
the fish as ovigerous females (Cabral, 1983;
Roubal, 1990). Alella pagelli, also from the
gills of sparids, occurs in the North Sea, the
Mediterranean and South Africa (Kabata,
1979). Alella ditrematis infects Japanese
embiotocid fish and Alella pterobrachiata
parasitizes Epinephelus merra in Australia
(Ho, 1983).
The genus Clavella contains approximately 19 species (Kabata, 1979) that
parasitize four orders of fishes in the Pacific
and Atlantic Oceans. The prevalence and
intensity of Clavella adunca (syn. uncinata)
(Fig. 14.25) on whiting (Merlangius merlangus) in the Irish Sea decreased with age
of fish and the movement of fish away from
inshore areas (Shotter, 1971).
Phylum Arthropoda
507
508
Hostparasite relationships
Site and host selection, course of infection
Salmincola copepodids spend some time
swimming in short bursts (Kabata and
Cousens, 1977), but most of their time is
spent on the bottom, where shadows and
shock waves trigger increased duration and
speed of swimming (Poulin et al., 1990;
Conley and Curtis, 1993). Brook trout fry
that remained motionless were less likely to
acquire copepodids than more active fish.
Infected fish became more active so tended
to acquire even more parasites (Poulin
et al., 1991).
Copepodids move over the surface of
the host using their second antennae and
maxillae. The maxillipeds make a cavity
in the hosts surface and the large adhesive
terminal plug of the frontal filament is
inserted into the cavity (frequently on to
underlying skeletal structures). The copepodid walks backwards and uncoils the
frontal filament; this evagination may take
35 h (Kabata and Cousens, 1973).
Following the chalimus stages, a young
female inserts the bulla into a cavity in the
hosts surface and plants the second
maxillae into it. The bulla is then expanded
by secretory substances from the maxillary
glands passing through the maxillae into
the bulla (Kabata and Cousens, 1973).
The distribution of the parasite on the
host is determined by the stage and density
of the parasite as well as the species and
size of the host. In sockeye salmon fry
(O. nerka), chalimi of S. californiensis are
found all over the body, whilst adults tend
Phylum Arthropoda
Histopathology
The pathology associated with lernaeopodid
copepods depends on the tissue infected,
the species of parasite, its size and the type
of bulla. In S. californiensis the burrowing
behaviour of young females prior to implantation of the bulla can lead to extensive
damage and even perforation of the body
wall into the viscera. Older parasites on the
opercular wall produced pressure on the
tips of the gill filaments, which resulted in a
reduction in length of several adjacent primary gill filaments. In juvenile sockeye
salmon, up to 25% of gill surface area was
lost through such crypting of the gill filaments (Kabata and Cousens, 1977). The
same parasite causes crypting in O. mykiss.
Sutherland and Wittrock (1985) attributed
it to retarded filament growth rather than
509
510
Mechanism of disease
In general, attachment causes greater damage to the host than does feeding (Kabata
and Cousens, 1977; Kabata, 1984; Sutherland
and Wittrock, 1985; Duston and Cusack,
2002). Attachment to the gill filaments, as
well as pressure from parasites within the
buccal cavity, damages the gills, leading to
a loss of respiratory surface area. In Alella
spp. both attachment and feeding determine the damage to the gills of A. australis,
since the number and length of filaments
affected are related to the length of the neck
In vitro culture
Detached egg sacs will develop and hatch.
Copepodids provided with a suitable host
will develop further.
Phylum Arthropoda
Diagnosis of infection
The large female parasites are usually visible with the naked eye on the gills, fins or
body of the fish or in the buccal and
opercular cavities.
Prevention and control
Hoffman (1970) recommended manual
removal. Chemicals such as 0.85% calcium
chloride, 0.2% copper sulphate, 1.7% magnesium sulphate, 0.2% potassium chlorate
and 1.2% sodium chloride were ineffective against adult Salmincola but were useful against copepodids at 3- or 4-day
intervals as long as was deemed necessary
(Hoffman, 1977). Manual removal together
with ivermectin (22,23-dihydroavermectin)
0.2 mg/kg body weight weekly twice or
three times by gavage after MS222 eliminated live S. californiensis from chinook
salmon. All associated necrosis of gill tissue
was resolved within 9 weeks. Emamectin
benzoate 0.2% premix (Slice) coated on to
pellets and fed to brook trout (700900 g)
for 7 days resulted in a 4060% reduction
in the mean number of adult female
S. edwardsii, whereas controls increased by
20%. The medicated fish also had better
511
Copepoda: Sphyrion
Sphyrion lumpi (Fig. 14.26) commonly
infects redfish (Sebastes mentella) in the
North Atlantic. Holdfasts left by dead parasites cause abscesses 2 cm or more across in
Fig. 14.26. Sphyrion species, adult females. A. S. lumpi. B. S. laevigatum from Genypterus capensis.
C. S. quadricornis from Coelorhynchus braueri. Bars = 10 mm. (A after Grabda, 1991, B and C after
Gayevskaya and Kovalaeva, 1984.)
512
Branchiura
Introduction
Argulids have been recognized as pests of
cultured trout in Europe and carp in China
since the 17th century (Wilson, 1902;
Kabata, 1985). They cause mortalities of
fish in aquaria, fish ponds, lakes and estuaries. Epizootics of Argulus foliaceus in a
Scottish loch twice closed an angling fishery for rainbow trout, apparently destroying
all the trout the first time (Northcott et al.,
1997). A similar infestation was thought to
be the cause of the collapse of a rainbow
trout fishery in a reservoir in Northern
Ireland and prevented the development of a
rainbow trout fishery in the Azores (Menezes
et al., 1990; Gault et al., 2002). Infested carp
and goldfish acquire secondary infections
of fungi and bacteria, which reduce their
commercial value (Shimura, 1983a). Though
less common in the sea, argulids occasionally cause problems in sea-caged salmonids
(Stuart, 1990; Jafri and Ahmed, 1994).
Phylum Arthropoda
513
Systematics
Parasite morphology and life cycle
Branchiura differ from Copepoda in that
they have compound eyes, continue to
moult after maturity, lay eggs singly and
develop without a true naupliar stage. Spermatophores are not normally produced and,
when they are, they contain products from
both testes. Argulids are closely related to
pentastomes (Abele et al., 1989; Martin and
Davis, 2001).
Of the 150 or so species of Branchiura,
about 100 belong to the genus Argulus
(Kabata, 1985). For keys to Branchiura and a
Fig. 14.27. Argulus monodi, adult female. a1 and a2, first and second antennae; c, compound eye;
e, egg; m1 and m2, first and second maxillae; p, proboscis; r, respiratory area; s, stylet; sr, seminal
receptacle. Bar = 1 mm. (After Fryer, 1959.)
514
Phylum Arthropoda
515
Hostparasite relationships
Site and host selection, course of infection
A. foliaceus and A. japonicus attach primarily to the caudal peduncle of carp in culture
ponds (Bazal et al., 1969). Site preference is
less marked for A. foliaceus on Xiphophorus
helleri. At 28C most parasites are on the
flank, caudal fin and pectoral fins; at lower
Fig. 14.28. Argulus coregoni first stage larva. a1 and a2, first and second antennae; m, mandibular palp;
m1 and m2, first and second maxillae; s, first swimming leg. Bar = 0.1 mm. (After Shimura, 1981.)
516
Phylum Arthropoda
517
Fig. 14.29. Argulus sp. lesion on the sciaenid Cynoscion regalis showing thickened epidermis (e) around
the border and erosion down to the stratum compactum of the dermis (from Noga et al., 1991).
518
Concurrent infection
Argulid infections are often concurrent with
saprolegniosis, which becomes the ultimate
cause of death (Bower-Shore, 1940; Allum
and Hugghins, 1959; Stammer, 1959; Rahman,
1996). Argulids have been shown to be
mechanical vectors for the virus that causes
spring viraemia of carp (SVCV) (Ahne,
1985). They may facilitate the entry of bacteria as O. masou exposed to water contaminated with Aeromonas salmonicida had a
higher mortality rate in tanks that also contained small numbers of Argulus coregoni
(10 per fish) than in tanks without the
parasite, though there was little correlation
between the location of furunculosis lesions
and the sites of attachment of the crustacean
(Shimura et al., 1983a).
Argulids are intermediate hosts for
fish-parasitic nematodes belonging to the
Anguillicolidae, Skrjabillanidae and Dracunculoidea (Moravec, 1978; Tikhomirova,
1983; Molnar and Szekely, 1998; Moravec
et al., 1999). They also carry epiphytes
(Van As and Viljoen, 1984; Viljoen and
Van As, 1985; Sutherland and Wittrock,
1986; Poly, 1998), though these are not
apparently infective to the fish. RushtonMellor and Whitfield (1993) report a disease of the carapace in A. foliaceus.
Diagnosis of infection
Argulus spp. can be seen scuttling over the
surface of the fish with the naked eye.
Phylum Arthropoda
519
Isopoda
Introduction
The suborder Cymothoida contains about
500 species that parasitize fish, all in the
superfamily Cymothooidea, in the families
Corallanidae, Aegidae, Cymothoidae and
Gnathiidae (Bunkley Williams and Williams,
1998a; Brandt and Poore, 2003). In this
review we first deal with the Cymothoidae
and then with other Flabellifera (Corallanidae, Aegidae and Cirolanoidea) and
conclude with Gnathiidae.
CYMOTHOIDAE
520
Host range
N. orbignyi occurs on at least ten families
of fishes, including Mugilidae, Sparidae,
Carangidae, Molidae and Holocephalidae.
The parasite is found in the Mediterranean,
in the tropical and southern Atlantic and in
Australasia (Trilles, 1975; Bruce, 1987). It is
the most abundant species of cymothoid on
the north-west shelf of Africa (Rokicki,
1997). Ceratothoa oestroides, a common
parasite in the Mediterranean, is found in
Sparidae, Carangidae, Clupeidae, Maenidae,
Scorpaenidae and Mugilidae. Paired parasites are commonly found in market-sized
bass in sea cages. Of other common species,
Olencira praegustator parasitizes menhaden along the east coast of the USA from
New Jersey to Florida (Kroger and Guthrie,
1972b) and N. acuminata is found in up to
40 species of fishes along the west coast of
the USA (Brusca, 1981).
Host specificity tends to be low in species of Nerocila and high in Mothocya and
Renocila (Bruce, 1990). In temperate waters
Anilocra spp. appear to have low specificity; Anilocra physodes, from the north-east
Atlantic and Mediterranean, is reported
from 25 genera of fishes in 13 families
(Trilles, 1975). In the tropics, not only do
Anilocra spp. show high host specificity
(Williams and Williams, 1981), but the species of host preferred may vary with locality
(Williams et al., 1982). On the Great Barrier
Reef at Heron Island, adult Anilocra
pomacentri parasitize the pomacentrid
Chromis nitida (see Adlard, 1990). At Lizard
Island they are found on two Pomacentrus
Systematics
Trilles (1991) recognized at least 334
species of cymothoids. Identification to
species is difficult because of unclear early
Phylum Arthropoda
521
Fig. 14.30. Cymothoid morphology. A. Mothocya rosea dorsal view. c, cephalon; cx, coxae; p, first
perionite; pt, pleotelson; u, uropod rami. (After Bruce, 1986a.) B. Ceratothoa guttata mouthparts.
a1, a2, first and second antennae; m, mandible; m2, second maxilla; mp, mandibular palp; mt, mouth;
mx, maxilliped; p, first pereopod (leg); pl, pleonite; r, rostrum. (After Bruce and Bowman, 1989.)
522
Phylum Arthropoda
523
524
Phylum Arthropoda
525
Fig. 14.31. Salmo salar buccal area. Ulceration and haemorrhage caused by Ceratothoa gaudichaudii in
Chile (from Sievers et al., 1996).
526
Phylum Arthropoda
527
Concurrent infection
In vitro culture
Eggs removed from brood pouches of
M. parvostis were raised in sea water and
hatched to produce larvae infective to fish
(Hatai and Yasumoto, 1980).
528
OTHER FLABELLIFERA
Phylum Arthropoda
529
530
ISOPODA: GNATHIIDAE
Introduction
Gnathiids are blood-feeding marine isopods
(with five pairs of legs), which have been
reported to cause mortality in captured
eels (Anguilla anguilla), sea-caged mullet
(Crenimugil crenilabis) and sea-caged snapper (Pagrus major) (Paperna and Overstreet,
1981; Mugridge and Stallybrass, 1983;
Patarnello et al., 1995).
Gnathiids infest many species of marine
and estuarine teleosts and elasmobranchs.
In the laboratory, larvae of Paragnathia
formica infect fishes of the families
Ammodytidae, Anguillidae, Gasterosteidae,
Labridae, Cyprinidae, Triglidae, Cottidae,
Gobiidae, Pleuronectidae, Trachinidae and
Callionymidae and even a freshwater
amphibian (Rana temporaria). They do not
attack several invertebrates or humans
(Monod, 1926). Some species of Gnathia
infest only elasmobranchs (Paperna and
Por, 1977; Honma et al., 1991). The group is
believed to have radiated in the cold waters
of the southern hemisphere (Cohen and
Poore, 1994).
The 160 or so species described are
based on the characters of the free-living
adult males. The third-stage larvae from fish
can be kept in vitro in sea water until they
moult into adults, the males of which can
then be identified (Hesse, 1855; Stoll, 1962;
Paperna and Por, 1977; Wagele, 1988, 1990;
Smit and Basson, 2002).
Phylum Arthropoda
531
Fig. 14.35. Diagrammatic life cycle of a gnathiid isopod (after Tanaka, 1998).
Hostparasite relationships
Site and host selection, course of infection
Praniza larvae that attack elasmobranchs
attach mainly to gills and gill septa (Paperna
and Por, 1977; Lester and Sewell, 1989;
Honma and Chiba, 1991) or around the cloaca
532
Parasite nutrition
The praniza is attached by its hooked rostrum, the hooked gnathopods (= pylopod
of Wagele, a modified first pair of legs) and
the hooked and serrated but immobile mandibles. Skin penetration is performed by the
maxillules, which make bursts of rapid tearing movements. A strong muscular oesophagus draws blood into the proventriculus,
apparently aided by salivary glands that
produce anticoagulants. The anterior hind
gut is rapidly filled, aided by the unfolding
of the bellows-like cuticle of the midpereon. Digestion takes place in the two
sac-like digestive glands (Juilfs and Wagele,
1987; Giannetto et al., 2003). Symbiotic bacteria up to 10 m long occur in the rectal
vesicle of G. calva (Juilfs and Wagele, 1987).
Concurrent infection
Foraminiferans, especially Cibicides wuellerstorfi, occur on the dorsal and ventral
surfaces of the head of male Gnathia stygia,
presumably as a result of a poorly groomed
head projecting from the burrow (Svavarsson and Davidsdottir, 1994). Gnathia
maxillaris that fed on blennies infected
with Haemogregarina bigemina developed
gametocytes in the hind gut, suggesting that
they could be a vector for the blood parasite
(Davies et al., 1994). Davies and Smit (2001)
suggested that transmission might be through
ingestion of infected isopods.
Phylum Arthropoda
Cirripedia: Anelasma
Introduction
Lepadid barnacles of the genus Anelasma
parasitize deepwater sharks of the subfamily Etmopterinae worldwide (Yano and
Musick, 2000). The parasites typically attach
to the body behind one of the dorsal spines,
to the dorsal fins or sometimes to other fins,
the claspers or elsewhere on the body. They
usually occur in pairs of similar size side by
side. One species has been described,
Anelasma squalicola (Loven, 1844).
533
Hostparasite relationships
Parasite prevalence peaked on fish (Etmopterus spinax) of 25 to 29 cm and then
decreased. The low prevalence in large fish
plus the absence of evidence of parasite loss
suggested to Hickling (1963) that parasitized fish had a higher mortality rate than
uninfected fish.
The parasite projects from the skin at
an angle. A granuloma develops around its
peduncle to cause an obvious swelling.
Adjacent muscle is replaced by fibrous connective tissue. The epithelium around the
parasite is intact and epithelial tongues
grow down into the cavity. The parasites
roots may extend 10 mm into the muscle;
adjacent to them are degenerating muscle
fibres, an increased number of blood vessels
and fibrous tissue typical of chronic inflammation (Johnstone and Frost, 1927).
Though the livers of infested fish 41 to
44 cm long were 10% lighter than those of
uninfested fish of the same length (Hickling,
1963), the main effect of the parasites
seems to be on the reproductive organs.
Hickling (1963) found that, in mature
female E. spinax, 98% of those parasitized
had inactive ovaries, compared with 42%
in non-parasitized fish. In mature males,
86% had reduced testes, compared with
0.05% in unparasitized fish. Yano and
Musick (2000) reported that the ova of a
534
Fig. 14.37. Anelasma sp. A pair in pockets anterior to the dorsal fin of Etmopterus granulosus from
Tasmania. The mantle has been partly withdrawn to reveal the visceral mass and white egg sacs. In the left
animal, the cirri (arrow) are extended. The mouth is near the base of the cirri close to the surface of the fish.
from classic earlier work on isopods, particularly the French school, including Monod,
Legrand, Trilles and Romestand, have been
vindicated and sometimes extended. However, many questions remain.
One aspect that has become particularly striking is the apparent interaction
between parasitic crustaceans. Males of the
gnathiid isopod G. calva are inhibited from
developing in the presence of another male.
Males of many cymothoids are inhibited
from changing into a female if a female is
present elsewhere on or in the fish. Often
only two isopods persist, a male and a
female. Similarly, the parasitic barnacle,
Anelasma, is usually found in pairs, side by
side. If a pheromone is involved in limiting
these numbers, is it transmitted though the
blood of the host, as suggested by Raibaut
and Trilles (1993), or carried in the water?
There must be a strong mechanism or mechanisms operating to produce these results.
Its elucidation may provide an additional
tool in controlling parasitic disease.
Lernaea cyprinacea has been a problem
in aquaculture for centuries and is likely to
be around for many more years. Details of
its biology that continue to remain clouded
include the host specificity of the copepodid
stage. Is it weak, as suggested by Grabda
(1963), or strong, as suggested by the data
of Haley and Winn (1959)? Wilson (1917)
stated that females were fertilized at the last
copepodid stage, but Grabda (1963) found
no copepodids with spermatophores, only
Phylum Arthropoda
535
Control
In wild fish stocks, the main tool we have
for controlling infection is fishing pressure.
An increase of this will decrease both the
population density and the average age of
the fish and this may be sufficient to eliminate the parasite (Forrester, 1956). In many
cases increasing fishing pressure is not an
option. In other cases, it needs to be applied
selectively, perhaps to a reservoir host or
only to areas where the parasite is abundant.
In aquaculture, there are more opportunities for parasite control. There are also
more opportunities for normally benign
parasites to cause disease. It is likely that
only a rolling combination of methods will
limit the effects of the highly evolved
multicellular organisms that are the parasitic Crustacea. Husbandry methods, such
as quarantine procedures and adjustment of
water flow, are widely employed. However,
information such as the factors that control
the numbers of argulids in natural fish
populations is currently unknown. Multispecies systems, such as wrasse in salmon
farms to control sea lice, may have applicability in the control of parasites such as
argulids and lernaeids.
Chemicals are widely used to control
infections. The rapidity with which lernaeids,
argulids and, to a lesser extent, caligoids
develop resistance to insecticides suggests
that we need to look for alternative ways of
controlling infections, especially as some
536
Acknowledgements
We thank Ms B. Gill for invaluable literature and secretarial assistance.
References
Abdelhalim, A.I., Lewis, J.W. and Boxshall, G.A. (1991) The life-cycle of Ergasilus sieboldi Nordmann
(Copepoda: Poecilostomatoida), parasitic on British freshwater fish. Journal of Natural History 25,
559582.
Abele, L.G., Kim, W. and Felgenhauer, B.E. (1989) Molecular evidence for inclusion of the phylum
Pentastomida in the Crustacea. Molecular Biology and Evolution 6, 685692.
Abrosov, V.N. and Bauer, O.N. (1959) Ergasilosis of the peled whitefish (Coregonus peled) in the Pskov
region. Bulletin of the State Scientific Research Institute of Lake and River Fisheries 49, 222226.
Adlard, R.D. (1990) The effects of the parasitic isopod Anilocra pomacentri Bruce (Cymothoidae) on the
population dynamics of the reef fish Chromis nitida Whitley (Pomacentridae). PhD thesis, University of
Queensland, Australia, 118 pp.
Adlard, R.D. and Lester, R.J.G. (1994) Dynamics of the interaction between the parasitic isopod, Anilocra
pomacentri, and the coral reef fish Chromis nitida. Parasitology 109, 311324.
Adlard, R.D. and Lester, R.J.G. (1995) The life cycle and biology of Anilocra pomacentri (Isopoda:
Cymothidae), an ectoparasitic isopod of the coral reef fish, Chromis nitida (Perciformes: Pomacentridae).
Australian Journal of Zoology 43, 271281.
Ahne, W. (1985) Argulusfoliaceus L. and Piscicola geometra L. as mechanical vectors of spring viraemia of
carp virus (SVCV). Journal of Fish Diseases 8, 241242.
Akhmerov, A.K. (1939) On the ecology of Lironeca amurensis. Annals of Leningrad University 43, 11.
Phylum Arthropoda
537
Alderman, D. (2002) Trends in therapy and prophylaxis. Bulletin of the European Association of Fish
Pathologists 22, 117125.
Al Hammdanne, A.H. and Al Taee, A.F. (1995) Pathological study of experimental infection of the common
carp with fish lice Argulus foliaceus. Iraqi Journal of Veterinary Sciences 8, 109112.
Allison, L.N. and Latta, W.C. (1969) Effects of Gill Lice (Salmincola edwardsii) on Brook Trout (Salvelinus
fontinalis) in Lakes. Research and Development Report 189, Michigan Department of Natural Resources,
Michigan.
Allum, M.A. and Hugghins, E.J. (1959) Epizootics of fish lice, Argulus biramosus, in two lakes of eastern South
Dakota. Journal of Parasitology 45 (2), 3334.
Alston, S., Boxshall, G.A. and Lewis, J.W. (1996) The life-cycle of Ergasilus briani Markewitsch, 1993
(Copepoda: Poecilostomatoida). Systematic Parasitology 35, 79110.
Alvarez, F. and Flores, M. (1997) Cymothoa exigua (Isopods: Cymothoidae) as parasite of Lutjanus peru
(Pisces: Lutjanidae) Manzanillo, Colima, Mexico. Revista de Biologia Tropical 4445, 391394.
Amado, M.A.P.M. and Rocha, C.E.F. (1996) Therodamas tamarae, a new species of copepod
(Poecilostomatoida: Ergasilidae) parasitic on Plagioscion squamosissimus (Heckel) from the Araguaia
River, Brazil; with a key to the species of the genus. Hydrobiologia 325, 7782.
Amado, M.A.P.M. and Rocha, C.E.F. (2001) Useful characters in identifying copepods of the genus Ergasilus
from plankton, with the description of male and female of E. sergipensis n. sp. Hydrobiologia 450,
149157.
Amanieu, M. (1963) Evolution des populations de Paragnathia formica (Hesse) au cours dun cycle annuel.
Bulletin of the Institute of Oceanography, Monaco 60 (261), 112.
Amin, A.M. (1981) On the crustacean ectoparasites of fishes from southeast Wisconsin. Transactions of the
American Microscopical Society 100, 142150.
Anon. (1980) ACT lake fish killed by parasite. Australian Fisheries 39 (6), 13.
Anstensrud, M. (1989) Experimental studies of the reproductive behaviour of the parasitic copepod
Lernaeocera branchialis (Pennellidae). Journal of the Marine Biological Association, UK 69,
465476.
Anstensrud, M. (1990a) Effects of mating on female behaviour and allometric growth in the two parasitic
copepods Lernaeocera branchialis (L., 1767) (Pennellidae) and Lepeophtheirus pectoralis (Muller, 1776)
(Caligidae). Crustaceana 59, 245258.
Anstensrud, M. (1990b) Male reproductive characteristics of two parasitic copepods, Lernaeocera branchialis
(L.) (Pennellidae) and Lepeophtheirus pectoralis (Mueller) (Caligidae). Journal of Crustacean Biology 10,
627638.
Anstensrud, M. (1990c) Mating strategies of two parasitic copepods (Lernaeocera branchialis (L.) (Pennellidae)
and Lepeophtheirus pectoralis (Mueller) (Caligidae)) on flounder: polygamy, sex-specific age at maturity
and sex ratio. Journal of Experimental Marine Biology and Ecology 136, 141158.
Anstensrud, M. (1990d) Moulting and mating in Lepeophtheirus pectoralis (Copepoda: Caligidae). Journal of
the Marine Biological Association, UK 70, 269281.
Anstensrud, M. and Schram, T.A. (1988) Host and site selection by larval stages and adults of the parasitic
copepod Lernaeenicus sprattae (Sowerby) (Copepoda, Pennellidae) in the Oslofjord. Hydrobiologia 167,
587594.
Aristotle (300 BC) De Historia Animalium V, 556 and VIII, 602.
Athanassopoulou, F., Bouboulis, D. and Martinsen, B. (2001) In vitro treatments of deltamethrin against the
isopod parasite Ceratothoa oestroides, a pathogen of sea bass Dicentrarchus labrax. Bulletin of the
European Association of Fish Pathologists 21, 2629.
Atkinson, D. (1995) Effects of temperature on the size of aquatic ectotherms: exceptions to the general rule.
Journal of Thermal Biology 20, 6174.
Avdeev, V.V. (1983) On the formation of zoocecidium in fishes under the influence of parasitic isopods of the
family Cymothoidae. Parazitologiya, Leningrad 17, 420422.
Avdeev, V.V. (1985) Specific features of the distribution of marine isopod crustaceans of the family
Cymothoidae (Isopods, Flabellifera). In: Hargis, W.J. (ed.) Parasitology and Pathology of Marine Organisms of the World Ocean. Technical Report NMFS 25, NOAA, pp. 8992.
Avenant, O.A. (1993) The male reproductive system and mechanisms of sperm transfer in Argulus japonicus
(Crustacea: Branchiura). Journal of Morphology 215, 5163.
Avenant, O.A. (1994) Integumental damage caused by Dolops ranarum (Stuhlmann, 1891) (Crustacea:
Branchiura) to Clarias gariepinus (Burchell), with reference to normal histology and wound-inflicting
structures. Journal of Fish Diseases 17, 641647.
538
Avenant, A. and Van As, J.G. (1986) Observations on the seasonal occurrence of the fish ectoparasite Dolops
ranarum (Stuhlmann, 1891) (Crustacea: Branchiura) in the Transvaal. South African Journal of Wildlife
Research 16, 6264.
Avenant-Oldewage, A. and Van As, J.G. (1990) The digestive system of the fish ectoparasite Dolops ranarum
(Crustacea: Branchiura). Journal of Morphology 204, 103112.
Bailey, R.E., Margolis, L. and Workman, G.D. (1989) Survival of certain naturally acquired freshwater parasites
of juvenile sockeye salmon, Oncorhynchus nerka (Walbaum) in hosts held in fresh and sea water, and
implications for their use as population tags. Canadian Journal of Zoology 67, 17571766.
Barker, D.E. and Cone, D.K. (2000) Occurrence of Ergasilus celestis (Copepoda) and Pseudodactylogryrus
anguillae (Monogenea) among wild eels (Anguilla rostrata) in relation to stream flow, pH and temperature and recommendations for controlling their transmission among captive eels. Aquaculture 187,
261274.
Bastide-Guillaume, C., Douellou, L., Romestand, B. and Trilles, J.P. (1987) Comparative study of two
Lernaeocera parasites of Merluccius merluccius and Trisopterus minutus capelanus from the Lion Gulf
(Sete, France). Morphobiometry, antigenic communities, enzymatic polymorphism. Revue des Traveaux
de lInstitut des Pches Maritimes, Nantes 49, 143154.
Bazal, K., Lucky, Z. and Dyk, V. (1969) Localisation of fish-lice and leeches on carps during the autumn fishing.
Acta Veterinaria (Brno) 38, 533544.
Becheikh, S., Rousset, V., Maamouri, F., Ben Hassine, O.K. and Raibaut, A. (1997) Pathological effects of
Peroderma cylindricum (Copepoda: Pennellidae) on the kidneys of its pilchard host, from Tunisian
coasts. Diseases of Aquatic Organisms 28, 5159.
Becker, J.H. and Grutter, A.S. (2004) Cleaner shrimp do clean. Coral Reefs 23, 515520.
Begg, G.S. and Bruno, D.W. (1999) The common dab as definitive host for the pennellid copepods
Lernaeocera branchialis and Haemobaphes cyclopterina. Journal of Fish Biology 55, 655657.
Bello, G., Vaglio, A. and Piscitelli, G. (1997) The reproductive cycle of Mothocya epimerica (Isopoda:
Cymothoidae), a parasite of the sand smelt, Atherina boyeri (Osteichthyes: Atherinidae), in the Lesina
Lagoon, Italy. Journal of Natural History 331, 10551066.
Bellwood, D.R. (1981) Two new species of Cardiodectes Wilson (Copepoda: Siphonostomatoida). Systematic
Parasitology 2, 149156.
Ben Hassine, O.K., Braun, M. and Raibaut, A. (1983) Etude comparative de linfestation de Mugil cephalus
cephalus Linne, 1758 par le copepode Ergasilus lizae Kroyer, 1863 dans deux lagunes du littoral
Mditerranen franais. Rapports et Procs-Verbeaux des Runions Commission International pour
lExploration Scientifique de la Mer Mditerrane, Monaco 28, 379384.
Ben Hassine, O.K., Raibaut, A., Ben Souissi, J. and Rousset, V. (1990) Morphologie de Peroderma cylindricum
Heller, 1865, copepode parasite de la sardine, Sardina pilchardus (Walbaum, 1792) et quelques aspects
de son cologie dans les eaux ctires tunisiennes. Annales des Sciences Naturelles 11, 916.
Ben Souissi, J. and Ben Hassine, O.K. (1991) Action pathogne de Peroderma cylindricum Heller, 1865
(Copepode parasite) sur la condition et le dveloppement des gonades de Sardina pilchardus (Walbaum,
1792) des ctes tunisiennes. Cahiers de Biologie Marine 32, 234.
Berland, B. (1983) The presence of the isopod Cirolana borealis and the amphipod Tmetonyx cicada in the
roes of cod (Gadus morhua) and saithe (Pollachius virens). Fiskers Gang 6/7, 175179 (abstract).
Berland, B. (1993) Salmon lice on wild salmon (Salmo salar L.) in western Norway. In: Boxshall, G.A. and
Defaye, D. (eds) Pathogens of Wild and Farmed Fish: Sea Lice. Ellis Horwood, New York, pp. 179187.
Berry, C.R., Babey, G.J. and Shrader, T. (1991) Effect of Lernaea cyprinacea (Crustacea: Copepoda) on stocked
rainbow trout (Oncorhynchus mykiss). Journal of Wildlife Diseases 27, 206213.
Bird, P.M. (1981) The occurrence of Cirolana borealis (Isopoda) in the hearts of sharks from Atlantic coastal
waters of Florida. Fishery Bulletin 79, 376382.
Bjordal, A. (1988) Cleaning symbiosis between wrasses (Labridae) and lice infested salmon (Salmo salar) in
mariculture. International Council for the Exploration of the Sea C.M. F:17, 18.
Bjordal, A. (1990) Wrasse as cleaner-fish for farmed salmon. Progress in Underwater Science 16, 1728.
Bjrn, P.A., Finstad, B. and Kristoffersen, R. (2001) Salmon lice infection of wild sea trout in marine and
freshwaters: the effects of salmon farms. Aquaculture Research 32, 947962.
Black, G.A. (1982) Gills as an attachment site for Salmincola edwardsii (Copepoda, Lernaeopodidae). Journal
of Parasitology 68, 11721173.
Black, G.A., Montgomery, W.L. and Whoriskey, F.G. (1983) Abundance and distribution of Salmincola
edwardsii (Copepoda) on anadromous brook trout, Salvelinus fontinalis, (Mitchill) in the Moisie River
system, Quebec. Journal of Fish Biology 22, 567575.
Phylum Arthropoda
539
Bouchet, G.C. (1985) Redescription of Argulus varians Bere, 1936 (Branchiura, Argulidae) including a
description of its early development and first larval stage. Crustaceana 49, 3035.
Bowers, J., Mustafa, A., Speare, D.J., Conboy, G.A., Brimacombe, M., Sims, D.E. and Burka, J.F. (2000)
The physiological response of Atlantic salmon, Salmo salar L., to a single experimental challenge with
sea lice, Lepeophtheirus salmonis. Journal of Fish Diseases 23, 165172.
Bower-Shore, C. (1940) An investigation of the common fish louse, Argulus foliaceus (Linn.). Parasitology 32,
361371.
Bowman, T.E. (1960) Description and notes on the biology of Lironeca puhi, n. sp. (Isopoda: Cymothoidae),
parasite of the Hawaiian moray eel, Gymnothorax eurostus (Abbott). Crustaceana 1, 8391.
Bowman, T.E. and Mariscal, R.N. (1968) Renocila heterozota, a new cymothoid isopod, with notes on its host,
the anemone fish, Amphiprion akallopisos, in the Seychelles. Crustaceana 14, 97104.
Boxshall, G.A. (1974a) The population dynamics of Lepeophtheirus pectoralis (Muller): seasonal variation in
abundance and age structure. Parasitology 69, 361371.
Boxshall, G.A. (1974b) Infections with parasitic copepods in North Sea marine fishes. Journal of the Marine
Biological Association, UK 54, 355372.
Boxshall, G.A. (1976) The host specificity of Lepeophtheirus pectoralis (Muller, 1776) (Copepoda: Caligidae).
Journal of Fish Biology 8, 255264.
Boxshall, G.A. (1977) The histopathology of infection by Lepeophtheirus pectoralis (Muller) (Copepoda:
Caligidae). Journal of Fish Biology 10, 411415.
Boxshall, G.A. (1990) The skeletomusculature of siphonostomatoid copepods, with an analysis of adaptive
radiation in structure of the oral cone. Philosophical Transactions of the Royal Society of London B 328,
167212.
Boxshall, G.A. (1998) Host specificity in copepod parasites of deep-sea fishes. Journal of Marine Systems 15,
215223.
Boxshall, G.A. (2000) Parasitic copepods (Copepoda: Siphonostomatoida) from deep-sea and mid-water
fishes. Systematic Parasitology 47, 173181.
Boxshall, G.A. (2004) An Introduction to Copepod Diversity. The Ray Society, Andover, UK, 966 pp.
Boxshall, G.A., Montu, M.A. and Schwarzbold, A. (1997) A new species of Lernaea L. (Copepoda:
Cyclopoida) from Brazil, with notes on its ontogeny. Systematic Parasitology 37, 195205.
Bragoni, G., Romestand, B. and Trilles, J.-P. (1983) Parasitism by cymothoids among sea-bass (Dicentrarchus
labrax Linnaeus) in rearing. II. Parasitic ecophysiology in Diana Pond, Corsica. Annales de Parasitologie
Humaine et Compare 58, 593609.
Bragoni, G., Romestand, B. and Trilles, J.-P. (1984) Parasitoses cymothoadien chez le loup, Dicentrarchus
labrax (Linnaeus, 1758) en levage. I. Ecologie parasitaire dans le cas de lEtang de Diana (Haute Corse)
(Isopoda, Cymothoidae). Crustaceana 47, 4451.
Brandal, P.O. and Egidius, E. (1977) Preliminary report on oral treatment against sea lice, Lepeophtheirus
salmonis with Neguvon. Aquaculture 10, 177178.
Brandal, P.O., Egidius, E. and Romslo, I. (1976) Host blood: a major food component for the parasitic
copepod Lepeophtheirus salmonis Kroyeri, 1838 (Crustacea: Caligidae). Norwegian Journal of Zoology
24, 341343.
Brandt, A. and Poore, G.C.B. (2003) Higher classification of the flabelliferan and related Isopoda based on a
reappraisal of relationships. Invertebrate Systematics 17, 893923.
Branson, E., Rnsberg, S. and Ritchie, G. (2000) Efficacy of teflubenzuron (Calicide) for the treatment of sea
lice, Lepeophtheirus salmonis (Kryer 1838), infestations of farmed Atlantic salmon (Salmo salar L.).
Aquaculture Research 31, 861867.
Brattey, J. (1997) Biological characteristics of Atlantic cod (Gadus morhua) from three inshore areas of northeastern Newfoundland. Northwest Atlantic Fisheries Organisation Scientific Council Studies 29, 3142.
Bravo, S. (2003) Sea lice in Chilean salmon farms. Bulletin of the European Association of Fish Pathologists 23,
197200.
Brickle, P., Buxton, N.G. and Villalon, E. (2003) Infection of Sphyrion laevigatum (Copepoda: Sphyriidae) on
Genypterus blacodes (Pisces: Ophidiidae) from the Falkland Islands, South Atlantic. Journal of Parasitology
89, 242244.
Bristow, G.A. and Berland, B. (1988) Haemobaphes cyclopterina (Fabricius, 1780) (Copepoda: Lernaeoceridae):
a new host record, Glyptocephalus cynoglossus (L.) with notes on the ecology of host and parasite. Sarsia
73, 287290.
Bron, J.E. and Treasurer, J.W. (1992) Sea lice (Caligidae) on wrasse (Labridae) from selected British wild and
salmon-farm sources. Journal of the Marine Biological Association, UK 72, 645650.
540
Bron, J.E., Sommerville, C., Jones, M. and Rae, G.H. (1991) The settlement and attachment of early stages
of the salmon louse, Lepeophtheirus salmonis (Copepoda: Caligidae) on the salmon host, Salmo salar.
Journal of Zoology 224, 201212.
Bron, J.E., Sommerville, C. and Rae, G.H. (1993) Aspects of the behaviour of copepodid larvae of the salmon
louse Lepeophtheirus salmonis (Kroyer, 1837). In: Boxshall, G.A. and Defaye, D. (eds) Pathogens of Wild
and Farmed Fish: Sea Lice. Ellis Horwood, New York, pp. 125142.
Bruce, N.L. (1983) Aegidae (Isopods: Crustacea) from Australia with descriptions of three new species. Journal
of Natural History 17, 757788.
Bruce, N.L. (1986a) Revision of the isopod crustacean genus Mothocya Costa, in Hope, 1851 (Cymothoidae:
Flabellifera), parasitic on marine fishes. Journal of Natural History 20, 10891192.
Bruce, N.L. (1986b) Australian Pleopodias Richardson, 1910, and Anilocra Leach, 1818 (Isopods:
Cymothoidae), crustacean parasites of marine fishes. Records of the Australian Museum 39, 85130.
Bruce, N.L. (1987) Australian species of Nerocila Leach, 1818, and Creniola n. gen. (Isopods: Cyrnothoidae),
crustacean parasites of marine fishes. Records of the Australian Museum 39, 355412.
Bruce, N.L. (1990) The genera Catoessa, Elthusa, Enispa, Ichthyoxenus, Idusa, Liloneca and Norileca n. gen.
(Isopods, Cymothoidae), crustacean parasites of marine fishes, with descriptions of eastern Australian
species. Records of the Australian Museum 42, 247300.
Bruce, N.L. and Bowman, T.E. (1989) Species of the parasitic isopod genera Ceratothoa and Glossobius
(Crustacea: Cymothoidae) from the mouths of flying fishes and halfbeaks (Beloniformes). Smithsonian
Contributions to Zoology 489, 128.
Bruno, D.W. and Stone, J. (1990) The role of saithe Pollachius virens as a host for Lepeophtheirus salmonis and
Caligus elongatus. Aquaculture 89, 201208.
Brusca, R.C. (1978a) Studies on the cymothoid fish symbionts of the eastern Pacific (Crustacea: Isopoda:
Cymothoidae). II. Biology and systematics of Lironeca vulgaris. Occasional Papers of the Allan Hancock
Foundation 2, 119.
Brusca, R.C. (1978b) Studies on the cymothoid fish symbionts of the Eastern Pacific (Isopoda, Cymothoidae) I.
Biology of Nerocila californica. Crustaceana 34, 141154.
Brusca, R.C. (1981) A monograph on the Isopoda Cymothoidae (Crustacea) of the eastern Pacific. Zoological
Journal of the Linnean Society 73, 117199.
Brusca, R.C. and Gilligan, M.R. (1983) Tongue replacement in a marine fish (Lutjanus guttatus) by a parasitic
isopod (Crustacea: Isopoda). Copeia 1983, 813815.
Brusca, R.C. and Iverson, E.W. (1985) A guide to the marine isopod Crustacea of Pacific Costa Rica. Revista de
Biologia Tropical 33 (suppl. 1), 177.
Bullar, J.F. (1876) The generative organs of the parasitic Isopoda. Journal of Anatomy and Physiology 11,
118123.
Bulow, F.J., Winningham, J.R. and Hooper, R.C. (1979) Occurrence of the copepod parasite Lernaea
cyprinacea in a stream fish population. Transactions of the American Fisheries Society 108, 100102.
Bunkley Williams, L. and Williams, E.H.J. (1998a) Isopods associated with fishes: a synopsis and corrections.
Journal of Parasitology 84, 893896.
Bunkley Williams, L. and Williams, E.H.J. (1998b) Ability of Pederson cleaner shrimp to remove juveniles of
the parasitic cymothoid isopod, Anilocra haemuli, from the host. Crustaceana 71, 862869.
Burrells, C., Williams, P.D. and Forno, P.F. (2001) Dietary nucleotides: a novel supplement in fish feeds.
1. Effects on resistance to disease in salmonids. Aquaculture 199, 159169.
Burridge, L.E., Hamilton, N., Waddy, S.L., Haya, K., Mercer, S.M., Greenhalgh, R., Tauber, R., Radecki, S.V.,
Crouch, L.S., Wislocki, P.G. and Endris, R.G. (2004) Acute toxicity of emamectin benzoate (SLICE) in
fish feed to American lobster, Homarus americanus. Aquaculture Research 35, 713722.
Buttner, J.K. and Hamilton, W. (1976) Ergasilus (Copepoda: Cyclopoida) infestation of coho and chinook
salmon in Lake Michigan. Transactions of the American Fisheries Society 105, 491493.
Byrnes, T. and Rohde, K. (1992) Geographical distribution and host specificity of ectoparasites of Australian
bream, Acanthopagrus spp. (Sparidae). Folia Parasitologica 39, 249264.
Cabral, P. (1983) Morphologie, biologie et cologie des copepodes parasites du loup Dicentrarchus labrax
(Linne, 1758) et du sar raye Diplodus sargus (Linne, 1758) de la region Languedocienne. PhD thesis,
Universit des Sciences et Techniques du Languedoc, Montpellier, France.
Caillet, C. and Raibaut, A. (1979) Observations exprimentales sur la sexualit du copepode caligoide
Clavellodes macrotrachelus (Brian, 1906), parasite branchial du sar Diplodus sargus (Linne, 1758).
Compte Rendu de lAcadmie des Sciences, Paris Ser. D 288, 223226.
Capart, A. (1948) Le Lernaeocera branchialis. Cellule 52, 159212.
Phylum Arthropoda
541
Chandran, A. and Nair, N.B. (1988) Functional morphology of the mouth tube of a lernaeopodid Pseudocharopinus narcinae (Pillai, 1962) (Copepoda: Siphonostomatoida). Hydrobiologia 167/168, 629634.
Charfi-Cheikhrouha, F., Zghidi, W., Ould Yarba, L. and Trilles, J.P. (2000) Les Cymothoidae (isopodes parasites de poissons) des ctes tunisiennes: cologie et indices parasitologiques. Systematic Parasitology 46,
143150.
Chinabut, S. (2002) A case study of isopod infestation in tilapia cage culture in Thailand. FAO Fisheries
Technical Paper 406, 201202.
Cloutman, D.G. and Becker, D.A. (1977) Some ecological aspects of Ergasilus centrarchidarum Wright
(Crustacea: Copepoda) on largemouth and spotted bass in Lake Fort Smith, Arkansas. Journal of Parasitology 63, 372376.
Cohen, B.F. and Poore, G.C.B. (1994) Phylogeny and biogeography of the Gnathiidae (Crustacea: Isopoda)
with descriptions of new genera and species, most from south-eastern Australia. Memoirs of the Museum
of Victoria 54, 271397.
Colorni, A., Trilles, J.P. and Golani, D. (1997) Livoneca sp. (Flabellifera: Cymothoidae), an isopod parasite in
the oral and branchial cavities of the Red Sea silverside Atherinomorus lacunosus (Perciformes,
Atherinidae). Diseases of Aquatic Organisms 31, 6571.
Conley, D.C. and Curtis, M.A. (1993) Effects of temperature and photoperiod on the duration of hatching,
swimming and copepodid survival of the parasitic copepod Salmincola edwardsii. Canadian Journal of
Zoology 71, 972976.
Conley, D.C. and Curtis, M.A. (1994) Larval development of the parasitic copepod Salmincola edwardsii on
brook trout (Salvelinus fontinalis). Canadian Journal of Zoology 72, 154159.
Conroy, G. and Conroy, D.A. (1986) The salinity tolerance of Ergasilus lizae from silver mullet (Mugil curema
Val., 1836). Bulletin of the European Association of Fish Pathologists 6, 108109.
Costello, M.J. (1993) Review of methods to control sea lice (Caligidae: Crustacea) infestation on salmon
(Salmo salar) farms. In: Boxshall, D.A. and Defaye, D. (eds) Pathogens of Wild and Farmed Fish: Sea Lice.
Ellis Horwood, New York, pp. 219252.
Costello, M. and Bjordal, A. (1990) Wrasse. How good is this natural control on sea-lice? Fish Farmer
May/June, 4446.
Costello, M. and Boxshall, B. (2000) Editorial. Aquaculture Research 31, 793794.
Cressey, R.F. (1978) Marine flora and fauna of the northeastern United States. Crustacea: Branchiura. NOAA
Technical Report NMFS Circular 414, 110.
Das, P., Kumar, D., Ghosh, A.K., Chakraborty, D.P. and Bhaumik, U. (1980) High yield of Indian major carps
against encountered hazards in a demonstration pond. Journal of the Inland Fisheries Society of India
12, 7078.
Daskalov, C. and Georgiev, L. (2001) Research on diagnosis, therapy and prophylaxis of lerneosis on carp.
Zhivotnov dni Nauki 38, 5052.
Daskalov, H., Stoikov, D. and Grozeva, N. (1999) A preliminary hygienic view in case of lernaeosis in the
common carp (Cyprinus carpio L.) based on clinical and pathomorphological observations. Bulgarian
Journal of Veterinary Medicine 2, 5964.
Davies, A.J. (1981) A scanning electron microscope study of the praniza larva of Gnathia maxillaris Montagu
(Crustacea, Isopoda, Gnathiidae), with special reference to the mouthparts. Journal of Natural History
15, 545554.
Davies, A.J. and Smit, N.J. (2001) The life cycle of Haemogregarina bigemina (Adeleina: Haemogregarinidae)
in South African hosts. Folia Parasitologica 48, 169177.
Davies, A.J., Eiras, J.C. and Austin, R.T.E. (1994) Investigations into the transmission of Haemogregarina
bigemina Laveran and Mesnil, 1901 (Apicomplexa: Adeleorina) between intertidal fishes in Portugal.
Journal of Fish Diseases 17, 283289.
Davies, I. and Rodger, G. (2000) A review of the use of ivermectin as a treatment for sea lice [Lepeophtheirus
salmonis (Kryer) and Caligus elongatus Nordmann] infestation in farmed Atlantic salmon (Salmo salar
L.). Aquaculture Research 31, 869883.
Delaney, P.M. (1989) Phylogeny and biogeography of the marine isopod family Corallanidae (Crustacea,
Isopoda, Flabellifera). Contributions in Science, Natural History Museum of Los Angeles County 409, 1.
Delaney, P.M. and Brusca, R.C. (1985) Two new species of Tridentella Richardson, 1905 (Isopoda:
Flabellifera: Tridentellidae) from California, with a rediagnosis and comments on the family, and a key to
the genera of Tridentellidae and Corallanidae. Journal of Crustacean Biology 5, 728742.
Dempster, R.P., Morales, P. and Glennon, F.X. (1988) Use of sodium chlorite to combat anchor worm
infestation of fish. Progressive Fish-Culturalist 50, 5155.
542
Dezfuli, B.S., Giari, L., Konecny, R., Jaeger, P. and Manera, M. (2003) Immunohistochemistry, ultrastructure
and pathology of gills of Abramis brama from Lake Mondsee, Austria, infected with Ergasilus sieboldi
(Copepoda). Diseases of Aquatic Organisms 53, 257262.
Dixon, B., Shinn, A. and Sommerville, C. (2004) Genetic characterisation of populations of the ectoparasitic
caligid, Lepeophtheirus salmonis (Kryer, 1837) using randomly amplified polymorphic DNA (RAPDs).
Aquaculture Research 35, 730741.
Do, T.T. (1982) Paraergasilus longidigitus Yin, 1954 (Copepoda, Poecilostomatoida) parasitic on Japanese
freshwater fishes, with a key to Japanese Ergasilidae. Fish Pathology 17, 139145.
Dogiel, V.A., Petrushevski, G.K. and Polyanski, Y.I. (eds) (1961) Parasitology of Fishes. Oliver and Boyd, Edinburgh, UK.
Donoghue, S. (1986) Thersitina gasterostei (Pagenstecher, 1861) (Copepoda: Ergasilidae) infecting the stickleback Pungitius pungitius L. at Chalk Marshes, Gravesend, Kent. Annales de Parasitologie Humaine et
Compare 61, 673682.
Donoghue, S. (1989) Histopathology of ten-spined stickleback, Pungitius pungitius L., infected by the parasitic copepod Thersitina gasterostei (Pagenstecher) with observations on the contents of the parasite gut.
Bulletin of the European Association of Fish Pathologists 9, 1921.
Dral, A.J., Bruins, E.B.A.W., Sondervan, P.J., Borg, R., Platvoet, D., Kouwenberg, J. and De Heus, D.J.
(2001) An infestation of Cirolana parva in the Aertis Aquarium, and its control. Bulletin de lInstitut
Oceanographique Monaco HS 20, 239243.
Dugatkin, L.A., Fitzgerald, G.L. and Lavoie, J. (1994) Juvenile three-spined sticklebacks avoid parasitized
conspecifics. Environmental Biology of Fishes 39, 215218.
Duston, J. and Cusack, R.R. (2002) Emamectin benzoate: an effective in-feed treatment against the gill parasite
Salmincola edwardsii on brook trout. Aquaculture 207, 19.
Egidius, E. (1985) Salmon lice, Lepeophtheirus salmonis. Journal of Animal Morphology and Physiology
26, 14.
Einszporn, T. (1964) Observations on the kind of food taken up by Ergasilus sieboldi Nordmann. Wiadomosci
Parazytologiczne 10, 527529.
Einszporn, T. (1965a) Nutrition of Ergasilus sieboldi Nordmann. I. Histological structure of the alimentary
canal. Acta Parasitologica Polonica 13, 7180.
Einszporn, T. (1965b) Nutrition of Ergasilus sieboldi Nordmann, II. The uptake of food and the food material.
Acta Parasitologica Polonica 13, 373380.
Einszporn-Orecka, T. (1973a) Changes in the picture of peripheral blood of tench Tinca tinca (L.) under the
influence of Ergasilus sieboldi Nordm. I. Composition of morphotic blood constituents of uninfected fish
in annual cycle. Acta Parasitologica Polonica 21, 29.
Einszporn-Orecka, T. (1973b) Changes in the picture of peripheral blood of tench Tinca tinca (L.) under the
influence of Ergasilus sieboldi Nordm. II. Changes in the leucocyte system. Acta Parasitologica Polonica
21, 38.
El Gharbi, S., Rousset, V. and Raibaut, A. (1985) Biology of Lernaeenicus sprattae (Sowerby, 1806) and
its pathogenic effects on pilchard populations from the coasts of Languedoc-Roussillon (French
Mediterranean). Revue des Traveaux de lInstitut Pches Maritimes, Nantes 47, 191201.
Ellis, A.E., Masson, N. and Munro, A.L.S. (1990) A comparison of proteases extracted from Caligus elongatus
(Nordmann, 1832) and Lepeophtheirus salmonis (Kroyer, 1838). Journal of Fish Diseases 13, 163165.
El Rashidy, H.H. and Boxshall, G.A. (2001) Biogeography and phylogeny of Dermoergasilus Ho and Do, 1982
(Copepoda: Ergasilidae), with descriptions of three new species. Systematic Parasitology 49, 89112.
Evans, N.A., Whitfield, P.J., Bamber, R.N. and Espin, P.M. (1983) Lernaeocera lusci (Copepoda: Pennellidae)
on bib (Trisopterus luscus) from Southampton Water. Parasitology 86, 161173.
Faisal, M., Easa, M.S., Shalaby, S.I. and Ibrahim, M.M. (1988) Epizootics of Lernaea cyprinacea (Copepoda:
Lernaeidae) in imported cyprinids to Egypt. Tropenlandwirt 89, 131141.
Faisal, M., Perkins, P.S. and Cooper, E.L. (1990) Infestation by the pennellid copepod Phrixocephalus
cincinnatus modulates cell mediated immune responses in the Pacific arrowtooth flounder, Atheresthes
stomias. In: Perkins, F.O. and Cheng, T.C. (eds) Pathology in Marine Science. Academic Press, London,
pp. 471478.
Fallang, A., Ramsay, J.M., Sevatdal, S., Burka, J.F., Jewess, P., Hamell, K.L. and Horsberg, T.E. (2004) Evidence
for occurrence of an organophosphate-resistant type of acetylcholinesterase in strains of sea lice
(Lepeophtheirus salmonis Kroyer). Pest Management Science 60 (12), 11631170.
Fast, M.D., Burka, J.F., Johnson, S.C. and Ross, N.W. (2003) Enzymes released from Lepeophtheirus salmonis
in response to mucus from different salmonids. Journal of Parasitology 89, 713.
Phylum Arthropoda
543
Fast, M.D., Ross, N.W., Craft, C.A., Locke, S.J., MacKinnon, S.L. and Johnson, S.C. (2004) Lepeophtheirus
salmonis: characterisation of prostaglandin E2 in secretory products of the salmon louse by RP-HPLC
and mass spectrometry. Experimental Parasitology 107, 513.
Forrester, C.R. (1956) The relation of stock density to milkiness of lemon sole in Union Bay, B.C. Journal of
the Fisheries Research Board of Canada 105, 11.
Fraile, L. (1986) Experimental demonstration of an attraction of the copepodus and adult stages of the
parasite Caligus minimus (Copepoda: Caligidae) for the bass Dicentrarchus labrax (Teleostei,
Serranidae). European Aquaculture Society, Special Publication 9, 185 (abstract).
Frerichs, G.N., Millar, S.D. and McManus, C. (1992) Atypical Aeromonas salmonicida isolated from healthy
wrasse (Ctenolabrus rupestris). Bulletin of the European Association of Fish Pathologists 12, 4849.
Friend, G.F. (1941) The life-history and ecology of the salmon gill-maggott Salmincola salmonea (L.) (copepod
crustacean). Transactions of the Royal Society of Edinburgh 60, 503541.
Frost, W.E. (1928) The nauplius larva of Anelasma squalicola (Loven). Journal of the Marine Biological
Association, UK 15, 125128.
Fryer, G. (1956) A report on the parasitic Copepoda and Branchiura of the fishes of Lake Nyasa. Proceedings
of the Zoological Society of London 127, 293344.
Fryer, G. (1959) A report on the parasitic Copepoda and Branchiura of the fishes of Lake Banguelu (Northern
Rhodesia). Proceedings of the Zoological Society of London 132, 517550.
Fryer, G. (1960) The spermatophores of Dolops ranarum (Crustacea, Branchiura): their structure, formation
and transfer. Quarterly Journal of Microscopical Science 101 (4), 407432.
Fryer, G. (1961) Variation and systematic problems in a group of lernaeid copepods. Crustaceana 2, 275285.
Fryer, G. (1964) Further studies on the parasitic Crustacea of African freshwater fishes. Proceedings of the Zoological Society of London 143, 79102.
Fryer, G. (1966) Habitat selection and gregarious behaviour in parasitic crustaceans. Crustaceana 10,
199209.
Fryer, G. (1968a) A new parasitic isopod of the family Cymothoidae from clupeid fishes of Lake Tanganyika
a further Lake Tanganyika enigma. Journal of Zoology 156, 3543.
Fryer, G. (1968b) The parasitic Crustacea of African freshwater fishes; their biology and distribution. Journal of
Zoology 156, 4595.
Fryer, G. (1981) The copepod Salmincola edwardsii as a parasite of Salvelinus alpinus in Britain, and a
consideration of the so-called relict fauna of Ennerdale Water. Journal of Zoology, London 193,
253268.
Fryer, G. (1982) The Parasitic Copepoda and Branchiura of British Freshwater Fishes. Freshwater Biological
Association, Ambleside, UK.
Fujita, S., Yoda, M. and Ugajin, I. (1968) Control of an ectoparasitic copepod, Caligus spinosus Yamaguti, on
the cultured adult yellowtail. Fish Pathology 2, 122127.
Gall, G.A.E., McClendon, E.L. and Schafer, W.E. (1972) Evidence on the influence of the copepod (Salmincola
californiensis) on the reproductive performance of a domesticated strain of rainbow trout (Salmo
gairdneri). Transactions of the American Fisheries Society 101, 345346.
Gault, N.F.S., Kilpatrick, D.J. and Stewart, M.T. (2002) Biological control of the fish louse in a rainbow trout
fishery. Journal of Fish Biology 60, 226237.
Gayerskaya, A.V. and Kovaleva, A.A. (1984) Crustacea of the genus Sphyrion (Copepoda, Sphyriidae) in
Atlantic fishes. Hydrobiological Journal 20, 4146.
Ghittino, C. (1987) Positive control of buccal lernaeosis in eel farming. Revista Italiana di Piscicoltura e
Ittiopatologia 22, 2629.
Giannetto, S., Marino, F., Paradiso, M.L., Macri, D., Bottari, T. and De Vico, G. (2003) Light and scanning
electron microscopy observations on Gnathia vorax (Isopoda: Gnathiidae) larvae. Journal of Submicroscopy, Cytology and Pathology 35, 161165.
Glover, K.A., Hamre, L.A., Skaala, O. and Nilsen, F. (2004) A comparison of sea louse (Lepeophtheirus
salmonis) infection levels in farmed and wild Atlantic salmon (Salmo salar L.) stocks. Aquaculture 232,
4152.
Gnanamuthu, C.P. (1950) Sex differences in the chalimus and adult forms of Caligus polycanthi, sp. nov.
(Crustacea, Copepoda) parasitic on Balistes maculatus from Madras. Zoological Survey Records of India
47, 159170.
Goater, T.M. and Jepps, S.F. (2002) Prevalence and intensity of Haemobaphes diceraus (Copepoda:
Pennellidae) from shiner perch, Cymatogaster aggregata (Embiotocidae). Journal of Parasitology 88,
194197.
544
Gonzlez, L. and Carvajal, J. (2003) Life cycle of Caligus rogercresseyi (Copepoda, Caligidae) parasite of
Chilean reared salmonids. Aquaculture 220, 101117.
Gonzlez, L., Carvajal, J. and Medina, A. (1997) Comparative susceptibility of rainbow trout and coho salmon
to ectoparasites of economic importance. Archivos de Medicina Veterinaria 29, 127132.
Gonzalez, R.A. and Tanzola, R.D. (2000) On the presence of Sarcotaces verrucosus (Copepoda) in the Southwest Atlantic. Acta Parasitologica 45, 345349.
Goodwin, A.E. (1999) Massive Lernaea cyprinacea infestations damaging the gills of channel catfish
polycultured with bighead carp. Journal of Aquatic Animal Health 11, 406408.
Grabda, J. (1963) Life cycle and morphogenesis of Lernaea cyprinacea L. Acta Parasitologica Polonica 11,
169199.
Grabda, J. (1972) Observations on penetration of Lernaeolophus sultanus (Milne Edwards, 1840) (Lernaeoceridae) in organs of Pneumatophorus colias (Gmelin, 1788). Acta Ichthyologica et Piscatoria I9,
115125.
Grabda, J. (1975) Observations on the localization and pathogenicity of Haemobaphes diveraus Wilson,
1917 (Copepoda: Lernaeoceridae) in the gills of Theragra chalcogramma (Pallas). Acta Ichthyologica et
Piscatoria 5, 1323.
Grabda, J. (1991) Marine Fish Parasitology. VCH, New York.
Grant, A.N. and Treasurer, J.W. (1993) The effects of fallowing on caligid infestation on farmed salmon (Salmo
salar L.) in Scotland. In: Boxshall, G.A. and Defaye, D. (eds) Pathogens of Wild and Farmed Fish: Sea
Lice. Ellis Horwood, New York, pp. 255260.
Grayson, T.H., Jenkins, P.G., Wrathmell, A.B. and Harris, J.E. (1991) Serum responses to the salmon louse,
Lepeophtheirus salmonis (Kroyer, 1838), in naturally infected salmonids and immunised rainbow trout,
Oncorhynchus mykiss (Walbaum), and rabbits. Fish and Shellfish Immunology 1, 141155.
Grayson, T.H., John, R., Wadsworth, S., Greaves, K., Cox, D., Roper, J., Wrathmell, A.B., Gilpin, M.L. and
Harris, J.E. (1995) Immunisation of Atlantic salmon against the salmon louse: identification of antigens
and effects on louse fecundity. Journal of Fish Biology 47, Suppl. A, 8594.
Gresty, K.A., Boxshall, G.A. and Nagasawa, K. (1993) Antennulary sensors of the infective copepodid larva of
the salmon louse, Lepeophtheirus salmonis (Copepoda: Caligidae). In: Boxshall, G.A. and Defaye, D.
(eds) Pathogens of Wild and Farmed Fish: Sea Lice. Ellis Horwood, New York, pp. 8398.
Grutter, A.S. (1999) Cleaner fish really do clean. Nature 398, 672673.
Grutter, A.S. (2000) Ontogenetic variation in the diet of the cleaner fish Labroides dimidiatus and its ecological
consequences. Marine Ecology Progress Series 197, 241246.
Grutter, A.S. (2001) Parasitic infection rather than tactile stimulation is the proximate cause of cleaning
behaviour in reef fish. Proceedings on the Royal Society of London Series B Biological Sciences 268,
13611365.
Grutter, A.S., Lester, R.J.G. and Greenwood, J. (2000) Emergence rates from the benthos of the parasitic
juveniles of gnathiid isopods. Marine Ecology Progress Series 22, 123127.
Guillaume, C., Doueellou, L., Romestand, B. and Trilles, J.P. (1985) Influence of a haematophagenous
parasite: Lernaeocera branchialis (L., 1767) (Crustacea, Copepoda, Pennellidae), on some erythrocytic
constants of the host fish: Merluccius merluccius. Revue des Traveaux de lInstitut des Pches Maritimes,
Nantes 47, 5561.
Gurney, R. (1948) The British species of fish-louse of the genus Argulus. Proceedings of the Zoological Society
of London 118 (3), 553558.
Guthrie, J.F. and Kroger, R.L. (1974) Schooling habits of injured and parasitized menhaden. Ecology 55, 208210.
Hakalahti, T. and Valtonen, E.T. (2003) Population structure and recruitment of the ectoparasite Argulus
coregoni Thorell (Crustacea: Branchiura) on a fish farm. Parasitology 127, 7985.
Hakalahti, T., Lankinen, Y. and Valtonen, E.T. (2004) Efficacy of emamectin benzoate in the control of
Argulus coregoni (Crustacea: Branchiura) on rainbow trout Oncorhynchus mykiss. Diseases of Aquatic
Organisms 60, 197204.
Hale, H.M. (1929) The Crustaceans of South Australia. Government of South Australia, Adelaide, Australia.
Haley, A.J. and Winn, H.E. (1959) Observations on a lernaean parasite of freshwater fishes. Transactions of
the American Fisheries Society 88, 128129.
Halisch, W. (1940) Anatomie und Biologie von Ergasilus minor. Zeitschrift fr Parasitenkunde 11,
284330.
Hamann, M.I. (1997) Ecological relationships between juveniles of Braga fluviatilis Richardson, 1911
(Crustacea, Cymothidea) and the host Serrasalmus spilopleura Kner, 1860 (Pisces, Characidae) in natural
populations of northeastern Argentina. Physis Section A los Oceanos sus Organismos 55, 1522.
Phylum Arthropoda
545
Harada, I. (1930) Studies on freshwater fauna of Formosa (1). A new species parasitic on Formosan freshwater
fishes. Journal of the Society of Tropical Aquaculture 2, 7176.
Hargis, W.J. (1958) Parasites and fishery problems. Proceedings of the Gulf and Caribbean Fishery Institute
1958, 5075.
Hastein, T. and Bergsjo, T. (1976) The salmon lice Lepeophtheirus salmonis as the cause of disease in farmed
salmonids. Revista Italiana Piscicoltura e Ittiopatologia 11, 35.
Hatai, K. and Yasumoto, S. (1980) A parasitic isopod, Irona melanosticta isolated from the gill chamber of
fingerlings of cultured yellowtail, Seriola quinqueradiata. Bulletin of Nagasaki Prefectural Institute of
Fisheries 6, 8796.
Hatai, K. and Yasumoto, S. (1981) Some notes on the ironasis of cultured young yellowtail, Seriola
quinqueradiata. Bulletin of Nagasaki Prefectural Institute of Fisheries 7, 7781.
Hatai, K. and Yasumoto, S. (1982a) Effects of Irona melanosticta on the growth of young rudderfish Girella
punctata. Bulletin of Nagasaki Prefectural Institute of Fisheries 8, 7579.
Hatai, K. and Yasumoto, S. (1982b) The effects of methyl isoxathion in eliminating the parasitic isopod Irona
melanosticta. Aquaculture, Japan 30, 147150.
Hattori, J. and Seki, M. (1956) An isopod, Irona melanosticta parasitic on Hemirhamphus sajori (T. and S.)
and its influence on the hosts. Dobutsugaku Zasshi 65, 422425.
Hayden, K.J. and Rogers, W.A. (1998). Neoergasilus japonicus (Poecilostomatoida: Ergasilidae), a parasitic
copepod new to North America. Journal of Parasitology 84, 8893.
Heegaard, P. (1947a) Discussion of the genus Sarcotaces (Copepoda) with a description of the first known
male of the genus. Kungliga Fysiografiska Sallskapets i Lund Forhandlingar 17, 122129.
Heegaard, P. (1947b) Contributions to the phylogeny of the arthropods: Copepoda. Spolia Zoologica Musei
Hauniensis 8, 1236.
Hesse, E. (1855) Sur les noms dAnce et de Pranize donns des Crustaces considrs comme des espces
distinctes, et ntant relement que des individus dune mme espce diffrents ges. Comptes Rendus
de lAcademie des Sciences, Paris 41.
Heuch, P.A. and Schram, T.A. (1996) Male mate choice in a natural population of the parasitic copepod
Lernaeocera branchialis (Copepoda: Pennellidae). Behaviour 133, 221239.
Heuch, P.A., Parsons, A. and Boxaspen, K. (1995) Diel vertical migration: a possible host-finding mechanism
in salmon louse (Lepeophtheirus salmonis) copepodids? Canadian Journal of Fisheries and Aquatic Sciences 52, 681689.
Heuch, P.A., Revie, C. and Gettinby, G. (2003) A comparison of epidemiological patterns of salmon lice,
Lepeophtheirus salmonis, infections on farmed Atlantic salmon, Salmo salar L., in Norway and Scotland.
Journal of Fish Diseases 26, 539551.
Heupel, M.R. and Bennett, M.B. (1999) The occurrence, distribution and pathology associated with gnathiid
isopod larvae infecting the epaulette shark, Hemiscyllium ocellatum. International Journal for Parasitology
29, 321330.
Hewitt, G.C. (1964) The postchalimus development of Lepeophtheirus polyprioni Hewitt, 1963 (Copepoda:
Caligidae). Transactions of the Royal Society of New Zealand, Zoology 4, 157159.
Hewitt, G.C. (1971) Two species of Caligus (Copepoda, Caligidae) from Australian waters, with a description
of some developmental stages. Pacific Science 25, 145164.
Hickling, C.F. (1963) On the small deep-sea shark Etmopterus spinax L., and its cirripede parasite Anelasma
squalicola (Loven). Journal of the Linnean Society 45, 1724.
Hindle, E. (1949) Notes on the treatment of fish infected with Argulus. Proceedings of the Zoological Society of
London 119 (1), 7981.
Hiramatsu, N., Fukada, H., Haruhisa, K., Kitamura, M., Shimizu, M., Fuda, H., Koybayashi, K. and Hara, A.
(2001) Serum immunoglobulin M (IgM) in Sakhalin taimen (Hucho perryi): purification, characterization,
circulating levels, and specific IgM production by the parasitic Salmincola stellatus. Suisan Zoshoku 49,
347355.
Hislop, J.R.G. and Shanks, A.M. (1981) Recent investigations on the reproductive biology of the haddock,
Melanogrammus aegleflnus, of the northern North Sea and the effects on fecundity of infection with the
copepod parasite Lernaeocera branchialis. Journal du Conseil 39, 244251.
Ho, J.-S. (1983) Copepod parasites of Japanese surfperches: their inference on the phylogeny and
biogeography of Embiotocidae in the Far East. Annual Report of the Sado Marine Biological Station,
Niigata University 13, 3162.
Ho, J.-S. (1989) Historical biogeography of Sphyrion (Copepoda: Sphyriidae). In: Proceedings of the Workshop on Sphyrion lumpi. Padagogische Hochschule, Gustrow, pp. 422.
546
Ho, J.-S. (1996) Cladistics of the Lernaeidae (Cyclopoida), a major family of freshwater fish parasites. Journal
of Marine Systems 15, 177183.
Ho, J.-S. (2000) The major problem of cage aquaculture in Asia relating to sea lice. In: Liao, I. and Lin, C. (eds)
Cage Aquaculture in Asia, Proceedings of the First International Symposium on Cage Aquaculture in
Asia. Asian Fisheries Society, Manila and World Aquaculture Society, Southeast Asian chapter, Bangkok,
pp. 1319.
Ho, J.-S. and Honma, Y. (1983) Lernaeolophus aceratus, a new species of copepod parasitic on rainbowfish
from the Sea of Japan, with notes on food and feeding. Journal of Crustacean Biology 3, 321328.
Ho, J.-S., and Kim, I.H. (1997) Lernaeid copepods (Cyclopoida) parasitic on freshwater fishes of Thailand.
Journal of Natural History 31, 6984.
Ho, J.-S. and Lin, C.-L. (2004) Sea Lice of Taiwan. Sueichan, Keelung.
Ho, J.-S. and Tonguthai, K. (1992) Flabelliferan isopods (Crustacea) parasitic on freshwater fishes of Thailand.
Systematic Parasitology 21, 203210.
Hoffman, G.L. (1970) Parasites of North American Freshwater Fishes. University of California Press, Berkeley,
California.
Hoffman, G.L. (1976) Parasites of Freshwater Fish. IV. The Anchor Parasite (Lernaea elegans) and Related
Species. Fish Disease Leaflet No. 46, US Fish and Wildlife Service, 8 pp.
Hoffman, G.L. (1977) Copepod parasites of freshwater fish: Ergasilus, Achtheres, and Salmincola. Fish Disease Leaflet No. 48, US Fish and Wildlife Service, 10 pp.
Hoffman, G.L. (1998). Parasites of North American Freshwater Fishes. Cornell University Press, Ithaca,
New York.
Hoffman, G.L. and Lester, R.J.G. (1987) Workshop 4F: crustacean parasites of fish. International Journal for
Parasitology 17, 10301031.
Hoffman, G.L. and Meyer, F.P. (1974) Parasites of Freshwater Fishes. TFH, Neptune City, New Jersey.
Hogans, W.E. (1989) Mortality of cultured Atlantic salmon, Salmo salar L., parr caused by an infection
of Ergasilus labracis (Copepoda: Poecilostomatoida) in the lower Saint John River, New Brunswick,
Canada. Journal of Fish Diseases 12, 529531.
Hogans, W.E. and Trudeau, D.J. (1989a) Caligus elongatus (Copepoda: Caligoida) from Atlantic salmon
(Salmo salar) cultured in marine waters of the lower Bay of Fundy. Canadian Journal of Zoology 67,
10801082.
Hogans, W.E. and Trudeau, D.J. (1989b) Preliminary studies on the biology of sea lice, Caligus elongatus,
Caligus curtus and Lepeophtheirus salmonis (Copepoda: Caligoida) parasitic on cage-cultured salmonids in
the lower Bay of Fundy. Canadian Technical Report of Fisheries and Aquatic Sciences 1715, 114.
Honma, Y. and Chiba, A. (1991) Pathological changes in the branchial chamber wall of stingrays, Dasyatis
spp., associated with the presence of juvenile gnathiids (Isopoda, Crustacea). Fish Pathology 26, 916.
Honma, Y., Tsunaki, S., Chiba, A. and Ho, J.-S. (1991) Histological studies on the juvenile gnathiid (Isopoda,
Crustacea) parasitic on the branchial chamber wall of the stingray, Dasyatis akejei, in the Sea of Japan.
Report of the Sado Marine Biological Station, Niigata University 21, 3747.
Horton, T. (2000) Ceratothoa steindachneri (Isopoda: Cymothoidae) new to British waters with a key to
north-east Atlantic and Mediterranean Ceratothoa. Journal of the Marine Biological Association of the
United Kingdom 80, 10411052.
Horton, T. and Okamura, B. (2001) Cymothoid isopod parasites in aquaculture: a review and case study of a
Turkish sea bass (Dicentrarchus labrax) and sea bream (Sparus auratus) farm. Diseases of Aquatic
Organisms 46, 181188.
Horton, T. and Okamura, B. (2003) Post-haemorrhagic anaemia in sea bass, Dicentrarchus labrax (L.), caused
by blood feeding of Ceratothoa oestroides (Isopoda: Cymothoidae). Journal of Fish Diseases 26,
401406.
Hoshina, T. and Suenaga, G. (1954) On a new species of parasitic copepods from Yamame (salmoid fish) of
Japan. Journal of the Tokyo University of Fisheries 41, 7579.
Hotta, H. (1962) The parasitism of saury (Cololabis saira) infected with parasitic Copepoda, Caligus macarovi
Gussev, during fishing season in 1961. Bulletin of the Tohoku Regional Fisheries Research Laboratory 21,
5056.
Hoy, T., Horsberg, T.E. and Nafstad, I. (1992) The disposition of ivermectin in Atlantic salmon (Salmo salar).
In: Michel, C. and Alderman, D.J. (eds) Chemotherapy in Aquaculture: from Theory to Reality. Office
International des Epizooties, Paris, pp. 461467.
Hudson, P.L. and Bowen, C.A. (2002) First record of Neoergasilus japonicus (Poecilostomatoida: Ergasilidae), a
parasitic copepod new to the Laurentian Great Lakes. Journal of Parasitology 88, 657663.
Phylum Arthropoda
547
Hughes, S.E. (1973) Some metazoan parasites of the Eastern Pacific saury, Cololabis saira. Fishery Bulletin 71,
943952.
Huizinga, H.W. (1972) Pathobiology of Artystone trysibia Schioedte (Isopoda: Cymothoidae), an
endoparasitic isopod of South American freshwater fishes. Journal of Wildlife Diseases 8, 225232.
Hwa, T.K. (1965) Studies on the life cycle of a fish louse (Caligus orientalis Gussev). Acta Zoologica Sinica 17,
4863.
Ingram, B.A. and Philbey, A.W. (1999) Occurrence of the parasite Ergasilus intermedius (Copepoda:
Ergasilidae) on the gills of Macquarie perch, Macquaria australasica (Percichthyidae). Proceedings of the
Linnean Society of New South Wales 121, 3944.
Ingvarsdttir, A., Birkett, M.A., Duce, I., Genna, R.L., Mordue, W., Pickett, J.A., Wadhams, L.J. and Mordue,
A.J. ( 2002) Semiochemical strategies for sea louse control: host location cues. Pest Management Science
58, 537545.
Inostroza, R., Sievers, G., Roa, J. and Aguirrebena, R. (1993) Seasonal prevalence and intensity of infection
with Ceratothoa gaudichaudii in salmon (Salmo salar) cultured in sea water in southern Chile. Archivos
de Medicina Veterinaria 25, 173179.
Isdal, E., Nylund, A. and Nvdal, G. (1997) Genetic differences among salmon lice (Lepeophtheirus salmonis)
from six Norwegian coastal sites: evidence from allozymes. Bulletin of the European Association of Fish
Pathologists 17, 1722.
Izawa, K. (1969) Life history of Caligus spinosus Yamaguti, 1939 obtained from cultured yellow tail, Seriola
quinqueradiata T. and S. (Crustacea: Caligoida). Report of Faculty of Fisheries, Prefectural University of
Mie 6, 127157.
Izawa, K. (1974) Sarcotaces, a genus of parasitic copepods (Cyclopoida: Phylichthyidae), found on Japanese
fishes. Publications of the Seto Marine Biological Laboratory 21, 179191.
Izawa, K. (1977) A new species of Peroderma Heller (Caligoida: Lernaeoceridae), parasitic on the fish
Bregmaceros japonicus Tanaka. Pacific Science 31, 253258.
Izawa, K. (1997) The copepodid of Peniculisa shiinoi Izawa, 1965 (Copepoda, Siphonostomatoida,
Pennellidae), single free-swimming larval stage of the species. Crustaceana 70, 911919.
Jafri, S.I.H. and Ahmed, S.S. (1994) Some observations on mortality in major carp due to fish lice and their
chemical control. Pakistan Journal of Zoology 26, 274276.
Johannessen, A. (1978) Early stages of Lepeophtheirus salmonis (Copepoda, Caligidae). Sarsia 63, 169176.
Johnson, K.A. and Heindel, J.A. (2001) Efficacy of manual removal and ivermectin gavage for control of
Salmincola californiensis (Wilson) infestation of chincook salmon, Oncorhynchus tshawytscha
(Walbaum), captive broodstocks. Journal of Fish Diseases 24, 197203.
Johnson, S.C. (1998) Crustacean parasites. In: Kent, M.L. and Poppe, T.T. (eds) Diseases of Seawater
Netpen-reared Salmonid Fishes. Fisheries and Oceans Canada, St Andrews, New Brunswick,
pp. 8090.
Johnson, S.C. and Albright, L.J. (1991a) The developmental stages of Lepeophtheirus salmonis (Kroyer, 1837)
(Copepoda: Caligidae). Canadian Journal of Zoology 69, 929950.
Johnson, S.C. and Albright, L.J. (1991b) Development, growth, and survival of Lepeophtheirus salmonis
(Copepoda: Caligidae) under laboratory conditions. Journal of the Marine Biological Association, UK 71,
425436.
Johnson, S.C. and Albright, L.J. (1992a) Comparative susceptibility and histopathology of the response of
naive Atlantic chinook and coho salmon to experimental infection with Lepeophtheirus salmonis
(Copepoda: Caligidae). Diseases of Aquatic Organisms 14, 179193.
Johnson, S.C. and Albright, L.J. (1992b) Effect of cortisol implants on the susceptibility and histopathology of
the response of naive coho salmon Oncorhynchus kisutch to experimental infection with
Lepeophtheirus salmonis (Copepoda: Caligidae). Diseases of Aquatic Organisms 14, 195205.
Johnson, S.C., Constible, J.M. and Richard, J. (1993) Laboratory investigations of the toxicological and
histopathological effects of hydrogen peroxide to salmon and its efficacy against the salmon louse
Lepeophtheirus salmonis. Diseases of Aquatic Organisms 17, 197204.
Johnston, C.E. and Dykeman, D. (1987) Observations on body proportions and egg production in the female
parasitic copepod (Salmincola salmoneus) from the gills of Atlantic salmon (Salmo salar) kelts exposed to
different temperatures and photoperiods. Canadian Journal of Zoology 65, 415419.
Johnstone, J. and Frost, W.E. (1927) The cirripede fish parasite Anelasma squalicola (Loven): its general morphology. Report of the Lancashire Sea-Fisheries Laboratory 35, 2991.
Jones, C.S. and Grutter, A.S. (2005) Parasitic isopods (Gnathia sp.) reduce haematocrit in captive blackeye
thicklip (Labridae) on the Great Barrier Reef. Journal of Fish Biology 66, 860.
548
Jones, J.B. (1980) A redescription of Caligus patulus Wilson, 1937 (Copepoda, Caligidae) from a fish farm in
the Philippines. Systematic Parasitology 2, 103116.
Jones, M.E.B. and Taggart, C.T. (1998). Distribution of gill parasite (Lernaeocera branchialis) infection in
Northwest Atlantic cod (Gadus morhua) and parasite induced host mortality: inference from tagging
data. Canadian Journal of Fisheries and Aquatic Sciences 55, 364375.
Jones, M.W., Sommerville, C. and Bron, J. (1990) The histopathology associated with the juvenile stages
of Lepeophtheirus salmonis on the Atlantic salmon, Salmo salar L. Journal of Fish Diseases 13, 303310.
Jones, M.W., Sommerville, C. and Wootten, R. (1992) Reduced sensitivity of the salmon louse,
Lepeophtheirus salmonis, to the organophosphate dichlorvos. Journal of Fish Diseases 15, 197202.
Jonsdottir, H., Bron, J.E., Wootten, R. and Turnbull, J.E. (1992) The histopathology associated with the
pre-adult and adult stages of Lepeophtheirus salmonis on the Atlantic salmon, Salmo salar L. Journal of
Fish Diseases 15, 521527.
Joy, J.E. (1976) Gill parasites of the spot Leiostomus xanthurus from Clear Lake, Texas. Transactions of the
American Microscopical Society 95, 6368.
Joy, J.E. and Jones, L.P. (1973) Observations on the inflammatory response within the dermis of a white bass,
Morone chrysops (Rafinesque), infected with Lernaea cruciata (Copepoda: Caligidae). Journal of Fish
Biology 5, 2123.
Juilfs, H.B. and Wagele, J.W. (1987) Symbiotic bacteria in the gut of the blood-sucking Antarctic fish parasite
Gnathia calva (Crustacea: Isopoda). Marine Biology 95, 493499.
Jungnitz, H.-A. (1989) Some food hygienical aspects of the invasion by Sphyrion lumpi from the point of view
of the veterinary control organisation of the GDR. In: Proceedings of the Workshop on Sphyrion lumpi.
Padagogische Hochschule, Gustrow, Germany, pp. 6568.
Kabata, Z. (1958) Lernaeocera obtusa n. sp. Its biology and its effects on the haddock. Scottish Home Department Marine Research 3, 126.
Kabata, Z. (1960) Observations on Clavella (Copepoda) parasitic on some British gadoids. Crustaceana 1,
342352.
Kabata, Z. (1966) Comments on the phylogeny and zoogeography of Lernaeopodidae (Crustacea: Copepoda).
International Congress of Parasitology E12, 10821083.
Kabata, Z. (1969a) Phrixocephalus cincinnatus Wilson, 1908 (Copepoda: Lernaeoceridae): morphology,
metamorphosis, and hostparasite relationship. Journal of the Fisheries Research Board of Canada 26,
921934.
Kabata, Z. (1969b) Revision of the genus Salmincola Wilson, 1915 (Copepoda: Lernaeopodidae). Journal of
the Fisheries Research Board of Canada 26, 29873041.
Kabata, Z. (1970) Crustacea as enemies of fishes. In: Snieszko, S.F. and Axelrod, H.R. (eds) Diseases of Fishes,
Book 1. TFH Publishers, Jersey City, New Jersey, 171 pp.
Kabata, Z. (1972) Developmental stages of Caligus clemensi (Copepoda: Caligidae). Journal of the Fisheries
Research Board of Canada 29, 15711593.
Kabata, Z. (1974) Mouth and mode of feeding of Caligidae (Copepoda), parasites of fishes, as determined by light
and scanning electron microscopy. Journal of the Fisheries Research Board of Canada 31, 15831588.
Kabata, Z. (1979) Parasitic Copepoda of British Fishes. Ray Society, London.
Kabata, Z. (1981) Copepoda (Crustacea) parasitic on fishes: problems and perspectives. Advances in
Parasitology 19, 171.
Kabata, Z. (1983) Two new genera of the family Lernaeidae (Copepoda: Cyclopoida) parasitic on freshwater
fishes of India. In: Selected Papers on Crustacea. Rabindranath Krishna Pillai Farewell Committee,
Trivandrum, India, pp. 6976.
Kabata, Z. (1984) Diseases caused by metazoans crustaceans. In: Kinne, O. (ed.) Diseases of Marine
Animals, Vol. IV, Pt 1. Biologische Anstalt Helgoland, Hamburg, Germany, pp. 321399.
Kabata, Z. (1985) Parasites and Diseases of Fish Cultured in the Tropics. Taylor and Francis, London.
Kabata, Z. (1988) Copepoda and Branchiura. In: Margolis, L. and Kabata, Z. (eds) Guide to the Parasites of
Fishes of Canada, Part II Crustacea. Department of Fisheries and Oceans, Ottawa, pp. 3127.
Kabata, Z. (1992) Copepods parasitic on Australian fishes, XV. Family Ergasilidae (Poecilostomatoida). Journal
of Natural History 26, 4766.
Kabata, Z. (2003). Copepods Parasitic on Fishes. Linnean Society, London.
Kabata, Z. and Cousens, B. (1972) The structure of the attachment organ of Lernaeopodidae (Crustacea:
Copepoda). Journal of the Fisheries Research Board of Canada 29, 10151023.
Kabata, Z. and Cousens, B. (1973) Life cycle of Salmincola californiensis (Dana 1852) (Copepoda:
Lernaeopodidae). Journal of the Fisheries Research Board of Canada 30, 881903.
Phylum Arthropoda
549
Kabata, Z. and Cousens, B. (1977) Hostparasite relationships between sockeye salmon, Oncorhynchus
nerka, and Salmincola californiensis (Copepoda: Lernaeopodidae). Journal of the Fisheries Research
Board of Canada 34, 191202.
Kabata, Z. and Hewitt, G.C. (1971) Locomotory mechanisms in Caligidae (Crustacea: Copepoda). Journal of
the Fisheries Research Board of Canada 28, 11431151.
Kannupandi, T. (1976) Cuticular adaptations in two parasitic copepods in relation to their modes of life. Journal of Experimental Marine Biology and Ecology 22, 235248.
Kashkovsky, V.V. and Kashkovskaya-Solomatova, V.P. (1986) Ecology of larvae of Ergasilus sieboldi
(Copepoda parasitica) in the Lake Arakul. Parazitologiya 20, 3238.
Kawatow, K., Muroga, K., Izawa, K. and Kasahara, S. (1980) Life cycle of Alella macrotrachelus (Copepoda)
parasitic on cultured black sea-bream. Journal of the Faculty of Applied Biological Sciences 19, 199214.
Kelly, H.D. and Allison, R. (1962) Observations on the infestation of a fresh water fish population by a marine
copepod (Ergasilus lizae Kroyer 1863). Proceedings of the Sixteenth Annual Conference of the Southeastern Association of Game and Fish 16, 236239.
Kensley, B. and Schotte, M. (1989) Guide to the Marine Isopod Crustaceans of the Caribbean. Smithsonian
Institution, Washington.
Kent, M.L. and Poppe, T.T. (eds) (1998) Diseases of Seawater Netpen-reared Salmonid Fishes. Pacific Biological Station Fisheries and Oceans Canada, British Columbia, Canada.
Kent, M.L., Whitaker, D.J., Moran, J.D.W. and Kabata, Z. (1997) Haemobaphes disphaerocephalus, an accidental parasite of seawater pen-reared Atlantic salmon. Canadian Veterinary Journal 38, 110111.
Keys, A.B. (1928) Ectoparasites and vitality. American Naturalist 62, 279282.
Khalifa, K.A. and Post, G. (1976) Histopathological effect of Lernaea cyprinacea (a copepod parasite) on fish.
The Progressive Fish-Culturalist 38, 110113.
Khan, R.A. (1984) Concurrent infections of two parasites, Lernaeocera branchialis (Copepoda) and
Trypanosoma murmanensis (Protozoa) in Atlantic Cod, Gadus morhua. In: 4th European Multicolloquium
of Parasitology p. 189.
Khan, R.A. (1988) Experimental transmission, development, and effects of a parasitic copepod, Lernaeocera
branchialis, on Atlantic cod, Gadus morhua. Journal of Parasitology 74, 586599.
Khan, R.A. and Lee, E.M. (1989) Influence of Lernaeocera branchialis (Crustacea: Copepoda) on growth rate of
Atlantic cod, Gadus morhua. Journal of Parasitology 75, 449454.
Khan, R.A., Lee, E.M. and Barker, D. (1990) Lernaeocera branchialis: potential pathogen to cod ranching.
Journal of Parasitology 76, 913917.
Khan, R.A., Ryan, K., Barker, D.E. and Lee, E.M. (1993) Effect of a single Lernaeocera branchialis (Copepoda)
on growth of Atlantic cod. Journal of Parasitology 79, 954958.
Khan, R.A., Munehara, H., Ryan, K. and Lawson, J.W. (1997) Influence of Haemobaphes cyclopterina and
H. intermedius (Copepoda) on Actic cod (Boreogadus saida) and tidepool sculpins (Oligocottus
maculosus), respectively. Canadian Journal of Zoology 75, 12801284.
Kim, I.-H. (1993) Developmental stages of Caligus punctatus Shiino, 1955 (Copepoda: Caligidae). In:
Boxshall, G.A. and Defaye, D. (eds) Pathogens of Wild and Farmed Fish: Sea Lice. Ellis Horwood,
New York, pp. 1629.
Kim, I.-H. (1998) Cirripeda, Symbiotic Copepoda, Pycnogonida. Illustrated Encyclopaedia of Fauna and Flora
of Korea Vol. 38. Ministry of Education, Seoul.
Kimura, S. (1970) Notes on the reproduction of water lice (Argulus japonica Thiele). Bulletin of Freshwater
Fisheries Research Laboratory 20, 109126.
Kirmse, P. (1987) Important parasites of Dover sole (Solea solea L.) kept under mariculture conditions. Parasitology Research 73, 466471.
Knudsen, K.K. and Sundnes, G. (1998) Effects of salinity on infection with Lernaeocera branchialis (L.)
(Copepoda: Pennellidae). Journal of Parasitology 84, 700704.
Koie, M. (1999) Metazoan parasites of flounder Platichthys flesus (L.) along a transect from the southwestern to
the northeastern Baltic Sea. ICES Journal of Marine Science 56, 157163.
Kroger, R.L. and Guthrie, J.F. (1972a) Occurrence of the parasitic branchiuran, Argulus alosae, on dying Atlantic menhaden, Brevoortia tyrannus, in the Connecticut River. Transactions of the American Fisheries Society 101, 559560.
Kroger, R.L. and Guthrie, J.F. (1972b) Incidence of the parasitic isopod, Olencira praegustators, in juvenile
Atlantic menhaden. Copeia 1972, 370374.
Kuitunen-Ekbaum, E. (1949) The occurrence of Sarcotaces in Canada. Journal of the Fisheries Research Board
of Canada 7, 505512.
550
Kularatne, M., Shariff, M. and Subasinghe, R.P. (1994a) Comparison of larval morphometrics of Lernaea
minuta, a copepod parasite of Puntius gonionotus from Malaysia, with those of L. cyprinacea and
L. polymorpha. Crustaceana 67, 288295.
Kularatne, M., Subasinghe, R.P. and Shariff, M. (1994b) Investigations of the lack of acquired immunity by the
Javanese carp, Puntius gonionotus (Bleeker), against the crustacean parasite, Lernaea minuta (Kuang).
Fish and Shellfish Immunology 4, 107114.
Kuperman, B.I. and Shulman, R.E. (1977) On the influence of some abiotic factors on the development of
Ergasilus sieboldi (Crustacea, Copepoda). Parazitologiya 11, 117121.
Kurochkin, Y.V. (1985) Applied and scientific aspects of marine parasitology. In: Hargis, W.J.J. (ed.)
Parasitology and Pathology of Marine Organisms of the World Ocean. Technical Report NMFS 25,
NOAA, Washington DC, pp. 1518.
Kussakin, O.G. (1979) Marine and Brackishwater Isopod Crustacea, Suborder Flabellifera. Academy of
Sciences USSR, Leningrad, Russia.
Kvamme, B.O., Skern, R., Frost, P. and Nilsen, F. (2004) Molecular characterisation of five trypsin-like
peptidase transcripts from the salmon louse (Lepeophtheirus salmonis) intestine. International Journal for
Parasitology 34, 823832.
Landau, M., Danko, M.J. and Slocum, C. (1995) The effect of the parasitic cymothoid isopod, Lironeca ovalis
(Say, 1818) on growth of young of the year bluefish, Pomatomus saltatrix (Linnaeus, 1766). Crustaceana
Leiden 68, 397400.
Landsberg, J.H., Vermeer, G.K., Richards, S.A. and Perry, N. (1991) Control of the parasitic copepod Caligus
elongatus on pond-reared red drum. Journal of Aquatic Animal Health 3, 206209.
Lanzing, W.J.R. and OConnor, P.F. (1975) Infestation of luderick (Girella tricuspidata) populations with
parasitic isopods. Australian Journal of Marine and Freshwater Research 26, 355361.
Lasee, B.A., Sutherland, D.R. and Moubry, M.E. (1988) Hostparasite relationships between burbot (Lota lota)
and adult Salmincola lotae (Copepoda). Canadian Journal of Zoology 66, 24592463.
Lavina, E.M. (1977) The biology and control of Caligus sp., an ectoparasite of the adult milkfish Chanos
chanos Forskal. SEAFDEC Quarterly Research Report, Aquaculture Department 1977, 1213.
Lawler, A.R., Howse, H.D. and Cook, D.W. (1974) Silver perch, Bairdiella chrysura: new host for
lymphocystis. Copeia 1974, 266269.
Legrand, J.-J. (1951) Etude statistique et exprimentale de la sexualit dAnilocra physodes L. (Crustace
Isopode Cymothoide). Bulletin de la Socit dHistoire Naturelle de Toulouse 86, 176183.
Legrand, J.-J. (1952) Contribution ltude exprimentale et statistique de la biologie dAnilocra physodes L.
Archives de Zoologie Exprimentale et Gnrale 89, 156.
Leonardos, I. and Trilles, J.P. (2003) Hostparasite relationships: occurrence and effect of the parasitic isopod
Mothocya epimerica on sand smelt Atherina boyeri in the Mesolongi and Etolikon Lagoons (W. Greece).
Diseases of Aquatic Organisms 54, 243251.
Lester, R.J.G. and Daniels, B.A. (1976) The eosinophilic cell of the white sucker, Catostomus commersoni.
Journal of the Fisheries Research Board of Canada 33, 139144.
Lester, R.J.G. and Roubal, F.R. (1995) Phylum Arthropoda. In: Woo, P.T.K. (ed.) Fish Diseases and Disorders,
vol. 1. Protozoan and Metazoan Infections. CAB International, Wallingford, UK, pp. 475598.
Lester, R.J.G. and Sewell, K.B. (1989) Checklist of parasites from Heron Island, Great Barrier Reef. Australian
Journal of Marine and Freshwater Research 37, 101128.
Lewis, A.G. (1963) Life history of the caligid copepod Lepeophtheirus dissimulatus Wilson, 1905 (Crustacea:
Caligoida). Pacific Science 17, 195242.
Lewis, A.G. (1969) A discussion of the maxillae of the Caligoidea (Copepoda). Crustaceana 16, 6577.
Lewis, R.M. and Hetter, W.F. (1968) Effect of temperature and salinity on the survival of young Atlantic
menhaden, Brevoortia tyrannus. Transactions of the American Fisheries Society 97, 344349.
Lin, C.-C., Ho, J.-S. and Chen, S.-N. (1994) Two species of Caligus (Copepoda, Caligidae) parasitic on black
sea bream (Acanthopagrus schlegeli) cultured in Taiwan. Fish Pathology 29, 253264.
Lin, C.L. and Ho, J.-S. (1993) Life history of Caligus epidemicus Hewitt parasitic on tilapia (Oreochromis
mossambicus) cultured in brackish water. In: Boxshall, G.A. and Defaye, D. (eds) Pathogens of Wild and
Farmed Fish: Sea Lice. Ellis Horwood, New York, pp. 515.
Lin, C.L., and Ho, J.S. (1998) Two new species of ergasilid copepods parasitic on fishes cultured in brackish
water in Taiwan. Proceedings of the Biological Society of Washington 111, 1527.
Lindsay, J.A. and Moran, R.L. (1976) Relationships of parasitic isopods, Lironeca ovalis and Olencira
praegustator to marine fish hosts in Delaware Bay. Transactions of the American Fisheries Society 1976
327332.
Phylum Arthropoda
551
Long, D.J. and Waggoner, B.M. (1993) The ectoparasitic barnacle Anelasma (Cirripedia, Thoracica,
Lepadomorpha) on the shark Centroscyllium nigrum (Chondrichthyes, Squalidae) from the Pacific
sub-Antarctic. Systematic Parasitology 26, 133136.
Lopmann, A. (1940) Uber die quantitative Bestimmung des Ergasilusbefalles an Schleien (Tinca vulgaris).
Zeitschriftfr Parasitenkunde 11, 474483.
Lysne, D.A. and Skorping, A. (2002) The parasite Lernaeocera branchialis on caged cod: infection pattern is
caused by differences in host susceptibilty. Parasitology 124, 6976.
McAndrew, K. (2002) Risks to small-scale cage farmers in Bangladesh, with emphasis on fish health experiences of the CARE-CAGE project. FAO Fisheries Technical Paper 406, 215223.
McAndrew, K., Sommerville, C., Wootten, R. and Bron, J.E. (1998) The effects of hydrogen peroxide treatment
on different life-cycle stages of the salmon louse, Lepeophtheirus salmonis (Kryer 1837). Journal of Fish
Diseases 21, 221228.
McGladdery, S.E. and Johnston, C.E. (1988) Egg development and control of the gill parasite, Salmincola
salmoneus, on Atlantic salmon kelts (Salmo salar) exposed to four different regimes of temperature and
photoperiod. Aquaculture 68, 193202.
MacKenzie, K. and Morrison, J.A. (1989) An unusually heavy infestation of herring (Clupea harengus L.) with
the parasitic copepod Caligus elongatus Nordmann, 1832. Bulletin of the European Association of Fish
Pathologists 9, 1213.
MacKinnon, B. (1991) Sea lice and Atlantic salmon, absence of immunoprotection in Salmo salar to Caligus
elongatus. Bulletin of the Aquaculture Association of Canada 91, 5860.
MacKinnon, B.M. (1992) Egg production in sea lice, Caligus elongatus. Bulletin of the Canadian Society for
Zoology 23, 79.
McMahon, T. (2000) Regulation and monitoring of marine aquaculture in Ireland. Journal of Applied Ichthyology 16, 177181.
McNeil, P.L., Jr (1961) The use of benzene hexachloride as a copepodicide and some observations on
lernaean parasites in trout rearing units. Progressive Fish-Culturalist 23, 127133.
Malta, J.C.O. (1982) The argulids (Crustacea: Branchiura) of Amazonia, Brazil. 2. Aspects of the ecology of
Dolops geayi Bouvier, 1897, and Argulus juparanaensis Castro, 1950. Acta Amazonia 12, 701705.
Malta, J.C.O. and Silva, E.N.S. (1986) Argulus amazonicus n. sp. a crustacean parasite of fishes from the Brazilian Amazon (Branchiura: Argulidae). Amazoniana 9, 485492.
Manal, E.M.A.A., Oifat, M.A. and El, S.E.M. (1995) Lernaeosis outbreak in cultured freshwater fish fingerlings
at Kafr El Sheikh governorate, Egypt. Egyptian Journal of Comparative Pathology and Clinical Pathology
8, 109121.
Mann, H. (1952) Lernaeocera branchialis (Copepoda parasitica) und seine Schadwirkung bei einigen
Gadiden. Archiv fr Fischereiwissenschaft 4, 133144.
Mann, H. (1970) Copepoda and Isopoda as parasites of marine fishes. In: Snieszko, S. (ed.) A Symposium
on Diseases of Fishes and Shellfishes. Special Publication 5, American Fisheries Society, Washington,
pp. 177189.
Marino, F., Giannetto, S., Paradiso, M.L., Bottari, T., De Vico, G. and Macri, B. (2004) Tissue damage
and haematophagia due to praniza larvae (Isopoda: Gnathiidae) in some aquarium seawater teleosts.
Diseases of Aquatic Organisms 59, 4347.
Marks, R.E., Juanes, F., Hara, J.A. and Conover, D.O. (1996) Occurrence and effect of the parasitic isopod,
Lironeca ovalis (Isopoda: Cymothoidae), on young of the year bluefish, Pomatomus saltatrix (Pisces:
Pomatomidae). Canadian Journal of Fisheries and Aquatic Sciences 53, 20522057.
Martin, J.W. and Davis, G.E. (2001) An updated classification of the recent Crustacea. Natural History
Museum of Los Angeles County Science Series 39, 1124.
Martin, M. (1932) On the morphology and classification of Argulus (Crustacea). Proceedings of the Zoological
Society of London Part 3, 1932, 771806.
Maxwell, J.G.H. (1982) Infestation of the jack mackerel, Trachurus declivis (Jenyns), with the cymothoid
isopod, Ceratothoa imbricatus in southeastern Australian waters. Journal of Fish Biology 20, 341350.
Mayer, P. (1879) Carcinologische Mittheilungen. VI Ueber den Hermaphroditismus bei einigen Isopoden.
Mittheilungen Zoologische Station zu Neapel 1, 165179.
Mederios, E.S.F. and Maltchik, L. (1999) The effects of hydrological disturbance on the intensity of infestation
of Lernaea cyprinacea in an intermittent stream fish community. Journal of Arid Environments 43,
351356.
Mees, T., Renaud, F. and Gabrion, C. (1990) A model for studying isolation mechanisms in parasite populations: the genus Lepeophtheirus (Copepoda, Caligidae). Journal of Experimental Zoology 254, 207214.
552
Mees, T., Raibaut, A. and Renaud, F. (1993) Comparative life history of two species of sea lice. In: Boxshall,
G.A. and Defaye, D. (eds) Pathogens of Wild and Farmed Fish: Sea Lice. Ellis Horwood, New York,
pp. 143150.
Mellergaard, S. and Lang, T. (1999) Diseases and parasites of Baltic cod (Gadus morhua) from the
Mecklenburg Bight to the Estonian coast. ICES Journal of Marine Science 56, 164168.
Menezes, J., Ramos, M.A., Pereira, T.G. and Moreira da Silva, A. (1990) Rainbow trout culture failure in a
small lake as a result of massive parasitosis related to careless fish introductions. Aquaculture 89,
123126.
Menzies, R.J., Bowman, T.E. and Alverson, F.G. (1955) Studies of the biology of the fish parasite Lironeca
convexa Richardson (Crustacea, Isopoda, Cymothoidae). Wasmann Journal of Biology 13, 277295.
Mikheev, V.N., Valtonen, E.T. and Rintamaki, K.P. (1998) Host searching in Argulus foliaceus L. (Crustacea:
Branchiura): the role of vision and selectivity. Parasitology 116, 425430.
Mikheev, V.N., Mikheev, A.V., Pasternak, A.F. and Valtonen, E.T. (2000) Light-mediated host searching strategies in a fish ectoparasite, Argulus foliaceus L. (Crustacea: Branchiura). Parasitology 120, 409416.
Mikheev, V.N., Pasternak, A.F., Valtonen, E.T. and Lankinen, Y. (2001) Spatial distribution and hatching of
overwintered eggs of a fish ectoparasite, Argulus coregoni (Crustacea: Branchiura). Diseases of Aquatic
Organisms 46, 123128.
Minchin, E.A. (1909) Observations on the flagellates parasitic in the blood of freshwater fishes. Proceedings of
the Zoological Society of London 1909, 230.
Mladineo, I. (2002) Prevalence of Ceratothoa oestroides (Risso,1826), a cymothoid isopode parasite, in cultured seas bass Dicentrarchus labrax L. on two farms in middle Adriatic Sea. Acta Adriatica 43, 97102.
Mladineo, I. (2003) Life cycle of Ceratothoa oestroides, a cymothoid isopod parasite from sea bass
Dicentrarchus labrax and sea bream Sparus aurata. Diseases of Aquatic Organisms 57, 97101.
Mladineo, I. and Valic, D. (2002) The mechanisms of infection of the buccal isopod Ceratothoa oestroides
(Risso, 1836), under experimental conditions. Bulletin of the European Association of Fish Pathologists
22, 304310.
Modin, J.C. and Veek, T.M. (2002) Biological control of the parasitic copepod Salmincola californiensis
in a commercial trout hatchery on the lower Merced River, California. North American Journal of
Aquaculture 64, 122128.
Moller, H. (1984) Daten zur Biologie der Elbfische. Moller, Kiel, Germany.
Moller, H. and Anders, K. (1986) Diseases and Parasites of Marine Fishes. Moller, Kiel, Germany.
Molnar, K. and Szekely, C. (1998) Occurrence of skrjabillanid nematodes in fishes of Hungary and in the
intermediate host, Argulus foliaceus L. Acta Veterinaria Hungarica 46, 451463.
Monod, T. (1926) Les Gnathiidae. Memoires de la Socit des Sciences Naturelles du Maroc 13, 1667.
Montalenti, G. (1948) Note sulla sistematica e la biologia di alcuni Cimotoidi del Golfo di Napoli. Archivio di
Oceanografia e Limnologia, Venezia 5, 2581.
Moran, J.D.W., Arthur, J.R. and Burt, M.D.B. (1996) Parasites of sharp-beaked redfishes (Sebastes fasciatus
and Sebastes mentella) collected from the Gulf of St. Lawrence, Canada. Canadian Journal of Fisheries
and Aquatic Sciences 53, 18211826.
Moravec, F. (1978) First record of Molnaria erythrophthalmi larvae in the intermediate host in Czechoslovakia.
Folia Parasitologia 25, 141142.
Moravec, F., Vidal, M.V. and Aguirre, M.L. (1999) Branchiurids (Argulus) as intermediate hosts of the
daniconematid nematode Mexiconema cichlasomae. Folia Parasitologica 46, 79.
Mordue, A.J. and Pike, A.W. (2002) Salmon farming: towards an integrated pest management strategy for sea
lice. Pest Management Science 58, 513514.
Morton, B. (1974) Host specificity and position on the host in Nerocila phaeopleura Bleeker (Isopoda,
Cymothoidae). Crustaceana 26, 143148.
Moser, M. and Sakanari, J. (1985) Aspects of host location in the juvenile isopod Lironeca vulgaris (Stimpson,
1857). Journal of Parasitology 71, 464468.
Moser, M. and Taylor, S. (1978) Effects of the copepod Cardiodectes medusaeus on the lanternfish
Stenobrachius leucopsarus with notes on hypercastration by the hydroid Hydrichthys sp. Canadian Journal of Zoology 56, 23722376.
Moser, M., Haldorson, L. and Field, L.J. (1985) The taxonomic status of Sarcotaces komaii and Sarcotaces
verrucosus (Copepoda: Phylichthyidae) and hostparasite relationships between Sarcotaces arcticus and
Sebastes spp. (Pisces). Journal of Parasitology 71, 472480.
Mugridge, R.E.R. and Stallybrass, H.G. (1983) A mortality of eels, Anguilla anguilla L., attributed to
Gnathiidae. Journal of Fish Diseases 6, 8182.
Phylum Arthropoda
553
Muroga, K., Kawatow, K. and Ichizono, H. (1981) Infestation by Alella macrotrachelus (Copepoda) of cultured
black sea-bream. Fish Pathology 16, 139144.
Mustafa, A., MacWilliams, C., Fernandez, N., Matchett, K., Conboy, G.A. and Burka, J.F. (2000a) Effects of
sea lice (Lepeophtheirus salmonis Kryer, 1837) infestation on macrophage functions in Atlantic salmon
(Salmo salar L.). Fish and Shellfish Immunology 10, 4759.
Mustafa, A., Speare, D., Daly, J., Conboy, G.A. and Burka, J.F. (2000b) Enhanced susceptibility of seawater
culture rainbow trout, Oncorhynchus mykiss (Walbaum), to the microsporidian Loma salmonae during a
primary infection with the sea louse, Lepeophtheirus salmonis. Journal of Fish Diseases 23, 337341.
Muzzall, P.M. (2000) Parasites of farm-raised trout in Michigan, U.S.A. Comparative Parasitology 67,
181189.
Muzzall, P.M., Peebles, C.R., Rosinski, J.L. and Hartson, D. (1995) Parasitic copepods on three species of
Centrarchids from Gull Lake, Michigan. Journal of Helminthological Society of Washington 62, 4852.
Nagasawa, K. (1987) Prevalence and abundance of Lepeophtheirus salmonis (Copepoda: Caligidae) on
high-seas salmon and trout in the North Pacific Ocean. Nippon Suisan Gakkaishi 53, 21512156.
Nagasawa, K. (2004) Sea lice, Lepeophtheirus salmonis and Caligus orientalis (Copepoda: Caligidae), of wild
and farmed fish in sea and brackish waters of Japan and adjacent regions: a review. Zoological Studies
43, 173178.
Nagasawa, K. and Maruyama, S. (1987) Occurrence and effects of Haemobaphes diceraus (Copepoda:
Pennellidae) on brown sole Limanda herzensteini off the Okhotsk coast of Hokkaido. Bulletin of the
Japanese Society of Scientific Fisheries 53, 991994.
Nagasawa, K., Imai, Y. and Ishida, K. (1985) Distribution, abundance, and effects of Pennella sp. (Copepoda:
Pennellidae), parasitic on the saury, Cololabis saira (Brevoort), in the western North Pacific Ocean and
adjacent seas, 1984. Bulletin of the Biogeographical Society of Japan 40, 3542.
Nagasawa, K., Imai, Y. and Ishida, K. (1988) Longterm changes in the population size and geographical distribution of Pennella sp. (Copepoda) on the saury, Cololabis saira, in the western North Pacific Ocean and
adjacent seas. Hydrobiologia 167/168, 571577.
Nagasawa, K., Ishida, I., Ogura, M., Tadokoro, K. and Hiramatsu, K. (1993) The abundance and distribution
of Lepeophtheirus salmonis (Copepoda: Caligidae) on six species of Pacific salmon in offshore waters of
the north Pacific Ocean and Bearing Sea. In: Boxshall, G.A. and Defaye, D. (eds) Pathogens of Wild and
Farmed Fish: Sea Lice. Ellis Horwood, New York, pp. 166178.
Nagasawa, K., Watanabe, J.R., Kimura, S. and Hara, A. (1994) Infection of Salmincola stellatus (Copepoda:
Lernaeopodidae) on Sakhalin Taimen Hucho perryi reared in Hokkaido. Bulletin of the Faculty of
Fisheries Hokkaido University 45, 109112.
Nagasawa, K., Ikuta, K. and Kitamura, S. (1997) Distribution of Salmincola carpionis (Copepoda:
Lernaeopodidae) in the buccal cavity of salmonids. Bulletin of National Research Institute of Aquaculture
26, 3539.
Nagasawa, K., Ikuta, K., Nakamura, H., Shikama, T. and Kitamura, S. (1998) Occurrence and effect of the
parasitic copepod Salmincola carpionis on salmonids in the Nikko District, central Japan. Journal of
Marine Systems 15, 269272.
Nair, G.A. and Nair, N.B. (1982) Effect of certain organophosphate biocides on the juvenile of the isopod
Alitropus typus M. Edwards (Crustacea: Flabellifera: Aegidae). Journal of Animal Morphology and Physiology 29, 265271.
Nair, G.A. and Nair, N.B. (1983) Effect of infestation with the isopod, Alitropus typus M. Edwards (Crustacea:
Flabellifera: Aegidae) on the haematological parameters of the host fish, Channa striatus (Bloch).
Aquaculture 30, 1119.
Nakajima, K., Izawa, S. and Egusa, S. (1974) Parasitic copepode, Pseudergasilus zacconis Yamaguti, found on
the gills on cultured ayu, Plecoglossus altivelis II. Fish Pathology 9, 9599.
Natarajan, P. and Nair, N.B. (1973) Observations on the nature of attack of Lernaeenicus hemirhamphi
Kirtisinghe on Hemirhamphus xanthopterus (Val.). Journal of Animal Morphology and Physiology 20,
5663.
Natarajan, P. and Nair, N.B. (1976) Effects of infestation by Lernaeenicus hemirhamphi on the biochemical
composition of the host fish Hemirhamphus xanthopterus. Journal of Animal Morphology and Physiology 23, 2531.
Nei, P. (2000) Microhabitat distribution of metazoan parasites on gills of Silurus asotus in Jiangkou Reservoir,
Jiangxi Province, China. Chinese Journal of Oceanography and Limnology 18, 5460.
Neubert, J. (1984) Investigations on the application of trichlorfon in control of parasites and food organisms in
inland fisheries. Zeitschrift fr die Binnenfischerei der DDR 31, 334336.
554
Nierkerk, J.P. and Kok, D.J. (1989) Chonopeltis australis (Branchiura): structural, developmental and functional aspects of the trophic appendages. Crustaceana 57, 5156.
Nierkerk, J.P. and Van As, J.G. (1986) Ultrastructure of mouthparts to illustrate the feeding mechanism of
Chonopeltis australis Boxshall, 1976 (Crustacea: Branchiura). In: ICOPA VI Handbook, Australian
Academy of Sciences, Canberra, Abstract No. 682, p. 249.
Noble, E.R., King, R.E. and Jacobs, B.L. (1963) Ecology of the gill parasites of Gillichthys mirabilis Cooper.
Ecology 44, 295305.
Noga, E.J. (1986) The importance of Lernaea cruciata (Le Sueur) in the initiation of skin lesions in
largemouth bass, Micropterus salmoides (Lacepede), in the Chowan River, North Carolina, USA. Journal
of Fish Diseases 9, 295302.
Noga, E.J., Mitchell, C.G., Groman, D.B. and Johnston, J.A.A. (1991) Dermatological diseases affecting fishes
of the Tar-Pamlico estuary, North Carolina. Diseases of Aquatic Organisms 10, 8792.
Northcott, S.J., Lyndon, A.R. and Campbell, A.D. (1997) An outbreak of freshwater fish lice, Argulus foliaceus
L., seriously affecting a Scottish stillwater fishery. Fisheries Managment and Ecology 4, 7375.
Novotny, A.J. and Mahnken, C.W. (1971) Predation on juvenile salmon by a marine isopod, Rocinela
belliceps pugetensis. Fishery Bulletin 69, 699701.
Nylund, A., Bjorknes, B. and Wallace, C. (1991) Lepeophtheirus salmonis a possible vector in the spread of
diseases on salmonids. Bulletin of the European Association of Fish Pathologists 11, 213216.
Nylund, A., Okland, S. and Bjorknes, B. (1992) Anatomy and ultrastructure of the alimentary canal
in Lepeophtheirus salmonis (Copepoda: Siphonostomatoida). Journal of Crustacean Biology 12,
423437.
Nylund, A., Wallace, C. and Hovland, T. (1993) The possible role of Lepeophtheirus salmonis (Kroyer) in the
transmission of infectious salmon anaemia. In: Boxshall, G.A. and Defaye, D. (eds) Pathogens of Wild
and Farmed Fish: Sea Lice. Ellis Horwood, New York, pp. 367373.
Ohtsuka, S., Ho, J.-S., Nagasawa, K., Morozinska-Gogol, J. and Piasecki, W. (2004) The identity of
Limnoncaea diuncata Kokubo, 1914 (Copepoda: Poecilostomatoida) from Hokkaido, Japan, with the relegation of Diergasilus Do, 1981 to a junior synonym of Thersitina Norman, 1905. Systematic Parasitology 57, 3544.
Ojha, J. and Hughes, G.M. (2001) Effect of branchial parasites on the efficiency of the gills of a freshwater
catfish, Wallago attu. Journal of Zoology, London 255, 125129.
Oldewage, W.H. and Van As, J.G. (1987) Observations on the attachment of a piscine gill parasitic ergasilid
(Crustacea: Copepoda). South African Journal of Zoology 22, 313317.
Olsson, P. (1872) Om Sarcotaces och Acrobothrium, tva nya parasitslagten fran fiskar. Ofversigt af Kongl.
Vetenskaps-Academiens Forhandlingarr 29, 3744.
Overstreet, R.M., Dykova, I. and Hawkins, W.E. (1992) Branchiura. In: Microscopic Anatomy of Invertebrates,
vol. 9: Crustacea. Wiley-Liss, New York, pp. 385413.
Padmavathi, P. and Prasad, M.K.D. (1998) An effective and economically feasible treatment of
organophosphate pesticide and common salt to eradicate the fish ectoparasite, Argulus japonicus Thiele
in carp culture ponds. Journal of Environmental Biology 19, 193203.
Palmer, R., Rodger, H., Drinan, E., Dwyer, C. and Smith, P.R. (1987) Preliminary trials of the efficacy of
ivermectin against parasitic copepods of Atlantic salmon. Bulletin of the European Association of Fish
Pathologists 7, 4754.
Papapanagiotou, E.P. and Trilles, J.P. (2001) Cymothoid parasite Ceratothoa parallela inflicts great losses on
cultured gilthead sea bream Sparus aurata in Greece. Diseases of Aquatic Organisms 45, 237239.
Papapanagiotou, E.P., Trilles, J.P. and Photis, G. (1999) First record of Emetha audouini, a cymothoid isopod
parasite, from cultured sea bass Dicentrarchus labrax in Greece. Diseases of Aquatic Organisms 38,
235237.
Paperna, I. (1975) Parasites and diseases of the grey mullet (Mugilidae) with special reference to the seas of the
Near East. Aquaculture 5, 6580.
Paperna, I. (1977) Copepod infections in fish in euryhaline environments. Wiadomosci Parazytologiczne 23,
183187.
Paperna, I. (1991) Diseases caused by parasites in the aquaculture of warm water fish. Annual Review of Fish
Diseases 1, 155194.
Paperna, I. and Lahav, M. (1974) Mortality amoung gray mullets in a seawater pond due to caligiid parasitic
copepod epizootic. Bamidgeh 26, 1215.
Paperna, I. and Overstreet, R.M. (1981) Parasites and diseases of mullets (Mugilidae). In: Oren, O.H. (ed.)
Aquaculture of Grey Mullets. University Press, Cambridge, pp. 411493.
Phylum Arthropoda
555
Paperna, I. and Por, F.D. (1977) Preliminary data on the Gnathiidae (Isopoda) of the northern Red Sea, the
Bitter Lakes and the eastern Mediterranean and the biology of Gnathia piscivora n. sp. Rapports et
Procs-Verbeaux des Runions Commission Internationale pour l'Exploration Scientifique de la Mer
Mditerrane Monaco 24 (4), 195197.
Paperna, I. and Zwerner, D.E. (1976) Studies on Ergasilus labracis Kroyer (Cyclopidea: Ergasilidae) parasitic on
striped bass, Morone saxatilis, from the lower Chesapeake Bay. I. Distribution, life cycle, and seasonal
abundance. Canadian Journal of Zoology 54, 449462.
Paperna, I. and Zwerner, D.E. (1981) Hostparasite relationship of Ergasilus labracis Kroyer (Cyclopidea,
Ergasilidae) and the striped bass, Morone saxatilis (Walbaum) from the lower Chesapeake Bay. Annales
de Parasitologie 57, 393405.
Parker, R.R. (1969) Validity of the binomen Caligus elongatus for a common parasitic copepod formerly misidentified with Caligus rapax. Journal of the Fisheries Research Board of Canada 26, 10131035.
Parker, R.R. and Margolis, L. (1964) A new species of parasitic copepod, Caligus clemensi sp. novo (Caligoida,
Caligidae) from pelagic fishes in the coastal waters of British Columbia. Journal of the Fisheries Research
Board of Canada 21, 873889.
Pascual, S., Gestal, C. and Abollo, E. (1997) Effect of Pennella sp. (Copepoda, Pennellidae) on the condition of
Illex coindetii and Todaropsis eblanae (Cephalopoda, Ommastrephidae). Bulletin of the European Association of Fish Pathologists 17, 9195.
Pascual, S., Gonzalez, A., Gestal, C., Abollo, E. and Guerra, A. (2001) Epidemiology of Pennella sp. (Crustacea:
copepoda), in exploited Illex coindetii stock in the NE Atlantic. Scientia Marina 65, 307312.
Pasternak, A., Mikheev, V. and Valtonen, E.T. (2004) Growth and development of Argulus coregoni
(Crustacea: Branchiura) on salmonid and cyprinid hosts. Diseases of Aquatic Organisms 58, 203207.
Patarnello, P.P., Fioravanti, M.L., Caggiano, M. and Restani, R. (1995) Infection by Gnathiidae (Crustacea:
Isopoda) in Pagrus major. Bollettino Societa Italiana di Patologica Ittica 7, 3236.
Perkins, P.S. (1983) The life history of Cardiodectes medusaeus (Wilson), a copepod parasite of lanternfishes
(Myctophidae). Journal of Crustacean Biology 3, 7087.
Perkins, P.S. (1985) Iron crystals in the attachment organ of the erythrophagous copepod Cardiodectes
medusaeus (Pennellidae). Journal of Crustacean Biology 5, 591605.
Petrushevsky, O.K. and Shulman, S.S. (1961) The parasitic diseases of fish in the natural waters of the USSR.
In: Dogiel, V.A., Petrushevski, G.K. and Polyanski, Y.I. (eds) Parasitology of Fishes. Oliver and Boyd,
Edinburgh, UK, pp. 299319.
Piasecki, W. (1989) Life cycle of Tracheliastes maculatus Koller, 1835 (Copepoda, Siphonostomatoida,
Lernaeopodidae). Wiadomosci Parazytologiczne 35, 187245.
Pike, A.W. (1989) Sea lice major pathogens of farmed Atlantic salmon. Parasitology Today 5, 291297.
Pike, A.W. and Wadsworth, S. (1999) Sealice on salmonids, their biology and control. Advances in Parasitology 44, 233337.
Pike, A.W., Mackenzie, K. and Rowland, A. (1993) Ultrastructure of the frontal filament in chalimus larvae of
Caligus elongatus and Lepeophtheirus salmonis from Atlantic salmon, Salmo solar. In: Boxshall, O.A. and
Defaye, D. (eds) Pathogens of Wild and Farmed Fish: Sea Lice. Ellis Horwood, New York, pp. 99113.
Pillai, N.K. (1985) Copepod Parasites of Marine Fishes. Zoological Survey of India, Calcutta.
Pironet, F.N. and Jones, J.B. (2000) Treatments for ectoparasites and diseases in captive Western Australian
dhufish. Aquaculture International 8, 349361.
Poly, W.J. (1998) New state, host and distribution records of the fish ectoparasite, Argulus (Branchiura), from
Illinosis (USA). Crustaceana 71, 18.
Poulin, R. and FitzGerald, G.J. (1987) The potential of parasitism in the structuring of a salt marsh stickleback
community. Canadian Journal of Zoology 65, 27932798.
Poulin, R. and FitzGerald, G.J. (1989a) Risk of parasitism and microhabitat selection in juvenile sticklebacks.
Canadian Journal of Zoology 67, 1418.
Poulin, R. and FitzGerald, G.J. (1989b) Shoaling as an anti-ectoparasite mechanism in juvenile sticklebacks
(Gasterosteus spp.). Behavioural Ecology and Sociobiology 24, 251255.
Poulin, R. and FitzGerald, G.J. (1989c) A possible explanation for the aggregated distribution of Argulus
canadensis Wilson, 1916 (Crustacea: Branchiura) on juvenile sticklebacks (Gasterosteidae). Journal of
Parasitology 75, 5860.
Poulin, R., Curtis, M.A. and Rau, M.E. (1990) Responses of the fish ectoparasite Salmincola edwardsii
(Copepoda) to stimulation, and their implication for host-finding. Parasitology 100, 417421.
Poulin, R., Rau, M.E. and Curtis, M.A. (1991) Infection of brook trout fry, Salvelinus fontinalis, by ectoparasitic
copepods: the role of host behaviour and initial parasite load. Animal Behaviour 41, 467476.
556
Puffer, H.W. and Beal, M.L. (1981) Control of parasitic infestations in killifish (Fundulus parvipinnis). Laboratory Animal Science 31, 200201.
Pulkkinen, K. and Valtonen, E.T. (1998) The use of parasites as tags to elucidate differences between whitefish
populations. Ergebnisse der Limnologie 50, 257271.
Radhakrishnan, S. (1977) Description of a new species of Peniculisa including its immature stages.
Hydrobiologia 52, 251255.
Radhakrishnan, S. and Nair, N.B. (1981a) Histopathology of the infection of Trichiurus savala Cuvier by
Caligus uruguayenses Thomsen (Copepoda: Caligidae). Fisch und Umwelt 10, 147152.
Radhakrishnan, S. and Nair, N.B. (1981b) Nature of Peniculisa wilsoni Radhakrishnan (Copepoda:
Lernaeoceridae) infestation of Diodon hystrix Lennaeus (Pisces: Diodontidae). Journal of Animal Morphology and Physiology 28, 7381.
Radhakrishnan, S. and Nair, N.B. (1981c) Histopathology of the infestation of Diodon hystrix L. by Peniculisa
wilsoni Radhakrishnan (Copepoda: Lernaeoceridae). Journal of Fish Diseases 4, 8387.
Rahman, M.M. (1995) Some aspects of the biology of a freshwater fish parasite, Argulus foliaceus (L.)
(Argulidae, Branchiura, Crustacea). Bangladesh Journal of Zoology 23, 7786.
Rahman, M.M. (1996) Effects of a freshwater fish parasite, Argulus foliaceus Linn. infection on common carp,
Cyprinus carpio Linn. Bangladesh Journal of Zoology 24, 5763.
Raibaut, A. (1985) Les cycles volutifs des copepodes parasites et les modalits de linfestation. Annales de
Biologie 24, 233274.
Raibaut, A. and Trilles, J.P. (1993) The sexuality of parasitic crustaceans. In: Baker, J.R. and Muller, R. (eds)
Advances in Parasitology. Harcourt Brace, London, pp. 367444.
Raibaut, A., Ben Hassine, O.K. and Prunus, G. (1975) Etude de linfestation de Mugil (Mugil) cephalus Linne,
1758 (Poissons, Teleosteens, Mugilides) par le copepode Ergasilus nanus van Beneden, 1870 dans Ie Lac
Ischkeul (Tunisia). Bulletin de la Socit Zoologique de France 100, 427437.
Rand, T.G. (1986) The histopathology of infestation of Paranthias furcifer (L.) (Osteichthyes: Serranidae)
by Nerocila acuminata (Schioedte and Meinert) (Crustacea: Isopoda: Cymothoidea). Journal of Fish
Diseases 9, 143146.
Ravichandran, S., Ranjit Singh, A.J.A., Veerappan, N. and Kannupandi, T. (1999) Effect of isopod parasite
Joryma brachysoma on Illisha melastoma from Parangipettai coastal waters (south-east coast of India).
Ecology Environment and Conservation 5, 95101.
Ravichandran, S., Singh, A.J.A.R. and Veerappan, N. (2001) Parasite induced vibriosis in Chirocentrus dorab
off Parangipettai coastal waters. Current Science 80, 622623.
Rawson, M.V., Jr (1977) Population biology of parasites of striped mullet, Mugil cephalus L. Crustacea. Journal
of Fish Biology 10, 441451.
Raynard, R.S., Bricknell, I.R., Billingsley, P.F., Nisbet, A.J., Vigneau, A. and Sommerville, C. (2002) Development of vaccines against sea lice. Pest Management Science 58, 569575.
Razmashin, D.A. and Shirshov, V.Y. (1981) Argulosis and its prevention in young coregonids reared
in south-western Siberia fish farms. Bolezni Ryb Vodnaya. Toksikologiya (Fish Diseases and Aquatic
Toxicology) 32.
Reichenbach-Klinke, H.H. and Landolt, M. (1973) Fish Pathology. TFH, Jersey City, New Jersey.
Reilly, P. and Mulcahy, M.F. (1993) Humoral antibody response in Atlantic salmon (Salmo salar L.) immunised with extracts derived from the ectoparasitic caligid copepods, Caligus elongatus (Nordmann,
1832) and Lepeophtheirus salmonis (Kroyer, 1838). Fish and Shellfish Immunology 3, 5970.
Revie, C., Gettinby, G., Treasurer, J.M. and Rae, G.H. (2002) The epidemiology of the sea lice, Caligus
elongatus Nordmann, in marine aquaculture of Atlantic salmon, Salmo salar L., in Scotland. Journal of
Fish Diseases 25, 391399.
Revie, C., Gettinby, G., Treasurer, J.M. and Wallace, C. (2003) Identifying epidemiological factors affecting
sea lice Lepeophtheirus salmonis abundance on Scottish salmon farms using general linear models. Diseases of Aquatic Organisms 57, 8595.
Rigby, D. and Tunnell, N. (1971) Internal anatomy and histology of female Pseudocharopinus dentatus
(Copepoda, Lernaeopodidae). Transactions of the American Microscopical Society 90, 6171.
Ritchie, G., Mordue, A.J., Pike, A.W. and Rae, G.H. (1993) The reproductive output of Lepeophtheirus salmonis
adult females in relation to seasonal variability of temperature and photoperiod. In: Boxshall, G.A. and
Defaye, D. (eds) Pathogens of Wild and Farmed Fish: Sea Lice. Ellis Horwood, New York, pp. 153165.
Ritchie, G., Rnsberg, S., Hoff, K.A. and Branson, E.J. (2002) Clinical efficacy of teflubenzuron (Calicide) for
the treatment of Lepeophtheirus salmonis infestations of farmed Atlantic salmon Salmo salar at low water
temperatures. Diseases of Aquatic Organisms 51, 101106.
Phylum Arthropoda
557
Roberts, L.S. (1970) Ergasilus (Copepoda, Cyclopoida): revision and key to species in North America. Transactions of the American Microscopical Society 89, 134161.
Robinson, G.R. (1981) Otter trawl sampling bias of the gill parasite Lironeca vulgaris from sand dab hosts,
Citharichthys spp. Fishery Bulletin 80, 907909.
Rogers, W.A. (1969) Ergasilus cyprinaceus sp. n. (Copepoda: Cyclopoida) from cyprinid fishes of Alabama,
with notes on its biology and pathology. Journal of Parasitology 55, 443446.
Rokicki, J. (1997) Variation and distribution of the fish parasitic isopod Nerocila orbignyi (Guerin-Meneville,
18291832) (Isopoda, Cymothoidae). Arthropoda Selecta 6, 5962.
Romero, R.C. and Kuroki, H.B. (1986) Pre-metamorphosis stages of two pennellids (Copepoda,
Siphonostomatoida) from their definitive hosts. Crustaceana 50, 166175.
Romero, R.C. and Kuroki, H.B. (1989) Lamelliform structures on the proboscis of Peniculus and Metapeniculus
(Copepoda: Pennellidae). Proceedings of the Biological Society of Washington 102, 912915.
Romestand, B. (1979) Etude cophysiologique des parasitoses Cymothoadiens. Annales de Parasitologie 54,
423448.
Romestand, B. and Trilles, J.-P. (1975) Les relations immunologiques hteparasite chez les Cymothoidae
(Isopoda, Flabellifera). Compte Rendu de l Acadmie des Sciences, Paris, Ser. D 280, 21712173.
Romestand, B. and Trilles, J.-P. (1976) Production dune substance anticoagulante par les glandes exocrines
cphalothoraciques des Isopodes Cymothoidae Meinertia oestroides (Risso, 1826) et Anilocra physodes
(L., 1758) (Isopoda, Flabellifera, Cymothoidae). Compte Rendu de lAcademie des Sciences, Paris 282,
663665.
Romestand, B. and Trilles, J.-P. (1977a) Influence des Cymothoadiens (Crustacea, Isopoda, Flabellifera) sur
certaines constantes hmatologiques des poissons htes. Zeitschrift fr Parasitenkunde 52, 9195.
Romestand, B. and Trilles, J.-P. (1977b) Dgnrescence de la langue des Bogues [(Boops hoops L., 1758)
(Teleosteens, Sparidae)] parasites par Meinertia oestroides (Risso, 1826) (Isopoda, Flabellifera,
Cymothoidae). Zeitschrift fr Parasitenkunde 54, 4753.
Romestand, B. and Trilles, J.-P. (1979) Influence des Cymothoadiens Meinertia oestroides, Meinertia parallela
et Anilocra physodes (Crustaces, Isopodes; parasites de poissons) sur la croissance des poissons htes
Boops hoops et Pagellus erythrinus (Sparides). Zeitschrift fr Parasitenkunde 59, 195202.
Romestand, B., Thuet, P. and Trilles, J.-P. (1982) Quelques aspects des mcanismes nutritionnels
chez lisopode Cymothoidae: Ceratothoa oestroides (Risso, 1826). Annales de Parasitologie 57,
7989.
Rose, M. and Hamon, M. (1953) A propos de Pennella varians Steenstrup et Lutken, 1861, parasite des
branchies de Cephalopodes. Bulletin de la Socit dHistoire Naturelle de lAfrique du Nord 44,
172183.
Ross, S.W., Sulak, K.J. and Munroe, T.A. (2001) Association of Syscenus infelix (Crustacea: Isopoda: Aegidae)
with benthopelagic rattail fishes, Nezumia spp. (Macrouridae), along the western North Atlantic continental slope. Marine Biology 138, 595601.
Roth, M. (1988) Morphology and development of the egg case in the parasitic copepod Haemobaphes
intermedius Kabata, 1967 (Copepoda: Pennellidae). Canadian Journal of Zoology 66, 25732577.
Roth, M., Richards, R.H. and Sommerville, C. (1993) Current practices in the chemotherapeutic control of sea
lice infestations in aquaculture: a review. Journal of Fish Diseases 16, 126.
Roth, M., Richards, R., Dobson, D.P. and Rae, G.H. (1996) Field trials on the efficacy of the organophosphate
compound Azimethiphos for the control of sea lice (Copepoda, Caligidae) infestations of farmed Atlantic
salmon (Salmo salar). Aquaculture 140, 197217.
Roubal, F.R. (1981) The taxonomy and site specificity of the metazoan ectoparasites on the black bream,
Acanthopagrus australis (Gunther), in northern New South Wales. Australian Journal of Zoology, Supplementary Series 84, 1100.
Roubal, F.R. (1986a) Studies on monogeneans and copepods parasitizing the gills of a sparid (Acanthopagrus
australis (Gunther)) in northern New South Wales. Canadian Journal of Zoology 64, 841849.
Roubal, F.R. (1986b) The histopathology of the copepod, Ergasilus lizae Kroyer, on the pseudobranchs
of the teleost, Acanthopagrus australis (Gunther) (family Sparidae). Zoologischer Anzeiger 217,
6574.
Roubal, F.R. (1987) Comparison of ectoparasite pathology on gills of yellow fin bream, Acanthopagrus australis
(Gunther) (Pisces: Sparidae): a surface area approach. Australian Journal of Zoology 35, 93100.
Roubal, F.R. (1989a) Pathological changes in the gill filaments of Acanthopagrus australis (family Sparidae)
associated with the post-settlement growth of a lernaeopodid copepod, Alella macrotrachelus. Journal of
Fish Biology 34, 333342.
558
Roubal, F.R. (1989b) Comparative pathology of some monogenean and copepod ectoparasites on the gills of
Acanthopagrus australis (family Sparidae). Journal of Fish Biology 34, 503514.
Roubal, F.R. (1990) Seasonal changes in ectoparasite infection of juvenile yellow fin bream, Acanthopagrus
australis (Gunther) (Pisces: Sparidae), from a small estuary in northern New South Wales. Australian Journal of Marine and Freshwater Research 41, 411427.
Roubal, F.R. (1994) Histopathology caused by Caligus epidemicus Hewitt (Copepoda: Caligidae) on captive
Acanthopagrus australis (Gunther) (Pisces: Sparidae). Journal of Fish Diseases 17, 631640.
Rough, K. (2000) An Illustrated Guide to the Parasites of Southern Bluefin Tuna, Thunnus maccoyii. Tuna Boat
Owners Association of South Australia, Canberra, Australia.
Rousset, V. and Raibaut, A. (1989) Peculiar cases of intracardiac parasitism in the pilchard, Sardina pilchardus
(Walbaum), by a pennellid copepod belonging to the genus Lernaeenicus. Journal of Fish Diseases 12,
263268.
Ruane, N., McCarthy, T.K. and Reilly, P. (1995) Antibody response to crustacean ectoparasites in rainbow
trout, Oncorhynchus mykiss (Walbaum), immunized with Argulus foliaceus L. antigen extract. Journal of
Fish Diseases 18, 529537.
Ruangpan, L. and Kabata, Z. (1984) An invertebrate host for Caligus (Copepoda, Caligidae)? Crustaceana 47,
219220.
Rushton-Mellor, S.K. (1994) The genus Argulus (Crustacea: Branchuira) in Africa: identification keys. Systematic Parasitology 28, 5163.
Rushton-Mellor, S.K. and Boxshall, G.A. (1994) The developmental sequence of Argulus foliaceus (Crustacea:
Branchiura). Journal of Natural History 28, 763785.
Rushton-Mellor, S.K. and Whitfield, P.J. (1993) Transmission and scanning electron microscope studies of
crustacean shell disease in fish lice of the genus Argulus (Crustacea: Branchiura). Journal of Zoology 229,
397404.
Russell, F.S. (1933) On the occurrence of young stages of Caligidae on pelagic young fish in the Plymouth
area. Journal of the Marine Biological Association, UK 18, 551553.
Sadowsky, V. and Soares Moreira, P. (1981) Occurrence of Squalus cubensis Rivero, 1936, in the Western
South Atlantic Ocean, and incidence of its parasitic copepod Lironeca splendida sp. n. Studies on Neotropical Fauna and Environment 16, 137150.
Sadzikowski, M.R. and Wallace, D.C. (1974) The incidence of Lironeca ovalis (Say) (Crustacea, Isopoda) and
its effects on the growth of white perch, Morone americana (Gmelin), in the Delaware River near Artificial Island. Chesapeake Science 15, 163165.
Sakuma, K.M., Ralston, S., Lenarz, W.H. and Embury, M. (1999) Effects of the parasitic copepod Cardiodectes
medusaeus on the lanternfishes Diaphus theta and Tarletonbeania crenularis off central California. Environmental Biology of Fishes 55, 423430.
Salm, v.d., A.L., Nolan, D.T., Spaning, F.A.T. and Bonga, S.E.W. (2000) Effects of infection with the
ectoparasite Argulus japonicus (Theile) and administration of cortisol on cellular proliferation and
apoptosis in the epidermis of common carp, Cyprinus carpio L., skin. Journal of Fish Diseases 23,
173184.
Sandifer, P.A. and Kerby, J.H. (1983) Early life history and biology of the common fish parasite, Lironeca ovalis
(Say) (Isopoda, Cymothoidae). Estuaries 6, 420425.
Sarig, S. (1971) Diseases of Fishes, Book 3: The Prevention and Treatment of Diseases of Warmwater Fishes.
TFH, Neptune City, New Jersey.
Sarusic, G. (1999) Preliminary report of infestation by isopod Ceratothoa oestroides (Risso, 1826), in marine
cultured fish. Bulletin of the European Association of Fish Pathologists 19, 110112.
Schaefer, S.A. (1993) A remarkable occurrence of isopod parasitism on an armoured catfish, Microlepidogaster maculipinnis. Journal of Fish Biology 42, 307310.
Schafer, J.W., Enriquez, R. and Monras, M. (1989) Preliminary results of two years ichthyopathological service
(19871989) in the south of Chile. In: IV EAFP Conference. EAFP, Santiago, p. 6 (abstract).
Schaperclaus, W., Kulow, H. and Schreckenbach, K. (1991) Fish Diseases, 5th edn. Oxion Press, New Delhi,
India.
Schluter, U. (1978) Beobachtungen zum Befall des Wirtes durch die Karpfenlaus Argulus foliaceus L.
(Crustacea, Branchiura). Zoologischer Anzeiger 200, 8591.
Schluter, U. (1979) Uber die Temperaturabhangigkeit des Wachstums und des Hautungszyklus von
Argulusfoliaceus (L.) (Branchiura). Crustaceana 37, 100106.
Schram, T.A. (1979) The life history of the eye-maggot of the sprat, Lernaeenicus sprattae (Sowberby)
(Copepoda, Lernaeoceridae). Sarsia 64, 279316.
Phylum Arthropoda
559
Schram, T.A. (1993) Supplementary descriptions of the developmental stages of Lepeophtheirus salmonis
(Kroyer, 1837) (Copepoda: Caligidae). In: Boxshall, G.A. and Defaye, D. (eds) Pathogens of Wild and
Farmed Fish: Sea Lice. Ellis Horwood, New York, pp. 3047.
Schram, T.A. and Anstensrud, M. (1985) Lernaeenicus sprattae (Sowerby) larvae in the Oslofjord plankton and
some laboratory experiments with the nauplius and copepodid (Copepoda: Penellidae). Sarsia 70,
127134.
Schultz, D.A. (1969) How to Know the Marine Isopod Crustaceans. Brown, Dubuque, Iowa.
Scott, P.W. and Fogel, B. (1983) Treatment of ornamental carp with anchorworm. Veterinary Record 113, 421.
Seenappa, D. and Venkateshappa, T. (2000) Multiple parasitic infestation on freshwater shark, Wallago attu
(Schneider) and associated gross pathology. Mysore Journal of Argricultural Sciences 34, 153156.
Segal, E. (1987) Behaviour of juvenile Nerocila acuminata (Isopoda, Cymothoidae) during attack, attachment
and feeding on fish prey. Bulletin of Marine Science 41, 351360.
Shafir, A. and Van As, J.G. (1986) Laying, development and hatching of eggs of the fish ectoparasite Argulus
japonicus (Crustacea: Branchiura). Journal of Zoology 210, 401414.
Shariff, M. (1981) The histopathology of the eye of big head carp, Aristichthys nobilis (Richardson), infested
with Lernaea piscinae Harding, 1950. Journal of Fish Diseases 4, 161168.
Shariff, M. and Roberts, R.J. (1989) The experimental histopathology of Lernaea polymorpha Yu, 1938 infection in naive Aristichthys nobilis (Richardson) and a comparison in naturally infected clinically resistant
fish. Journal of Fish Diseases 12, 405414.
Shariff, M. and Sommerville, C. (1986a) Identification and distribution of Lernaea spp. in peninsular Malaysia.
In: Maclean, J.L., Dizon, L.B. and Hosillos, L.V. (eds) First Asian Fisheries Forum. Asian Fisheries Society,
Manila, pp. 269272.
Shariff, M. and Sommerville, C. (1986b) The life cycles of Lernaea polymorpha and L. cyprinacea. In:
Maclean, J.L., Dizon, L.B. and Hosillos, L.V. (eds) First Asian Fisheries Forum. Asian Fisheries Society,
Manila, pp. 273278.
Shariff, M. and Sommerville, C. (1986c) Effects of Lernaea polymorpha on the growth of big head carp,
Aristichthys nobilis. In: ICOPA VI Handbook, Australian Academy of Sciences, Canberra, Abstract no.
598, p. 227.
Shariff, M. and Sommerville, C. (1990) Comparative morphology of adult Lernaea polymorpha Yu and
Lernaea cyprinacea Linnaeus. In: Hirano, R. and Hanyu, I. (eds) Second Asian Fisheries Forum. Asian
Fisheries Society, Manila, pp. 717720.
Shariff, M., Kabata, Z. and Sommerville, C. (1986) Host susceptibility to Lernaea cyprincaea L. and its
treatment in a large aquarium system. Journal of Fish Diseases 9, 393401.
Sherman, K. and Wise, J.P. (1961) Incidence of the cod parasite Lernaeocera branchialis L. in the New England
area and its possible use as an indicator of cod populations. Limnology and Oceanography 6, 6167.
Shields, R.J. (1978) Procedures for the laboratory rearing of Lernaea cyprinacea L. (Copepoda). Crustaceana
35, 259264.
Shields, R.J. and Goode, R.P. (1978) Host rejection of Lernaea cyprinacea L. (Copepoda). Crustaceana 35,
301307.
Shields, R.J. and Sperber, R.G. (1974) Osmotic relationships of Lernaea cyprinacea L. (Copepoda). Crustaceana
26, 157171.
Shields, R.J. and Tidd, W.M. (1968) Effect of temperature on the development of larval and transformed
females of Lernaea cyprinacea L. (Lernaeidae). Crustaceana 15, Suppl. 1, 8795.
Shields, R.J. and Tidd, W.M. (1974) Site selection on hosts by copepodids of Lernaea cyprinacea L.
(Copepoda). Crustaceana 27, 225230.
Shiino, S.M. (1958) Copepods parasitic on Japanese fishes. 17. Lernaeidae. Report of the Faculty of Fisheries,
Prefectural University of Mie 3, 75100.
Shimura, S. (1981) The larval development of Argulus coregoni Thorell (Crustacea: Branchiura). Journal of
Natural History 15, 331348.
Shimura, S. (1983a) Seasonal occurrence, sex ratio and site preference of Argulus coregoni Thorell (Crustacea:
Branchiura) parasitic on cultured freshwater salmonids in Japan. Parasitology 86, 537552.
Shimura, S. (1983b) SEM observation on the mouth tube and preoral sting of Argulus coregoni Thorell and
Argulus japonicus Thiele (Crustacea: Branchiura). Fish Pathology, Tokyo 18, 151156.
Shimura, S. and Asai, M. (1984) Argulus americanus (Crustacea: Branchiura) parasitic on the bowfin, Amia
calva, imported from North America. Fish Pathology, Tokyo 18, 199213.
Shimura, S. and Inoue, K. (1984) Toxic effects of extract from the mouth-parts of Argulus coregoni Thorell
(Crustacea: Branchiura). Bulletin of the Japanese Society of Scientific Fisheries 50, 729.
560
Shimura, S., Inoue, K., Kudo, M. and Egusa, S. (1983a) Studies on effects of parasitism of Argulus coregoni
(Crustacea: Branchiura) on furunculosis of Oncorhynchus masou (Salmonidae). Fish Pathology, Tokyo
18, 3740.
Shimura, S., Inoue, K., Kasai, K. and Saito, H. (1983b) Hematological changes of Oncorhynchus masou
(Salmonidae) caused by the infection of Argulus coregoni (Crustacea: Branchiura). Fish Pathology, Tokyo
18, 157162.
Shotter, R.A. (1971) The biology of Clavella uncinata (Muller) (Crustacea: Copepoda). Parasitology 63,
419430.
Shotter, R.A. (1973) A comparison of the parasite fauna of young whiting, Odontogadus merlangus (L.)
(Gadidae) from an inshore and an offshore location off the Isle of Man. Journal of Fish Biology 5,
185195.
Shotter, R.A. (1976) The distribution of some helminth and copepod parasites in tissues of whiting, Merlangius
merlangus L., from Manx waters. Journal of Fish Biology 8, 101117.
Sievers, G., Palacios, P., Inostroza, R. and Dolz, H. (1995) Evaluation of the toxicity of 8 insecticides in
Salmo salar and the in vitro effects against the isopod parasite, Ceratothoa gaudichaudii. Aquaculture
134, 916.
Sievers, G., Lobos, C., Inostroza, R. and Ernst, S. (1996) The effect of the isopod parasite Ceratothoa
gaudichaudii on the body weight of farmed Salmo salar in southern Chile. Aquaculture 143, 16.
Sievers, G., Lobos, C. and Inostroza, R. (1997) Variation of infestation intensity with infective stages of the
isopod Ceratothoa gaudichaudii in farmed salmon in the south of Chile. Archivos de Medicina
Veterinaria 29, 121125.
Silva-Souza, A.T., Almeida, S.C. and Machado, P.M. (2000) Effect of the infestation by Lernaea cyprinacea
Linnaeus, 1758 (Copepoda, Lernaeidae) on the leucocytes of Schizodon intermedius Garavello and
Britski, 1990 (Osteichthyes, Anostomidae). Revista Brasilerira de Biologia 60, 217220.
Singhal, R.N., Jeet, S. and Davies, R.W. (1986) Chemotherapy of six ectoparasitic diseases of cultured fish.
Aquaculture and Fisheries Management 54, 165171.
Singhal, R.N., Jeet, S. and Davies, R.W. (1990) The effects of argulosis-saproleniasis on the growth and production of Cyprinus carpoi. Hydrobiologia 202, 2731.
Slinn, D.J. (1970) An infestation of adult Lernaeocera (Copepoda) on wild sole, Solea solea, kept under hatchery conditions. Journal of the Marine Biological Association, UK 50, 787800.
Smit, N.J. and Basson, L. (2002) Gnathia pantherina sp. n. (Crustacea: Isopods: Gnathiidae), a temporary ectoparasite of some elasmobranch species from southern Africa. Folia Parasitologica 49,
137151.
Smit, N.J., Basson, L. and Van As, J.G. (2003) Life cycle of the temporary fish parasite, Gnathia africana
(Crustacea: Isopoda: Gnathiidae). Folia Parasitologica 50, 135142.
Smith, J.A. and Whitfield, P.J. (1988) Ultrastructural studies on the early cuticular metamorphosis of adult
female Lernaeocera branchialis (L.) (Copepoda, Pennellidae). Hydrobiologia 167/168, 607616.
Sproston, N.G. (1942) The developmental stages of Lernaeocera branchialis (Linn.). Journal of the Marine
Biological Association, UK 25, 441466.
Sproston, N.G. and Hartley, P.H.T. (1941a) The ecology of some parasitic copepods of gadoids and other
fishes. Journal of the Marine Biological Association, UK 25, 361392.
Sproston, N.G. and Hartley, P.H.T. (1941b) Observations on the bionomics and physiology of Trebius
caudatus and Lernaeocera branchialis (Copepoda). Journal of the Marine Biological Association, UK 25,
393417.
Stammer, J. (1959) Beitrage zur Morphologie, Biologie und Bekiimpfung der Karpfenlause. Zeitschrift fr
Parasitenkunde 19, 135208.
Stekhoven, J.H.S. (1936) Beobachtungen zur Morphologie und Physiologie der Lernaeocera branchialis L. und
der Lernaeocera lusci Bassett-Smith (Crustacea parasitica). Zeitschrift fr Parasitenkunde 8, 659697.
Stekhoven, J.H.S. and Punt, A. (1937) Weitere Beitriige zur Morphologie und Physiologie der Lernaeocera
branchialis L. Zeitschrift fr Parasitenkunde 9, 648668.
Stephenson, A.B. (1976) Gill damage to fish produced by buccal parasites. Records of the Aukland Institute
and Museum 13, 167173.
Stephenson, A.B. (1987) Additional notes on Lironeca neocyttus (Isopoda: Cymothoidae). Records of the
Aukland Institute and Museum 24, 135142.
Stepien, C.A. and Brusca, C.B. (1985) Nocturnal attacks on nearshore fishes in southern Calfornia by crustacean zooplankton. Marine Ecology 25, 91105.
Phylum Arthropoda
561
Stoll, C. (1962) Cycle volutif de Paragnathia formica (Hesse) (Isopode-Gnathiidae). Cahiers de Biologie
Marine 3, 401416.
Stone, J., Sutherland, I., Sommerville, C., Richards, R.H. and Endris, R.G. (2000) The duration and efficacy following oral treatment with emamectin benzoate against infestations of sea lice, Lepeophtheirus salmonis
(Kryer), in Atlantic salmon Salmo salar L. Journal of Fish Diseases 23, 185192.
Stuart, R. (1990) Sea lice, a maritime perspective. Bulletin of the Aquaculture Association of Canada 90,
1824.
Sundnes, G., Mork, J., Solemdal, P. and Solemdal, K. (1997) Lernaeocera branchialis (L., 1767) on cod in
Baltic waters. Helgolander Meeresuntersuchungen 51, 191196.
Sutherland, D.R. and Wittrock, D.D. (1985) The effects of Salmincola californiensis (Copepoda:
Lernaeopodidae) on the gills of farm-raised rainbow trout, Salmo gairdneri. Canadian Journal of Zoology
63, 28932901.
Sutherland, D.R. and Wittrock, D.D. (1986) Surface topography of the branchiuran Argulus appendiculosus
Wilson, 1907 as revealed by scanning electron microscopy. Zeitschrift fr Parasitenkunde 72, 405415.
Svavarsson, J. and Davidsdottir, B. (1994) Foraminiferan (Protozoan) epizoites on Arctic isopods (Crustacea)
as indicators of isopod behaviour? Marine Biology 118, 239246.
Szidat, L. (1966) Untersuchungen Tiber den Entwicklungszyklus von Meinertia gaudichaudii (Milne Edwards,
1840) Stebbing, 1886 (Isopoda, Cymothoidae) und die Entstehung eines sekundiiren Sexualdimorphismus
bei Parasitischen asseln der Familie Cymothoidae Schioedte u. Meinert, 1881. Zeitschrift fr
Parasitenkunde 27, 124.
Tamuli, K.K. and Shanbhogue, S.L. (1995) Biological control of Lernaea L. infection employing Oreochromis
mossambica, Peters. Journal of the Assam Science Society 37, 123128.
Tamuli, K.K. and Shanbhogue, S.L. (1996a) Efficacy of some commonly available chemicals in the treatment
of anchor worm (Lernaea bhadraensis) infection. Environment and Ecology 14, 259267.
Tamuli, K.K. and Shanbhogue, S.L. (1996b) Incidence and intensity of anchor worm Lernaea bhadraensis
infection on cultivated carps. Environment and Ecology 14, 282288.
Tamuli, K.K. and Shanbhogue, S.L. (1996c) Acquired immunity of Indian major carp Catla catla to infection of
the anchor worm Lernaea bhadraensis. Environment and Ecology 14, 518523.
Tanaka, K. (1998) Current knowledge on gnathiid isopods. Biological Sciences 49, 213218.
Tanaka, K. (2002) Predation risks involved in the parasitic behaviour of gnathiid isopods (Crustacea). Japanese
Journal of Benthology 57, 8589.
Tanaka, K. and Aoki, M. (1998) Crustacean infauna of the demosponge Halichondria okadai (Kadota) with reference to the life cycle of Gnathia sp. (Isopoda: Gnathiidea). In: Watanabe, Y. and Fusetani, N. (eds)
Sponge Sciences: Multidisciplinary Perspectives. Springer Verlag, Tokyo, pp. 259267.
Tanaka, K. and Aoki, M. (2000) Seasonal traits of reproduction in a gnathiid isopod Elaphognathia cornigera
(Nunomura, 1992). Zoological Science 17, 467475.
Templeman, W., Hodder, V.M. and Fleming, A.M. (1976) Infection of lumpfish (Cyclopterus lumpus) with
larvae and of Atlantic cod (Gadus morhua) with adults of the copepod, Lernaeocera branchialis, in and
adjacent to the Newfoundland area, and inferences there from on inshoreoffshore migrations of cod.
Journal of the Fisheries Research Board of Canada 33, 711731.
Thatcher, V.E. (1988) Asotana magnifica n. sp. (Isopoda, Cymothoidae), an unusual parasite (commensal?) of
the buccal cavities of piranhas (Serrasalmus sp.) from Roraima, Brazil. Amazoniana 10, 239248.
Thatcher, V.E. (1998) Copepods and fishes in the Brazilian Amazon. Journal of Marine Systems 15, 97112.
Thatcher, V.E. (2000) The isopod parasites of South American fishes. In: Salgado-Maldonado, G., Aldrete, A.N.G.
and Vidal-Martinez, V.M. (eds) Metazoan Parasites in the Neotropics a Systematic and Ecological
Perspective. Instituto de Biologia, Universidad Nacional Autonoma de Mexico (UNAM), Mexico City,
pp. 193226.
Thatcher, V.E. and Blumenfeldt, C.L. (2001) Anilocra montti sp. n. (Isopoda, Cymothoidae) a parasite of caged
salmon and trout in Chile. Revista Brasileira de Zoologia 18, 269276.
Thatcher, V.E. and Boeger, W.A. (1983) The parasitic crustaceans of fishes from the Brazilian Amazon. 4.
Ergasilus colomesus n. sp. (Copepoda: Cyclopoida) from an ornamental fish, Colomesus asellus
(Tetraodontidae) and aspects of its pathogenicity. Transactions of the American Microscopical Society
102, 371379.
Thatcher, V.E. and Carvalho, M.L. (1988) Artystone minima n. sp. (Isopoda, Cymothoidae), a body cavity
parasite of the pencil fish (Nannostomus beckfordi Guenther) from the Brazilian Amazon. Amazoniana
10, 255265.
562
Thatcher, V.E. and Williams, E.H.J. (1998) Comparative morphology of three native lernaeids (Copepoda:
Cyclopoida) from Amazonian fishes and descriptions of two new genera. Journal of Aquatic Animal
Health 10, 300308.
Thomassen, J.M. (1993) Hydrogen peroxide as a delousing agent for Atlantic salmon. In: Boxshall, G.A. and
Defaye, D. (eds) Pathogens of Wild and Farmed Fish: Sea Lice. Ellis Horwood, New York, pp. 290295.
Thoney, D.A. and Burreson, E.M. (1988) Lack of a specific humoral antibody response in Leiostomus
xanthurus (Pisces: Sciaenidae) to parasitic copepods and monogeneans. Journal of Parasitology 74,
191193.
Thorsen, D.H. and Trilles, J.P. (2002) The occurrence of Anilocra capensis and Nerocila armata (Isopoda:
Cymothoidae) in the Canary Islands with comments on their novel hosts. Bulletin of Marine Science 70,
227231.
Thurston, J.P. (1969) The biology of Lernaea barnimiana (Crustacea: Copepoda) from Lake George, Uganda.
Revue de Zoologie et de Botanique Africaines 80, 1533.
Tidd, W.M. and Shields, R.J. (1963) Tissue damage inflicted by Lernaea cyprinacea Linnaeus, a copepod parasitic on tadpoles. Journal of Parasitology 49, 693696.
Tikhomirova, V.A. (1983) Carp lice intermediate hosts of Skrjabillanidae nematodes. Vliyanie
Antropogennykh Faktorov na Strukturu i Funktsionirovanie Ekosystem Kalinin, State University, Kalinin,
pp. 104109.
Tinsley, M.C. and Reilly, S.D. (2002) Reproductive ecology of the saltmarsh-dwelling marine ectoparasite
Paragnathia formica (Crustacea: Isopoda). Journal of the Marine Biological Association of the United
Kingdom 82, 7984.
Tirard, C., Berrebi, P., Raibaut, A. and Renaud, F. (1993) Biodiversity and biogeography in heterospecific teleostean (Gadidae)copepod (Lernaeocera) associations. Canadian Journal of Zoology 71,
16391645.
Todd, C., Walker, A., Wolff, K., Northcott, S.J., Walker, A.F., Ritchie, M.G., Hoskins, R., Abbott, R.J. and
Hazon, N. (1997) Genetic differentiation of populations of the copepod sea louse Lepeophtheirus
salmonis (Kryer) ectoparasitic on wild and farmed salmonids around the coasts of Scotland: evidence
from RAPD markers. Journal of Experimental Marine Biology and Ecology 210, 251274.
Todd, C.D., Walker, A.M., Ritchie, M.G., Graves, J.A. and Walker, A.F. (2004) Population genetic differentiation of sea lice (Lepeophtheirus salmonis) parasitic on Atlantic and Pacific salmonids: analyses of
microsatellite DNA variation among wild and farmed hosts. Canadian Journal of Fisheries and Aquatic
Sciences 61, 11761190.
Treasurer, J.W. (1993) Management of sea lice (Caligidae) with wrasse (Labridae) on Atlantic salmon (Salmo
salar L.) farms. In: Boxshall, G.A. and Defaye, D. (eds) Pathogens of Wild and Farmed Fish: Sea Lice. Ellis
Horwood, New York, pp. 335345.
Treasurer, J.W., Wadsworth, S. and Grant, A. (2000) Resistance of sea lice, Lepeophtheirus salmonis (Kroyer),
to hydrogen peroxide on farmed Atlantic salmon, Salmo salar. Aquaculture Research 31, 855860.
Trilles, J.-P. (1964a) A propos dun fait particulier dthologie parasitaire chez les isopodes Cymothoidae:
la relation de taille entre parasites et poissons. Note prliminaire. Vie et Milieu 15, 365369.
Trilles, J.-P. (1964b) Variations morphologiques du crane chez les tlostens Sparidae et Centracanthidae en
rapport avec lexistence sur ces poissons de certains Cymothoidae parasites. Annales de Parasitologie
39, 627630.
Trilles, J.-P. (1968) Recherches sur les isopodes Cymthoidae des ctes franaises I. Thse dEtat, Universit de
Montpellier, France, 181 pp.
Trilles, J.-P. (1975) Les Cymothoidae (Isopoda, Flabellifera) des ctes franaises. II. Les Anilocridae Schioedte
et Meinert, 1881. Genres Anilocra Leach, 1818, et Nerocila Leach, 1818. Bulletin du Musum National
dHistoire Naturelle, Paris, Section A 200, 303346.
Trilles, J.-P. (1991) Les Cymothoidae (Crustacea, Isopoda) du monde. Studia Marina 21/22, 5288.
Trilles, J.-P. and Hipeau-Jacquotte, R. (1996) Associations et parasitisme chez les crustaces. In: Grasse, P.P.
(ed.) Trait de zoologie, anatomie, systmatiques, biologie. Masson, Paris, pp. 187234.
Tsai, M.L. and Dai, C.F. (1999) Ichthyoxenus fushanensis, new species (Isopoda: Cymothoidae), parasite of
the freshwater fish Varicorhinus barbatulus from Northern Taiwan. Journal of Crustacean Biology 19,
917923.
Tucker, C., Norman, R., Shinn, A.P., Bron, J.E., Sommerville, C. and Wootten, R (2002) A single cohort time
delay model of the life-cycle of the salmon louse Lepeophtheirus salmonis on Atlantic salmon Salmo
salar. Fish Pathology 37, 107118.
Phylum Arthropoda
563
Tully, O. (1989) The succession of generations and growth of the caligoid copepods Caligus elongatus and
Lepeophtheirus salmonis parasitising farmed Atlantic salmon smolts (Salmo salar L.). Journal of the
Marine Biological Association, UK 69, 279287.
Tully, O. and Whelan, K.F. (1992) The impact of sea lice (Lepeophtheirus salmonis) infestation of sea trout
(Salmo trutta L.) along the west coast of Ireland, 19891991. In: Pathological Conditions of Wild
Salmonids. SOAFD Marine Laboratory, Aberdeen, UK (abstract).
Turner, W.R. and Roe, R.B. (1967) Occurrence of the parasitic isopod Olencira praegustator in the yellowfin
menhaden, Brevoortia smithi. Transactions of the American Fisheries Society 96, 357359.
Tuuha, H., Valtonen, E.T. and Taskinen, J. (1992) Ergasilid copepods as parasites of perch Perca fluviatilis and
roach Rutilus rutilus in central Finland: seasonality, maturity and environmental influence. Journal of
Zoology 228, 405422.
Uehara, J.K., Sholz, A.T., Lang, B.Z. and Anderson, E. (1984) Prevalence of the ectoparasitic copepod Lernaea
cyprinacea L. on four species of fish in Medical Lake, Spokane County, Washington. Journal of Parasitology 70, 183184.
Ueki, N. and Sugiyama, T. (1979) Mass mortality of cultured juvenile black sea bream Mylio macrocephalus
in cold water season 1. Influence of the gill-parasitic copepod Clavellodes macrotrachelus. Bulletin of
the Fisheries Experimental Station, Okayama, Japan 1979, 197201.
Upton, N.P.D. (1987a) Asynchronous male and female life cycles in the sexually dimorphic, harem-forming
isopod Paragnathia formica (Crustacea: Isopoda). Journal of the Zoological Society of London 212,
677690.
Upton, N.P.D. (1987b) Gregarious larval settlement within a restricted intertidal zone and sex differences in
subsequent mortality in the polygynous saltmarsh isopod Paragnathia formica (Crustacea: Isopoda). Journal of the Marine Biological Association of the United Kingdom 67, 663678.
Urawa, S. (1998) A study of Lepeophtheirus salmonis (Copepoda, Caligidae) on sea water-cultured coho
salmon (Oncorhynchus kisutch) and rainbow trout (O. mykiss) in Japan. Bulletin of the National Salmon
Resources Centre 1, 3538.
Urawa, S. and Kato, T. (1991) Heavy infections of Caligus orientalis (Copepoda: Caligidae) on caged rainbow
trout Oncorhynchus mykiss in brackish water. Fish Pathology 26, 161162.
Urawa, S., Muroga, K. and Izawa, K. (1979) Caligus orientalis Gussev (Copepoda) parasitic on akame (Lize
akame). Fish Pathology 13, 139146.
Urawa, S., Muroga, K. and Kasahara, S. (1980a) Naupliar development of Neoergasilus japonicus (Copepoda:
Ergasilidae). Bulletin of the Japanese Society of Scientific Fisheries 46, 941947.
Urawa, S., Muroga, K. and Kasahara, S. (1980b) Studies on Neoergasilus japonicus (Copepoda: Ergasilidae), a
parasite of freshwater fishes II. Development in copepodid stage. Journal of the Faculty of Applied
Biological Science, Hiroshima University 19, 2138.
Uzmann, J.R. and Rayner, H.J. (1958) Record of the parasitic copepod Lernaea cyprinacea L. in Oregon and
Washington fishes. Journal of Parasitology 44, 452453.
Valtonen, E.T., Koskivaara, M. and Brummer-Korvenkontio, H. (1987) Parasites of fishes in central Finland in
relation to environmental stress. In: Lake Paeijaenne Symposium, 1987. Biology Research Report
University of Jyvaeskylae, 10, pp. 129130.
Van As, J.G. and Viljoen, S. (1984) A taxonomic study of sessile peritrichs (Ciliophora: Peritricha) associated with crustacean fish ectoparasites in South Africa. South African Journal of Zoology 19,
275279.
Van Damme, P.A. and Ollevier, F. (1995) Morphological and morphometric study of crustacean parasities
within the genus Lernaeocera. International Journal for Parasitology 25, 14011411.
Van Damme, P.A., Ollevier, F. and Hamerlynck, O. (1994) Pathogenicity of Lernaeocera lusci and L.
branchialis in bib and whiting in the North Sea. Diseases of Aquatic Organisms 19, 6165.
Van Damme, P.A., Geets, A., Hamerlynck, O. and Ollevier, F. (1997) The suprapopulation dynamics of
Lernaeocera branchialis and L. lusci in the Oosterschelde: seasonal abundance on three definitve host
species. ICES Journal of Marine Science 54, 2431.
Vaughan, G.E. and Coble, D.W. (1975) Sublethal effects of three ectoparasites on fish. Journal of Fish Biology
7, 283294.
Viljoen, S. and Van As, J.G. (1985) Cases of aquatic parasitism and hyperparasitism. South African Journal of
Science 81, 701.
Vulpe, V., Nastasa, V. and Cura, P. (2000) Studies about the therapeutic modalities in parasitoles of the fish
culture. Lucrai Stiinifice Medicina Veterinara Universitatea de Stiinte 43, 376379.
564
Vu-Tan-Tue, K. (1963) Sur la prsence de dents vomriennes et ptrygoidlennes chez Boops boops (L.)
(Pisces, Sparidae), en rapport avec lisopode phortique intrabuccal Meinertia. Vie et Milieu 14,
225232.
Wagele, J.-W. (1988) Aspects of the life-cycle of the Antarctic fish parasite Gnathia calva Vanhoffen
(Crustacea: Isopoda). Polar Biology 8, 287291.
Wagele, J.-W. (1990) Growth in captivity and aspects of reproductive biology of the Antarctic fish parasite
Aega antarctica (Crustacea, Isopoda). Polar Biology 10, 521527.
Wagner, G.N. and McKinley, R.S. (2004) Anaemia and salmonid swimming performance: the potential effects
of sublethal sea lice infection. Journal of Fish Biology 64, 10271038.
Wagner, G.N., McKinley, R., Bjrn, P.A. and Finstad, B. (2003) Physiological impact of sea lice on swimming
performance of Atlantic salmon. Journal of Fish Biology 62, 10001009.
Watanabe, Y., Kosaka, S., Tanino, Y. and Takahashi, S. (1985) Occurrence of parasitic copepod Pennella sp.
on the Pacific saury Cololabis saira in 1983. Bulletin of the Tohoku Regional Fisheries Research Laboratory 47, 3746.
Waugh, D.N., Bennett, T. and Dugoni, T.L. (1989) The incidence of the cymothoid isopod Lironeca
californica on fishes in Campbell Cove, Sonoma County, California. Bulletin of the Southern California
Academy of Science 88, 3339.
Weinstein, M.P. and Heck, K.L. (1977) Biology and hostparasite relationships of Cymothoa excisa (Isopoda,
Cymothoidae) with three species of snappers (Lutjanidae) on the Caribbean coast of Panama. Fishery
Bulletin 75, 875877.
White, H.C. (1940) Sea lice (Lepeophtheirus) and death of salmon. Canadian Journal of Fisheries and Aquatic
Sciences 5, 172175.
White, H.C. (1942) Life history of Lepeophtheirus salmonis. Journal of the Fisheries Research Board of Canada
6, 2429.
Whitfield, P.J., Pilcher, M.W., Grant, H.J. and Riley, J. (1988) Experimental studies on the development of
Lernaeocera branchialis (Copepoda: Pennellidae): population processes from egg production to maturation on the flatfish host. Hydrobiologia 167/168, 579586.
Wierzejski,A. (1877) Ueber Schmarotzerkrebse von Cephalopoden. Zeitschrift fr wissen Zoologie 29,
562582.
Wijeyaratne, M.J.S. and Gunawardene, R.S. (1988) Chemotherapy of ectoparasite, Ergasilus ceylonensis of
Asian cichlid, Etroplus suratensis. Journal of Applied Ichthyology 4, 97100.
Williams, E.H. and Bunkley-Williams, L. (2000) On the generic placement of Livoneca sp. a critique of
Colorni et al. (1997). Diseases of Aquatic Organisms 40, 233234.
Williams, E.H. and Williams, L.B. (1982) Mothocya bohlkeorum, new species (Isopoda: Cymothoidae) from
West Indian cardinalfishes (Apogonidae). Journal of Crustacean Biology 2, 570577.
Williams, E.H. and Williams, L.B. (1985) Cuna insularis, n. gen. and n. sp. (Isopoda: Cymothoidae) from the
gill chamber of the sergeant major, Abudefduf saxatilis (Linnaeus) (Osteichthyes) in the West Indies. Journal of Parasitology 71, 209214.
Williams, E.H. and Williams, L.B. (1986) The first Anilocra and Pleopodias isopods (Crustacea: Cymothoidae)
parasitic on Japanese fishes, with three new species. Proceedings of the Biological Society of Washington
99, 647657.
Williams, E.H. and Williams, L.B. (1992) Renocila loriae and R. richardsonae (Crustacea: Isopoda:
Cymothoidae), external parasites of coral reef fishes from New Guinea and the Philippines. Proceedings
of the Biological Society of Washington 105, 299309.
Williams, E.H., Williams, L.B., Waldner, R.E. and Kimmel, J.J. (1982) Predisposition of a pomacentrid fish,
Chromis multilineatus (Guichenot) to parasitism by a cymothoid isopod, Anilocra chromis Williams and
Williams. Journal of Parasitology 68, 942945.
Williams, E.H., Bunkley-Williams, L. and Williams, L.B. (1994) Four cases of unusual crustacean fish associations and comments on parasitic processes. Journal of Aquatic Animal Health 6, 202208.
Williams, L.B. and Williams, E.H. (1979) The ability of various West Indian cleaners to remove parasitic
isopod juveniles of the genus Anilocra a preliminary report. Proceedings of the Association of Island
Marine Laboratories of the Caribbean 14, 28.
Williams, L.B. and Williams, E.H. (1981) Nine new species of Anilocra (Crustacea: Isopoda: Cymothoidae),
external parasites of West Indian coral reef fishes. Proceedings of the Biological Society of Washington
94, 10051047.
Phylum Arthropoda
565
Williams, L.B. and Williams, E.H. (1985) Brood pouch release of Anilocra chromis Williams and Williams
(Isopoda, Cymothoidae) a parasite of brown chromis, Chromis multilineatus (Guichenot) in the
Caribbean. Crustaceana 49, 9295.
Williams, L.B. and Williams, E.H. (1986) Ichthyological notes about fishes collected for parasite examination
around Sesoko Island, Okinawa. Galaxea 5, 217221.
Wilson, C.B. (1902) North American parasitic copepods of the family Argulidae, with a bibliography of the
group and a systematic review of all known species. Proceedings of the US National Museum 25,
635742.
Wilson, C.B. (1905a) North American parasitic copepods belonging to the family Caligidae. Pt. 1. The
Caliginae. Proceedings of the US National Museum 28, 479672.
Wilson, C.B. (1905b) Habits and life-history of parasitic copepods. Biological Bulletin of the Marine Biological
Laboratory 8, 236237.
Wilson, C.B. (1911) North American parasitic copepods. Part 9. The Learnaeopodidae. Proceedings of the US
National Museum 39, 189226.
Wilson, C.B. (1915) North American parasitic copepods belonging to the family Lernaeopodidae, with a revision of the entire family. Proceedings of the US National Museum 47, 565729.
Wilson, C.B. (1917) North American parasitic copepods belonging to the Lernaeidae with a revision of the
entire family. Proceedings of the US National Museum 53, 1150.
Wing, B.L. and Moles, D.A. (1995) Behavior of Rocinela angustata (Isopoda, Aegidae), an ectoparasite of
Alaskan marine fishes. Journal of Aquatic Animal Health 7, 3437.
Woo, P.T.K. and Shariff, M. (1990) Lernaea cyprinacea L. (Copepoda: Caligidae) in Helostoma temmincki
Cuvier and Valenciennes: the dynamics of resistance in recovered and naive fish. Journal of Fish
Diseases 13, 485494.
Wootten, R., Smith, J.W. and Needham, E.A. (1977) Studies on the salmon louse, Lepeophtheirus. Bulletin de
lOffice International des Epizooties 87, 521522.
Wootten, R., Smith, J.W. and Needham, E.A. (1982) Aspects of the biology of the parasitic copepods
Lepeophtheirus salmonis and Caligus elongatus on farmed salmonids, and their treatment. Proceedings
of the Royal Society of Edinburgh 81B, 185197.
Wright, R.V., Lechanteur, Y.A.R.G., Prochazka, K. and Griffiths, C.L. (2001) Infection of hottentol
Pachymetopon blochii by the fish louse Anilocra capensis (Crustacea: Isopoda) in False Bay, South
Africa. African Zoology 36, 177183.
Yamaguti, S. (1963) Parasitic Copepoda and Branchiura of Fishes. Interscience, New York.
Yano, K. and Musick, J.A. (2000) The effect of the mesoparasitic barnacle Anelasma on the development of
reproductive organs of deep-sea squaloid sharks, Centroscyllium and Etmopterus. Environmental Biology
of Fishes 59, 329339.
Zeddam, J.L., Berrebi, P., Renaud, F., Raibaut, A. and Gabrion, C. (1988) Characterization of two species of
Lepeophtheirus (Copepoda, Caligidae) from flatfishes. Description of Lepeophtheirus europaensis sp.
nov. Parasitology 96, 129144.
Zmerzlaya, E.I. (1972) Ergasilus sieboldi Nordmann, 1832, its development, biology and epizootic significance. Izvestiya Gosudarstvennogo Nauchnoissledovateleskogo Instituta Ozernogo i Rechnogo
Rybonog Zhozuaistva 80, 132177.
15
School of Marine Science, Virginia Institute of Marine Science, College of William and
Mary, Gloucester Point, VA 23062, USA
Introduction
Leeches are the only important fish pathogens in the phylum Annelida. Both freshwater and marine leeches have worldwide
distribution and they occur in a diversity
of habitats. Leeches can potentially affect
the health of fishes in a variety of ways.
Their most important role is as vectors of
potentially pathogenic organisms. Both
freshwater and marine leeches are known
to transmit haemoflagellates of the genera
Trypanosoma and Cryptobia (= Trypanoplasma) and the intracellular haemogregarines and piroplasmas to fish. There
is accumulating evidence that leeches can
also transmit viruses and bacteria. In addition, leeches may affect the host by the
sheer amount of blood withdrawn during
feeding. The feeding or attachment wounds
caused by leeches may also serve as sites
for secondary pathogenic invaders.
Aquatic leeches also serve as second
intermediate hosts for Digenea (Chapter 10),
harbouring metacercaria of a number of different species. Most of these worms are
adults in waterfowl, but some mature in
freshwater fishes. However, none of these
Digenea has been implicated in pathology
of fishes so they are not considered further
in this review. Additional information on
566
Host Range
Leeches that parasitize fishes are primarily in the families Glossiphoniidae and
Piscicolidae. Glossiphoniid leeches occur
on a wide variety of freshwater fishes, as
well as other freshwater aquatic vertebrates.
Piscicolid leeches occur on both freshwater
and marine fishes. Freshwater fish leeches
are most abundant in temperate lakes, ponds
and streams, and occur worldwide on all continents except Antarctica. Marine leeches are
known from all seas, but are most abundant
in polar to temperate regions. They occur
primarily on demersal species of all major fish
groups, including lampreys, elasmobranchs
and teleosts.
567
568
E.M. Burreson
Fig. 15.2. Phylogenetic tree of the leeches demonstrating monophyly of the Glossiponiidae and
Piscicolidae, but not of the Rhynchobdellida. From Borda and Siddall, 2003, courtesy of Molecular
Phylogenetics and Evolution.
retained in all Piscicolidae and most Glossiphoniidae (Borda and Siddall, 2003). However, the ancestral feeding preference of
the Arhynchobdellida cannot be determined from recent phylogenetic analyses
(Borda and Siddall, 2003). Thus, it is not
clear whether the ancestor was sanguivorous, with subsequent loss of blood feeding
in the Erpobdellidormes, Haemopidae and
other some groups, or whether the ancestor
was predacious with reacquisition of
sanguivory in the Hirudiniformes.
569
570
E.M. Burreson
Leeches as Pathogens
Hostparasite relationships
Clinical signs and gross pathology
Leeches alone are generally not considered
important fish pathogens. Effects are usually localized and restricted to attachment
and/or feeding sites on the skin, fins, gills
or mouth. The muscular caudal sucker used
for attachment usually causes little damage;
however, leeches that are semi-permanent
parasites may elicit a substantial host tissue
response at the attachment site. Rhynchobdellid leeches feed on host blood or tissue fluid by means of a protrusible proboscis,
which is inserted into host tissue and
this feeding activity may produce localized
571
572
E.M. Burreson
Diagnosis of infection
Leeches can be difficult to collect and to
identify. They often leave the host after
feeding and, therefore, may go undetected
even when abundance is high. They are
usually sufficiently large to be detected by
the naked eye and occur on the body surface and fins or in the gill cavity or mouth.
If possible, leeches should be collected by
gently dislodging the caudal sucker with
forceps and placing them in a dish containing water. For proper identification it is
important to observe leeches alive and to
note as many external characters as possible.
It may be necessary to relax leeches in weak
alcohol or another narcotizing agent prior to
examination. Careful observation should be
made of pigmentation colour and pattern,
number and arrangement of eyes on the oral
sucker, ocelli on the body and caudal sucker,
number of lateral pulsatile vesicles, if present, and arrangements of papillae, tubercles
or other obvious external characters. Leeches
that have been fixed unrelaxed are almost
impossible to identify because they usually
contract strongly or curl into a tight ball,
making observation of important characters
difficult. Leeches relaxed prior to fixation
in formalin will usually retain their pigmentation and eyes for long periods; however, pigmentation fades rapidly after transfer
to alcohol. Leeches that have been fixed and
then preserved in alcohol are often difficult to
identify, especially to species. Generic determination of many leeches, especially piscicolids, may depend on internal anatomy,
which can only be determined with serial
sections. All these difficulties combine to
make identification of leeches, even for
experts, problematic.
573
574
E.M. Burreson
harbour endosymbiotic bacteria in specialized anterior crop diverticula called mycetomes or oesophageal diverticula (Jennings
and Van Der Lande, 1967; Sawyer, 1986;
Siddall et al., 2003). These bacteria aid in
digestion of blood by providing normally
deficient digestive enzymes; however, they
may be mistaken for bacteria that are
pathogenic to fish.
575
576
Table 15.1.
Leech species
Freshwater
Glossiphoniidae
Hemiclepsis marginata (O.F. Mller)
Batracobdelloides tricarinata
(Blanchard)
Piscicolidae
Piscicola geometra L.
Haematozoa transmitted
E.M. Burreson
Table 15.1.
Marine
Piscicolidae
Pontobdella muricata L.
Haematozoa transmitted
Leech species
577
578
E.M. Burreson
Fig. 15.5. Important leech vectors of pathogenic haematozoa in fishes. Vertical line beside each leech is
5.0 mm. See text for identification characters. Hemiclepsis marginata redrawn from Mann, 1961, courtesy of
Pergamon Press; Piscicola salmositica redrawn from Klemm, 1982, courtesy of US Environmental Protection
Agency.
579
580
E.M. Burreson
581
582
E.M. Burreson
but later, on the basis of further collections, Sawyer et al. (1975) considered
C. carolinensis to be a junior synonym of
C. vividus. However, they transferred the
species to the genus Calliobdella as C. vivida.
The species was thoroughly described by
Sawyer and Chamberlain (1972). The
subcylindrical body is not distinctly divided
into trachelosome and urosome; total
length can be up to 40 mm, but most
mature individuals are approximately 18
to 30 mm long. The oral sucker is well
developed and has two pairs of concentric
eyes (Fig. 15.5). The caudal sucker is
slightly wider than the maximum body
width, is attached strongly eccentrically
and lacks ocelli. Pigmentation varies from
none to faint, segmental, transverse
bands, usually reddish brown in colour,
especially obvious on the trachelosome.
Paired, segmental, punctiform ocelli are
often visible dorsolaterally and ventrolaterally on the body. Eleven pairs of
pulsatile vesicles are usually obvious on
the lateral margins of the urosome. Keys
that include C. vivida are in Appy and
Dadswell (1981) and Sawyer (1986).
The life cycle of C. vivida has been
studied through field collections and
laboratory experiments by Sawyer and
Hammond (1973) in South Carolina and by
Burreson and Zwerner (1982) in Chesapeake
Bay. In Chesapeake Bay leeches are abundant from December through March,
when water temperature averages 4 to 8C.
Leeches begin to deposit cocoons as early as
February, but most cocoon deposition
occurs in late April and early May when
water temperature is about 15 to 17C. In
the laboratory a single large leech deposited
51 cocoons over a 6-day period (Burreson
and Zwerner, 1982). Leeches die after
depositing cocoons and no leech has
been collected in nature after June. Eggs
oversummer in the cocoon and begin hatching in the autumn, when water temperature decreases to between 15 and 18C,
usually late October to early November in
Chesapeake Bay, but as late as December in
South Carolina. Unfed C. vivida are strong
swimmers and are routinely collected in
plankton nets.
583
584
E.M. Burreson
585
586
E.M. Burreson
(Siddall et al., 2001) and have also questioned some of the traditional classification
based on morphology. Increased taxon sampling is needed before revised classifications can be proposed, but such studies
are under way. Phylogenetic studies have
resulted in an increased interest in fish
leech taxonomy and recent studies have
reported new species, even in areas that
were thought to be well studied (e.g.
Bielecki, 1997; Burreson and Williams,
2004). Unfortunately, the fish leech
fauna in many parts of the world is still
poorly known. Our knowledge is especially
inadequate for the marine fauna of the
southern hemisphere, but, even in areas
where the fauna is relatively well known,
taxonomic confusion persists (Barta and
Sawyer, 1990).
References
Ahne, W. (1985) Argulus foliaceus L. and Piscicola geometra L. as mechanical vectors of spring viraemia of
carp virus (SVCV). Journal of Fish Diseases 8, 241242.
Apakupakul, K., Siddall, M.E. and Burreson, E.M. (1999) Higher level relationships of leeches (Annelida:
Clitellata: Euhirudinea) based on morphology and gene sequences. Molecular Phylogenetics and
Evolution 12, 350359.
Appy, R.G. and Cone, D.K. (1982) Attachment of Myzobdella lugubris (Hirudinea: Piscicolidae) to logperch,
Percina caprodes, and brown bullhead, Ictalurus nebulosus. Transactions of the American Microscopical Society 101, 135141.
Appy, R.G. and Dadswell, M.J. (1981) Marine and estuarine piscicolid leeches (Hirudinea) of the Bay of
Fundy and adjacent waters with a key to species. Canadian Journal of Zoology 59, 183192.
Badham, C. (1916) On an ichthyobdellid parasitic on the Australian sand whiting (Sillago ciliata). Quarterly
Journal of Microscopical Science (New Series) 62, 141.
Barta, J.R. and Sawyer, R.T. (1990) Definition of a new genus of glossiphoniid leech and a redescription of the
type species, Clepsine picta Verrill, 1872. Canadian Journal of Zoology 68, 19421950.
Bauer, O.N. (1961) Parasitic diseases of cultured fishes and methods of their prevention and treatment.
In: Dogiel, V.A., Petrushevski, G.K. and Polyanski, Y.I. (eds) Parasitology of Fishes. Oliver and Boyd,
Edinburgh, UK, pp. 265298.
Bauer, O.N., Musselius, V.A. and Strelkov, Y.A. (1973) Diseases of Pond Fishes. Israel Program for Scientific
Translations, Jerusalem.
Becker, C.D. (1980) Haematozoa from resident and anadromous fishes of the central Columbia River: a
survey. Canadian Journal of Zoology 58, 356362.
Becker, C.D. and Katz, M. (1965a) Transmission of the hemoflagellate, Cryptobia salmositica Katz, 1951, by a
rhynchobdellid vector. Journal of Parasitology 51, 9599.
Becker, C.D. and Katz, M. (1965b) Distribution, ecology, and biology of the salmonid leech, Piscicola
salmositica (Rhynchobdellae: Piscicolidae). Journal of the Fisheries Research Board of Canada 22,
11751195.
Becker, C.D. and Katz, M. (1965c) Infections of the hemoflagellate, Cryptobia salmositica Katz, 1951, in freshwater teleosts of the Pacific coast. Transactions of the American Fisheries Society 94, 327333.
Becker, C.D. and Overstreet, R.M. (1979) Haematozoa of marine fishes from the northern Gulf of Mexico.
Journal of Fish Diseases 2, 469479.
587
Bielecki, A. (1988) Leeches (Hirudinea) parasites of fish. Wiadomosci Parazytologiczne 34, 310 (in
Polish).
Bielecki, A. (1997) Fish leeches of Poland in relation to the Palaearctic piscicolines (Hirudinea: Piscicolidae:
Piscicolinae). Genus 8, 223375.
Borda, E. and Siddall, M.E. (2003) Arhynchobdellida (Annelida: Oligochaeta: Hirudinida): phylogenetic
relationships and evolution. Molecular Phylogenetics and Evolution 30, 213225.
Bower, S.M. and Margolis, L. (1984) Distribution of Cryptobia salmositica, a haemoflagellate of fishes, in
British Columbia and the seasonal pattern of infection in a coastal river. Canadian Journal of Zoology
62, 25122518.
Bower, S.M. and Thompson, A.B. (1987) Hatching of the Pacific salmon leech (Piscicola salmositica) from
cocoons exposed to various treatments. Aquaculture 66, 18.
Bower, S.M., Margolis, L. and MacKay, R.J. (1985) Potential usefulness of chlorine for controlling Pacific
salmon leeches, Piscicola salmositica, in hatcheries. Canadian Journal of Fisheries and Aquatic Science
42, 19861993.
Bragg, R.R., Oosthuizen, J.H. and Lordan, S.M. (1989) The leech Batrachobdelloides tricarinata Blanchard,
1987 (Hirudinea: Glossiphoniidae) as a possible reservoir of the rainbow trout pathogenic Streptococcus
spp. Onderstepoort Journal of Veterinary Research 56, 203204.
Brumpt, M.E. (1905) Trypanosomes et trypanosomoses. Revue Scientifique 4, 321332.
Brumpt, M.E. (1906a) Mode de transmission et volution des trypanosomes des poissons. Description de
quelques espces de trypanoplasmes des poissons d'eau douce. Trypanosome d'un crapaud Africain.
Comptes Rendus des Sances de la Socit de Biologie 60, 162164.
Brumpt, M.E. (1906b) Expriences relatives au mode de transmission des trypanosomes et des trypanoplasmes
par les hirudines. Comptes Rendus des Sances de la Socit de Biologie 61, 7779.
Burreson, E.M. (1975) Biological studies on the hemoflagellates of Oregon marine fishes and their potential
leech vectors. Unpublished PhD thesis, Oregon State University, Corvallis, Oregon.
Burreson, E.M. (1977) Two new species of Malmiana (Hirudinea: Piscicolidae) from Oregon coastal waters.
Journal of Parasitology 63, 130136.
Burreson, E.M. (1979) Structure and life cycle of Trypanoplasma beckeri sp. n. (Kinetoplastida), a parasite of
the cabezon, Scorpaenichthys marmoratus, in Oregon coastal waters. Journal of Protozoology 26,
343347.
Burreson, E.M. (1982) The life cycle of Trypanoplasma bullocki (Strout) (Zoomastigophorea: Kinetoplastida).
Journal of Protozoology 29, 7277.
Burreson, E.M. and Pratt, I. (1972) Trypanosoma pacifica sp. n. from the English sole Parophrys vetulus Girard
from Oregon. Journal of Protozoology 19, 555556.
Burreson, E.M. and Williams, J.I. (2004) A new species of Oceanobdella (Hirudinida: Piscicolidae) from the
plain sculpin, Myoxocephalus jaok, from Bristol Bay, Alaska. Journal of Parasitology 90 (4), 789792.
Burreson, E.M. and Zwerner, D.E. (1982) The role of host biology, vector biology, and temperature in the
distribution of Trypanoplasma bullocki infections in the lower Chesapeake Bay. Journal of Parasitology
68, 306313.
Burreson, E.M. and Zwerner, D.E. (1984) Juvenile summer flounder, Paralichthys dentatus, mortalities in the
western Atlantic Ocean caused by the hemoflagellate Trypanoplasma bullocki: evidence from field and
experimental studies. Helgolnder Meeresuntersuchungen 37, 343352.
Conroy, D.A. and Herman, R.L. (1970) Erwin Amlacher Textbook of Fish Diseases. T.F.H. Publications, Jersey
City, New Jersey.
Cope, O.B. (1958) Incidence of external parasites on cutthroat trout in Yellowstone Lake. Proceedings of the
Utah Academy of Science Arts and Letters 35, 95100.
Cruz-Lacierda, E.R., Toledo, J.D., Tan-Fermin, J.D. and Burreson, E.M. (2000) Marine leech (Zeylanicobdella
arugamensis) infestation in cultured orange-spotted grouper, Epinephelus coioides. Aquaculture 185,
191196.
Cusack, R. and Cone, D.K. (1986) A review of parasites as vectors of viral and bacterial diseases of fish.
Journal of Fish Diseases 9, 169171.
Davies, R.W. (1991) Annelida: leeches, polychaetes, and acanthobdellids. In: Thorp, J.H. and Covich, A.P.
(eds) Ecology and Classification of North American Freshwater Invertebrates. Academic Press, San
Diego, California, pp. 437479.
Dombrowski, H. (1953) Die Nahrungsmenge des Fischegels Piscicola geometra L. (Zugleich ein Beitrage
zur Physiologie des Blutes des Karpfens Cyprinus carpio L.) Biologische Zentralblatt, Leipzig 72,
311314.
588
E.M. Burreson
Dykov, I. and Lom, J. (1979) Histopathological changes in Trypanosoma danilewskyi Laveran & Mesnil,
1904 and Trypanoplasma borelli Laveran & Mesnil, 1902 infections of goldfish, Carassius aurata (L.).
Journal of Fish Diseases 2, 381390.
Earp, B.J. and Schwab, R.L. (1954) An infestation of leeches on salmon fry and eggs. Progressive Fish Culturist
16, 122124.
Elliott, J.M. and Mann, K.H. (1979) A Key to the British Freshwater Leeches with Notes on their Life Cycle and
Ecology. Scientific Publication No. 40, Freshwater Biological Association, Cumbria, UK.
Epshtein, V.M. (1961) A review of the fish leeches (Hirudinea, Piscicolidae) from the northern seas of the
SSSR. Doklady Akademii Nauk SSSR 141, 11211124.
Epshtein, V.M. (1962) A survey of fish leeches (Hirudinea Piscicolidae) from the Bering and Okhotsk Seas and
from the Sea of Japan. Doklady Akademii Nauk SSSR 141, 648651.
Epshtein, V.M. (1968) Revision of the genera Oxytonostoma and Johanssonia (Hirudinea: Piscicolidae).
Zoologicheskii Zhurnal 47, 10111021 (in Russian, translated by P.G. Rossbacher, Oregon State
University).
Epshtein, V.M. (1987) Phylum Annelida. In: Bauer, O.N. (ed.) Opredelitel Parazitov Presnovodnykh Ryb
Fauny SSSR. Vol. 3, Paraziticheskie Mnogokletochnye (Part 2). Nauka, Leningrad, pp. 340372 (translated from Russian by the Multilingual Translation Directorate, Canada).
Epshtein, V.M., Utevsky, A.Y. and Utevsky, S.Y. (1994) The system of fish leeches (Hirudinea: Piscicolodae).
Genus 5, 401409.
Harding, W.A. (1910) A revision of the British leeches. Parasitology 3, 130201.
Hayunga, E.G. and Grey, A.J. (1976) Cystobranchus meyeri sp. n. (Hirudinea: Piscicolidae) from Catostomus
commersoni Lacpde in North America. Journal of Parasitology 62, 621627.
Jennings, J.B. and Van Der Lande, V.M. (1967) Histochemical and bacteriological studies on digestion in
nine species of leeches (Annelida: Hirudinea). Biological Bulletin 133, 166183.
Johansson, L. (1899) Die Ichthyobdelliden im Zoologischen Reichsmuseum in Stockholm. fversigt Af
Kungliga Vetenskapsakademiens Frhandlingar 55, 665687.
Jones, S.R.M. and Woo, P.T.K. (1990a) Redescription of the leech Desserobdella phalera (Graf, 1899) n.
comb. (Rhynchobdellida: Glossiphoniidae), with notes on its biology and occurrence on fishes.
Canadian Journal of Zoology 68, 19511955.
Jones, S.R.M. and Woo, P.T.K. (1990b) The biology of Trypanosoma phaleri n. sp. from bowfin, Amia calva L.,
in Canada and the United States. Canadian Journal of Zoology 68, 19561961.
Kabata, Z. (1985) Parasites and Diseases of Fish Cultured in the Tropics. Taylor & Francis, London and
Philadelphia.
Keysselitz, G. (1906) Generations und Wirtswechsel von Trypanoplasma borreli Laveran et Mesnil. Archiv fr
Protistenkunde 7, 174.
Khaibulaev, K.K. (1970) The role of leeches in the life cycle of blood parasites of fishes. Parazitologiya 4,
1317 (in Russian).
Khaibulaev, K.K. and Guseinov, M.A. (1982) Experimental study of the biology of some flagellates from the genera
Trypanosoma Grudy, 1841 (Trypanosomidae Doflein, 1911) and Cryptobia Leidy, 1846 (Bodonidae Stenn,
1878). Izvestiya Akademii Nauk Azerbaidzhanskoi SSR, Biologicheskie Nauki 2, 8791.
Khalifa, K.A. (1985) Leeches on freshwater farmed fishes in Iraq. Journal of Wildlife Diseases 21, 312313.
Khan, R.A. (1976) The life cycle of Trypanosoma murmanensis Nikitin. Canadian Journal of Zoology 54,
18401849.
Khan, R.A. (1977) Susceptibility of marine fish to trypanosomes. Canadian Journal of Zoology 55,
12351241.
Khan, R.A. (1978a) A new Hemogregarine from marine fishes. Journal of Parasitology 64, 3544.
Khan, R.A. (1978b) A redescription of Trypanosoma cotti Brumpt and Lebailly, 1904 and its development in
the leech, Calliobdella punctata. Annales de Parasitologie (Paris) 53, 461466.
Khan, R.A. (1980) The leech as a vector of a fish piroplasm. Canadian Journal of Zoology 58, 16311637.
Khan, R.A. (1982) Biology of the marine piscicolid leech Johanssonia arctica (Johansson) from Newfoundland.
Proceedings of the Helminthological Society of Washington 49, 266278.
Khan, R.A. (1984) Simultaneous transmission of a piscine piroplasm and trypanosome by a marine leech.
Journal of Wildlife Diseases 20, 339341.
Khan, R.A. (1991) Trypanosome occurrence and prevalence in the marine leech Johanssonia arctica and its
host preferences in the northwestern Atlantic Ocean. Canadian Journal of Zoology 69, 23742380.
Khan, R.A. and Meyer, M.C. (1976) Taxonomy and biology of some Newfoundland marine leeches
(Rhynchobdellae: Piscicolidae). Journal of the Fisheries Research Board of Canada 33, 16991714.
589
Khan, R.A. and Paul, A.J. (1995) Life cycle studies on arcto-boreal leeches. Journal of the Helminthological
Society of Washington 62, 105110.
Khan, R.A., Lee, E.M. and Whitty, W.S. (1991) Blood protozoans of fish from the Davis Strait in the northwestern Atlantic Ocean. Canadian Journal of Zoology 69, 410413.
Klemm, D.J. (1982) Leeches (Annelida: Hirudinea) of North America. EPA600/382025, US Environmental
Protection Agency, Cincinnati, Ohio.
Kruse, P., Steinhagen, D. and Krting, W. (1989) Development of Trypanoplasma borreli (Mastigophora:
Kinetoplastida) in the leech vector Piscicola geometra and its infectivity for the common carp, Cyprinus
carpio. Journal of Parasitology 75, 527530.
Lainson, R. (1981) On Cyrilia gomesi (Neiva & Pinto, 1926) gen. nov. (Haemogregarinidae) and Trypanosoma
bourouli Neiva & Pinto, in the fish Synbranchus marmoratus: simultaneous transmission by the leech
Haementeria lutzi. In: Canning, E.U. (ed.) Parasitological Topics. Society of Protozoologists, Lawrence,
Kansas, pp. 150158.
Laird, M. and Bullock, W.L. (1969) Marine fish haematozoa from New Brunswick and New England. Journal
of the Fisheries Research Board of Canada 26, 10751102.
Laveran, A. and Mesnil, F. (1912) Trypanosomes et trypanosomiases, 2nd edn. Masson, Paris.
Lger, L. (1904) Sur les hmoflagells des Cobitis barbatula L. 1. Trypanosoma barbatulae. Comptes Rendus
des Sances de la Socit de Biologie 57, 344345.
Letch, C.A. (1979) Host restriction, morphology and isoenzymes among trypanosomes of some British
freshwater fishes. Parasitology 79, 107117.
Letch, C.A. (1980) The life cycle of Trypanosoma cobitis Mitrophanow 1883. Parasitology 80, 163169.
Letch, C.A. and Ball, S.J. (1979) Prevalence of Trypanosoma cobitis Mitrophanow, 1883 in fishes from the
River Lee. Parasitology 79, 119124.
Light, J.E. and Siddall, M.E. (1999) Phylogeny of the leech family Glossiphoniidae based on mitochondrial
gene sequences and morphological data. Journal of Parasitology 85, 813823.
Lom, J. (1979) Biology of the trypanosomes and trypanoplasms of fish. In: Lumsden, W.H.R. and Evans, D.A.
(eds) Biology of the Kinetoplastida, vol. 2. Academic Press, London, pp. 269237.
Lukin, E.I. (1976) Leeches of fresh and brackish water bodies. In: Fauna of the USSR, vol. 1. Academy of
Science of the USSR, Leningrad (in Russian).
McCarthy, A.M. (1990) Experimental observations on the specificity of Apatemon minor Yamaguti, 1933
(Digenea: Strigeidae) toward leech (Hirudinea) second intermediate hosts. Journal of Helminthology 64,
161167.
Mace, T.F. and Davis, C.C. (1972) Energetics of a hostparasite relationship as illustrated by the leech
Malmiana nuda, and the shorthorn sculpin Myoxocephalus scorpius. Oikos 23, 336343.
Madill, J. (1988) New Canadian records of leeches (Annelida: Hirudinea) parasitic on fish. Canadian Field
Naturalist 102, 685688.
Malecha, J. (1984) Cycle biologique de l'hirudine rhynchobdelle Piscicola geometra L. Hydrobiologia 118,
237243.
Mann, K.H. (1955) The ecology of the British freshwater leeches. Journal of Animal Ecology 24, 98119.
Mann, K.H. (1961) Leeches (Hirudinea). Their Structure, Physiology, Ecology and Embryology. Pergamon
Press, New York.
Markevich, A.P. (1963) Parasitic Fauna of Freshwater Fish of the Ukrainian SSR. Israel Program for Scientific
Translations, Jerusalem.
Meyer, F.P. (1969) A potential control for leeches. Progressive Fish Culturist 31, 160163.
Meyer, M.C. (1946a) Further notes on the leeches (Piscicolidae) living on freshwater fishes of North America.
Transactions of the American Microscopical Society 65, 237249.
Meyer, M.C. (1946b) A new leech, Piscicola salmositica n. sp. (Piscicolidae), from steelhead trout (Salmo
gairdneri gairdneri Richardson, 1838). Journal of Parasitology 32, 467476.
Meyer, M.C. and Khan, R.A. (1979) Taxonomy, biology, and occurrence of some marine leeches in
Newfoundland waters. Proceedings of the Helminthological Society of Washington 46, 254264.
Mulcahy, D., Klaybor, D. and Batts, W.N. (1990) Isolation of infectious hematopoietic necrosis virus from a
leech (Piscicola salmositica) and a copepod (Salmincola sp.), ectoparasites of sockeye salmon
Oncorhynchus nerka. Diseases of Aquatic Organisms 8, 2934.
Mundie, J.H. and Traber, R.E. (1983) Carrying capacity of an enhanced side-channel for rearing salmonids.
Canadian Journal of Fisheries and Aquatic Science 40, 13201322.
Needham, E.A. (1969) Protozoa parasitic in fish. Unpublished PhD thesis, University of London.
590
E.M. Burreson
Negele, R.-D. (1975) Fish leeches as pests and vectors of disease. Fish und Umwelt 1, 123126 (Canadian
Translation of Fisheries and Aquatic Sciences No. 4812).
Negm-Eldin, M.M. (1997) Trypanosoma mukasai (Hoare, 1932) in its biological vector Batracobdelloides
tricarinata (Blanchard, 1897) and their life cycles. Deutsche Tieraerztliche Wochenschrift 104,
215219.
Negm-Eldin, M.M. and Davies, R.W. (1998) Simultaneous transmission of Trypanosoma mukasai,
Babesiosoma mariae and Cyrilia nili to fish by the leech Batracobdelloides tricarinata. Deutsche
Tieraerztliche Wochenschrift 106, 526528.
Neumann, R.O. (1909) Studien ber protozoische Parasiten im Blut von Meeresfischen. Zeitschrift fr
Hygiene und Infektionskrankheiten 64, 1112.
Noga, E.J., Bullis, R.A. and Miller, G.C. (1990) Epidemic oral ulceration in largemouth bass (Micropterus
salmoides) associated with the leech Myzobdella lugubris. Journal of Wildlife Diseases 26, 132134.
Paperna, I. and Overstreet, R.M. (1981) Parasites and diseases of mullets (Mugilidae). In: Oren, O.H. (ed.)
Aquaculture of Grey Mullets. Cambridge University Press, Cambridge, pp. 411493.
Paperna, I. and Zwerner, D.E. (1974) Massive leech infestation on a white catfish (Ictalurus catus): a
histopathological consideration. Proceedings of the Helminthological Society of Washington 41, 6467.
Prost, M., Studnicka, M. and Niezgoda, J. (1974) Efficacy of some methods controlling leeches in water.
Aquaculture 3, 287294.
Putz, R.E. (1972a) Cryptobia catacactae sp. n. (Kinetoplastida: Cryptobiidae), a hemoflagellate of some cyprinid fishes of West Virginia. Proceedings of the Helminthological Society of Washington 39, 1822.
Putz, R.E. (1972b) Biological studies on the hemoflagellates Cryptobia cataractae and Cryptobia salmositica.
US Sport Fisheries and Wildlife Technical Paper 63, 325.
Qadri, S.S. (1962) An experimental study of the life cycle of Trypanosoma danilewskyi in the leech,
Hemiclepsis marginata. Journal of Protozoology 9, 254258.
Robertson, M. (1907) Studies on a trypanosome found in the alimentary canal of Pontobdella muricata.
Proceedings of the Royal Physical Society of Edinburgh 17, 83108.
Robertson, M. (1909) Further notes on a trypanosome found in the alimentary tract of Pontobdella muricata.
Quarterly Journal of Microscopical Science 54, 119139.
Robertson, M. (1911) Transmission of flagellates living in the blood of certain freshwater fishes. Philosophical
Transactions of the Royal Society of London, Series B 202, 2950.
Rohde, K. (1984) Diseases caused by metazoans: helminths. In: Kinne, O. (ed.) Diseases of Marine Animals,
vol. 4, part 1. Biologische Anstalt Helgoland, Hamburg, Germany, pp. 193320.
Roubal, F.R. (1986) Histopathology of leech, Austrobdella bilobata Ingram, infestation on the yellowfin bream,
Acanthopagrus australis (Gnther), in northern New South Wales. Journal of Fish Diseases 9, 213223.
Rupp, R.S. and Meyer, M.C. (1954) Mortality among brook trout, Salvelinus fontinalis, resulting from attacks of
freshwater leeches. Copeia 1954, 294295.
Sanjeeva Raj, P.J. (1974) A review of the fish-leeches of the Indian Ocean. Journal of the Marine Biological
Association of India 16, 381397.
Sawyer, R.T. (1986) Leech Biology and Behaviour, vol. 2. Feeding Biology, Ecology, and Systematics. Oxford
Scientific Publications, Oxford, UK.
Sawyer, R.T. and Chamberlain, N.A. (1972) A new species of marine leech (Annelida: Hirudinea) from South
Carolina, parasitic on the Atlantic menhaden, Brevoortia tyrannus. Biological Bulletin 142, 470479.
Sawyer, R.T. and Hammond, D.H. (1973) Observations on the marine leech Calliobdella carolinensis
(Hirudinea: Piscicolidae), epizootic on the Atlantic menhaden. Biological Bulletin 145, 373388.
Sawyer, R.T., Lawler, A.R. and Overstreet, R.M. (1975) Marine leeches of the eastern United States and the
Gulf of Mexico with a key to the species. Journal of Natural History 9, 633667.
Shanavas, K.R. (1991) Trypanosoma punctati Hasan and Qasim, 1962 from Channa punctatus Bloch in
Kerala, India, with observations on its vector-phase development and transmission. Archiv fr
Protistenkunde 140, 201208.
Shanavas, K.R., Ramachandran, P. and Janardanan, K.P. (1989) Trypanoplasma ompoki sp. n. from freshwater
fishes in Kerala, India, with observations on its vector-phase development and transmission. Acta
Protozoologica 28, 293302.
Shulman, S.S. (1961) Zoogeography of parasites of USSR freshwater fishes. In: Dogiel, V.A., Petrushevski, G.K.
and Polyanski, Y.I. (eds) Parasitology of Fishes. Oliver and Boyd, Edinburgh, pp. 180229.
Siddall, M.E. and Burreson, E.M. (1994) The development of a haemogregarine of Lycodes raridens from
Alaska in its definitive host. Journal of Parasitology 80, 569575.
591
Siddall, M.E. and Burreson, E.M. (1996) Leeches (Oligochaeta?: Euhirudinea), their phylogeny and the evolution of life-history strategies. Hydrobiologia 334, 277285.
Siddall, M.E. and Desser, S.S. (1992a) Ultrastructure of gametogenesis and sporogony of Haemogregarina
(sensu lato) myoxocephali (Apicomplexa: Adeleina) in the marine leech Malmiana scorpii. Journal of
Protozoology 39, 545554.
Siddall, M.E. and Desser, S.S. (1992b) Alternative leech vectors for frog and turtle trypanosomes. Journal of
Parasitology 78, 562563.
Siddall, M.E. and Desser, S.S. (1993) Ultrastructure of merogonic development of Haemogregarina (sensu
lato) myoxocephali (Apicomplexa: Adeleina) in the marine leech Malmiana scorpii and localization of
infective stages in the salivary cells. European Journal of Protistology 29, 191201.
Siddall, M.E. and Desser, S.S. (2001) Developmental stages of Haemogregarina delagei in the leech
Oxytonostoma typica. Canadian Journal of Zoology 79, 18971900.
Siddall, M.E., Apakupakul, A., Burreson, E.M., Coates, K.A., Ersus, C., Gelder, S.R., Kllersj, M. and
Trapido-Rosenthal, H. (2001) Validating Livanow: molecular data agree the leeches, branchiobdellidans,
and Acanthobdella peledina form a monophyletic group of oligochaetes. Molecular Phylogenetics and
Evolution 21, 346351.
Siddall, M.E., Perkins, S.L. and Desser, S.S. (2003) Leech mycetome symbionts are a new lineage of
alphaproteobacteria related to the Rhizobiaceae. Molecular Phylogenetics and Evolution 30, 178186.
Singhal, R.N., Jeet, S. and Davies, R.W. (1986) Chemotherapy of six ectoparasitic diseases of cultured fish.
Aquaculture 54, 165171.
Sloan, N.A., Bower, S.M. and Robinson, S.M.C. (1984) Cocoon deposition on three crab species and fish
parasitism by the leech Notostomum cyclostoma from deep fjords in northern British Columbia.
Marine Ecology Progress Series 20, 5158.
Sos, . (1965) Identification key to the leech (Hirudinoidea) genera of the world, with a catalogue of the
species. I. Family: Piscicolidae. Acta Zoologica Academiae Scientiarum Hungaricae 11, 417463.
Spelling, S.M. and Young, J.O. (1986a) Seasonal occurrence of metacercariae of the trematode Cotylurus
cornutus Szidat in three species of lake-dwelling leeches. Journal of Parasitology 72, 837845.
Spelling, S.M. and Young, J.O. (1986b) The population dynamics of metacercariae of Apatemon gracilis
(Trematoda: Digenea) in three species of lake-dwelling leeches. Parasitology 93, 517530.
Spelling, S.M. and Young, J.O. (1986c) The occurrence of metacercariae of the trematode Cyathocotyle opaca
in three species of lake-dwelling leeches. Freshwater Biology 16, 609614.
Thompson, D.H. (1927) An epidemic of leeches on fishes in Rock River. Bulletin of the Illinois Natural History
Survey 17, 195201.
Trontelj, P., Sket, B. and Steinbrck, G. (1999) Molecular phylogeny of leeches: congruence of nuclear and
mitochondrial rDNA data sets and the origin of bloodsucking. Journal of Zoological Systematics and Evolution Research 37, 141147.
Verrill, E.A. (1872) Descriptions of North American fresh water leeches. American Journal of Science 3,
126139.
Vojtek, J., Opravilov, V. and Vojtkov, L. (1967) The importance of leeches in the life cycle of the order
Strigeidida (Trematoda). Folia Parasitologica (Praha) 14, 107119.
Wales, J.H. and Wolf, H. (1955) Three protozoan diseases of trout in California. California Fish and Game 41,
183187.
Wilkialis, J. (1970) Investigations on the biology of leeches of the Glossiphoniidae family. Zoologica Poloniae
20, 2954.
Woo, P.T.K. (1979) Trypanoplasma salmositica: experimental infections in rainbow trout, Salmo gairdneri.
Experimental Parasitology 47, 3648.
Woo, P.T.K. (1987) Cryptobia and cryptobiosis in fishes. Advances in Parasitology 26, 199237.
Wood, J.W. (1979) Diseases of Pacific Salmon: Their Prevention and Treatment, 3rd edn. Hatchery Division,
State of Washington Department of Fisheries, Olympia, Washington.
Woods, L.C., III, McCarthy, M.A., Kraeuter, J.N. and Sager, D.R. (1990) Infestation of striped bass, Morone
saxatilis, by the leech Myzobdella lugubris. In: Perkins, F.O. and Cheng, T.C. (eds) Pathology in Marine
Science. Academic Press, San Diego, California, pp. 277282.
16
Introduction
Trematodiasis
Fish-borne trematodiasis is especially important in South East Asia, the Far East and
regions where people are dependent on freshwater fish as the major source of protein.
Infections by both large and small digenetic
trematodes are common. Although the diseases per se are seldom fatal, they can
cause morbidity and serious complications.
The route of infection is by ingesting
metacercariae located in muscles and subcutaneous and other tissues of fish.
592
Clonorchiasis
Clonorchiasis is caused by Clonorchis
sinensis (Cobbold, 1875) Looss, 1907, which
is located in the bile duct of humans. The
adult worm measures 815 mm about
4 mm and is characterized by the presence
of two highly branched testes and a prominent seminal receptacle (Fig. 16.1). The worm
also matures in cats, dogs, pigs and rats.
Although this trematode has also been
referred to as Opisthorchis (see Muller, 1975),
the old nomenclature is retained here because
of its wider acceptance by the medical profession. Furthermore, in Asia, clonorchiasis
is considered as distinct from opisthorchiasis (which will be described later).
Epidemiology
Clonorchiasis is still regularly encountered
in Hong Kong, southern China, Taiwan and
South Korea.
In Hong Kong, no natural transmission
of the parasite occurs. The snail intermediate hosts cannot propagate in the local fish
ponds, which have high salinities. Also, in
recent years, many ponds have been developed into apartment blocks. This disease is
due to the consumption of infected cyprinid fish imported from the Chinese mainland. Duchastel (1984) reported that 13.4%
of 25,095 Hong Kong residents who applied
to emigrate to Canada during 19791981
had ova in stool samples. Most applicants
were students under 25 years old. Li (1991)
reported that the infection rates in the
Chinese population varied from 1 to 48%.
A national survey in China during 19881992
showed that the infection occurred in 22
provinces (Yu et al., 1994).
In Taiwan, there were three endemic
areas: Miao-li in the north, Sun-moon in the
middle and Mei-nung in the south. However, recent surveys have shown that the
areas may be more widespread due to an
increase in consumption of raw fish. The
infection seemed to be more common in
Hakkanase and farmers than in other groups
(Chen, 1991a).
593
594
R.C. Ko
Fig. 16.4.
Many freshwater fishes, and in particular members of Cyprinidae, serve as the second intermediate host. Yoshimura (1965)
listed 81 species that are susceptible to
C. sinensis, including 71 species in the
Cyprinidae, two species each in the
Ophiocephalidae and Eleotridae and one
species each in the Bagridae, Cyprinodontidae, Clupeidae, Osmeridae, Cichlidae and
Gobiidae. In China, 43 species of freshwater
fishes
(Cyprinidae,
Cyprinodontidae,
Ophiocephalidae, Eleotridae and Gobidae)
have been found to be infected. Among
these, the most heavily and widely distributed species are Pseudorasbora parva,
Rhodeus ocellatus and Cultriculus kneri.
However, the major species which are commonly eaten raw are Ctenophargyndon
idellus, Hypothalmicthys molitrix, Mylopharyngodon aethiops and Culter aburnus.
In southern China, the traditional practice
of building outside toilets above carp ponds
and the use of night soil for pond enrichment sustain the infection in the cultured
fish population (Fig. 16.4). In Taiwan,
Tilapia mossambica and Ophiocephalus
maculatus are two common species eaten
raw. In South Korea, 36 species of fish
belonging to Cyprinidae, Bargridae and
A carp pond in Hong Kong, showing an outside toilet over pond (original).
Clupeidae can serve as the second intermediate host. The important species are:
P. parva, Sarcocheilichthys sinensis, Hemibarbus labeo, Acanthorhodeus gracilis,
Acanthorhodeus taenianalis, Puntungia
herzi, Pseudogobio esocinus, Gnathopogon
spp., Acheilognathus intermedia and C. kneri
(see Rim, 1986; Soh and Min, 1990). In
Japan, Komiya and Suzuki (1964) reported
that metacercariae were frequently found in
P. parva, Sarcocheilichthys variegates,
Acheilognathus lanceolata and Tribolodon
hakonensis. However, the importance of
these fishes as sources of infection in recent
years is not known.
Pathogenesis
The pathology of clonorchiasis was studied
extensively (Ong, 1962; Hou and Pang,
1964; Gibson and Sun, 1965; Mcfadzean
and Yeung, 1966; Chan and Teoh, 1967).
The infection has also been implicated in
recurrent pyogenic cholangitis (Cook et al.,
1954; Ong, 1962), cholangiohepatitis (Fung,
1961) and cholangiocarcinoma (Hou, 1956;
Belamaric, 1973; Abdel-Rahim, 2001;
Watanapa and Watanapa, 2002).
The histopathology of clonorchiasis
was first described in detail by Hou (1955).
After ingestion, the excysted metacercaria
reach the bile duct by direct migration
from the intestine. The adult worms ingest
blood in the bile ducts. Hepatic parenchymal
damage and portal hypertension are usually
absent in light and uncomplicated infections. The lesions are usually localized in
the distal biliary passages, particularly
those in the left lobe of the liver. The extent
of the lesions is dependent on worm burden
and on the presence of a secondary bacterial
infection. The latter complication commonly leads to biliary obstruction due to
extensive adenomatous proliferation, calculi and cholangitis. During the acute stage
of infection, the mucosa of bile ducts is
oedematous, with desquamation of the epithelium. Later, due to inflammatory responses, the bile ducts become thickened
and crypt formation occurs. Metaplasia of
the epithelial cells follows, resulting in proliferation of glandular-like structures in the
595
mucosa which are responsible for producing mucin in the bile. During chronic and
heavy infections, continuous hyperplasia
may cause formation of adenomatous tissue. This is probably elicited by continuous
mechanical and chemical stimulation
(Flavell, 1981). Recurrent attacks of suppurative cholangitis may occur due to biliary
obstruction by the trematodes. Atrophy of
the biliary epithelium and underlying
hepatic cells may also develop.
Clonorchiasis may also cause pancreatitis (Hou, 1955). Hou reported that as many
as 50 worms were recovered from pancreatic ducts. The main ducts were dilated. A
limited degree of periductal fibrosis and
adenomatous tissue occurred but with considerable squamous metaplasia. Mcfadzean
and Yeung (1966) reported that, in 110
Chinese patients in Hong Kong suffering
from acute pancreatitis of unknown aetiology, 83% were infected with C. sinensis.
Hou (1956) noted a close correlation
between clonorchiasis and primary liver
carcinoma. The close association between
this trematode infection and cholangiocarcinoma was further elaborated by
Belamaric (1973), Purtillo (1976) and
Schwartz (1980). Kim (1984) suggested that
exogenous carcinogenic promoters, nutritional, immunological and genetic factors,
probably induce goblet-cell metaplasia and
dysplasia of the bile-duct epithelial cells,
resulting in carcinoma. Ona and Dytoc (1991)
reported two cases with unusual manifestations. Watanapa and Watanapa (2002),
however, after reviewing the literature, concluded that C. sinensis is only a probable
cause of cholangiocarcinoma.
Symptoms
In endemic areas, patients with an enlarged
liver and a history of eating raw or undercooked freshwater fish should be examined
for clonorchiasis. In light and acute infections, more than half of the patients are
usually asymptomatic. However, some
show general malaise, abdominal discomfort, occasional diarrhoea, slight fever,
eosinophilia (520%), gall-bladder syndrome, paroxymal epigastric pain, mild
596
R.C. Ko
Immunoassays
Despite numerous attempts, a highly specific and sensitive antigen for detecting
clonorchiasis is still not available. Takei
and Chun (1976) produced fractions from
crude somatic extracts using gel filtration
on a Sephadex G-100 column, followed by
disc electrophoresis. A fraction, KD1, containing protein and carbohydrate was produced and tested, using serum samples from
32 clonorchiasis patients. All tests were
positive. Negative reactions were observed in
samples from uninfected persons and patients
with schistosomiasis, ascariasis, filariasis
and hookworms. Sawada et al. (1976) purified antigens by using Biogel-A filtration.
Laboratory diagnosis
597
Diagnosis by imaging
Computed tomography scanning (CT),
magnetic resonance imaging (MRI) and
ultrasound can also be used to diagnose
clonorchiasis. In a study involving 17
patients with clonorchiasis alone and
25 patients with clonorchiasis and hepatobiliary malignancies, CT showed a diffuse,
minimal or mild dilatation of the intrahepatic bile ducts in 14 cases. However, a
diffuse dilatation of the ducts was observed
in all patients with both parasite and biliary
malignancies (Choi et al., 1989).
In a study of 947 clonorchiasis patients
using ultrasound, gall stones were seen in
85 cases, common bile duct stones in three
and a hepatic stone in one (Hon et al.,
1989). Lim et al. (1989) presented sonographic findings in 59 proven cases.
In heavy infections, intraoperative
cholangiography can show multiple filling
defects in the common bile duct, common
hepatic duct and left hepatic duct (Nishioka
and Donnelly, 1990).
Treatment
There was no effective drug to treat
clonorchiasis until praziquantel became
available. Chen (1991b) reported a 96% cure
rate among 356 patients with praziquantel
(60 mg/kg of body weight, divided into
three doses in 12 days).
Control
The feasibility of using 60Co gamma irradiation to control the infectivity of metacercariae was explored (Duan et al., 1993). The
median lethal dose (LD50) of irradiation for
metacercariae in fish was 0.05 kGy and the
minimal effective dose was 0.15 kGy.
Opisthorchiasis
Opisthorchiasis is a zoonosis that is mainly
caused by O. viverrini (Poirrier, 1886) Stiles
and Hassall, 1869 and Opisthorchis felineus
(Rivolta, 1884) Blanchard, 1895. The natural definitive host for the former species is
the civet cat (Felis viverrini). Cats, dogs,
598
R.C. Ko
599
600
R.C. Ko
different. The two species are also distinguished by the pattern of flame cells in the
cercariae and metacercariae (Belding, 1965).
Epidemiology
The disease usually occurs in villages and
localities near rivers or reservoirs in Siberia
and Central Europe where fish are eaten
raw. In the Ukraine, most infections are
acquired by eating fish on the first day of
salting (see Muller, 1975). However, the
prevalence of this infection in humans is
usually lower than that of O. viverrini.
Biology of parasite
The biology of this species is similar to that
of O. viverrini. The first intermediate host
is Bithynia leachii and cyprinids are the
second intermediate hosts. The important
fish hosts are C. carpio, Idus melanotus,
Abramis brama, Barbus barbus, Tinca
tinca, Blicca bjoerkna, Leuciscus rutilis and
Scardinus erythrophthalmus.
Pathogenesis, symptoms and treatment
Hepatic lesions, symptoms and treatment
are similar to those of O. viverrini.
Laboratory diagnosis
Faecal examination is the common method.
The ovum is morphologically similar to that
of O. viverrini. Serodiagnosis has also been
employed. Teplukhin et al. (1987) used IHA
and somatic or E/S antigens to detect antibodies. They concluded that somatic antigens were 1.5 times more sensitive than E/S
antigens. Gitsu et al. (1987) reported that
ELISA detected 31.8% of 323 patients passing fewer than 10 eggs/g of faeces and 86.3%
with more than 1000 eggs/g.
Small trematodes
Besides O. viverrini, infections by numerous species of small trematodes (0.53 mm
in length), especially members of the Heterophyidae, are also common in South East
Asia and the Far East (northern Thailand,
Laos, Cambodia, Vietnam, Indonesia, the
Cestodiasis
There are relatively few cases of fish-borne
cestode infections in humans. The cestodes
that mature in the small intestine of humans
are not very pathogenic and the diseases are
never fatal. Diphyllobothriasis is the major
cestodiasis transmitted by freshwater,
marine and anadromous fishes.
Diphyllobothriasis
The disease is caused by pseudophyllid
cestodes belonging to the genus Diphyllobothrium. The genus is characterized by a
holdfast structure at the anterior extremity,
called the bothrium (Fig. 16.5), and a highly
coiled uterus with a uterine pore in the
mature proglottids. The adult worm grows
601
602
R.C. Ko
603
the Salmonidae, Percidae and various species common in lakes and reservoirs can be
infected, e.g. E. lucius, Stizostedion vitreum,
Stizostedion canadense, Lota maculosa,
Lota lota, Perca flavescens, Oncorhynchus
nerka, O. keta, O. gorbuscha, Salmo
gairdneri, S. leucomaenis, Salvelinus malma,
Salvelinus namaycush, etc.
Pathogenesis
The adult worm attaches to the mucosa of
the ileum and occasionally, the jejunum.
Although a catarrhal condition may be produced in the mucosa, the parasite generally
elicits little pathogenicity. For unknown
reasons, the worm depletes vitamin B12
from its definitive host for its own extensive
growth and development.
Symptoms
Most infections are asymptomatic but sometimes epigastric pains, cramp-like abdominal
pains, diarrhoea or constipation, nausea,
vomiting, loss of weight, anorexia and
eosinophilia may occur. The major clinical
manifestation in some patients is pernicious
anaemia due to vitamin B12 deficiency, and
there is central nervous system involvement.
604
R.C. Ko
Nematodiasis
Fish-borne nematodiases are generally caused
by the incidental infection of humans with
Capillariasis
Capillariasis is caused by Capillaria
philippinensis (Chitwood et al., 1968). This
species is most unusual because it can
mature either in humans or in experimentally infected monkeys and birds. Moreover, the worm can either produce eggs or
larvae. The disease was first known to occur
in humans in 1963, when the nematode was
found at the autopsy of a Filipino in Manila
(Chitwood et al., 1964). C. philippinensis
has since been recognized as a medically
important parasite.
Updates on the disease were given by
Cross (1990, 1998, 2000). C. philippinensis
is a trichuroid nematode with a narrow and
filiform anterior region. The male worms
measure 1.53.9 mm in length; the females
are 2.55.3 mm in length. A trichuroid
nematode is also characterized by a glandular structure called the stichosome, which
is located posterior to the muscular oesophagus. Most known species have extraordinary life cycles. However, C. philippinensis
is the only known capillarid that is transmitted to humans via fish. The life cycle has
only been established by experimental
infections of monkeys, Mongolian gerbils,
fish and birds (Cross et al., 1972; Bhaibulaya
and Indra-Ngarm, 1979). Presumably the
natural cycle is similar (Cross and BasacaSevilla, 1989).
Epidemiology
Capillariasis was originally presumed to be
an indigenous disease of the Philippines,
605
606
Fig. 16.7.
R.C. Ko
607
Symptoms
Gnathostomiasis
The onset is marked by borborygmi and diffuse abdominal pain. This is followed by
intermittent diarrhoea, two to five times a
day, especially after every meal. The stool is
watery, greenish yellow in colour with a
foul odour. The volume may reach 2 l/day
in severely ill patients. A marked proteinlosing enteropathy and steatorrhoea generally result in the loss of large quantities of
protein, fat and minerals in the stool. With
the onset of diarrhoea, rapid weight loss
occurs. Muscle wasting, weakness, emaciation, abdominal distension and oedema are
prominent. Distant heart sounds, hypotension and other cardiac abnormalities
may be present in some patients. Death due
to cardiac failure may occur 2 weeks to
2 months after the initial onset of symptoms.
Laboratory studies have shown a decrease
in the excretion of xylose, hypokalaemia,
hypocalcaemia and hypoproteinaemia. An
increase in IgE is common (Watten et al.,
1972; Cross and Basaca-Sevilla, 1989).
Laboratory diagnosis
The standard laboratory diagnostic method
is by stool examination to search for the
characteristic eggs, larvae and adults. Several
stool samples may sometimes be required to
detect the infection. Duodenal aspiration
can be used to recover the worms.
IHA and double diffusion tests using
antigens prepared from a chicken capillarid
(Capillaria obsignata) have been evaluated
for serodiagnosis but the test lacks both
specificity and sensitivity (Banzon et al.,
1975). An ELISA test using somatic antigens of adult C. philippinensis was also
unsatisfactory (Cross and Chi, 1978).
Epidemiology
The disease occurs in South East Asia, China,
Japan, Korea, the Indian subcontinent, the
Treatment
Mebendazole is the drug of choice. The dosage is 400 mg/day (in divided doses) for
2030 days. Few relapses occur with this
regimen. Albendazole is also effective at the
same regimen as mebendazole (Cross and
Basaca-Sevilla, 1987). However, treatment
with thiabendazole may result in relapses
(Cross, 2000).
608
R.C. Ko
Biology of parasite
Only the biology of G. spinigerum and
G. hispidum is briefly described.
The adult worms are located in the
stomach wall of the definitive host, where
unembryonated ova are deposited and
passed to the outside via the intestine. The
ovum (6279 m 3642 m) is characterized by a polar thickening (Fig. 16.10).
Embryonation occurs in fresh water and,
upon ingestion by copepods, the hatched
first-stage larva penetrates the digestive
tract and reaches the haemocoel, where it
develops into the second-stage larva. When
the infected copepod is ingested by the second intermediate host (a freshwater fish or
frog), the second-stage larva enters the muscle and moults into the third-stage worm,
which is eventually encysted. A fully grown
third-stage larva (45 mm) is infective to
the definitive host (Fig. 16.11). Other fish,
609
610
R.C. Ko
Anisakiasis
Anisakiasis refers to infection by larval
ascaridoid nematodes whose normal definitive hosts are marine mammals. The genera
involved are Anisakis, Pseudoterranova
and Contracaecum. Larvae from squids and
marine fish can invade the gastrointestinal
tract of humans, causing an eosinophilic
granuloma syndrome. In Europe, it has also
been referred to as the herring worm disease. The first human infection was documented in the Netherlands in 1955 and then
later in Japan (van Thiel et al., 1960; Asami
et al., 1965). However, in the Netherlands,
since the passage of legislation against eating raw herring and requiring fish to be
611
612
R.C. Ko
613
614
R.C. Ko
Symptoms
Acute gastric infections are manifested by
gastric pain, nausea and vomiting 46 h
after ingesting raw infected seafood. During
the chronic phase, vague epigastric pain,
nausea and vomiting may last from several
weeks to 2 years. In more than 50% of the
recorded cases, eosinophils varied from 4 to
41%. Occult blood may occur in the gastric
juice and stools.
The onset of intestinal anisakiasis occurs
within 7 days after ingesting infected raw
seafood. The symptoms are severe pain in
the lower abdomen, with nausea and vomiting. The pressure point, unlike appendicitis, is vague and there is no muscular
rigidity. Marked leucocytosis is common
but eosinophilia is rare. Straw-coloured
ascites may be present.
Laboratory diagnosis
Fibre-optic gastroscopy is most useful to
diagnose gastric anisakiasis. The diagnosis
of intestinal cases, however, relies mainly
on clinical symptoms and a history of eating raw seafood. X-rays, after administration of a barium meal, may show segmented
movement of the barium and jagged stricture of the regional intestine, with proximal
enlargement and a radiolucent area (Oshima,
1972; Higashi et al., 1987). Ultrasound has
also been used to diagnose intestinal
anisakiasis (Shirahama et al., 1992).
Many serodiagnostic methods have
been tried, e.g. skin test, CFT, IFAT and
ELISA (Yoshimura, 1966; Kikuchi et al.,
1970; Ruitenberg, 1970; Suzuki et al., 1970;
Boczon, 1988). The major problem is the
failure to isolate specific antigens. Kennedy
et al. (1988) reported extensive antigenic
relationships between the somatic and E/S
antigens of A. simplex and those of other
ascarids, such as Ascaris suum, Ascaris
lumbricoides and Toxocara canis. Rodero
et al. (2001) attempted to purify A. simplex
antigens by affinity chromatography.
E/S antigens were used in immunoblots
to diagnose human anisakiasis (Akao et al.,
1990; Petithory et al., 1991; Iglesias et al.,
1993).
Monoclonal antibodies
Takahasi et al. (1986) developed two mAbs,
An1 and An2, from type I larvae. Using
SDS-PAGE and Western blotting, An1 precipitated a band of 34 kDa and An2 bands of
40 and 42 kDa, respectively. An2 was also
detected in the E/S antigens using ELISA.
Yagihashi et al. (1990) reported that serum
from patients reacted strongly to An2 in
micro-ELISA.
Five mAbs (UA2, UA3, UA5, UA6, UA8)
were produced by Iglesias et al. (1997).
Lorenzo et al. (1999) found that UA2R
antigens (two proteins with molecular mass
(MM) 48 and 67 kDa) were recognized by
mAb UA2. UA3R antigens (two proteins
with MM 139 and 154 kDa) were recognized by mAb UA3. Ninety-five per cent of
Japanese anisakiasis patients and 84% of
the allergy patients showed detectable IgG1
antibodies to the UA3R antigens. All allergy
patients showed IgE antibodies to these
antigens.
IgE
Specific IgE was found in anisakiasis
patients (Kasuya and Koga, 1992). Garcia
et al. (1997) found that IgE immunoblotting
was useful in diagnosing A. simplex allergy.
Daschner et al. (1999) considered that a rise
of total and specific IgE in the first month
after an allergic reaction is a good indication of gastro-allergic anisakiasis, even if
the parasite cannot be seen by gastroscopy.
Using ethanol precipitation and reversedphase HPLC, Moneo et al. (2000) isolated an
E/S protein of 24 kDa (named Ani s1) that is
IgE-binding. Caballero and Moneo (2002)
suggested that hypersensitivity and intestinal anisakiasis can be diagnosed by determining the specific IgE directed towards
this major allergen.
Fish screening
Although a reliable serological method has
not been developed to mass-screen fish for
anisakid worms, Huber et al. (1989) briefly
reported on the use of ELISA to detect antibodies against A. simplex in the saithe fish,
P. virens. A good correlation was observed
615
Control
Fish-borne parasitic zoonoses can be controlled by requiring all fish or fish products
to be deep-frozen or well cooked before consumption. Guidelines can be posted on a
website. Irradiating fish with high levels of
gamma-radiation (200 Gy) can reduce the
infectivity of larval parasites in muscles
and minimize the risk of transmission (Chai
et al., 1995). However, this may not be a cost
effective measure for large-scale or routine
operation. The high cost of the commercial
irradiator and the problems of disposing of
radioactive wastes are the limiting factors.
Conclusions
Since the biology and pathogenesis of many
fish-borne parasites still remain unknown,
it is possible that new zoonoses may be discovered if clinicians and public health
workers are better informed about parasitic
diseases.
Theoretically, fish-borne
parasitic
zoonoses can easily be prevented by refraining from eating raw seafood. However, in
many parts of the world, such an eating
habit represents an established way of life
or part of the inherent culture. It cannot be
616
R.C. Ko
Acknowledgements
The author is very grateful for the invaluable assistance of Ms Y.Y.Y. Chung in preparing this chapter. Dr John Cross kindly
provided the pictures of C. philippinensis
and his review papers.
References
Abdel-Rahim, A.Y. (2001) Parasitic infections and hepatic neoplasia. Digestive Diseases 19, 288291.
Adams, A.M., Berry, M., Wekell, M.M. and Deardorff, T.L. (1990) Juvenile anisakids in Pacific herring. In:
Abstracts of 33rd Southeast Asian Medical Education Organization Tropical Medicine Regional Seminar,
Chiangmai, Thailand, Southeast Asian Medical Education Organization (SEAMEO) Regional Tropical
Medicine and Public Health Project, Bangkok, Thailand, p. 42.
Ahmed, L., el-Dib, N.A., el-Boraey, Y. and Ibrahim, M. (1999) Capillaria philippinensis: an emerging parasite
causing severe diarrhoea in Egypt. Journal of Egyptian Society of Parasitology 29, 483493.
Ahn, Y.K., Chung, P.R., Lee, K.T. and Soh, C.T. (1987) Epidemiological survey of Metagonimus yokogawai
infection in the Eastern coast area of Kangwon Province, Korea. Korean Journal of Parasitology 25, 5968
(in Korean).
Akao, N., Ohyama, T., Kondo, K. and Takakura, Y. (1989) Immunoblot analysis of human gnathostomiasis.
Annals of Tropical Medicine and Parasitology 83, 635637.
Akao, N., Ohyama, T. and Kondo, K. (1990) Immunoblot analysis of serum IgG, IgA and IgE response against
larval excretorysecretory antigens of Anisakis simplex in patients with gastric anisakiasis. Journal of
Helminthology 64, 310318.
Amornpunt, S., Sarasombath, S. and Sirisinha, S. (1991) Production and characterization of monoclonal antibodies against the excretorysecretory antigens of the liver fluke (Opisthorchis viverrini). International
Journal for Parasitology 21, 421428.
Anantaphruti, M.T. (1989a) ELISA for diagnosis of gnathostomiasis using antigens from Gnathostoma
doloresia and G. spinigerum. Southeast Asian Journal of Tropical Medicine and Public Health 20,
297304.
Anantaphruti, M.T. (1989b) Demonstration of species specific antigens of Gnathostoma spinigerum, a preliminary report. Southeast Asian Journal of Tropical Medicine and Public Health 20, 305312.
Ando, K., Ishikura, K., Nakakugi, T., Shimono, Y., Tamai, T., Sugawa, M., Limviroj, W. and Chinzei Y. (2001)
Five cases of Diphyllobothrium nihonkaiense infection with discovery of plerocercoids from an infective
source, Oncorhynchus masou ishikawae. Journal of Parasitology 87, 96100.
Arambulo, P.V. and Thakur, A. (1990) Current status of food-borne parasitic zoonoses in Latin America and
the Carribean. In: Abstracts of 33rd Southeast Asian Medical Organization Tropical Medicine Regional
Seminar, Chiangmai, Thailand, Southeast Asian Medical Education Organization (SEAMEO) Regional
Tropical Medicine and Public Health Project, Bangkok, Thailand, p. 117.
Asami, K., Watanuki, T., Sakai, H., Imano, H. and Okamoto, R. (1965) Two cases of stomach granuloma
caused by Anisakis-like larvae nematodes in Japan. American Journal of Tropical Medicine and Hygiene
14, 119123.
Ashby, B.S., Appleton, P. and Dawson, I. (1964) Eosinophilic granuloma of gastro-intestinal tract caused by
herring parasite, Eustoma rotundatum. British Medical Journal 1, 11411145.
Audicana, M.T., Ansotegui, I.J., de-Corres, L.F. and Kennedy, M.W. (2002) Anisakis simplex: dangerous
dead and alive? Trends in Parasitology 18, 2025.
Austin, D.N., Mikhail, M.G., Chiodini, P.L. and Murray-Lyon, I.M. (1999) Intestinal capillariasis acquired in
Egypt. European Journal of Gastroenterology and Hepatology 11, 935936.
617
Banzon, T.C., Lewer, R.M. and Yagore, M.G. (1975) Serology of Capillaria philippinensis infection: reactivity
of human sera to antigens prepared from Capillaria obsignata and other helminths. American Journal of
Tropical Medicine and Hygiene 24, 256263.
Bashirullah, A.K.M. (1972) Occurrence of Gnathostoma spinigerum Owen, 1836, in Dacca, Bangladesh.
Journal of Parasitology 58, 187188.
Belamaric, J. (1973) Intrahepatic bile duct carcinoma and Clonorchis sinensis in Hong Kong. Cancer 31,
468473.
Belding, D.L. (1965) Text Book of Parasitology. Appleton-Century-Crofts, New York.
Belizario, V.Y., de-Leon, W.U., Esparar, D.G., Galang, J.M., Fantone, J. and Verdadero, C. (2000) Compostela
Valley: a new endemic focus for Capillariasis philippinensis. Southeast Asian Journal of Tropical Medicine and Public Health 31, 478481.
Bhaibulaya, M. and Indra-Ngarm, S. (1979) Amaurornis phoenicurus and Ardeiola bacchus as experimental
definitive hosts for Capillaria philippinensis in Thailand. International Journal for Parasitology 9,
321322.
Bhaibulaya, M., Indra-Ngarm, S. and Anathapruit, M. (1979) Freshwater fishes of Thailand as experimental
intermediate host for Capillaria philippinensis. International Journal for Parasitology 9, 105108.
Boczon, K. (1988) Diagnosis of anisakis infection. Wiadomosci Parazytologiczne 34, 1117 (in Polish).
Caballero, M.L. and Moneo, I. (2002) Specific IgE determination to Ani s1, a major allergen from Anisakis
simplex, is a useful tool for diagnosis. Annals of Allergy, Asthma, and Immunology 89, 7477.
Chai, J.Y. and Lee, S.H. (1991) Intestinal trematodes infecting humans in Korea. Southeast Asian Journal of
Tropical Medicine and Public Health 22 (suppl.), 163170.
Chai, J.Y. and Lee, S.H. (2002) Food-borne intestinal trematode infections in the Republic of Korea. Parasitology International 51, 129154.
Chai, J.Y., Hong, S.J., Lee, S.H. and Seo, B.S. (1988) Stictodora sp. (Trematoda: Heterophyidae) recovered
from a man in Korea. Korean Journal of Parasitology 26, 127132.
Chai, J.Y., Kim, S.J., Kook, J. and Lee, S.H. (1995) Effects of gamma-irradiation on the survival and development of Metagonimus yokogawai metacercariae in rats. Korean Journal of Parasitology 33, 297308.
Chai, J.Y., Song, T.E., Han, E.T., Guk, S.M., Park, Y.K., Choi, M.H. and Lee, S.H. (1998) Two endemic foci of
heterophyids and other intestinal fluke infections in southern and western coastal areas in Korea. Korean
Journal of Parasitology 36, 155161.
Chaicumpa, W., Ruangkunaporn, V., Nopparatana, C., Chongsa, N.M., Tapachaisri, P. and Sebasuban, P.
(1991) Monoclonal antibody to a diagnostic Mr 24,000 antigen, of Gnathostoma spinigerum. International Journal for Parasitology 21, 735738.
Chaicumpa, W., Ybanez, L., Kitikoon, V., Pungpak, S., Ruangkunapron, Y., Chongsanguan, M. and
Sornamani, S. (1992) Detection of Opisthorchis viverrini antigens in stools using specific monoclonal
antibody. International Journal for Parasitology 22, 527531.
Chan, P.H. and Teoh, T.B. (1967) The pathology of Clonorchis sinensis infestation of the pancreas. Journal of
Pathology and Bacteriology 93, 185189.
Changbrunrung, S., Ratarasaru, S., Hongtong, K., Miagasena. P., Vutikes, S. and Migasen, S. (1988) Lipid
composition of serum lipoprotein in opisthorchiasis. Annals of Tropical Medicine and Parasitology 82,
263269.
Chen, C.Y., Hsieh, W.C., Shih, H.H. and Chen, S.N. (1987a) Detection of serum antibody to Clonorchis sinensis
by enzyme-linked immunosorbent assay. Journal of Formosan Medical Association 86, 706711.
Chen, C.Y., Hsieh, W.C., Shih, H.H. and Chen, S.N. (1987b) Evaluation of enzyme-linked immunosorbent
assay for immunodiagnosis of clonorchiasis. Chinese Journal of Microbiology and Immunology 20,
241246.
Chen, C.Y., Shin, J.W., Chen, S.N. and Hsieh, W.C. (1989) A preliminary study of clinical stages in
clonorchiasis. Chinese Journal of Microbiology and Immunology 22, 193200.
Chen, E.R. (1991a) Food-borne parasitic zoonoses in Taiwan. Southeast Asian Journal of Tropical Medicine
and Public Health 22 (suppl.), 6263.
Chen, E.R. (1991b) Clonorchiasis in Taiwan. Southeast Asian Journal of Tropical Medicine and Public Health
22 (suppl.), 184185.
Chichino, G., Bernuzzi, A.M., Bruno, A., Cevini, C., Atzori, C. Malfitano, A. and Scaglia, M. (1992) Intestinal
capillariasis (Capillaria philippinensis) acquired in Indonesia: a case report. American Journal of Tropical
Medicine and Hygiene 47, 1012.
Chitanondh, H. and Rosen, L. (1967) Fatal encephalomyelitis caused by the nematode, Gnathostoma
spinigerum. Americal Journal of Tropical Medicine and Hygiene 16, 638645.
618
R.C. Ko
Chitwood, M.B. (1970) Nematodes of medical significance found in fish market. American Journal of Tropical
Medicine and Hygiene 19, 599602.
Chitwood, M.B. (1975) Phocanema-type larval nematode coughed up by a boy in California. American
Journal of Tropical Medicine and Hygiene 24, 710711.
Chitwood, M.B., Velasquez, C. and Salazar, N.G. (1964) Physiological changes in a species of Capillaria
(Trichuroidea) causing a fatal case of human intestinal capillariasis. In: Proceedings of the First International Congress of Parasitology (Rome, Italy), vol. 2, p. 797.
Chitwood, M.B., Velasquez, C. and Salazar, N.G. (1968) Capillaria philippinensis sp. n. (Nematoda:
Trichuroidea) from intestine of man in the Philippines. Journal of Parasitology 54, 368371.
Cho, K.M. and Soh, C.T. (1974) Evaluation of the indirect fluorescent antibody test with adult worm antigen
for the immunodiagnosis of clonorchiasis. Yonsei Reports of Tropical Medicine 5, 4556.
Cho, K.M. and Soh, C.T. (1976) Indirect fluorescent antibody test with adult worm antigen for the
immunodiagnosis of clonorchiasis. Yonsei Reports of Tropical Medicine 7, 2639.
Choi, B.I., Kim, H.J., Han, M.C., Do, Y.S., Han, M.H. and Lee, S.H. (1989) CT findings of clonorchiasis.
American Journal of Roentgenology 152, 281284.
Chung, H.L., Weng, H.C. Hou, T.C. and Ho, L.Y. (1955) Cross intradermal reactions of patients with
paragonimiasis, clonorchiasis and schistosomiasis to different trematode antigen and their clinical
significance. Chinese Medical Journal 73, 368378.
Chung, P.R., Sohn, W.M., Jung, Y., Pai, S.H. and Nam, M.S. (1997) Five human cases of Diphyllobothrium
latum infection through eating raw flesh of redlip mullet, Liza haematocheila. Korean Journal of Parasitology 35, 283289 (in Korean).
Chung, Y.B., Chung, B.S., Choi, M.H., Chai, J.Y. and Hong, S.T. (2000) Partial characterization of a 17 kDa
protein of Clonorchis sinensis. Korean Journal of Parasitology 38, 9597.
Chunlertrith, K., Mairiang, P. and Sukeepaisarnjaroen, W. (1992) Intestinal capillariasis: a cause of chronic
diarrhea and hypoalbuminea. Southeast Asian Journal of Tropical Medicine and Public Health 23,
433436.
Cook, J., Hou, P.C., Ho, H.C. and Mcfadzean, A.J.S. (1954) Recurrent pyogenic cholangitis. British Journal of
Surgery 42, 188203.
Cross, J.H. (1990) Intestinal capillariasis. Parasitology Today 6, 2628.
Cross, J.H. (1998) Capillariosis. In: Palmer, S.R., Soulsby, E.J.L. and Simpson, D.I.H (eds) Zoonoses: Biology,
Clinical Practice, and Public Health Control. Oxford University Press, Oxford, UK, pp. 759772.
Cross, J.H. (2000) Fish- and invertebrate-borne helminthes. In: Hui, Y.H., Sattar, S.A., Murrell, K.D., Nip, W.K.
and Stanfield, P.S (eds) Fishborne Disease Handbook, 2nd edn. Marcel Dekker, New York, pp. 249288.
Cross, J.H. and Basaca-Sevilla, V. (1987) Albendazole in the treatment of intestinal capillariasis. Southeast
Asian Journal of Tropical Medicine and Public Health 18, 507510.
Cross, J.H. and Basaca-Sevilla, V. (1989) Intestinal capillariasis. Progress in Clinical Parasitology 1, 105119.
Cross, J.H. and Basaca-Sevilla, V. (1991) Capillaria phillipinensis: a fish-borne parasitic zoonosis. Southeast
Asian Journal of Tropical Medicine and Public Health 22 (suppl.), 153157.
Cross, J.H. and Bhaibulaya, M. (1983) Intestinal capillariasis in the Philippines and Thailand. In: Croll, N. and
Cross, J.H. (eds) Human Ecology and Infectious Diseases. Academic Press, Orlando, Florida,
pp. 103136.
Cross, J.H. and Chi, J.C.H. (1978) The ELISA test in the detection of antibodies to some parasitic diseases.
In: Proceedings of Southeast Asia Medical Education Organization Tropical Medicine 18th Seminar,
Kuala Lumpur, Malaysia, Malaysian Society of Parasitology and Tropical Medicine, pp. 178182.
Cross, J.H., Banzon, T.C., Clarke, M.D., Basaca-Sevilla, V., Watten, R.H. and Dizon, J.J. (1972) Studies on the
experimental transmission of Capillaria philippinensis in monkeys. Transactions of Royal Society of Tropical Medicine and Hygiene 66, 819827.
Cross, J.H., Banzon, T.C. and Singson, C.N. (1978) Further studies on Capillaria philippinensis: development
of the parasite in the Mongolian gerbil. Journal of Parasitology 64, 208213.
Cross, J.H., Singson, C.N., Battad, S. and Basaca-Sevilla, V. (1979) Intestinal capillariasis: epidemiology, parasitology and treatment. In: Health Policies in Developing Countries. International Congress Series 24,
Royal Society of Medicine, pp. 8287.
Curtis, M.A. and Bylund, G. (1991) Diphyllobothriasis: fish tapeworm disease in the circumpolar north. Arctic
Medical Research 50, 1824.
Daengsvang, S. (1949) Human gnathostomiasis in Siam with reference to the method of prevention. Journal of
Parasitology 35, 116121.
619
620
R.C. Ko
Gracia-Bara, M.T., Matheu, V., Zubeldia, J.M., Rubio, M., Ordoqui, E., Lopez-Saez, M.P., Sierra, Z.,
Tornero, P. and Baeza, M.L. (2001) Anisakis simplex-sensitized patients: should fish be excluded from
their diet? Annals of Allergy, Asthma, and Immunology 86, 679685.
Hahm, J.H., Lee, J.S. and Rim, H.J. (1984) Comparative study on the indirect immunofluorescent antibody
test, complement fixation test and ELISA in diagnosis of human clonorchiasis. Korea University Medical
Journal 21, 177184 (in Korean).
Han, J.H., Eom, K.S. and Rim H.J. (1986) Comparative studies on the immunodiagnosis of clonorchiasis by
means of micro-ELISA using sera and blood collected in filter paper. Korea University Medical Journal
23, 1325 (in Korean).
Harinasuta, C. (1984) Parasitic diseases of public health importance in Southeast Asia epidemiology, treatment and control. In: Ko, R.C. (ed.) Current Perspectives in Parasitic Diseases. Departments of Zoology
and Medicine, University of Hong Kong, Hong Kong, pp. 128.
Haswell-Elkins, M.R., Satarug, S., Tsuda, M., Mairiang, E., Esmui, H., Sithithaworn, P., Mairiang, P.,
Saitoh, M., Yongvanit, P. and Elkins, D.B. (1994) Liver fluke infection and cholangiocarcinoma: model
of endogenous nitric oxide and extragastric nitrosation in human carcinogenesis. Mutation Research
305, 241252.
Hayashi, S. and Kamo, H. (1983) Studies on the effect and mode of action of paramomycin sulfate against
tapeworm. Japanese Journal of Antibiotics 34, 552565 (in Japanese).
Higashi, M., Tanaka, K., Kitada, T., Nakatake, K. and Tsuji, M. (1987) Anisakiasis confirmed by radiography of
the large intestine. Gastrointestinal Radiology 13, 8586.
Hirai, K., Torii, M., Suzuki, N. and Kamo, H. (1988) Occurrence of human cases infected with Diphyllobothrium yonagoense in Shikoku Island, Japan. Japanese Journal of Parasitology 37, 1319 (in Japanese).
Hon, M.F., Ker, C.G., Sheen, P.C. and Chen, E.R. (1989) The ultrasound survey of gallstone diseases of
patients infected with Clonorchis sinensis in southern Taiwan. Journal of Tropical Medicine and Hygiene
92, 108111.
Hou, P.C. (1955) The pathology of Clonorchis sinensis infestation of the liver. Journal of Pathology and
Bacteriology 70, 5364.
Hou, P.C. (1956) Relationship between primary carcinoma of liver and infestation with Clonorchis sinensis.
Journal of Pathology and Bacteriology 72, 239246.
Hou, P.C. and Pang, S.C.L. (1964) Clonorchis sinensis infestation in man in Hong Kong. Journal of Pathology
and Bacteriology 87, 245250.
Hu, Y.X., Cao, W.J., Tan, W., Hu, R.Y. and Qi, Z.Q. (1989) Preliminary study on the diagnosis of
clonorchiasis by charcoal granule agglutination test. Chinese Journal of Parasitic Diseases Control 2,
279281 (in Chinese).
Huang, W. and Bussieras, J. (1988) Anisakides et anisakidoses humaines. Premier partie: donnes
bibliographiques. Annales de Parasitologie Humaine et Compare 63, 119132 (in French).
Huber, B., Bacou, J. and Belveze, H. (1989) Epidemiology of human anisakiasis: incidence and sources in
France. American Journal of Tropical Medicine and Hygiene 40, 301303.
Huber, C., Martlbauer, E., Priebe, K. and Terplan, G. (1989) Entwicklung und Anwendung eines ELISA
zum Nachweis von antikorpern Gegen Anisakis simplex (Nematoda) beim Seelachs Pollachius virens.
Deutsche Veterinarmedizinische Gesellschaft 28, 272275 (in German).
Iglesias, L., Valero, A., Benitez, R. and Adroher, F.J. (2001) In vitro cultivation of Anisakis simplex: pepsin
increases survival and moulting from fourth larval to adult stage. Parasitology 123, 285291.
Iglesias, R., Leiro, J., Ubeira, F.M., Santamarina, M.T. and Sanmartin, M.L. (1993) Anisakis simplex: antigen
recognition and antibody production in experimentally infected mice. Parasite Immunology 15,
243250.
Iglesias, R., Leiro, J., Santamarina, M.T., Sanmartn, M.L. and Ubeira, F.M. (1997) Monoclonal antibodies
against diagnostic Anisakis simplex antigens. Parasitology Research 83, 755761.
Iijima, T. (1889) The source of Bothriocephalus latus in Japan. Journal of College of Science, Imperial
University, Tokyo 12, 4956.
Im, K.I. (1974) Indirect fluorescent antibody test for the diagnosis of clonorchiasis in rabbit and human. Yonsei
Journal of Medical Science 7, 194205 (in Korean).
Ishikura, H. (1968) On the anisakiasis. Hokkaido Igaku Zasshi 43, 8399 (in Japanese).
Ito, K. (1925) On the complement fixation reaction on experimental clonorchiasis in animals. Aichi Igakkai
Zasshi 32, 900914 (in Japanese).
Jin, S.W., Lee, J.S. and Rim, H.J. (1983) Comparative studies of ELISA test by use of the immune animal sera in
clonorchiasis and paragonimiasis. Korea University Medical Journal 20, 191199 (in Korean).
621
Jones, R.E., Deardorff, T.L. and Kayes, S.G. (1990) Anisakis simplex: histopathological changes in experimentally infected CBA/J mice. Experimental Parasitology 70, 305313.
Jongsuksuntigul, P. and Imsomboon, T. (1998) Epidemiology of opisthorchiasis and national control program
in Thailand. Southeast Asian Journal of Tropical Medicine and Public Health 29, 327332.
Kagei, N. (1969) Life cycle of the genus Anisakis. Saishin Igaku 24, 389400 (in Japanese).
Kamo, H. (1988) Diphyllobothriasis. In: Balows, A., Hausler, W.J.Jr., Ohaski, M. and Turano, A.J. (eds) Laboratory Diagnosis of Infectious Diseases. Vol I. Bacterial, Mycotic and Parasitic Diseases. Springer-Verlag,
New York, pp. 821830.
Kamo, H., Yazaki, S., Fukumoto, S., Fujino, T., Koga, M., Ishii, Y. and Matsuo, E. (1988a) The first human case
infected with Diphyllobothrium hians (Diesing, 1850). Japanese Journal of Parasitology 37, 2935.
Kamo, H., Maejima, J., Yazaki, S., Fukumoto, S. and Yammishi, Y. (1988b) Human infection with
Diphyllobothrium yonagoense in KinkiTokai Districts. Japanese Journal of Parasitology 37, 6266.
Kang, G., Mathan, M., Ramakrishna, B.S., Mathai, E. and Sarada, V. (1994) Human intestinal capillariasis: first
report from India. Transactions of Royal Society of Tropical Medicine and Hygiene 88, 204.
Karlstedt, K.A., Paatero, G.I., Makela, J.H. and Wikgren, B.J. (1992) A hidden break in the 28.0S rRNA from
Diphyllobothrium dendriticum. Journal of Helminthology 66, 193197.
Kasuya, S. and Koga, K. (1992) Significance of detection of specific IgE in Anisakis related diseases. Areugi 41,
106110 (in Japanese).
Kasuya, S., Khambooruang, C., Amano, K., Murase, T., Araki, H., Kato, Y., Kumada, Y., Kajama, A.,
Higuchi, M., Naklamura, J., Tomida, K. and Makina, S. (1989) Intestinal parasitic infections among
school children in Chiang Mai, Northern Thailand: an analysis of the present situation. Journal of Tropical Medicine and Hygiene 92, 360364.
Kates, S., Wright, K.A. and Wright, R. (1973) A case of human infection with the cod nematode Phocanema
sp. American Journal of Tropical Medicine and Hygiene 22, 606608.
Kennedy, M.W., Tierney, J., Ye, P., McMonagle, F.A., McIntosh, A., Mclaughlin, D. and Smith, J.W. (1988)
The secreted and somatic antigens of the third-stage larva of Anisakis simplex and antigenic relationship
with Ascaris suum, Ascaris lumbricoides and Toxocara canis. Molecular and Biochemical Parasitology
31, 3546.
Kikuchi, K., Toyokawa, O., Nakamura, K., Ishiyama, H., Yokota, H., Sato, H., Natori, T., Ishikura, H. and
Aziawa, M. (1970) Immunopathology of experimental anisakiasis. Minophagen Medical Review 15,
5458 (in Japanese).
Kikuchi, S.H., Kosugi, H., Satoh, H. and Haysahi, S. (1972) Studies on the pathogenicity of the larvae of a
species of Terranova (Anisakinae, Nematoda) to experimental animals. Yokohama Igaku 22, 297304
(in Japanese).
Kim, H.J., Park, C. and Cho, S.Y. (1997) A case of extragastrointestinal anisakiasis involving a mesocolic
lymph node. Korean Journal of Parasitology 35, 6366.
Kim, M.S., Lee, J.S. and Rim, H.J. (1982) Studies on the clinical aspects of clonorchiasis in Korea. Korea
University Medical Journal 19, 107121 (in Korean).
Kim, S.I. A (1998) A Clonorchis sinensis-specific antigen that detects active human clonorchiasis. Korean Journal of Parasitology 36, 3745.
Kim, T.Y., Kang, S.Y., Ahn, I.Y., Cho, S.Y. and Hong, S.J. (2001a) Molecular cloning and characterization of
an antigenic protein with a repeating region from Clonorchis sinensis. Korean Journal of Parasitology 39,
5766.
Kim, T.Y., Kang, S.Y., Park, S.H., Sukontason, K., Sukontason, K. and Hong, S.J. (2001b) Cystatin capture
enzyme-linked immunosorbent assay for serodiagnosis of human clonorchiasis and profile of captured
antigenic protein of Clonorchis sinensis. Clinical and Diagnositc Laboratory Immunology 8, 10761080.
Kim Y.L. (1984) Liver carcinoma and liver fluke infection. Arzneimittel-Forschung 34, 11211126.
King, S. and Scholz, T. (2001) Trematodes of the family Opisthorchiidae: a mini-review. Korean Journal of Parasitology 39, 209221.
Ko, R.C., Ling, J. and Adal, M.N. (1980) Cephalic anatomy of a gnathostomatid nematode, Echinocephalus
sinensis, parasite of oysters and rays. Journal of Morphology 165, 301317.
Ko, R.C., Chan, S.W., Lam, K., Farrington, M., Wong, H.W. and Yuen, P. (1987) Four documented cases of
eosinophilic meningoencephalitis due to Angiostrongylus cantonensis in Hong Kong. Transactions of
Royal Society of Tropical Medicine and Hygiene 81, 807810.
Kobayashi, A., Koyama, T., Kumada, M., Komiya. Y., Oshima, T., Kagei, N., Ishii, T. and Machida, M. (1966)
A survey of marine fishes and squids for the presence of anisakinae larvae. Japanese Journal of Parasitology 15, 348349 (in Japanese).
622
R.C. Ko
Kobayashi, J., Vannachone, B., Sato, Y., Manivong, K., Nambanya, S. and Inthakone, S. (2000) An epidemiological study on Opisthorchis viverrini infection in Laos villages. Southeast Asian Journal of Tropical
Medicine and Public Health 31, 128132.
Koga, M., Ishii, Y., Lou, Y.S., Higo, H., Fujino, T., Huang, W.C., Min, W.P., Xia, B.F. and Liu, J.Y. (1996)
Southeast Asian Journal of Tropical Medicine and Public Health 27, 542547.
Komiya, Y. and Suzuki, N. (1964) Biology of Clonorchis sinensis. Progress of Medical Parasitology in Japan 1,
551600.
Korbsrisate, S., Mongkolsuk, S., Haynes, J.R., Wong, Q. and Sirisinha, S. (1992) Cloning and characterization
of ribosomal RNA genes from Opisthorchis viverrini. Parasitology 104, 323329.
Kosugi, K., Kikuchi, S., Hirabayashi, H. and Hayashi, S. (1970) Seasonal occurrence of the larvae of Anisakis
and related nematodes in fishes from Sagami Bay, the results of two years observation, 1968 to 1969.
Japanese Journal of Parasitology 19, 106107 (in Japanese).
Kowalowska-Grochouska, K., Quinn, J., Perry, I. and Sherbanink, R. (1989) A case of anisakiasis Alberta.
Canadian Diseases Weekly Report 15, 221223.
Koyama, T., Kobayashi, A., Kumada, M., Komiya, A., Oshima, T., Kagei, N., Ishii, T. and Machida, M.
(1969) Morphological and taxonomical studies on anisakidae larvae found in marine fishes and squids.
Japanese Journal of Parasitology 18, 466487 (in Japanese).
Kuiper, F.C. (1964) Eosinophilic phlegmonous inflammation of the alimentary canal caused by a parasite from
the herring. Pathologia et Microbiologia 27, 925930.
Kwon, K.H., Lee, J.S. and Rim, H.J. (1984) The use of IFAT in the diagnosis of human clonorchiasis. Korea University Medical Journal 21, 91100.
Laffon-Leal, S.M., Vidal-Martinez, V.M. and Arjona-Torres, G. (2000) Cebiche a potential source of human
anisakiasis in Mexico? Journal of Helminthology 74, 151154.
Le, T.X. and Rojekittikhun, W. (2000) A survey of infective larvae of Gnathostoma in eels sold in Ho Chi Minh
City. Southeast Asian Journal of Tropical Medicine and Public Health 31, 133137.
Lee, J.S. (1975) Immunoelectrophoretic studies of Clonorchis sinensis. Korean University Medical Journal 12,
17 (in Korean).
Lee, K.W., Suhk, H.C., Pai, K.S., Shin, H.J., Jung, S.Y., Han, E.T. and Chai, J.Y. (2001) Diphyllobothrium latum
infection after eating domestic salmon flesh. Korean Journal of Parasitology 39, 319321.
Lee, O.R., Chung, P.R. and Nam, H.S. (1988) Studies on the immunodiagnosis of rabbit clonorchiasis. 2.
Immunoaffinity purification of whole worm antigen and characterization of egg, metacercariae and adult
antigens of Clonorchis sinensis. Korean University Medical Journal 26, 7386.
Lee, S.C., Chung, Y.B., Kong, K.Y. and Cho, S.Y. (1993) Antigenic protein fractions of Metagonimus yokogawi
reacting with patient sera. Kisaengchunghak-Chapchi 31, 4348.
Lee, S.H., Hong, S.T., Chai, J.Y., Kim, W.H., Kim, Y.T., Song, I.S., Kim, S.W., Chi, B.I. and Cross, J.H. (1993)
A case of intestinal capillariasis in the Republic of Korea. American Journal of Tropical Medicine and
Hygiene 48, 542546.
Lee, S.H., Chai, J.Y., Seo, M., Kook, J., Huh, S., Ryang, Y.S. and Ahn, Y.K. (1994) Two rare cases of
Diphyllobothrium latum parvum type infection in Korea. Korean Journal of Parasitology 32, 117120.
Lee, S.K., Shin, B.M., Chung, N.S., Chai, J.Y. and Lee, S.H. (1994) Second report on intestinal parasites among
the patients of Seoul Paik Hospital (19841992). Korean Journal of Parasitology 32, 2733 (in Korean).
Li, X. (1991) Food-borne parasitic zoonoses in the Peoples Republic of China. Southeast Asian Journal of
Tropical Medicine and Public Health 22 (suppl.), 3134.
Lichtenfels, J.R. and Brancato, F.P. (1976) Anisakid larva from the throat of an Alaskan Eskimo. American
Journal of Tropical Medicine and Hygiene 25, 691693.
Lim, J.H., Ko, Y.T., Lee, D.H. and Kim, S.Y. (1989) Clonorchiasis: sonographic findings in 59 proven cases.
American Journal of Roentgenology 152, 761764.
Little, M.D. and MacPhail, J.C. (1972) Large nematode larva from abdominal cavity of a man in Massachusetts.
American Journal Tropical Medicine and Hygiene 21, 948950.
Little, M.D. and Most, H. (1973) Anisakid larva from the throat of a woman in New York. American Journal
Tropical Medicine and Hygiene 22, 609612.
Liu, Y.S., Du, W.P., Wu, Y.M., Chen, Y.G., Zhen, K.Y., Shi, J.M., Hu, X.Z., Li, G.Y., You, C.F. and Wu, Z.X.
(1995) Application of dot-immuno gold-silver staining in the diagnosis of clonorchiasis. Journal of
Tropical Medicine and Hygiene 98, 151154.
Lorenzo, S., Iglesias, R., Audcana, M.T., Garca-Villaescusa, R., Pardo, F., Sanmartn, M.L. and Ubeira, F.M.
(1999) Human immunoglobulin isotype profiles produced in response to antigens recognized by
monoclonal antibodies specific to Anisakis simplex. Clinical and Experimental Allergy 29, 10951101.
623
Ma, H.W., Jiang, T.J., Quan, F.S., Chen, X.G., Wang, H.D., Zhang, Y.S., Cui, M.S., Zhi, W.Y. and Jiang, D.C.
(1997) The infection status of anisakid larvae in marine fish and cephalopods from the Bohai Sea, China
and their taxonomical consideration. Korean Journal of Parasitology 35, 1924.
Mcfadzean, A.J.S. and Yeung, R.T.T. (1966) Acute pancreatitis due to Clonorchis sinensis. Transactions of
Royal Society of Tropical Medicine and Hygiene 60, 466470.
Machi, T., Okino, S., Saito, Y., Horita, Y., Taguchi, T., Nakazawa, T., Nakamura, Y., Hirai, H., Miyamori, H.
and Kitagawa, S. (1997) Severe chest pain due to gastric anisakiasis. Internal Medicine 36, 2830.
Maleewong, W., Loahabhan, P., Wongkham, C., Intapan, P., Morakote, N. and Khamboonrugang, C. (1992a)
Effects of albendazole on Gnathostoma spinigerum in mice. Journal of Parasitology 78, 125126.
Maleewong, W., Wongkham, C., Intapan, P., Mahaisavariya, Danseegaew, W., Pipitgool, V. and Morakote,
N. (1992b) Detection of circulating parasite antigens in murine gnathostomiasis by a two-site
enzyme-linked immunosorbent assay. American Journal Tropical Medicine and Hygiene 46, 8084.
Maleewong, W., Intapan, P., Wongwajana, S., Sitthithaworn, P., Pipitgool, V., Wongkham, C., and
Daenseegaew, W. (1992c) Prevalence and intensity of Opisthorchis viverrini in rural community near
the Mekong River on the Thai-Laos border in northeast Thailand. Journal of Medical Association of
Thailand 75, 231235.
Matsura, T., Bylund, G. and Sugane, K. (1992) Comparison of restriction fragment length polymorphisms of
ribosomal DNA between Diphyllobothrium nihonkaiense and D. latum. Journal of Helminthology 66,
261266.
Meyers, B. (1963) The migration of Anisakis-type larvae in experimental animals. Canadian Journal of
Zoology 41, 147148.
Mimori, T., Tada, I., Kawabat, M., Ollague, L.W., Calero, H.G. and Chong, Y.F. (1987) Immunodiagnosis
of human gnathostomiasis in Ecuador by skin test and ELISA using Gnathostoma doloresi antigens.
Japanese Journal of Tropical Medicine and Hygiene 15, 191196.
Minamoto, T., Sawaguchi, K., Ogino, T. and Mai, M. (1991) Anisakiasis of the colon: report of two cases with
emphasis on the diagnostic and therapeutic value of colonoscopy. Endoscopy 23, 5052.
Moneo, I., Caballero, M.L., Gomez, F., Ortega, E. and Alonso, M.J. (2000) Isolation and characterization of
a major allergen from the fish parasite Anisakis simplex. Journal of Allergy and Clinical Immunology 106,
177182.
Mori, H. (1957) Studies on the liver fluke. Acta Scholae Medica Gifu 5, 601603 (in Japanese).
Muller, R. (1975) Worms and Disease A Manual of Medical Helminthology. Willliam Heinemann Medical
Books, London.
Muratov, I.V., Posokhov, P.S., Romanenko, N.A., Zimin, A.S. and Glazzyrina, G.F. (1992) The epidemiological characteristics of diphyllobothriasis caused by Diphyllobothrium klebanovskii in the Amur River
basin. Meditsinskaya Parazitologiya Moskow 3, 4647 (in Russian).
Nawa, Y., Imai, J.I., Abe, T., Kisanuki, H. and Tsuda, K. (1988) A case report of intestinal capillariasis the
second case found in Japan. Japanese Journal of Parasitology 37, 113118.
Nawa, Y., Maruyama, H. and Ogata, K. (1997) Current status of gnathostomiasis dorolesi in Miyazaki
Prefecture, Japan. Southeast Asian Journal of Tropical Medicine and Public Health 28 (suppl. 1),
1113.
Nishibuko, K. (1961) Studies on experimental gnathostomiasis with special reference to hostparasite relationship in Gnathostoma spinigerum I. Experimental feeding of albino rat with larval Gnathostoma
spingerum obtained from Ophicephalus argus. Endemic Disease Bulletin Nagaski University 5, 199207
(in Japanese).
Nishioka, N.S. and Donnelly, S.S. (1990) A 72-year-old Chinese woman with recent abdominal pain and a
right-sided abdominal mass. New England Journal of Medicine 323, 467475.
Nontasut, P., Bussaratid, V., Chullawichit, S., Charoensook, N. and Visetsuk, K. (2000) Comparison of
ivermectin and albendazole treatment for gnathostomiasis. Southeast Asian Journal of Tropical Medicine
and Public Health 31, 374377.
Nopparatana, C., Setasuban, P., Chaicumpa, W. and Tapchaisri, P. (1991) Purification of Gnathostoma
spinigerum specific antigen and immunodiagnosis of human gnathostomiasis. International Journal for
Parasitology 21, 677687.
Nuamtanong, S., Waikagul, J. and Anantaphruti, M.T. (1998) Gnathostome infection in swamp eels,
Fluta alba, in central Thailand. Southeast Asian Journal of Tropical Medicine and Public Health 29,
144147.
Ogata, K., Imai, J.I. and Yukifumi, N. (1988) Three confirmed and five suspected cases of Gnathostoma
doloresi infection found in Miyazaki Prefecture, Kyushu. Japanese Journal of Parasitology 37, 358364.
624
R.C. Ko
Ogata, K., Nawa, Y., Akahane, H., Diaz-Camacho, S.P., Lamothe-Argumedo, R. and Cruz-Reyes, A. (1998)
Short report: gnathostomiasis in Mexico. American Journal of Tropical Medicine and Hygiene 58,
316318.
Ona, F.V. and Dytoc, J.N. (1991) Clonorchis associated cholangiocarcinoma: a report of two cases with
unusual manifestations. Gasteroenterology 101, 831839.
Ong, G.B. (1962) A study of recurrent pyogenic cholangitis. Archives of Surgery 84, 192225.
Oshima, T. (1972) Anisakis and anisakiasis in Japan and adjacent area. Progress of Medical Parasitology in
Japan 4, 301393.
Oshima, T. (1984) Anisakiasis, diphyllobothriasis and creeping disease changing pattern of parasitic disease
in Japan. In: Ko, R.C. (ed.) Current Perspectives in Parasitic Diseases. Departments of Zoology and Medicine, University of Hong Kong, Hong Kong, pp. 93102.
Oshima, T. and Wakai, R. (1983) Epidemiology of Diphyllobothrium latum infection among Japanese people,
especially on the infection of cherry salmon with D. latum plerocercoid. Japanese Journal of Antibiotics
36, 566572 (in Japanese).
Ohnishi, K. and Murata, M. (1993) Single dose treatment with praziquantel for human Diphyllobothium nihon
kaiense infections. Transactions of the Royal Society of Tropical Medicine and Hygiene 87, 482483.
Oyamada, T., Kudo, N., Yoshikawa, H., Oyamada, T., Yoshikawa, T. and Suzuki, N. (1997) Survey for
Gnathostoma nipponicum larvae in gobiid freshwater fish and infectivity of the larvae to a gobiid fish
(Chaenogobius urotaenia). Journal of Veterinary Medical Science 59, 671675.
Oyangi, T. (1967) Experimental studies on the visceral migrans of gastro-intestinal walls due to Anisakis
larvae. Japanese Journal of Parasitology 16, 470493 (in Japanese).
Pacheco, G., Wykoff, D.E. and Jung, R.C. (1960) Trial of an indirect haemagglutination test for the diagnosis
of infections with Clonorchis sinensis. American Journal of Tropical Medicine and Hygiene 9, 367370.
Paggi, L., Mattiucci, S. and DAmelio, S. (2001) Allozyme and PCR-RFLP markers in anisakid nematodes,
aetiological agents of human anisakidosis. Parassitologia 43 (suppl. 1), 2127.
Petithory, J.C., Rousseau, M. and Siodlak, F. (1991) Seroepidemiological data on anisakiasis: prophylactic
consequences in fish products. Bulletin de lAcadmie Nationale de Mdecine 175, 273277 (in French).
Phillipson, R.F. and Mcfadzean, J.A. (1962) Clonorchis, Opisthorchis and Paragonimus gel diffusion studies.
Transactions of Royal Society of Tropical Medicine and Hygiene 56, 13.
Plyuscheva, G.L., Romanenko, N.A., Gerasimov, I.V., Suleimanov, N.T., Stepanov, L.G., Akulova, L.M.,
Volodin, Yu, F., Vorobeva, N.P. and Khrolenko, E.T. (1987a) Establishment of diphyllobothriasis foci in
the Krasnoyarsk reservoir. Meditsinskaya Parazitologiya i Parazitarnye Bolezni 1, 6467 (in Russian).
Plyuscheva, G.L., Romanenko, N.A. and Gerasimov, I.V. (1987b) The role of anthropogenic factors in the
establishment of foci of diphyllobothriasis in reservoirs. Meditsinskaya Parazitologiya i Parazitarnye
Bolezni 6, 7478 (in Russian).
Prempracha, N., Tengchaisri, T., Chawengkirttikul, R., Boonpucknavig, S., Thamavit, W., Duongchawee, G.
and Sirisinha, S. (1994) Identification and potential use of a soluble tumor antigen for the detection of
liver-fluke-associated cholangiocarcinoma induced in hamster model. International Journal of Cancer
57, 691695.
Pungpak, S., Akai, P.S., Longenecker, B.M., Ho, M., Befus, A.D. and Bunnag, D. (1990) Tumour markers in
the detection of opisthorchiasis associated cholangiocarcinoma. In: Abstracts of 33rd Southeast Asian
Medical Organization Tropical Medicine Regional Seminar, Chiangmai, Thailand, Southeast Asian Medical Education Organization (SEAMEO) Regional Tropical Medicine and Public Health Project, Bangkok,
Thailand, p. 55.
Punyagupta, S. (1979) Angiostrongyliasis: clinical features and human pathology. In: Cross, J. (ed.) Studies on
Angiostrongyliasis in Eastern Asia and Australia. Special Publication No. 2, US Naval Medical Research
Unit, pp. 138150.
Punyagupta, S. and Bunnag, T. (1990) Eosinophilic myeloencephalitis: invasion of the central nervous system
by Gnathostoma spinigerum. In: Abstracts of 33rd Southeast Asian Medical Organization Tropical Medicine Regional Seminar, Chiangmai, Thailand, Southeast Asian Medical Education Organization
(SEAMEO) Regional Tropical Medicine and Public Health Project, Bangkok, p. 65.
Purtilo, D.T. (1976) Clonorchiasis and hepatic neoplasms. Tropical and Geographical Medicine 28, 2127.
Revenga, J.E. (1993) Diphyllobothrium dendriticum and Diphyllobothrium latum in fishes from southern
Argentina. Journal of Parasitology 79, 379383.
Riganti, M., Pungpak, S., Punpoowong, B., Bunnag, D. and Harinasuta, T. (1989) Human pathology of
Opisthorchis viverrini infection: a comparison of adults and children. Southeast Asian Journal of Tropical
Medicine and Public Health 20, 95100.
625
Rim, H.S. (1986) The Current Pathobiology and Chemotherapy of Clonorchiasis. Korean Journal of Parasitology 24, (suppl.), Monographic Series No. 3, Korean Society for Parasitology, Seoul, South Korea.
Rim, H.S. (1988) Clonorchiasis. In: Balows, A., Hausler, W.J., Jr, Ohashi, M. and Turano, A. (eds) Laboratory
Diagnosis of Infectious Diseases. Vol. 1. Bacterial, Mycotic and Parasitic Diseases. Springer-Verlag,
New York, pp. 801810.
Rodero, M., Jimnez, A., Chivato, T., Laguna, R. and Cullar C. (2001) Purification of Anisakis simplex antigen
by affinity chromatography. Parasitology Research 87, 736740.
Rojas-Molina, N., Pedraza-Sanchez, S., Torres-Bibiano, B., Meza-Martinez, H. and Escobar-Gutierrez, A.
(1999) Gnathostomosis, an emerging foodborne zoonotic disease in Acapulco, Mexico. Emerging Infectious Diseases 5, 264266.
Rojekittikhun, W., Pubampen, S. and Waikagul, J. (1998) Seasonal variation in the intensity of Gnathostoma
larvae in swamp eels (Fluta alba) sold in a local market in Bangkok. Southeast Asian Journal of Tropical
Medicine and Public Health 29, 148153.
Rosenberg, E.B., Whalen, G.E., Bennich, H. and Johansson, S.G.O. (1970) Increased circulating IgE in
a new parasitic disease human intestinal capillariasis. New England Journal of Medicine 283,
11481149.
Ruitenberg, E.J. (1970) Anisakiasis pathogenesis, serodiagnosis and prevention. PhD thesis in Rijks University,
Utrecht, the Netherlands.
Ruitenberg, E.J., Berkvens, J.M. and Duyzings, M.J. (1971) Experimental Anisakis marina infections in rabbits.
Journal of Comparative Pathology 81, 157163.
Ryoji, S. (1922) Diagnostic value of complement fixation test for clonorchiasis. Okayama Igakkai Zasshi 384,
112 (in Japanese).
Sadun, E.H., Walton, B.C., Buck, A.A. and Lee, B.K. (1959) The use of purified antigen in the diagnosis of
Clonorchiasis sinensis by means of intradermal and complement fixation test. Journal of Parasitology 45,
129134.
Sagara, I. (1953) Studies on Gnathostoma. Part II. Migration route of larvae of Gnathostoma spinigerum in the
rats body and histopathological changes caused along the route. Igaku Kenkyuu 23, 822836 (in
Japanese).
Sagua, H., Neira, I., Araya, J. and Gonzalex, J. (2001) New cases of Diphyllobothrium pacificum (Nybelin,
1931) Margolis, 1956 human infection in north of Chile, probably related with El Nino phenomenon,
19752000. Boletin Chileno de Parasitologia 56, 2225 (in Spanish).
Saksirisampant, W., Kulkaew, K., Nuchprayoon, S., Yentakham, S. and Wiwanitkit, V. (2002) A survey of
the infective larvae of Gnathostoma spinigerum in swamp eels bought in a local market in Bangkok,
Thailand. Annals of Tropical Medicine and Parasitology 96, 191195.
Sanchez-Velasco, P., Mendizbal, L., Antn, E.M., Ocejo-Vinyals, G., Jerez J. and Leyva-Cobin F. (2000)
Association of hypersensitivity to the nematode Anisakis simplex with HLA class II DRB1
1502-DQB10601 haplotype. Human Immunology 61, 314319.
Sawada, T., Kazutoshi, T. and Chun, S.K. (1976) Studies on the purification of antigens for hemagglutination
test on clonorchiasis. Japanese Journal of Experimental Medicine 46, 337342.
Schwartz, D.A. (1980) Review: helminths in the induction of cancer: Opisthorchis viverrini, Clonorchis
sinensis and cholangiocarcinoma. Tropical and Geographical Medicine 32, 95100.
Seo, B.S., Lee, S.H., Cho, S.Y., Chai, J.Y., Hong, S.T., Han, I.S., Sohn, J.S., Cho, B.H., Ahn, S.R., Lee, S.K.,
Chung, S.C., Kang, K.S., Shin, H.S. and Hwang, I.S. (1981) An epidemiologic study on clonorchiasis and
metagonimiasis in river-side area in Korea. Korean Journal of Parasitology 19, 137150.
Setasuban, P., Jewjhangarnwanit, S., Rojanakittikoon, V., Yaemput, S., Dekumyoy, P., Akabane, H. and
Kojima, S. (1991) Gnathostomiasis in Thailand: a survey on intermediate hosts of Gnathostoma spp. with
special reference to a new type of larvae found in Fluta alba. Southeast Asian Journal of Tropical Medicine and Public Health 22 (suppl.), 220224.
Shirahama, M., Koga, T., Ishibashi, H., Uchida, S., Ohta, Y. and Shimoda, Y. (1992) Intestinal anisakiasis: US
in diagnosis. Radiology 185, 789793.
Sirisinha, S., Sahassananda, D., Bunnag, D. and Rim, H.J. (1990) Immunological analysis of Opisthorchis and
Clonorchis antigens. Journal of Helminthology 64, 133138.
Sirisinha, S., Chaewengkirttikual, R. and Sermswan, R. (1991) Immunodiagnosis of opisthorchiasis. Southeast
Asian Journal of Tropical Medicine and Public Health 22 (suppl.), 179183.
Sirisinha, S., Chaengkirttikual, R., Tayapiwatana, C., Naiyanetr, C., Waikagul, J., Radomyos, P. and
Podoprigora, G.I. (1992) Specific and cross-reactive monoclonal antibodies to the 89 kDa antigen of
Opisthorchis viverrini. Southeast Asian Journal of Tropical Medicine and Public Health 23, 489490.
626
R.C. Ko
Sirisinha, S., Chaengkirttikual, R., Haswell-Elkins, M.R., Elkins, D.B., Kaewkes, S. and Sithithaworn, P. (1995)
Evaluation of a monoclonal antibody-based enzyme linked immunosorbent assay. American Journal of
Tropical Medicine and Hygiene 52, 521524.
Sithithaworn, P., Pipitgool, V., Srisawangwong, T., Elkins, D.B. and Haswell-Elkins, M.R. (1997) Seasonal
variation of Opisthorchis viverrini infection in cyprinoid fish in northeast Thailand: implications for parasite control and food safety. Bulletin of World Health Organization 75, 125131.
Smith, J.W. (1983) Anisakis simplex (Rudolphi, 1809, det. Krabbe, 1878) (Nematoda: Ascaridoidea):
morphology and morphometry of larvae from euphausiids, and fish and a review of the life history and
ecology. Journal of Helminthology 57, 205224.
Soh, C.T. (1984) The current status of human parasitic infections in Korea. In: Ko, R.C. (ed.) Current Perspectives in Parasitic Diseases. Department of Zoology and Medicine, University of Hong Kong, Hong Kong,
pp. 8392.
Soh, C.T. and Min, D.Y. (1990) Field operational research on the occurrence of clonorchiasis in Korea. In:
Abstracts of 33rd Southeast Asia Medical Organization Tropical Medicine Regional Seminar, Chiangmai,
Thailand, Southeast Asian Medical Education Organization (SEAMEO) Regional Tropical Medicine and
Public Health Project, Bangkok, p. 52.
Sornmani, S. (1990) Opisthorchiasis and the control programme in Thailand. In: Abstracts of 33rd Southeast
Asian Medical Organization Tropical Medicine Regional Seminar, Chiangmai, Thailand, Southeast Asian
Medical Education Organization (SEAMEO) Regional Tropical Medicine and Public Health Project,
Bangkok, p. 53.
Stromnes, E. and Andersen, K. (2000) Spring rise of whale worm (Anisakis simplex; Nematoda, Ascaridoidea)
third-stage larvae in some fish species from Norwegian waters. Parasitology Research 86, 619624.
Sugane, K., Liu, Q. and Matsuura, T. (1989) Restriction fragment length polymorphism of Anisakinae larvae.
Journal of Helminthology 63, 269274.
Sukontason, K., Piangjai, S., Muangyimpong, Y., Sukontason, K., Methanitikorn, R. and Chaithong, U. (1999)
Prevalence of trematode metacercariae in cyprinoid fish of Ban Pao. Southeast Asian Journal of Tropical
Medicine and Public Health 30, 365370.
Sun, S.C., Cross, J.H., Berg, H.S., Kau, S.L., Singson, C.N., Banzon, T.C. and Watten, R.H. (1974)
Ultrastructural studies of intestinal capillariasis Capillaria philippinensis in human and gerbil hosts.
Southeast Asian Journal of Tropical Medicine and Public Health 5, 524533.
Sun, T. and Gibson, J.B. (1969) Antigens of Clonorchis sinensis in experimental and human infections.
An analysis by gel diffusion technique. American Journal of Tropical Medicine and Hygiene 18,
241252.
Suntharasamai, P., Riganti, M., Chittamas, S. and Desakorn, V. (1990) Treatment of gnathostomiasis with
albendazole: a randomized double-blind placebo controlled trial. In: Abstracts of 33rd Southeast Asian
Medical Organization Tropical Medicine Regional Seminar, Chiangmai, Thailand, Southeast Asian Medical Education Organization (SEAMEO) Regional Tropical Medicine and Public Health Project, Bangkok,
Thailand, p. 69.
Suzuki, H., Ohnuma, H., Karasawa, Y., Ohbayashi, M., Koyama, T., Kumada, M. and Yokogawa, M. (1972)
Terranova (Nematoda: Anisakidae) infection in man. 1. Clinical features of five cases of Terranova larva
infection. Japanese Journal of Parasitology 21, 252256.
Suzuki, T., Shiraki, T., Seikino, S., Otsuru, M. and Ishikura, H. (1970) Studies on the immunodiagnosis of
anisakiasis. III. Intradermal test with purified antigen. Japanese Journal of Parasitology 19, 19
(in Japanese).
Tada, I., Araki, T., Matsuda, H., Araki, K., Akakane, H. and Mimori, T. (1987) A study on immunodiagnosis of
gnathostomiasis by ELISA and double diffusion with special reference to the antigenicity of Gnathostoma
doloresi. Southeast Asian Journal of Tropical Medicine and Public Health 18, 444448.
Takabe, K., Ohki, S., Kunihiro, O., Sakashita, T., Endo, I., Ichikawa, Y., Sekido, H., Amano, T., Nakatani, Y.,
Suzuki, K. and Shimada, H. (1998) Anisakidosis: a cause of intestinal obstruction from eating sushi.
American Journal of Gastroenterology 93, 11721173.
Takahasi, S., Sato, N. and Ishikura, H. (1986) Establishment of monoclonal antibodies that discriminate the
antigen distribution specifically found in Anisakis larva (type I). Journal of Parasitology 72, 960962.
Takakura, Y. (1988) Experimental studies on Gnathostoma hispidum Fedchenko, 1872: migration and development of the larvae in the rats and piglets. Japanese Journal of Parasitology 37, 6775.
Takei, K. and Chun, S.K. (1976) Purification of antigens from Clonorchis sinensis worm for complement fixation test. Japanese Journal of Experimental Medicine 46, 399403.
627
Teplukhin, Yu.V., KaralNik, B.V., Gorbunova, L.A., Slemnev, V.F. and Nikityak, G.V. (1987) Detection of
antibodies in patients with chronic opisthorchiasis. Meditsinskaya Parazitologiya i Parazitarnye Bolezni
6, 2124 (in Russian).
Tierney, L.M., Jr, McPhee, S.J. and Papadakis, M.A. (2001) Current Medical Diagnosis and Treatment. Lange
Medical Books, McGraw-Hill, New York.
Tuntipopipat, S., Chawengkiattikul, R., Witoon-Panich, R., Chemichanya, S. and Sirisinha, S. (1989) Antigens,
antibodies and immune complexes in cerebral fluid of patients with cerebral gnathostomiasis. Southeast
Asian Journal of Tropical Medicine and Public Health 20, 439446.
Usutani, T. (1966) Histological studies on experimental animals administered with Anisakis-like larvae from
marine fish. Shikoku Acta Medica 22, 486503 (in Japanese).
Valero, A., Martin-Sanchez, J., Reyes-Muelas, E. and Adroher, F.J. (2000) Larval anisakids parasitizing the
blue whiting Micromesistius poutassou from Motril Bay in the Mediterranean region of southern Spain.
Journal of Helminthology 74, 361364.
van Thiel, P.H.F., Kuipers, F.C. and Roskam, R. (1960) A nematode parasite of herring, causing acute abdominal syndromes in man. Tropical Geographical Medicine 2, 97113.
Vatanasapt, V., Uttaravichien, T., Mairiang, E.O., Pavioijkul, C., Chartbanchanchai, W. and Haswell-Elkins, M.
(1990) Cholangiocarcinoma in northeast Thailand. Lancet 335, 116117.
Waikagul, J. (1998) Opisthorchis viverrini metacercaria in Thai freshwater fish. Southeast Asian Journal of
Tropical Medicine and Public Health 29, 324326.
Watanapa, P. and Watanapa, W.B. (2002) Liver fluke-associated cholangiocarcinoma. British Journal of
Surgery 89, 962970.
Watten, R.H., Becker, W.M., Cross, J.H., Gunning, J.J. and Jarimillo, J. (1972) Clinical studies of capillariasis
philippinensis. Transactions of Royal Society of Tropical Medicine and Hygiene 66, 828834.
Wongratanacheewin, S. and Sirisinha, S. (1987) Analysis of Opisthorchis viverrini antigens: physiochemical
characterization and antigen localization. Southeast Asian Journal of Tropical Medicine and Public
Health 18, 511520.
Wongratanacheewin, S., Chawengkirttikul R., Bunnag, D. and Sirisinha, S. (1988) Analysis of Opisthorchis
viverrini antigens by immunoprecipitation and polyacrylamide gel electrophoresis. Parasitology 96,
119128.
Wongratanacheewin, S., Pumidonming, W., Sermswan, R.W. and Maleewong, W. (2001) Development of
a PCR-based method for the detection of Opisthorchis viverrini in experimentally infected hamsters.
Parasitology 122, 175180.
Wu, Z.X., Du, W.P., Rong, Y.W., Ji, H. and Yuan, S.Y. (1993) The use of dot-immunogold-staining (dot-IGSS),
dot-ELISA and dot-IGSS to detect serum antibodies from clonorchiasis patients: a comparative study.
Southeast Asian Journal of Tropical Medicine and Public Health 24, 677679.
Wykoff, D.E. (1959) Studies on Clonorchis sinensis. II. Development of an antigen for complement fixation and
fixation and studies on the antibody response in infected rabbits. Experimental Parasitology 8, 5157.
Wykoff, D.E., Harinasuta, C., Juttijudata, P. and Winn, M.M. (1965) Opisthorchis viverrini in Thailand the
life cycle and comparison with O. felineus. Journal of Parasitology 51, 207214.
Yagihashi, A., Sato, N., Takahashi, S., Ishikura, H. and Kikuch, K. (1990) A serodiagnostic assay by
microenzyme-linked immunosorbent assay for human anisakiasis using a monoclonal antibody specific
for Anisakis larvae antigen. Journal of Infectious Diseases 161, 955998.
Yamaguchi, T., Kudo, N., Kawadam S., Nakade, Y. and Takada, N. (1968) Studies on larva migrans (24). The
incidence of infection of Anisakis larvae in marine fishes. Japanese Journal of Parasitology 17, 262.
Yamane, Y., Kamno, H., Yazaki, S., Fukumoto, S. and Maejima, J. (1981) On a new marine species of the
genus Diphyllobothrium (Cestoda: Pseudophyllidae) found from a man in Japan. Japanese Journal of
Parasitology 30, 101111.
Yamane, Y., Kamno, H., Bylund, G. and Wikgren, B.J.P. (1986) Diphyllobothrium nihonkaisiense sp. nov.
(Cestoda: Diphyllobothridae) revised identification of Japanese broad tapeworm. Shimane Journal of
Medical Science 10, 2948.
Yang, W.Y., Lee, J.S. and Rim, H.J. (1983) The use of ELISA in the diagnosis of human clonorchiasis. Korea
University Medical Journal 20, 201210 (in Korean).
Yang, W.Y., Lee, J.S. and Rim, H.J. (1984) Studies on the changing patterns of specific IgG antibody in the sera
of rabbits infected with Clonorchis sinensis. Korea University Medical Journal 21, 8188 (in Korean).
Yen, C.M. and Chen, E.R. (1989) Counterimmunoelectrophoresis test on human Clonorchis sinensis infection.
Southeast Asian Journal of Tropical Medicine and Public Health 20, 433438.
628
R.C. Ko
Yen, C.M., Chen, E.R., Hou, M.F. and Chang, J.H. (1992) Antibodies of different immunoglobulin isotypes in
serum and bile of patients with clonorchiasis. Annals of Tropical Medicine and Parasitology 86,
263269.
Yokogawa, M. and Yoshimura, H. (1967) Clinico-pathologic studies on larval anisakiasis in Japan. American
Journal of Tropical Medicine and Hygiene 16, 723728.
Yokogawa, M., Yoshimura, H. and Tsuji, M. (1965) Experimental studies on Anisakis-like larva infection.
I. Inoculation to small laboratory animals and immunological reaction. Japanese Journal of Parasitology
14, 606607 (in Japanese).
Yong, T.S., Im, K.I. and Chung, P.R. (1991) Diagnosis of clonorchiasis by ELISA-inhibition test using
Clonorchis sinensis specific monoclonal antibody. Southeast Asian Journal of Tropical Medicine and
Public Health 22 (suppl.), 186188.
Yong, T.S., Yang, H.J., Park, S.J., Kim, Y.K., Lee, D.H. and Lee, S.M. (1998) Immunodiagnosis of clonorchiasis
using a recombinant antigen. Korean Journal of Parasitology 36, 183190.
Yoshimura, H. (1965) The life cycle of Clonorchis sinensis: a comment on the presentation in the seventh
edition of Craig and Fausts Clinical Parasitology. Journal of Parasitology 61, 961966.
Yoshimura, H. (1966) Eosinophilic granuloma due to Anisakis larva penetrating the gastrointestinal tract of
man. Minophagen Medical Review 11, 105114 (in Japanese).
Young, P.C. and Lowe, D. (1969) Larval nematodes from fish of the subfamily Anisakinae and gastrointestinal
lesions in mammals. Journal of Comparative Pathology 79, 301313.
Yu, S., Xu, L., Jiang, Z., Xu, S., Han, J., Zhu, Y., Chang, J., Lin, J. and Xu, F. (1994) Report on the first nationwide survey of the distribution of human parasites in China. 1. Regional distribution of parasite species.
Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 12, 241247 (in Chinese).
Zhu, X., Gasser, R.B., Podolska, M. and Chilton, N.B. (1998) Characterisation of anisakid nematodes with
zoonotic potential by nuclear ribosomal DNA sequences. International Journal for Parasitology 28,
19111921.
17
Introduction
Numerous species of parasites have been
described from various shellfish, especially
representatives of the Mollusca and
Crustacea (see Lauckner, 1983; Sparks,
1985; Sindermann and Lightner, 1988;
Sindermann, 1990). Some parasites have
had a serious impact on wild populations
and shellfish aquaculture production. This
chapter is confined to parasites that cause
significant disease in economically important shellfish that are utilized for either
aquaculture or commercial harvest. These
pathogenic parasites are grouped taxonomically. However, the systematics of protozoa
(protistans) is currently in the process of
revision (Patterson, 2000; Cox, 2002; CavalierSmith and Chao, 2003). Because no widely
accepted phylogeny has been established,
parasitic protozoa will be grouped according to the hierarchy used in both volumes
edited by Lee et al. (2000). In that publication, Perkins (2000b) tentatively included
species in the genera Bonamia and Mikrocytos
in the phylum Haplosporidia. As discussed
below, subsequent analysis has verified that
Bonamia spp. and Mikrocytos roughleyi are
Haplosporidia but that Mikrocytos mackini
is not and has unknown taxonomic affiliations. In addition, several other pathogenic
protozoa (three species unofficially grouped
as Paramyxea that parasitize oysters; and a
recently encountered pathogen of pandalid
629
630
S.M. Bower
Fig. 17.1. Histological images of plasmodia (p) and developing spores (s) of unidentified Microsporida in
crustaceans in British Columbia, Canada. A. Infection congesting the connective tissue between the
hepatopancreas tubules (t) of a Pandalus platyceros in which the muscle tissue was not infected.
B. Infection replacing the skeletal muscle (m) tissue of a Pandalus jordani in which the hepatopancreas was
not infected. C. Similar infection to B in a Cancer magister. All bars = 10 m.
Hostparasite relationships
Microsporidians replace host tissue with
spores as they grow, without invoking host
inflammatory responses. Infected individuals exhibit poor stress resistance and poor
stamina and are thus prone to loss by predation and to poor survival following capture
and handling. Infection of the gonad by
some species renders infected individuals
sterile and may cause feminization of
infected male penaeids (Lightner, 1996).
631
Alveolates
Apicomplexa
Diagnosis of infection
Infected tissue, especially muscle, is eventually replaced by spores, giving it an
opaque appearance. Due to this white discoloration, heavy infections are apparent
and justify the common names of cotton,
milk or cooked shrimp and crabs. In
addition, the cuticle of some crustaceans
may have blue-black discoloration due
to expansion of cuticular melanophores
(Lightner, 1996). The fluorescent technique
described by Weir and Sullivan (1989) for
screening for Microsporida in histological
sections may be useful for detecting light
infections. A molecular probe has been
developed for the detection of Agmasoma
sp. in Penaeus spp. (Pasharawipas et al.,
1994).
Prevention and control
The only known method of prevention is
removal and destruction (freezing may not
destroy spores) of infected individuals
(Lightner, 1988; Overstreet, 1988). The
intermediate hosts (fin fish) should be
excluded from culture systems and water
supplies (e.g. Ameson penaei became infective for pink shrimp following passage
through the gut of a shrimp predator, the
spotted sea trout (Cynoscion nebulosus)
(Lightner, 1988)). A single treatment of
buquinolate (used to treat coccidiosis in
boiler chickens) prevented microsporidosis
caused by A. michaelis in most exposed
blue crab (Overstreet, 1975). Lightner (1988)
suggested that Fumidil B (an antibiotic used
to control microsporidosis in honeybees)
and benomyl (a systemic fungicide used to
Introduction
Many species of gregarines and coccidians
have been described from shellfish. Because
information to date indicates that most of
these species are relatively benign in pathogenicity, they will not be mentioned here.
However, two species of coccidia have been
associated with pathology.
Coccidians (family Eimeriidae) have
been described from the kidneys and less
frequently other organs of bivalves. Although
they were all designated as species of
Pseudoklossia (Upton, 2000), only the first
(type) species and one other appear to be
heteroxenous. Because the other species
undergo monoxenous development in their
molluscan host, Desser and Bower (1997)
proposed the creation of a new genus,
Margolisiella, to accommodate these parasites. Disease concerns were associated with
Margolisiella kabatai (Fig. 17.2A) in Pacific
littleneck clams (Protothaca staminea) that
were found on the surface of the substrate
in Washington State (Morado et al., 1984)
and Margolisiella (= Pseudoklossia) haliotis,
which can occur in extremely heavy infections in the kidneys of abalone (Haliotis
spp.) from California (Friedman et al., 1995).
In addition to gregarines and coccidians,
Levine (1978) proposed that Perkinsus marinus (= Dermocystidium marinum = Labyrinthomyxa marina), a pathogen of eastern
(American) oyster (Crassostrea virginica),
also be included within the phylum
Apicomplexa. Subsequent taxonomic analysis based on nucleotide sequences indicated that this parasite may be more closely
related to the Dinoflagellida (Perkins, 1996;
632
S.M. Bower
Fig. 17.2. Histological images of Apicomplexa in molluscs from British Columbia, Canada. A. Mature
microgamont (m) with peripherally arranged microgametes and trophozoites (t) of Margolisiella kabati in the
cytoplasm of renal epithelial cells with hypertrophied nuclei (arrows) in Protothaca staminea.
B and C. Trophozoites (t), mature trophozoites (signet-ring stage, r) and two schizonts (s) consisting of two
and eight trophozoites, respectively, of Perkinsus qugwadi in the connective tissue of the gonad of
Patinopecten yessoensis. All bars = 20 m.
633
634
S.M. Bower
several layers of haemocytes can encapsulate trophozoites. Also, host cell destruction appeared limited to the immediate
vicinity of the pathogen. Advanced infections were characterized by haemocyte activation and recruitment, with concomitant
exuberant production of haemocyte-derived
oxygen intermediates (oxyradicals), which
may be associated with the pathogenesis of
the disease (Anderson et al., 1992).
Foci of infection or abscesses containing thousands of P. marinus and host debris
may attain several hundred micrometres in
diameter during later stages of infection.
In addition, the pathogen often occludes
haemolymph sinuses. Although the epithelium and adductor muscle are invaded,
they do not appear to be damaged until late
in the infection. By the time the eastern
oyster becomes moribund, large numbers of
P. marinus have accumulated in all tissues.
Paynter and Burreson (1991) have indicated
that, in Chesapeake Bay, groups of eastern
oysters, which incurred high prevalences
and intensities of infection, exhibited low
mortalities during their first year but suffered high mortalities during the following
year. Bushek and Allen (1996a,b) observed
variations in the virulence of P. marinus to
genotypically different stocks of eastern
oysters and proposed that different strains
of P. marinus may vary in virulence or different oyster stocks may vary in resistance
to infection.
In vitro propagation
P. marinus is one of the few shellfish pathogens that can be maintained by continuous
in vitro propagation of the trophozoite
(La Peyre, 1996; Casas et al., 2002b). In
addition to having biological characteristics
similar to the histozoic stages of P. marinus
(i.e. morphology, antigenicity, biochemistry
and development in thioglycollate medium,
as described by Ray (1966a)), some cultured
isolates were infective to eastern oysters.
The transformation of the trophozoites
into prezoosporangia in RFTM (Ray,
1966a) is frequently referred to as a culture
technique. However, prezoosporangia have
poor survival in RFTM. The subsequent
635
636
S.M. Bower
replanting. Goggin et al. (1990) further recommended that the spread of Perkinsus sp.
from shellfish processing plants could be
prevented by not returning untreated
mollusc tissues to the sea.
Although P. marinus persisted in eastern oysters held at low salinities (6 ppt), it
was less virulent at salinities below 9 ppt
(Ragone and Burreson, 1993). The occurrence of disease only at higher salinities has
been used in management practices (Paynter
and Burreson, 1991). In Chesapeake Bay,
uninfected eastern oyster seed are acquired
from areas of low salinity, which are not
suitable for oyster culture because oyster
growth and condition are reduced by low
salinity. In the Gulf of Mexico, where warmer
temperatures allow the infection to remain
active year-round, freshwater diversions
into high-salinity bays have been proposed
in order to revive or enhance areas that are
marginally productive for eastern oysters
(Andrews and Ray, 1988). The possibility of
breeding eastern oysters that are resistant to
P. marinus is under investigation (Gaffney
and Bushek, 1996). Also, the introduction
of a non-endemic species that is more tolerant of P. marinus (Meyers et al., 1991) is
being considered as a method for the recovery
of stable oyster production in areas of
Chesapeake Bay where native eastern oysters
have been eliminated (Mann et al., 1991).
Related pathogens
Prezoosporangia of Perkinsus sp. have been
detected by RFTM in many species of
Mollusca from temperate to tropical waters
of the world. For example, in Australia,
Perkinsus spp. were detected in at least 30
species of Mollusca (Lester et al., 1990).
Although Perkinsus sp. was associated with
giant clam (Tridacna gigas) mortalities (Alder
and Braley, 1989) and lesions in the tissues of
pearl oysters (Pinctada maxima) (Norton
et al., 1993), many Perkinsus sp. infections
seem to have no detectable adverse affects on
their hosts (Goggin et al., 1990).
In addition to P. marinus, six other species have been named. The most distinctive
species is Perkinsus qugwadi, considered
enzootic in British Columbia, Canada, but
only known from Japanese scallops (Patinopecten yessoensis) that were introduced
into Canada from Japan for culture purposes
(Blackbourn et al., 1998). Scallops native to
enzootic areas (Chlamys rubida and Chlamys
hastata) were resistant to infection, while
mortalities among cultured Japanese scallops
often exceeded 90% (Bower et al., 1999).
Unlike all other Perkinsus spp., P. qugwadi:
(i) proliferated and was pathogenic at cool
temperatures (815C); (ii) developed
zoospores within tissues of juvenile living
hosts instead of outside the host; and
(iii) did not produce prezoosporangia in
RFTM or stain blue-black with Lugols iodine
(Bower et al., 1998). In addition to these differences, phylogenetic analyses based on
the internal transcribed spacer (ITS) regions
of rRNA of P. qugwadi consistently place
this species at the base of a clade containing
the other Perkinsus spp. (Coss et al., 2001;
Casas et al., 2002a,b; Dungan et al., 2002).
The second named species was
Perkinsus olseni, first reported as a pathogen
of abalone (Haliotis rubra) in Australia
(Lester and Davis, 1981). This species is now
reported from three other species of abalone
(Haliotis laevigata, Haliotis cyclobates and
Haliotis scalaris) along the southern coast
of Australia and is often associated with significant mortalities. It is also believed to
occur in a wide variety of molluscan species from the Great Barrier Reef but was not
detected in abalone from that area (Goggin
and Lester, 1995). Perkinsus olseni was
experimentally transmitted and highly
infectious to a range of molluscs under
laboratory conditions (Goggin et al., 1989).
The third species to be named was
Perkinsus atlanticus, a pathogen of native
clams (Ruditapes (= Tapes = Venerupis)
decussatus, Ruditapes (= Tapes) semidecussatus, Ruditapes pullastra, Venerupis
aurea, Venerupis pullastra) and the introduced Manila clam (Venerupis (= Tapes
= Ruditapes) philippinarum) along the coasts
of Portugal, Spain (Galicia and Huelva areas)
and the Mediterranean Sea (Azevedo, 1989;
Rodrguez et al., 1994; Ords et al., 2001;
Casas et al., 2002a).
In the late 1990s, a Perkinsus sp. was
associated with significant mortalities of
637
638
S.M. Bower
Ciliophora
Two closely related genera of holotrich ciliates (class Oligohymenophorea, subclass
Fig. 17.4. A. Histological images through Mesanophrys pugettensis (arrows) in the haemal sinuses of the
heart of Cancer magister from British Columbia, Canada. B. Wet-mount preparation (Nomarski optics) of
Paramoeba invadens (hyaline region (h), nucleus (n) and parasome (p)) from in vitro culture isolated from
Strongylocentrotus droebachiensis in Nova Scotia, Canada (courtesy of R.E. Scheibling). C and D.
Histological section through Hematodinium sp. (plasmodium (p), trophozoites (t) and binary fission in
trophozoites (b)) in the heart sinus (haemocyte (h)) of Chionoecetes tanneri from British Columbia, Canada.
All bars = 10 m.
Dinozoa (Dinoflagellida)
Introduction
The parasitic Dinoflagellida in the genus
Hematodinium spp. (order Syndiniales) are
significant pathogens of commercially harvested crabs and lobsters (Shields, 1994).
Host range
The first reported and type species,
Hematodinium perezi, was originally
described from the haemolymph of crabs
(C. maenas and Liocarcinus (= Portunus)
depurator) from European waters (Chatton
and Poisson, 1930) and was more recently
reported to cause high mortalities in
C. pagurus and Necora puber in France
(Wilhelm and Mialhe, 1996). On the western side of the North Atlantic Ocean, from
New Jersey to the western coast of Florida
and in the Gulf of Mexico to southern
Texas, a Hematodinium sp. that is believed
to be the same parasite was reported from
other species of crabs, including the blue
crab, C. sapidus (Couch, 1983). Based on
results from epizootiology studies, Messick
and Shields (2000) suggested that this parasite represented a significant threat to blue
crab populations in high-salinity estuaries
along the Atlantic and Gulf coast of the
USA. The second species, Hematodinium
australis, occurs in Portunus pelagicus,
Scylla serrata and possibly Trapezia spp.
639
640
S.M. Bower
Diagnosis of infection
The non-motile trophozoites are evident
as numerous spheres (6 to 18 m in diameter)
in wet mount preparations of haemolymph
from discoloured crustacea examined microscopically ( 100 magnification). Hematodinium spp. are also apparent in histological
sections (Figs. 17.4C, D). However, the paucity of morphological characteristics for species identification has resulted in the
development of PCR techniques based on the
nucleotide sequences of parts of the SSU
rDNA gene (Hudson and Adlard, 1996).
Gruebl et al. (2002) described an 18S rRNA
gene-targeted PCR-based diagnostic technique capable of detecting one Hematodinium sp. in 300,000 blue crab haemocytes.
The partial sequences of the 18S rDNA gene
of Hematodinium sp. from blue crabs
deposited in GenBank (accession numbers
AF421184 and AF286023) are nearly identical to the equivalent sequences of the parasite from C. tanneri in British Columbia,
which is believed to be a different species.
Because of this close association, this region
of the genome will not be useful in differentiating between species. The development of
specific molecular tools to differentiate
between species will probably necessitate the
analysis of more divergent genes, such as the
ITS regions of the SSU rDNA. Currently such
gene sequences are not available for most
Hematodinium spp. from various crustaceans
around the world.
Field and Appleton (1996) developed
an indirect fluorescent antibody test (IFAT)
to detect Hematodinium sp. in the haemolymph and tissues of Norway lobsters. This
technique was more sensitive than gross
observations and wet-mount examinations
and was capable of detecting low-level
haemolymph infections as well as previously
undiagnosable tissue infections. However,
the species specificity of this assay has not
been assessed.
Prevention and control
The management of the Tanner crab fishery
to avoid product quality problems (bitter crab
syndrome) with infections of Hematodinium
641
Stramenopiles
Residual heterotrophic Stramenopiles
Labyrinthulida
Introduction
Only one named species of Labyrinthulida
has been documented as a pathogen of
economically important shellfish. Labyrinthuloides haliotidis, an achlorophyllous,
eukaryotic protist, is pathogenic to small,
juvenile, northern abalone (Haliotis kamtschatkana) and small, juvenile, red abalone
(Haliotis rufescens) (Bower, 1987a).
Host range
To date, L. haliotidis has only been
observed in small abalone (less than 1 cm in
shell length) from an abalone culture facility in British Columbia. Within 2 weeks of
first being detected in a raceway, over 90%
of the small abalone succumbed to infection
and the disease quickly spread between
raceways. The high mortalities caused by L.
haliotidis were one of the reasons why this
Fig. 17.5. Electron micrographs of Labyrinthuloides haliotidis from British Columbia, Canada. A.
Trophozoite within the muscle tissue of a juvenile abalone (Haliotis kamtschatkana) showing the nucleus (n)
and the ectoplasmic net (en) originating from the sagenogenetosome. B. Zoosporoblast from sea water
containing well-developed zoospores. C. Zoospore illustrating the subapical attachment site of the two
flagella, the coarse texture of the longer anterior flagellum, where debris has attached to the mastigonemes,
and the thin tapered tip of the short posterior flagellum. All bars = 2 m.
642
S.M. Bower
cured infected abalone. However, this treatment had the disadvantages of: (i) being detrimental to diatoms upon which the abalone
fed; (ii) being ineffective against non-growing
but infective zoospores such that reinfection
occurred within 2 to 3 weeks following treatment; and (iii) inducing resistant forms (as
few as three successive treatments resulted
in the production of forms twice as resistant
to cyclohexamide) (Bower, 1989). Ozone
treatment of incoming water may only be efficacious if ozone exposure is greater than
0.97 mg ozone/l for 25 min (Bower et al.,
1989c).
Amoeboid protists
Introduction
Two species in the order Euamoebida
and family Paramoebidae are significant
pathogens of shellfish. Paramoeba perniciosa
is the cause of grey crab disease or paramoebiasis in the blue crab (C. sapidus) and is
infectious to other crustaceans. Paramoeba
invadens is pathogenic to sea urchins (Strongylocentrotus droebachiensis).
Host range
P. perniciosa has been reported in blue
crabs along the east coast of the USA from
Connecticut to Florida, including the highsalinity areas of Chincoteague Bay and
Chesapeake Bay, where it periodically
causes mass mortalities and has caused ongoing low-level mortalities since 1967 (Couch,
1983; Sparks, 1985). Epizootics with high
mortalities (about 17%) were reported from
Chincoteague Bay in early summer and mortalities (2030%) were observed in shedding
tanks (for production of newly moulted
softshell crab) (Johnson, 1988). It has also
been reported from the rock crab Cancer
irroratus, the exotic European green crab
C. maenas and the American lobster
H. americanus (Couch, 1983).
P. invadens was associated with mass
mortalities of the sea urchin along the Atlantic
coast of Nova Scotia in the early 1980s (Jones,
1985; Jones et al., 1985). From 1980 to 1983
sea urchin mortalities were estimated to be
643
644
S.M. Bower
In vitro propagation
Introduction
Included within the Haplosporidia are several species that are significant pathogens of
oysters. Species of Haplosporidia were first
described from oysters in the early 1960s
and since that time the group and its affiliations have undergone several changes in
classification. Initially these parasites were
included in an order that was changed from
Haplosporida to Balanosporida in the phylum
Ascetospora (Sprague, 1979; Levine et al.,
1980), Perkins (1990) indicating that they
were sufficiently distinct to warrant the status of phylum with the name Haplosporidia.
Subsequently, Siddall et al. (1995) indicated
that the haplosporidians are more closely
related to alveolates (ciliates, dinoflagellates
and apicomplexans) than to other sporeforming protozoans based on sequence
comparisons of the 16S SSU rDNA gene.
More recently, Cavalier-Smith and Chao
(2003) indicated that the order status
should be reinstated under the recently
Haplosporidia (Haplospora)
645
Fig. 17.6. Histological images (A to D) and tissue imprint (E) of Haplosporidia in oysters. A to C.
Developmental stages of Haplosporidium nelsoni in Crassostrea virginica from Nova Scotia, Canada.
A. Plasmodia (arrows) in the connective tissue of the digestive gland between the tubules. B. Sporocysts
(arrows) within the epithelium of the digestive-gland tubules. C. Spores with a prominent operculum (arrow)
in the disrupted tissue of a digestive-gland tubule (courtesy of M. Maillet). D and E. Bonamia ostreae from
heavily infected Ostrea edulis from France. D. Numerous B. ostreae (arrows) located within haemocytes in
the connective tissue between the tubules of the digestive gland. E. Imprint of connective tissue containing
many B. ostreae (arrows), some with two nuclei, freed from ruptured haemocytes. All bars = 10 m.
646
S.M. Bower
647
648
S.M. Bower
The possibility of growing non-native oyster species that appear to be more resistant
to H. nelsoni, such as the Pacific oyster and
Suminoe oyster (Crassostrea ariakensis =
Crassostrea rivularis) are being assessed.
Related pathogens
In addition to numerous reports of unidentified species of Haplosporidium or Minchinia
in marine invertebrates (Burreson and Ford,
2004), three named species occur in bivalves
of economic importance.
H. costale (commonly referred to as
SSO, an acronym for seaside organism) has
been detected in eastern oysters along the
east coast of North America but has caused
significant disease only in high-salinity
(> 25 ppt) areas from Delaware to Virginia
(Andrews, 1988c). It can be differentiated from
H. nelsoni by: (i) a smaller spore size (3.1 m
by 2.6 m); (ii) occurrence of sporulation
throughout all connective tissue and not in
the epithelium of the digestive gland; (iii)
antigenic differences; and (iv) speciesspecific molecular diagnosis, as indicated
above. Initially thought to have a regular
and clearly defined life cycle (a 4- to 6-week
period of disease, sporulation and concurrent mortalities in May and June, followed
by an 8- to 10-month prepatent period in
newly exposed oysters), the application of
molecular diagnostic tools has revealed
unseasonably advanced infections in the
autumn (Stokes and Burreson, 2001). Also,
mixed infections with H. nelsoni are more
frequent than originally thought. H. costale
is not as serious a pathogen as H. nelsoni
and losses can be minimized by harvesting
oysters at 18 to 24 months of age (Andrews,
1988c).
Haplosporidium (= Minchinia) armoricana causes brown meat disease in flat
oysters (Ostrea edulis) in Brittany (France)
to Spain and in the Netherlands among
flat oysters imported from Brittany (van
Banning, 1985a; Azevedo et al., 1999).
Numerous operculate spores (5.0 to 5.5 m
by 4.0 to 4.5 m) with two long projections
(70 to 100 m) in sporocysts (35 to 50 m in
diameter) throughout the connective tissue
result in brownish discoloration of heavily
649
BONAMIA OSTREAE
650
S.M. Bower
Hostparasite relationships
Bonamiasis is usually systemic because
B. ostreae normally resides within haemocytes and has not been reported in other
host cells. Infections are often accompanied
by dense, focal haemocyte infiltration into
the connective tissue of the gill and mantle
and around the gut, and may result in tissue
lesions (Cochennec-Laureau et al., 2003a).
Many of the infiltrating haemocytes contain
several microcells (Fig. 17.6D), which are
often in cytoplasmic vacuoles. As the infection progresses, infected haemocytes occur
in the vascular sinuses, and microcells may
be released by lysis of haemocytes and
found free in necrotic tissues (Balouet et al.,
1983). Two years of age appeared to be critical for disease development in oysters, and
infection level was statistically independent of oyster gonadal development and sex
(Culloty and Mulcahy, 1996).
In vitro tests were used to determine that
haemocytes of Pacific oysters were able to
bind more B. ostreae than were haemocytes
of flat oysters (Fisher, 1988), but haemocyte
infection rates were similar for both species
(Mourton et al., 1992). The apparent inability of flat oyster haemocytes to inactivate
the parasites once they are ingested may
explain differences in susceptibility and
disease development in oysters (Chagot
et al., 1992; Xue and Renault, 2000).
Propagation
B. ostreae is readily propagated in vivo by
injection of infected haemocytes or purified
parasite suspensions and by cohabitation of
diseased and uninfected oysters (Hervio
et al., 1995). Comps (1983) reported in vitro
proliferation of B. ostreae in the presence of
flat oyster cells after 48 h of incubation but
the viability of the cultures over longer periods was not indicated.
Diagnosis of infection
Microcells are detected by histological
examination (Grizel et al., 1988). Although
many infected oysters appear normal, others
may have yellow discoloration and/or extensive lesions (i.e. perforated ulcers) on the
gills and mantle. The isolation and purification of B. ostreae from infected flat oysters (Mialhe et al., 1988a) have led to
the production of monoclonal antibodies
(Rogier et al., 1991) and the development
of an IFAT (Boulo et al., 1989) and of an
ELISA diagnostic technique with 90%
reliability in comparison with standard
histopathological light microscopic examinations (Cochennec et al., 1992). Because
classical histological (Fig. 17.6D) and heart
smear (Fig. 17.6E) techniques are unreliable for detecting light infections (Culloty
et al., 2003) and immunoassays (ELISA
kits) are no longer commercially available,
molecular diagnostic techniques were
developed.
A PCR reaction specific for an rDNA
amplicon (528 base pairs (bp) spanning
341 bp of 18S rDNA and 187 bp of ITS1)
with a gene sequence resembling that
belonging to members of the phylum
Haplosporidia was identified and found to
detect the parasite in naturally infected
O. edulis in Maine, USA (Carnegie et al.,
2000). This PCR assay proved to be more
sensitive, more specific and less ambiguous than standard histological and cytological (tissue imprint) techniques. Another
DNA probe identified from the same area
of the genome also detected another species of Bonamia (see B. exitiosus below)
and H. nelsoni (Cochennec et al., 2000).
651
Related pathogens
Bonamia exitiosus has devastated dredge
oysters (O. (= T.) chilensis (= lutaria)) populations in the Foveaux Strait south of South
Island, New Zealand (Hine et al., 2001b).
Stocks of dredge oysters were reduced by
67% in 1990 and by 91% in 1992 from levels
recorded in 1975. The commercial dredge
oyster fishery was closed in 1993, with severe
economic impacts on South Island coastal
communities (Doonan et al., 1994). Like
B. ostreae, B. exitiosus resides in haemocytes, is small in size (2 to 7 m) and has
light and dense forms, which vary in
prevalence seasonally (Hine, 1991a,b). However, B. exitiosus can de differentiated from
B. ostreae by antigenic features (Mialhe et al.,
1988b), divergent regions in the SSU rDNA
sequence and ultrastructural differences in
652
S.M. Bower
653
Fig. 17.7. Transmission electron micrographs (A and B) and a histological image (C) of Mikrocytos mackini
in the cells of Crassostrea gigas and Ostrea edulis, respectively, from British Columbia, Canada. A. Protist (p)
against the host cell nucleus (hn) and two closely associated host mitochondria (hm). B. Higher
magnification of a host mitochondrium (hm) with tube-like structures (arrows) extending into the cytoplasm
of M. mackini (p). C. Several M. mackini (p) in the cytoplasm of vesicular connective-tissue cells (hn, nuclei
of host cells) of the labial palps of O. edulis. D. Tissue imprint of the gonad of Crassostrea gigas from Japan
with a sporangiosorus (s) of Marteilioides chungmuensis in each ovum against the host cell nucleus (hn).
Each sporangiosorus contains two sporonts and each sporont contains one basophilic developing spore.
A and B bars = 0.5 m, C and D bars = 10 m.
Paramyxea
Introduction
These spore-forming bivalve pathogens were
initially assigned to the phylum Ascetospora
in the same class (Stellatosporea) as the
haplosporidians (Levine et al., 1980).
Because of significant morphological and
developmental
differences,
Desportes
(1984) moved them to the class Paramyxea
and order Marteiliida, and Desportes and
Perkins (1990) suggested that the class
Paramyxea be raised to the rank of phylum.
Based on an SSU rDNA gene sequence that
was very different from all known sequences of eukaryotic organisms, including
myxosporeans and haplosporeans, Berthe
et al. (2000) supported this phylum designation. These parasites are characterized by
the presence of several cells enclosed inside
one another, which arose by a process of
internal cleavage (endogenous budding)
within a stem cell. Included in this group are
pathogens in two genera, Marteilia (several
species) and Marteilioides (two species),
that have had a significant impact on
bivalve production in different areas of the
world. Each genus will be presented
separately.
MARTEILIA SPP.
654
S.M. Bower
At the initiation of sporulation, uninucleate segments become delimited within the cytoplasm of the sporangiosorus to
form the sporangial primordia (secondary
cells). Eventually, eight to 16 sporangial
primordia (each about 12 m in diameter at
maturity) form within the sporangiosorus,
which retains its nucleus and enlarges to
about 30 m in diameter. Each sporangial
primordium matures into a sporont containing two to four spore primordia (tertiary
cells), which mature into spores (Fig. 17.8).
Each spore contains three uninucleate
sporoplasms of graded sizes, with each of
the smaller sporoplasms being enclosed
within the cytoplasm of the next largest one
(i.e. consecutive internal cleavage of two
sporoplasms within the spore primordium)
(Perkins, 1976). A continuous spore wall
with no operculum occurs around each
spheroid mature spore, which measures
655
656
S.M. Bower
Hostparasite relationships
Signs of disease in oysters include a poor
condition index, with glycogen loss (emaciation), discoloration of the digestive gland,
cessation of growth, tissue necrosis and
mortalities (Sindermann, 1990). The pathogenesis of M. refringens remains obscure due
to the lack of consistent correlation between
the degree of infection and mortality
(Lauckner, 1983). Some flat oysters kept in
high-prevalence areas for extended periods
showed characteristic signs of disease without notable numbers of parasites, while
other flat oysters heavily infected with young
sporangiosori and mature spores exhibited
virtually no histological alterations. To
explain these inconsistencies, Balouet (1979)
and van Banning (1979) suggested that either:
(i) the parasite produced toxins inconsistently;
(ii) the parasite required the synergistic
effect of another, as yet unidentified, pathogen; (iii) an intermediate host was required to
amplify parasite abundance; and/or (iv)
unfavourable environmental conditions
(e.g. physicochemical factors in sea water)
played prominent roles in determining the
apparent pathogenicity of M. refringens.
Anderson et al. (1994a) determined that fluctuations in pH, salinity and water temperature in close proximity to the Sydney rock
oysters did not correlate with epizootics of
M. sydneyi.
Diagnosis of infection
Because there are no specific clinical signs,
infection can best be confirmed by histological
examination (Grizel, 1979; Kleeman et al.,
2002a). A diagnostic feature is the presence
of Marteilia spp. in histological sections of
the digestive gland tubule epithelium and
occasionally in the gills and palps (Sindermann, 1990). Gutirrez (1977) described a
modified staining technique for enhancing
the detection of the parasite in paraffinembedded histological sections. An IFAT,
based on the polyclonal antibodies that were
specific for sporulating stages of M. sydneyi,
failed to detect presporulation stages of M.
sydneyi in the connective tissue of recently
infected oysters (Anderson et al., 1994b).
657
Phylum Annelida
The cosmopolitan spionid polychaetes
include several species (most in the genera
Polydora and Boccardia) that burrow into
the shells of living molluscs. Spionid polychaetes are filter feeders and do not derive
nutrients from their host; however, the burrows that they create in mollusc shells can
be problematic. Due to the overall low economic significance of this group of parasites, the taxonomic problems, as indicated
by Lauckner (1983), will not be reiterated
here. Instead, instances where these polychaetes have had an impact on commercial
stocks of molluscs in various parts of the
world will be mentioned.
In European waters, mortalities and
loss of market quality of blue mussels were
caused by Polydora ciliata (Lauckner,
1983). The burrows excavated by P. ciliata
in blue mussel shells not only caused
unsightly blisters containing compacted
mud but also resulted in significant reductions in shell strength, thereby increasing
susceptibility to predation by birds and
shore crabs (Kent, 1981). Nacreous blisters
658
S.M. Bower
Fig. 17.9. Histological images (A and B) and electron micrographs (C and D) of an unnamed protist with
unknown taxonomic affiliations from Pandalus platyceros in British Columbia, Canada. A. Plasmodium with
numerous nuclei. B. Trophozoites in the process of binary fission showing metaphase (m), late telophase (t)
and one cell in which the nucleus has recently divided (d). C. Trophozoite in late metaphase with an intact
nuclear membrane surrounding condensed chromosomes (c), which are connected by microtubules (mt) to
spindle-pole bodies (s) emerging through the nuclear envelope. D. A higher magnification of C illustrating
the microtubules connecting to the spindle-pole body at a gap in the nuclear membrane. A and B bars =
10 m, C bar = 2.5 m and D bar = 0.5 m.
Phylum Trematoda
Numerous species of digenean trematodes
have been described from various shellfish
worldwide. In general, the trematodes that
cause the greatest economic impact are species in the families Bucephalidae and Fellodistomidae that utilize bivalves as primary
hosts. In such instances, miracidia are infective to bivalves and the larval trematode life
stages of sporocyst and development of
cercariae occur within the tissues of the
bivalve. Four cases in which trematodes
from other families were reported to cause
pathology are noted.
Family Bucephalidae
Introduction
Numerous species of Bucephalidae (suborder
Gasterostomata) have been described from
marine and freshwater fishes and the larval
forms have been reported from bivalves
worldwide. However, few experimental life
cycle studies have been conducted. Thus,
659
Fig. 17.10. Histological images (A and B) and a wet mount (C) of Prosorhynchus squamatus from Mytilus
edulis in Nova Scotia, Canada (courtesy of S.E. McGladdery). A. Anterior end of sporocyst sectioned
through oral sucker (os) adjacent to digestive-gland tubule (dgt). B. Sporocyst containing cercaria sectioned
through the trilobate tail (tt). C. Cercaria with trilobate tail (tt) and curled furcae (f). All bars = 50 m.
660
S.M. Bower
Hostparasite relationships
Bucephalid sporocysts and cercariae cause
castration of infected bivalves, tissue necrosis and debilitation, expressed as a significant reduction in tolerance of environmental
stress (Lauckner, 1983). Despite the severe
pathology associated with Bucephalus sp.
infection in eastern oysters, there is usually
little host response to the parasite, but
massive biochemical alterations have been
observed (Lauckner, 1983).
Family Fellodistomidae
Although numerous species of this family
parasitize many marine pelecypods as primary hosts and secondary hosts worldwide (Lauckner, 1983; Wolf et al., 1987),
Proctoeces maculatus, which infects blue
mussels as well as other mollusca, has the
greatest economic impact. Thus, this section
presents information only on P. maculatus.
P. maculatus from shellfish and fin fish
appear in the literature under a variety of
synonyms, and life stages have been
described from a wide variety of bivalves
and gastropods (Bray, 1983). Metacercariae
occur in various mollusca (including species
of Amphineura, Gastropoda, Cephalopoda
and Lamellibranchiata), Polychaeta (Annelida) and Echinoidea (Echinodermata).
Adults have been reported in mollusc-eating
fishes (mainly labrids and sparids) in tropical and subtropical areas, as well as in some
Gastropoda, Lamellibranchiata and Polychaeta. However, sporocysts have only been
reported from blue mussels, gallo mussels,
and hooked mussels (Ischadium recurvum).
The wide host tolerance, global distribution
in tropical and temperate marine waters
and morphometric variability led Lauckner
(1983) to speculate that more than one species of trematode may have been included
661
662
S.M. Bower
Phylum Cestoda
Metacestodes (larval cestodes) have been
reported from a wide variety of aquatic
invertebrates. Among marketed shellfish,
metacestode infections are economically
insignificant. Nevertheless, there are a few
isolated instances of high prevalences and
intensities of metacestodes in bivalves and
crustacea from various subtropical and
tropical areas of the world (Lauckner, 1983;
Sparks, 1985; Sindermann, 1990). Metacestodes of Echeneibothrium spp. were
associated with unusual behaviour of
Pacific littleneck clams (P. (= Venerupis)
staminea) and fringed littleneck clams
(Protothaca laciniata) in California (Warner
and Katkansky, 1969) and caused histopathology and gonad atrophy in Atlantic
calico scallops (A. gibbus) in North Carolina
(Singhas et al., 1993). In most cases, the
final hosts of the cestodes are fishes, mainly
elasmobranchs.
Phylum Nematoda
Nematodes are uncommon as parasites of
shellfish (Lauckner, 1983; Sindermann, 1990).
However, the exceptions are all larval stages
and include the following:
1. Various species of the gnathostomid
genus Echinocephalus from oysters, scallops and abalone from tropical and subtropical marine waters. Although the pathology
in the bivalve hosts is minimal, there is concern that at least some species may
have public health significance as potential
invaders of the human digestive tract. The
species (Echinocephalus pseudouncinatus)
in pink abalone (Haliotis corrugata) from
California causes blisters and weakens the
foot as a holdfast organ in heavily infected
specimens (Sindermann, 1990).
2. An ascaridoid Sulcascaris sulcata is
widespread in warm seas and has a considerable host range, including scallops and
clams (Lauckner, 1983; Sindermann, 1990).
Although S. sulcata is a minor pathogen for its
hosts, significant economic impact occurred
on the east coast of North America where a
haplosporidian hyperparasite (Urosporidium
spisuli) caused the usually white to yellowish coloured worm to become dark brown.
The epizootic spread of the hyperparasite in
S. sulcata parasitizing Atlantic surf clams
(Spisula solidissima) in the mid-1970s
caused considerable economic concern for
aesthetic reasons (Payne et al., 1980).
3. Angiostrongylus
cantonensis,
the
rat lungworm that causes human eosinophilic meningoencephalitis in parts of Asia,
can utilize eastern oysters and quahogs
(M. mercenaria) as aberrant intermediate hosts
under experimental conditions (Sparks, 1985).
These findings could be significant for some of
the Pacific Islands where the rat lungworm
occurs and oysters and clams may be eaten
raw or poorly cooked (Lauckner, 1983).
4. The codworm Phocanema decipiens in
the North Atlantic has been observed in blue
mussels and softshell clams (M. arenaria),
which may serve as paratenic hosts for this
parasite (Lauckner, 1983).
Phylum Arthropoda
The pathogenic arthropods all belong to
the class Crustacea (subclass Copepoda,
mainly in the order Cyclopoida and subclass Malacostraca, order Isopoda). Because
the economic significance of all species is
either disputable or confined to small local
areas, these pathogens are only briefly
mentioned.
663
Subclass Copepoda
Subclass Malacostraca
Conclusions
A wide variety of parasites have been identified as causing significant economic losses
in shellfish production worldwide. Many of
these pathogens have the potential of causing significant losses either in endemic areas
or if they inadvertently become established
in other areas. In the past, transplants of
commercial shellfish have been notorious
for the accidental introduction of associated
parasites (Sindermann, 1990, 1993). In order
to avoid future disasters, all movements of
shellfish must be conducted with caution.
Equally essential is the acquisition of
information on agents of disease, including
parasites, such that risks associated with
impending movements and aquaculture
practices can be accurately assessed. This
information should also prove useful for
treating or controlling a disease in the event
that an accidental introduction occurs.
664
S.M. Bower
References
Alder, J. and Braley, R. (1989) Serious mortality in populations of giant clams on reefs surrounding Lizard
Island, Great Barrier Reef. Australian Journal of Marine and Freshwater Research 40, 205213.
Alderman, D.J. (1979) Epizootiology of Marteilia refringens in Europe. Marine Fisheries Review 41, 6769.
Anderson, I.G. (1990) Diseases in Australian invertebrate aquaculture. In: Proceedings, Fifth International Colloquium on Invertebrate Pathology and Microbial Control, Society for Invertebrate Pathology, 2024
August 1990. Society of Invertebrate Pathology, Adelaide, Australia, pp. 3848.
Anderson, I.G., Shariff, M. and Nash, G. (1989) A hepatopancreatic microsporidian in pond-reared tiger
shrimp, Penaeus monodon, from Malaysia. Journal of Invertebrate Pathology 53, 278280.
Anderson, R.S., Paynter, K.T. and Burreson, E.M. (1992) Increased reactive oxygen intermediate production
by hemocytes withdrawn from Crassostrea virginica infected with Perkinsus marinus. Biological Bulletin
183, 476481.
Anderson, T.J. and Lester, R.J.G. (1992) Sporulation of Marteilioides branchialis n. sp. (Paramyxea) in the Sydney rock oyster, Saccostrea commercialis: an electron microscope study. Journal of Protozoology 39,
502508.
Anderson, T.J., Wesche, S. and Lester, R.J.G. (1994a) Are outbreaks of Marteilia sydneyi in Sydney rock
oysters, Saccostrea commercialis, triggered by a drop in environmental pH? Australian Journal of Marine
and Freshwater Research 45, 12851287.
Anderson, T.J., McCaul, T.F., Boulo, V., Robledo, J.A.F. and Lester, R.J.G. (1994b) Light and electron
immunohistochemical assays on paramyxea parasites. Aquatic Living Resources 7, 4752.
Anderson, T.J., Adlard, R.D. and Lester, R.J.G. (1995) Molecular diagnosis of Marteilia sydneyi (Paramyxea) in
Sydney rock oysters, Saccostrea commercialis (Angas). Journal of Fish Diseases 18, 507510.
Andrews, J.D. (1982) Epizootiology of late summer and fall infections of oysters by Haplosporidium nelsoni,
and comparison to annual life cycle of Haplosporidium costalis, a typical haplosporidan. Journal of
Shellfish Research 2, 1523.
Andrews, J.D. (1988a) Epizootiology of the disease caused by the oyster pathogen Perkinsus marinus and its
effects on the oyster industry. American Fisheries Society Special Publication 18, 4763.
Andrews, J.D. (1988b) Haplosporidium nelsoni disease of oysters. In: Sindermann, C.J. and Lightner, D.V.
(eds) Disease Diagnosis and Control in North American Marine Aquaculture. Elsevier, Amsterdam,
pp. 291295.
Andrews, J.D. (1988c) Haplosporidium costale disease of oysters. In: Sindermann, C.J. and Lightner, D.V.
(eds) Disease Diagnosis and Control in North American Marine Aquaculture. Elsevier, Amsterdam,
pp. 296299.
Andrews, J.D. and Ray, S.M. (1988) Management strategies to control the disease caused by Perkinsus
marinus. American Fisheries Society Special Publication 18, 257264.
Armstrong, D.A., Burreson, E.M. and Sparks, A.K. (1981) A ciliate infection (Paranophrys sp.) in laboratory-held
Dungeness crabs, Cancer magister. Journal of Invertebrate Pathology 37, 201209.
Audemard, C., Le Roux, F., Barnaud, A., Collins, C., Sautour, B., Sauriau, P.-G., De Montaudouin, X.,
Coustau, C., Combes, C. and Berthe, F. (2002) Needle in a haystack: involvement of the copepod
Paracartia grani in the life-cycle of the oyster pathogen Marteilia refringens. Parasitology 124,
315323.
Auffret, M. and Poder, M. (1983) Studies on Marteilia maurini, parasite of Mytilus edulis from the north
coasts of Brittany. Revue des Travaux de lInstitut des Pches Maritimes 47, 105109 (in French, with
English abstract).
Azevedo, C. (1989) Fine structure of Perkinsus atlanticus n. sp. (Apicomplexa, Perkinsea) parasite of the clam
Ruditapes decussatus from Portugal. Journal of Parasitology 75, 627635.
Azevedo, C. (2001) Ultrastructural description of the spore maturation stages of the clam parasite Minchinia
tapetis (Vilela, 1951) (Haplosporida: Haplosporidiidae). Systematic Parasitology 49, 189194.
Azevedo, C., Montes, J. and Corral, L. (1999) A revised description of Haplosporidium armoricanum, parasite
of Ostrea edulis L. from Galicia, northwestern Spain, with special reference to the spore-wall filaments.
Parasitology Research 85, 977983.
Balouet, G. (1979) Marteilia refringens considerations of the life cycle and development of Abers disease in
Ostrea edulis. Marine Fisheries Review 41, 6466.
Balouet, G., Poder, M. and Cahour, A. (1983) Haemocytic parasitosis: morphology and pathology of lesions
in the French flat oyster, Ostrea edulis L. Aquaculture 34, 114.
665
Barber, B.J., Ford, S.E. and Haskin, H.H. (1988) Effects of the parasite MSX (Haplosporidium nelsoni) on oyster
(Crassostrea virginica) energy metabolism. I. Condition index and relative fecundity. Journal of Shellfish
Research 7, 2531.
Barber, B.J., Ford, S.E. and Littlewood, D.T.J. (1991) A physiological comparison of resistant and susceptible
oysters Crassostrea virginica (Gmelin) exposed to the endoparasite Haplosporidium nelsoni (Haskin,
Stauber & Mackin). Journal of Experimental Marine Biology Ecology 146, 101112.
Barrow, J.H. and Taylor, B.C. (1966) Fluorescent-antibody studies of haplosporidian parasites of oysters in
Chesapeake and Delaware bays. Science 153, 15311533.
Berthe, F.C., Pernas, M., Zerabib, M., Haffner, P., Thbault, A. and Figueras, A.J. (1998) Experimental transmission of Marteilia refringens with special consideration of its life cycle. Diseases of Aquatic Organisms
34, 135144.
Berthe, F.C.J., Le Roux, F., Peyretaillade, E., Peyret, P., Rodriguez, D., Gouy, M. and Vivars C.P. (2000)
Phylogenetic analysis of the small subunit ribosomal RNA of Marteilia refringens validates the existence
of phylum Paramyxea (Desportes and Perkins, 1990). Journal of Eukaryotic Microbiology 47, 288293.
Blackbourn, J., Bower, S.M. and Meyer, G.R. (1998) Perkinsus qugwadi sp. nov. (incertae sedis), a pathogenic
protozoan parasite of Japanese scallops, Patinopecten yessoensis, cultured in British Columbia, Canada.
Canadian Journal of Zoology 76, 942953.
Blateau, D., LeCoguic, Y., Mialhe, E., Grizel, H. and Flamion, G. (1990) Treatment of mussels (M. edulis)
against the copepode Mytilicola intestinalis. In: Figueras, A. (ed.) Abstracts, Fourth International Colloquium on Pathology in Marine Aquaculture, 1721 September 1990. Imprine Grafol, S.A., Dep. Legal,
Vigo (Pontevedra), Spain, pp. 9798 (in French).
Boudry, P., Chatain, B., Naciri-Graven, Y., Lemaire, C. and Andrrard (1996) Genetical improvement of
marine fish and shellfish: a French perspective. Proceedings of FOID 96, vol. 5, pp. 141150.
Bougrier, S., Tig, G., Bachre, E. and Grizel, H. (1986) Ostrea angasi acclimatization to French coasts.
Aquaculture 58, 151154.
Boulo, V., Mialhe, E., Rogier, H., Paolucci, F. and Grizel, H. (1989) Immunodiagnosis of Bonamia ostreae
(Ascetospora) infection of Ostrea edulis L. and subcellular identification of epitopes by monoclonal antibodies. Journal of Fish Diseases 12, 257262.
Bower, S.M. (1987a) Labyrinthuloides haliotidis n. sp. (Protozoa: Labyrinthomorpha), a pathogenic parasite of
small juvenile abalone in a British Columbia mariculture facility. Canadian Journal of Zoology 65,
19962007.
Bower, S.M. (1987b) Pathogenicity and host specificity of Labyrinthuloides haliotidis (Protozoa:
Labyrinthomorpha), a parasite of juvenile abalone. Canadian Journal of Zoology 65, 20082012.
Bower, S.M. (1987c) Artificial culture of Labyrinthuloides haliotidis (Protozoa: Labyrinthomorpha), a pathogenic parasite of abalone. Canadian Journal of Zoology 65, 20132020.
Bower, S.M. (1988) Circumvention of mortalities caused by Denman Island oyster disease during mariculture
of Pacific oysters. American Fisheries Society Special Publication 18, 246248.
Bower, S.M. (1989) Disinfectants and therapeutic agents for controlling Labyrinthuloides haliotidis (Protozoa:
Labyrinthomorpha), an abalone pathogen. Aquaculture 78, 207215.
Bower, S.M. (1990) Shellfish diseases on the west coast of Canada. Bulletin of the Aquaculture Association of
Canada 90, 1922.
Bower, S.M. and Meyer, G.R. (2002) Morphology and ultrastructure of a protistan pathogen in the
haemolymph of shrimp (Pandalus spp.) in the northeastern Pacific Ocean. Canadian Journal of Zoology
80, 10551068.
Bower, S.M., Whitaker, D.J. and Elston, R.A. (1989a) Detection of the abalone parasite Labyrinthuloides
haliotidis by a direct fluorescent antibody technique. Journal of Invertebrate Pathology 53, 281283.
Bower, S.M., McLean, N. and Whitaker, D.J. (1989b) Mechanism of infection by Labyrinthuloides haliotidis
(Protozoa: Labyrinthomorpha), a parasite of abalone (Haliotis kamtschatkana) (Mollusca: Gastropoda).
Journal of Invertebrate Pathology 53, 401409.
Bower, S.M., Whitaker, D.J. and Voltolina, D. (1989c) Resistance to ozone of zoospores of the thraustochytrid
abalone parasite, Labyrinthuloides haliotidis (Protozoa: Labyrinthomorpha). Aquaculture 78, 147152.
Bower, S.M., Hervio, D. and Meyer, G.R. (1997) Infectivity of Mikrocytos mackini, the causative agent of Denman Island disease in Pacific oysters Crassostrea gigas, to various species of oysters. Diseases of Aquatic
Organisms 29, 111116.
Bower, S.M., Blackbourn, J. and Meyer, G.R. (1998) Distribution, prevalence, and pathogenicity of the protozoan Perkinsus qugwadi in Japanese scallops, Patinopecten yessoensis, cultured in British Columbia,
Canada. Canadian Journal of Zoology 76, 954959.
666
S.M. Bower
Bower, S.M., Blackbourn, J., Meyer, G.R. and Welch, D.W. (1999) Effect of Perkinsus qugwadi on various
species and strains of scallops. Diseases of Aquatic Organisms 36, 143151.
Bower, S.M., Meyer, G.R., Phillips, A., Workman, G. and Clark, D. (2003) New host and range extension of
bitter crab syndrome in Chionoecetes spp. caused by Hematodinium sp. Bulletin of the European
Association of Fish Pathologists 23, 8691.
Bray, R.A. (1983) On the fellodistomid genus Proctoeces Odhner, 1911 (Digenea), with brief comments on
two other fellodistomid genera. Journal of Natural History 17, 321339.
Brehlin, M., Bonami, J.R., Cousserans, F. and Vivars, C.P. (1982) True plasmodial forms exist in Bonamia
ostreae, a pathogen of the European flat oyster Ostrea edulis. Compte Rendu Hebdomadaire des
Sanaces de lAcadmie des Sciences, Paris, Srie III 295, 4548 (in French, with English abstract).
Burreson, E.M. (1988) Use of immunoassays in haplosporidan life cycle studies. American Fisheries Society
Special Publication 18, 298303.
Burreson, E.M. (1994) Further evidence of regular sporulation by Haplosporidium nelsoni in small oysters,
Crassostrea virginica. Journal of Parasitology 80, 10361038.
Burreson, E.M. (2000) Disease diagnosis by PCR: foolproof or foolhardy? Journal of Shellfish Research 19, 642
(abstract).
Burreson, E.M. and Ford, S.E. (2004) A review of recent information on the Haplosporidia, with special
reference to Haplosporidium nelsoni (MSX disease). Aquatic Living Resources 17, 499517.
Burreson, E.M. and Ragone Calvo, L.M. (1996) Epizootiology of Perkinsus marinus disease of oysters in
Chesapeake Bay, with emphasis on data since 1985. Journal of Shellfish Research 15, 1734.
Burreson, E.M., Robinson, M.E. and Villalba, A. (1988) A comparison of paraffin histology and hemolymph
analysis for the diagnosis of Haplosporidium nelsoni (MSX) in Crassostrea virginica (Gmelin). Journal of
Shellfish Research 7, 1923.
Burreson, E.M., Stokes, N.A. and Friedman, C.S. (2000) Increased virulence in an introduced pathogen:
Haplosporidium nelsoni (MSX) in the eastern oyster Crassostrea virginica. Journal of Aquatic Animal
Health 12, 18.
Bushek, D. and Allen, S.K. (1996a) Hostparasite interactions among broadly distributed populations of the
eastern oyster Crassostrea virginica and the protozoan Perkinsus marinus. Marine Ecology Progress Series
139, 127141.
Bushek, D. and Allen, S.K. (1996b) Races of Perkinsus marinus. Journal of Shellfish Research 15, 103107.
Bushek, D., Ford, S.E. and Allen, S.K. (1994) Evaluation of methods using Rays fluid thioglycollate medium
for diagnosis of Perkinsus marinus infection in the eastern oyster, Crassostrea virginica. Annual Review of
Fish Diseases 4, 201217.
Caceres-Martinez, J., Macias-Montes de Oca, P. and Vasquez-Yeomans, R. (1998) Polydora sp. infestation
and health of the Pacific oyster Crassostrea gigas cultured in Baja California, NW Mexico. Journal of
Shellfish Research 17, 259264.
Cahour, A. (1979) Marteilia refringens and Crassostrea gigas. Marine Fisheries Review 41, 1920.
Carnegie, R.B., Barber, B.J., Culloty, S.C., Figueras, A.J. and Distel, D.L. (2000) Development of a PCR assay
for detection of the oyster pathogen Bonamia ostreae and support for its inclusion in the Haplosporidia.
Diseases of Aquatic Organisms 42, 199206.
Carnegie, R.B., Meyer, G.R., Blackbourn, J., Cochennec-Laureau, N., Berthe, F.C.J. and Bower, S.M. (2003)
Molecular detection of the oyster parasite Mikrocytos mackini and a preliminary phylogenetic analysis.
Diseases of Aquatic Organisms 54, 219227.
Casas, S.M., Villalba, A. and Reece, K.S. (2002a) Study of perkinsosis in the carpet shell clam Tapes
decussatus in Galicia (NW Spain). I. Identification of the aetiological agent and in vitro modulation of
zoosporulation by temperature and salinity. Diseases of Aquatic Organisms 50, 5165.
Casas, S.M., La Peyre, J.F., Reece, K.S., Azevedo, C. and Villalba, A. (2002b) Continuous in vitro culture of the
carpet shell clam Tapes decussatus protozoan parasite Perkinsus atlanticus. Diseases of Aquatic Organisms 52, 217231.
Cavalier-Smith, T. and Chao, E.E.-Y. (2003) Phylogeny of Choanozoa, Apusozoa, and other protozoa and
early eukaryote megaevolution. Journal of Molecular Evolution 56, 540563.
Chagot, D., Bachre, E., Ruano, F., Comps, M. and Grizel, H. (1987) Ultrastructural study of sporulated instars
of a haplosporidian parasitizing the clam Ruditapes decussatus. Aquaculture 67, 262263.
Chagot, D., Boulo, V., Hervio, D., Mialhe, E., Bachre, E., Mourton, C. and Grizel, H. (1992) Interactions
between Bonamia ostreae (Protozoa: Ascetospora) and hemocytes of Ostrea edulis and Crassostrea
gigas (Mollusca: Bivalvia): entry mechanisms. Journal of Invertebrate Pathology 59, 241249.
667
Chatton, E. and Poisson, R. (1930) On the existence of dinoflagellate parasites Hematodinium perezi n. g.,
n. sp. (Syndinidae) in the blood of crabs. Comptes Rendus des Sances de la Socit de Biologie et de ses
Filiales 105, 553557 (in French).
Cheng, T.C. (1967) Marine molluscs as hosts for symbioses with a review of known parasites of commercially
important species. In: Russell, F.S. (ed.) Advances in Marine Biology, vol. 5. Academic Press, New York,
pp. 1424.
Childers, R.K., Reno, P.W. and Olson, R.E. (1996) Prevalence and geographic range of Nadelspora canceri
(Microspora) in Dungeness crab Cancer magister. Diseases of Aquatic Organisms 24, 135142.
Chintala, M.M. and Fisher, W.S. (1991) Disease incidence and potential mechanisms of defense for
MSX-resistant and -susceptible eastern oysters held in Chesapeake Bay. Journal of Shellfish Research 10,
439443.
Choi, K.S., Wilson, E.A., Lewis, D.H., Powell, E.N. and Ray, S.M. (1989) The energetic cost of Perkinsus
marinus parasitism in oysters: quantification of the thioglycollate method. Journal of Shellfish Research 8,
125131.
Choi, K., Lewis, D.H., Powell, E.N., Frelier, P.F. and Ray, S.M. (1991) A polyclonal antibody developed from
Perkinsus marinus hypnospores fails to cross react with other life stages of P. marinus in oyster
(Crassostrea virginica) tissues. Journal of Shellfish Research 10, 411415.
Choi, K.-S., Park, K.-I., Lee, K.-W. and Matsuoka, K. (2002) Infection intensity, prevalence, and histopathology
of Perkinsus sp. in the Manila clam, Ruditapes philippinarum, in Isahaya Bay, Japan. Journal of Shellfish
Research 21, 119125.
Chu, F.E. and Greene, K.H. (1989) Effect of temperature and salinity on in vitro culture of the oyster pathogen,
Perkinsus marinus (Apicomplexa: Perkinsea). Journal of Invertebrate Pathology 53, 260268.
Cigarra, J. and Elston, R. (1997) Independent introduction of Bonamia ostreae, a parasite of Ostrea edulis to
Spain. Diseases of Aquatic Organisms 29, 157158.
Cochennec, N., Hervio, D., Panatier, B., Boulo, V., Mialhe, E., Rogier, H., Grizel, H. and Paolucci, F. (1992)
A direct monoclonal antibody sandwich immunoassay for detection of Bonamia ostreae (Ascetospora) in
hemolymph samples of the flat oyster Ostrea edulis (Mollusca: Bivalvia). Diseases of Aquatic Organisms
12, 129134.
Cochennec, N., Renault, T., Boudry, P., Chollet, B. and Gerard, A. (1998) Bonamia-like parasite found in the
Suminoe oyster Crassostrea rivularis reared in France. Diseases of Aquatic Organisms 34, 193197.
Cochennec, N., LeRoux, F., Berthe, F. and Gerard, A. (2000) Detection of Bonamia ostreae based on small
subunit ribosomal probe. Journal of Invertebrate Pathology 76, 2632.
Cochennec-Laureau, N., Auffret, M., Renault, T. and Langlade, A. (2003a) Changes in circulating and
tissue-infiltrating hemocyte parameters of European flat oysters, Ostrea edulis, naturally infected with
Bonamia ostreae. Journal of Invertebrate Pathology 83, 2330.
Cochennec-Laureau, N., Reece, K.S., Berthe, F.C.J. and Hine, P.M. (2003b) Mikrocytos roughleyi taxonomic
affiliation leads to the genus Bonamia (Haplosporidia). Diseases of Aquatic Organisms 54, 209217.
Comps, M. (1976) Marteilia lengehi n. sp., parasite of the oyster Crassostrea cucullata Born. Revue des
Travaux de lInstitut des Pches Maritimes 40, 347349 (in French, with English summary).
Comps, M. (1983) Culture in vitro of Bonamia ostreae hemocytic parasite of the flat oyster Ostrea edulis
L. Compte Rendu Hebdomadaire des Sances de lAcadmie des Sciences, Paris, Srie III 296, 931933
(in French, with English abstract).
Comps, M., Pichot, Y. and Papagianni, P. (1981) Research on Marteilia maurini n. sp. parasite the mussel
Mytilus galloprovincialis Lmk. Revue des Travaux de lInstitut des Pches Maritimes 45, 211214 (in
French, with English abstract).
Cook, T., Folli, M., Klinck, J., Ford, S. and Miller, J. (1998) The relationship between increasing sea-surface
temperature and the northward spread of Perkinsus marinus (Dermo) disease epizootics in oysters.
Estuarine, Coastal and Shelf Science 46, 587597.
Coss, C.A., Robledo, J.A.F., Ruiz, G.M. and Vasta, G.R. (2001) Description of Perkinsus andrewsi n. sp.
isolated from the baltic clam (Macoma balthica) by characterization of the ribosomal RNA locus and
development of a species-specific PCR-based diagnostic assay. Journal of Eukaryotic Microbiology 48,
5261.
Couch, J.A. (1983) Diseases caused by protozoa. In: Provenzano, A.J. (ed.) The Biology of Crustacea. Vol. 6,
Pathobiology. Academic Press, New York, pp. 79111.
Couch, J.A., Farley, C.A. and Rosenfield, A. (1966) Sporulation of Minchinia nelsoni (Haplosporida,
Haplosporidiidae) in Crassostrea virginica (Gmelin). Science 153, 15291531.
668
S.M. Bower
Coustau, C., Combes, C., Maillard, C., Renaud, F. and Delay, B. (1990) Prosorhynchus squamatus
(Trematoda) parasitosis in the Mytilus edulisMytilus galloprovincialis complex: specificity and
hostparasite relationships. In: Perkins, F.O. and Cheng, T.C. (eds) Pathology in Marine Science,
Academic Press, New York, pp. 291298.
Coustau, C., Robbins, I., Delay, B., Renaud, F. and Mathieu, M. (1993) The parasitic castration of the mussel
Mytilus edulis by the trematode parasite Prosorhynchus squamatus: specificity and partial characterization of endogenous and parasite-induced anti-mitotic activities. Comparative Biochemistry and
Physiology 104A, 229233.
Cox, F.E.G. (2002) Systematics of the parasitic protozoa. Trends in Parasitology 18, 108.
Crosby, M.P. and Roberts, C.F. (1990) Seasonal infection intensity cycle of the parasite Perkinsus marinus (and
an absence of Haplosporidium spp.) in oysters from a South Carolina salt marsh. Diseases of Aquatic
Organisms 9, 149155.
Culloty, S.C. and Mulcahy, M.F. (1996) Season-, age-, and sex-related variations in the prevalence of
bonamiasis in flat oyster (Ostrea edulis L.) on the south coast of Ireland. Aquaculture 144, 5363.
Culloty, S.C., Novoa, B., Pernas, M., Longshaw, M., Mulcahy, M.F., Feist, S.W. and Figueras, A. (1999) Susceptibility of a number of bivalve species to the protozoan parasite Bonamia ostreae and their ability to
act as a vector for this parasite. Diseases of Aquatic Organisms 37, 7380.
Culloty, S.C., Cronin, M.A. and Mulcahy, M.F. (2001) An investigation into the relative resistance of Irish flat
oysters Ostrea edulis L. to the parasite Bonamia ostreae (Pichot et al. 1980). Aquaculture 199, 229244.
Culloty, S.C., Cronin, M.A. and Mulcahy, M.F. (2003) Possible limitations of diagnostic methods recommended for the detection of the protistan, Bonamia ostreae in the European flat oyster, Ostrea edulis.
Bulletin of the European Association of Fish Pathologists 23, 6771.
Dare, P.J. (1982) The susceptibility of seed oysters of Ostrea edulis L. and Crassostrea gigas Thunberg to
natural infestation by the copepod Mytilicola intestinalis Steuer. Aquaculture 26, 201211.
Davey, J.T. (1989) Mytilicola intestinalis (Copepoda: Cyclopoida): a ten year survey of infested mussels in a
Cornish estuary, 19781988. Journal of the Marine Biological Association of the United Kingdom 69,
823836.
Davey, J.T. and Gee, J.M. (1988) Mytilicola intestinalis, a copepod parasite of blue mussels. American Fisheries Society Special Publication 18, 6473.
Day, J.M., Franklin, D.E. and Brown, B.L. (2000) Use of competitive PCR to detect and quantify
Haplosporidium nelsoni infection (MSX disease) in the eastern oyster (Crassostrea virginica). Marine
Biotechnology 2, 456465.
De la Herrn, R., Garrido-Ramos, M.A., Navas, J.I., Ruiz Rejn, C. and Ruiz Rejn, M. (2000) Molecular
characterization of the ribosomal RNA gene region of Perkinsus atlanticus: its use in phylogenetic
analysis and as a target for a molecular diagnosis. Parasitology 120, 345353.
Desportes, I. (1984) The Paramyxea Levine 1979: an original example of evolution towards multicellularity.
Origins of Life 13, 343352.
Desportes, I. and Perkins, F.O. (1990) Phylum Paramyxea. In: Margulis, L., Corliss, J.O., Melkonian, M. and
Chapman, D.J. (eds) Handbook of Protoctista. Jones and Bartlett Publishers, Boston, Massachusetts,
pp. 3035.
Desser, S.S. and Bower, S.M. (1997) Margolisiella kabatai gen. et sp. n. (Apicomplexa: Eimeriidae), a
parasite of native littleneck clams, Protothaca staminea, from British Columbia, Canada, with a taxonomic revision of the coccidian parasites of bivalves (Mollusca: Bivalvia). Folia Parasitologica 44,
241247.
Diggles, B.K., Cochennec-Laureau, N. and Hine, P.M. (2003) Comparison of diagnostic techniques for
Bonamia exitiosus from flat oysters Ostrea chilensis in New Zealand. Aquaculture 220, 145156.
Doonan, I.J., Cranfield, H.J. and Michael, K.P. (1994) Catastrophic reduction of the oyster, Tiostrea chilensis
(Bivalvia: Ostreidae), in Foveaux Strait, New Zealand, due to infestation by the protistan Bonamia sp.
New Zealand Journal of Marine and Freshwater Research 28, 335344.
Dungan, C.F. and Roberson, B.S. (1993) Binding specificities of mono- and polyclonal antibodies to the
protozoan oyster pathogen Perkinsus marinus. Diseases of Aquatic Organisms 15, 922.
Dungan, C.F., Hamilton, R.M., Hudson, K.L., McCollough, C.B. and Reece, K.S. (2002) Two epizootic diseases in Chesapeake Bay commercial clams, Mya arenaria and Tagelus pledius. Diseases of Aquatic
Organisms 50, 6778.
Eaton, W.D., Love, D.C., Botelho, C., Meyers, T.R., Imamura, K. and Koeneman, T. (1991) Preliminary
results on the seasonality and life cycle of the parasitic dinoflagellate causing bitter crab disease in
Alaskan Tanner crabs (Chionoecetes bairdi ). Journal of Invertebrate Pathology 57, 426434.
669
Elston, R.A., Farley, C.A. and Kent, M.L. (1986) Occurrence and significance of bonamiasis in European flat
oysters Ostrea edulis in North America. Diseases of Aquatic Organisms 2, 4954.
Farley, C.A. (1965) Acid-fast staining of haplosporidian spores in relation to oyster pathology. Journal of
Invertebrate Pathology 7, 144147.
Farley, C.A. (1968) Minchinia nelsoni (Haplosporida) disease syndrome in the American oyster Crassostrea
virginica. Journal of Protozoology 15, 585599.
Farley, C.A. (1975) Epizootic and enzootic aspects of Minchinia nelsoni (Haplosporida) disease in Maryland
oysters. Journal of Protozoology 22, 418427.
Farley, C.A., Wolf, P.H. and Elston, R.A. (1988) A long-term study of microcell disease in oysters with a
description of a new genus, Mikrocytos (g. n.) and two new species, Mikrocytos mackini (sp. n.) and
Mikrocytos roughleyi (sp. n.). Fishery Bulletin 86, 581593.
Feng, S.L. (1988) Host response to Proctoeces maculatus infection in the blue mussel, Mytilus edulis L. Journal
of Shellfish Research 7, 118 (abstract).
Field, R.H. and Appleton, P.L. (1995) A Hematodinium-like dinoflagellate infection of the Norway lobster
Nephrops norvegicus: observations on pathology and progression of infection. Diseases of Aquatic
Organisms 22, 115128.
Field, R.H. and Appleton, P.L. (1996) An indirect fluorescent antibody technique for the diagnosis of
Hematodinium sp. infection of the Norway lobster Nephrops norvegicus. Diseases of Aquatic Organisms
24, 119204.
Field, R.H., Hills, J.M., Atkinson, R.J.A., Magill, S. and Shanks, A.M. (1998) Distribution and seasonal prevalence of Hematodinium sp. infection of the Norway lobster (Nephrops norvegicus) around the west coast
of Scotland. ICES Journal of Marine Science 55, 846858.
Fisher, W.S. (1988) In vitro binding of parasites (Bonamia ostreae) and latex particles by hemocytes of susceptible and insusceptible oysters. Developmental and Comparative Immunology 12, 4353.
Fong, D., Chan, M.M.-Y., Rodriguez, R., Chen, C.-C., Liang, Y., Littlewood, D.T.J. and Ford, S.E. (1993) Small
subunit ribosomal RNA gene sequence of the parasitic protozoan Haplosporidium nelsoni provides a
molecular probe for the oyster MSX disease. Molecular and Biochemical Parasitology 62, 139142.
Ford, S.E. (1992) Avoiding the transmission of disease in commercial culture of molluscs, with special reference to Perkinsus marinus (Dermo) and Haplosporidium nelsoni (MSX). Journal of Shellfish Research 11,
539546.
Ford, S.E. (1996) Range extension by the oyster parasite Perkinsus marinus into the northeastern United States:
response to climate change? Journal of Shellfish Research 15, 4556.
Ford, S.E. (2002) Development of high disease resistance in a wild oyster population. Journal of Shellfish
Research 21, 387 (abstract).
Ford, S.E. and Figueras, A.J. (1988) Effects of sublethal infection by the parasite Haplosporidium nelsoni (MSX)
on gametogenesis, spawning, and sex ratios of oysters in Delaware Bay, USA. Diseases of Aquatic
Organisms 4, 121133.
Ford, S.E. and Haskin, H.H. (1982) History and epizootiology of Haplosporidium nelsoni (MSX), an oyster
pathogen in Delaware Bay, 19571980. Journal of Invertebrate Pathology 40, 118141.
Ford, S.E. and Haskin, H.H. (1988) Management strategies for MSX (Haplosporidium nelsoni) disease in
eastern oysters. American Fisheries Society Special Publication 18, 249256.
Ford, S.E. and Kanaley, S.A. (1988) An evaluation of hemolymph diagnosis for detection of the oyster parasite
Haplosporidium nelsoni (MSX). Journal of Shellfish Research 7, 1118.
Ford, S.E. and Tripp, M.R. (1996) Disease and defense mechanisms. In: Kennedy, V.S., Newell, R.I.E. and
Eble, A.F. (eds) The Eastern Oyster Crassostrea virginica. Maryland Sea Grant, College Park, Maryland,
pp. 581660.
Ford, S.E., Figueras, A.J. and Haskin, H.H. (1990a) Influence of selective breeding, geographic origin, and
disease on gametogenesis and sex ratios of oysters, Crassostrea virginica, exposed to the parasite
Haplosporidium nelsoni (MSX). Aquaculture 88, 285301.
Ford, S.E., Kanaley, S.A., Ferris, M. and Ashton-Alcox, K.A. (1990b) Panning, a technique for enrichment of
the oyster parasite Haplosporidium nelsoni (MSX). Journal of Invertebrate Pathology 56, 347352.
Ford, S.E., Kanaley, S.A. and Littlewood, D.T.J. (1993) Cellular responses of oysters infected with
Haplosporidium nelsoni: changes in circulating and tissue-infiltrating hemocytes. Journal of Invertebrate
Pathology 61, 4957.
Ford, S., Powell, E., Klinck, J. and Hofmann, E. (1999) Modeling the MSX parasite in eastern oyster
(Crassostrea virginica) populations. I. Model development, implementation, and verification. Journal of
Shellfish Research 18, 475500.
670
S.M. Bower
Friedman, C.S. (1996) Haplosporidian infection of the Pacific oyster, Crassostrea gigas (Thunberg), in
California and Japan. Journal of Shellfish Research 15, 597600.
Friedman, C.S. and Perkins, F.O. (1994) Range extension of Bonamia ostreae to Maine, U.S.A. Journal of
Invertebrate Pathology 64, 179181.
Friedman, C.S., Gardner, G.R., Hedrick, R.P., Stephenson, M., Cawthorn, R.J. and Upton, S.J. (1995)
Pseudoklossia haliotis sp. n. (Apicomplexa) from the kidney of California abalone, Haliotis spp.
(Mollusca). Journal of Invertebrate Pathology 66, 3338.
Gaffney, P.M. and Bushek, D. (1996) Genetic aspects of disease resistance in oysters. Journal of Shellfish
Research 15, 135140.
Gauthier, J.D. and Fisher, W.S. (1990) Hemolymph assay for diagnosis of Perkinsus marinus in oysters
Crassostrea virginica (Gmelin, 1791). Journal of Shellfish Research 9, 367371.
Gee, J.M. and Davey, J.T. (1986) Stages in the life cycle of Mytilicola intestinalis Steuer, a copepod parasite of
Mytilus edulis (L.), and the effect of temperature on their rates of development. Journal du Conseil
International pour lExploration de la Mer 42, 254264.
Goggin, C.L. (1994) Variation in the two internal transcribed spacers and 5.8S ribosomal RNA from five
isolates of the marine parasite Perkinsus (Protista, Apicomplexa). Molecular and Biochemical Parasitology 65, 179182.
Goggin, C.L. and Lester, R.J.G. (1995) Perkinsus, a protistan parasite of abalone in Australia: a review. Marine
Fisheries Research 46, 639646.
Goggin, C.L., Sewell, K.B. and Lester, R.J.G. (1989) Cross-infection experiments with Australian Perkinsus
species. Diseases of Aquatic Organisms 7, 5559.
Goggin, C.L., Sewell, K.B. and Lester, R.J. (1990) Tolerances of Perkinsus spp. (Protozoa, Apicomplexa) to
temperature, chlorine and salinity. Journal of Shellfish Research 9, 145148.
Goggin, C.L., McGladdery, S.E., Whyte, S.K. and Cawthorn, R.J. (1996) An assessment of lesions in bay scallops Argopecten irradians attributed to Perkinsus karlssoni (Protozoa, Apicomplexa). Diseases of Aquatic
Organisms 24, 7780.
Grizel, H. (1979) Marteilia refringens and oyster disease recent observations. Marine Fisheries Review 41,
3839.
Grizel, H. (1986) Epidemiology of bivalve molluscs: analysis of present data and perspectives of development.
European Aquaculture Society, Special Publications 9, 122 (in French, with English abstract).
Grizel, H., Comps, M., Bonami, J.R., Cousserans, F., Duthoit, J.L. and LePennec, M.A. (1974) Research on
the agent of digestive gland disease of Ostrea edulis Linne. Science et Pche, Bulletin dInformation
et de Documentation de lInstitut Scientifique et Technique des Pches Maritimes 240, 730 (in
French).
Grizel, H., Comps, M., Raguenes, D., Leborgne, Y., Tig, G. and Martin, A. G. (1983) Results of acclimatization trials of Ostrea chilensis on the coast of Brittany. Revue des Travaux de lInstitut des Pches
Maritimes 46, 209225 (in French, with English abstract).
Grizel, H., Bachere, E., Mialhe, E. and Tig, G. (1986) Solving parasite-related problems in cultured
molluscs. In: Howell, M.J. (ed.) Parasitology Quo Vadit? Proceedings of the Sixth International
Congress of Parasitology. Australian Academy of Science, Canberra, Australia, pp. 301308.
Grizel, H., Mialhe, E., Chagot, D., Boulo, V. and Bachre, E. (1988) Bonamiasis: a model study of diseases in
marine molluscs. American Fisheries Society Special Publication 18, 14.
Gruebl, T., Frischer, M.E., Sheppard, M., Neumann, M., Maurer, A.N. and Lee, R.F. (2002) Development
of an 18SrRNA gene-targeted PCR-based diagnostic for the blue crab parasite Hematodinium sp. Diseases of Aquatic Organisms 49, 6170.
Gutirrez, M. (1977) Technique for staining the agent of digestive gland disease of flat oysters, Ostrea edulis L.
Investigacion Pesquera (Barcelona) 41, 643645 (in Spanish, with English summary).
Hamaguchi, M., Suzuki, N., Usuki, H. and Ishioka, H. (1998) Perkinsus protozoan infection in short-necked
clam Tapes (= Ruditapes) philippinarum in Japan. Fish Pathology (Tokyo) 33, 473480.
Handley, S.J. (1997) Optimizing subtidal oyster production, Marlborough Sounds, New Zealand: spionid
polychaete infestations, water depth and spat stunting. Journal of Shellfish Research 16, 143150.
Haskin, H.H. and Ford, S.E. (1982) Haplosporidium nelsoni (MSX) on Delaware Bay seed oyster beds: a
hostparasite relationship along a salinity gradient. Journal of Invertebrate Pathology 40, 388405.
Haskin, H.H., Stauber, L.A. and Mackin, J.A. (1966) Minchinia nelsoni n. sp. (Haplosporida,
Haplosporidiidae): causative agent of the Delaware Bay oyster epizotic. Science 153, 14141416.
Hervio, D., Bachre, E., Boulo, V., Cochennec, N., Vuillemin, V., Le Coguic, Y., Cailletaux, G., Mazuri J.
and Mialhe, E. (1995) Establishment of an experimental infection protocol for the flat oyster, Ostrea
671
edulis, with the intrahaemocytic protozoan parasite, Bonamia ostreae: application in the selection of
parasite-resistant oysters. Aquaculture 132, 183194.
Hervio, D., Bower, S.M. and Meyer, G.R. (1996) Detection, isolation and experimental transmission of
Mikrocytos mackini, a microcell parasite of Pacific oysters Crassostrea gigas (Thunberg). Journal of
Invertebrate Pathology 67, 7279.
Hine, P.M. (1991a) The annual pattern of infection by Bonamia sp. in New Zealand flat oysters, Tiostrea
chilensis. Aquaculture 93, 241251.
Hine, P.M. (1991b) Ultrastructural observations on the annual infection pattern of Bonamia sp. in flat oysters
Tiostrea chilensis. Diseases of Aquatic Organisms 11, 163171.
Hine, P.M. and Thorne, T. (2000) A survey of some parasites and diseases of several species of bivalve
mollusc in northern Western Australia. Diseases of Aquatic Organisms 40, 6778.
Hine, P.M. and Wesney, B. (1992) Interrelationships of cytoplasmic structures in Bonamia sp. (Haplosporidia)
infecting oysters Tiostrea chilensis: an interpretation. Diseases of Aquatic Organisms 14, 5968.
Hine, P.M., Bower, S.M., Meyer, G.R., Cochennec-Laureau, N. and Berthe, F.C.J. (2001a) Ultrastructure of
Mikrocytos mackini, the cause of Denman Island disease in oysters Crassostrea spp. and Ostrea spp. in
British Columbia, Canada. Diseases of Aquatic Organisms 45, 215227.
Hine, P.M., Cochennec-Laureau, N. and Berthe, F.C.J. (2001b) Bonamia exitiosus n. sp. (Haplosporidia)
infecting flat oysters Ostrea chilensis in New Zealand. Diseases of Aquatic Organisms 47, 6372.
Hoese, H.D. (1964) Studies on oyster scavengers and their relation to the fungus Dermocystidium marinum.
Proceedings of the National Shellfisheries Association 53, 161174.
Hofmann, E.E., Powell, E.N., Klinck, J.M. and Saunders, G. (1995) Modelling diseased oyster populations: I.
Modelling Perkinsus marinus infection in oysters. Journal of Shellfish Research 14, 121151.
Howell, M. (1967) The trematode, Bucephalus longicornutus (Manter, 1954) in the New Zealand mud-oyster,
Ostrea lutaria. Transactions of the Royal Society of New Zealand, Zoology 8, 221237.
Hudson, D.A. and Adlard, R.D. (1996) Nucleotide sequence determination of the partial SSU rDNA gene and
ITS1 region of Hematodinium cf. perezi and Hematodinium-like dinoflagellates. Diseases of Aquatic
Organisms 24, 5560.
Hudson, D.A. and Shields, J.D. (1994) Hematodinium australis n. sp., a parasitic dinoflagellate of the sand
crab Portunus pelagicus from Moreton Bay, Australia. Diseases of Aquatic Organisms 19, 109119.
Hudson, E.B. and Hill, B.J. (1991) Impact and spread of bonamiasis in the UK. Aquaculture 93, 279285.
Imanaka, S., Itoh, N., Ogawa, K. and Wakabayashi, H. (2001) Seasonal fluctuations in the occurrence of
abnormal enlargement of the ovary of Pacific oyster Crassostrea gigas at Gokasho Bay, Mie, Japan. Fish
Pathology (Tokyo) 36, 8391.
Itoh, N., Oda, T., Ogawa, K. and Wakabayashi, H. (2002) Identification and development of a paramyxean
ovarian parasite in the Pacific oyster Crassostrea gigas. Fish Pathology (Tokyo) 37, 2328.
Itoh, N., Oda, T., Yoshinaga, T. and Ogawa, K. (2003) DNA probes for detection of Marteilioides chungmuensis
from the ovary of Pacific oyster Crassostrea gigas. Fish Pathology (Tokyo) 38, 163169.
Jellett, J.F. and Scheibling, R.E. (1988) Virulence of Paramoeba invadens Jones (Amoebida, Paramoebidae)
from monoxenic and polyxenic culture. Journal of Protozoology 35, 422424.
Jellett, J.F., Wardlaw, A.C. and Scheibling, R.E. (1988) Experimental infection of the echinoid
Strongylocentrotus droebachiensis with Paramoeba invadens: quantitative changes in the coelomic
fluid. Diseases of Aquatic Organisms 4, 149157.
Johnson, P.T. (1977) Paramoebiasis in the blue crab, Callinectes sapidus. Journal of Invertebrate Pathology 29,
308320.
Johnson, P.T. (1988) Paramoebiasis of blue crabs. In: Sindermann, C.J. and Lightner, D.V. (eds) Disease Diagnosis and Control in North American Marine Aquaculture. Elsevier, Amsterdam, pp. 204207.
Jones, G.M. (1985) Paramoeba invadens n. sp. (Amoebida, Paramoebidae), a pathogenic amoeba from the sea
urchin, Strongylocentrotus droebachiensis, in eastern Canada. Journal of Protozoology 32, 564569.
Jones, G.M., Hebda, A.J., Scheibling, R.E. and Miller, R.J. (1985) Histopathology of the disease causing mass
mortalities of sea urchins (Strongylocentrotus droebachiensis) in Nova Scotia. Journal of Invertebrate
Pathology 45, 260271.
Jonsson, P.R. and Andr, C. (1992) Mass mortality of the bivalve Cerastoderma edule on the Swedish west coast
caused by infestation with the digenean trematode Cercaria cerastodermae I. Ophelia 36, 151157.
Kamaishi, T. and Yoshinaga, T. (2002) Detection of Haplosporidium nelsoni in Pacific oyster Crassostrea gigas
in Japan. Fish Pathology (Tokyo) 37, 193195.
Kent, R.M.L. (1981) The effect of Polydora ciliata on the shell strength of Mytilus edulis. Journal du Conseil
International pour lExploration de la Mer 39, 252255.
672
S.M. Bower
Kern, F.G., Sullivan, L.C. and Takata, M. (1973) Labyrinthomyxa-like organisms associated with mass
mortalities of oysters Crassostrea virginica, from Hawaii. Proceedings of the National Shellfisheries
Association 63, 4346.
Kleeman, S.N. and Adlard, R.D. (2000) Molecular detection of Marteilia sydneyi, pathogen of Sydney rock
oysters. Diseases of Aquatic Organisms 40, 137146.
Kleeman, S.N., Adlard, R.D. and Lester, R.J.G. (2002a) Detection of the initial infective stages of the protozoan parasite Marteilia sydneyi in Saccostrea glomerata and their development through to sporogenesis.
International Journal for Parasitology 32, 767784.
Kleeman, S.N., Le Roux, F., Berthe, F. and Adlard, R.D. (2002b) Specificity of PCR and in situ hybridization
assays designed for detection of Marteilia sydneyi and M. refringens. Parasitology 125, 131141.
Ko, Y.-T., Ford, S.E. and Fong, D. (1995) Characterization of the small subunit ribosomal RNA gene of the
oyster parasite Haplosporidium costale. Molecular Marine Biology and Biotechnology 4, 236240.
Lama, A. and Montes, J. (1993) Influence of depth of culture in the infection of the European flat oyster
(Ostrea edulis L.) by Bonamia ostreae. Bulletin of the European Association of Fish Pathologists 13,
1720.
La Peyre, J.F. (1996) Propagation and in vitro studies of Perkinsus marinus. Journal of Shellfish Research 15,
89101.
Lauckner, G. (1983) Diseases of Mollusca: Bivalvia. In: Kinne, O. (ed.) Diseases of Marine Animals. Vol. II:
Introduction, Bivalvia to Scaphopoda. Biologische Anstalt Helgoland, Hamburg, Germany, pp. 477961.
Lauckner, G. (1984) Impact of trematode parasitism on the fauna of a North Sea tidal flat. Helgolnder
Meeresuntersuchungen 37, 185199.
Launey, S., Barre, M., Gerard, A. and Naciri-Graven, Y. (2001) Population bottleneck and effective size in
Bonamia ostreae-resistant populations of Ostrea edulis as inferred by microsatellite markers. Genetic
Research 78, 259270.
Lee, J.J., Leedale, G.F. and Bradbury, P. (eds) (2000) An Illustrated Guide to the Protozoa, 2nd edn, vols 1 and
2. Society of Protozoologists, Allen Press, Lawrence, Kansas, 1431 pp.
Leipe, D.D., Tong, S.M., Goggin, C.L., Slemenda, S.B., Pieniazek, N.J. and Sogin, M.L. (1996) 16S-like rDNA
sequences from Developayella elegans, Labyrinthuloides haliotidis, and Proteromonas lacertae confirm
that the stramenopiles are a primarily heterotrophic group. European Journal of Protistology 32,
449458.
Le Roux, F., Audemard, C., Barnaud, A. and Berthe, F. (1999) DNA Probes as potential tools for the detection
of Marteilia refringens. Marine Biotechnology 1, 588597.
Lester, R.J.G. (1986) Field and laboratory observations on the oyster parasite Marteilia sydneyi. In: Cremin, M.,
Dobson, C. and Moorhouse, D.E. (eds) Parasite Lives. University of Queensland Press, St Lucia,
Queensland, pp. 3340.
Lester, R.J.G. and Davis, G.H.G. (1981) A new Perkinsus species (Apicomplexa, Perkinsea) from the abalone
Haliotis ruber. Journal of Invertebrate Pathology 37, 181187.
Lester, R.J.G., Goggin, C.L. and Sewell, K.B. (1990) Perkinsus in Australia. In: Perkins, F.O. and Cheng, T.C.
(eds) Pathology in Marine Science. Academic Press, San Diego, California, pp. 189199.
Levine, N.D. (1978) Perkinsus gen. n. and other new taxa in the protozoan phylum Apicomplexa. Journal of
Parasitology 64, 549.
Levine, N.D., Corliss, J.O., Cox, F.E.G., Deroux, G., Grain, J., Honigberg, B.M., Leedale, G.F., Loeblich, A.R.,
Lom, J., Lynn, D., Merinfeld, E.G., Page, F.C., Poljansky, G., Sprague, V., Vavra, J. and Wallace, F.G.
(1980) A newly revised classification of the Protozoa. Journal of Protozoology 27, 3758.
Lightner, D.V. (1975) Some potentially serious disease problems in the culture of penaeid shrimp in North
America. In: Proceedings of the Third U.S.Japan Meeting on Aquaculture, 1516 October 1974, Tokyo,
Japan, Japan Sea Regional Fisheries Research Laboratory, Niigata, Japan, pp. 7597.
Lightner, D.V. (1988) Cotton shrimp disease of penaeid shrimp. In: Sindermann, C.J. and Lightner, D.V.
(eds) Disease Diagnosis and Control in North American Marine Aquaculture. Elsevier, Amsterdam,
pp. 7075.
Lightner, D.V. (1996) A Handbook of Shrimp Pathology and Diagnostic Procedures for Disease of Cultured
Penaeid Shrimp. World Aquaculture Society, Baton Rouge, Louisiana.
Love, D.C., Rice, S.D., Moles, D.A. and Eaton, W.D. (1993) Seasonal prevalence and intensity of bitter crab
dinoflagellate infection and host mortality in Alaskan Tanner crabs Chionoecetes bairdi from Auke Bay,
Alaska, USA. Diseases of Aquatic Organisms 15, 17.
McGladdery, S.E., Cawthorn, R.J. and Bradford, B.C. (1991) Perkinsus karlssoni n. sp. (Apicomplexa) in bay
scallops Argopecten irradians. Diseases of Aquatic Organisms 10, 127137.
673
Machkevski, V.K. (1985) Some aspects of the biology of the trematode, Proctoeces maculatus, in connection with the development of mussel farms on the Black Sea. In: Hargis, J.W.J. (ed.) Parasitology and
Pathology of Marine Organisms of the World Ocean. NOAA technical report NMFS 25, United States
Department of Commerce, Seattle, Washington, pp. 109110.
Machkevski, V.K. (1988) Effect of Proctoeces maculatus parthenitae on the growth of Mytilus galloprovincialis.
Parazitologiya 22, 341344 (in Russian, with English summary).
Machkevski, V.K. and Shchepkina, A.M. (1985) Infection of the Black Sea mussels with larval Proctoeces
maculatus and its effects on the glycogen content in the tissues of the host. Ehkologiya Morya 20, 6973
(in Russian, with English summary).
McLaughlin, S.M. and Faisal, M. (2001) Pathogenesis of Perkinsus spp. in bivalve molluscs. Bulletin of the
National Research Institute of Aquaculture Supplement 5, 111117.
McLaughlin, S.M., Tall, B.D., Shaheen, A., Elsayed, E.E. and Faisal, M. (2000) Zoosporulation of a new
Perkinsus species isolated from the gills of the softshell clam Mya arenaria. Parasite 7, 115122.
Mann, R., Burreson, E.M. and Baker, P.K. (1991) The decline of the Virginia oyster fishery in Chesapeake Bay:
considerations for introduction of a non-endemic species, Crassostrea gigas (Thunberg, 1793). Journal of
Shellfish Research 10, 379388.
Matthews, R.A. (1974) The life-cycle of Bucephaloides gracilescens (Rudolphi, 1819) Hopkins, 1954
(Digenea: Gasterostomata). Parasitology 68, 112.
Matthiessen, G.C. and Davis, J.P. (1992) Observations on growth rate and resistance to MSX
(Haplosporidium nelsoni) among diploid and triploid eastern oysters (Crassostrea virginica (Gmelin,
1791)) in New England. Journal of Shellfish Research 11, 449454.
Messick, G.A. and Shields, J.D. (2000) Epizootiology of the parasitic dinoflagellate Hematodinium sp. in the
American blue crab Callinectes sapidus. Diseases of Aquatic Organisms 43, 139152.
Meyers, J.A., Burreson, E.M., Barber, B.J. and Mann, R. (1991) Susceptibility of diploid and triploid Pacific
oysters, Crassostrea gigas (Thunberg, 1793) and eastern oysters, Crassostrea virginica (Gmelin, 1791), to
Perkinsus marinus. Journal of Shellfish Research 10, 433437.
Meyers, T.R., Koeneman, T.M., Botelho, C. and Short, S. (1987) Bitter crab disease: a fatal dinoflagellate
infection and marketing problem for Alaskan Tanner crabs Chionoecetes bairdi. Diseases of Aquatic
Organisms 3, 195216.
Meyers, T.R., Botelho, C., Koeneman, T.M., Short, S. and Imamura, K. (1990) Distribution of bitter crab
dinoflagellate syndrome in southeast Alaskan Tanner crabs Chionoecetes bairdi. Diseases of Aquatic
Organisms 9, 3743.
Meyers, T.R., Lightner, D.V. and Redman, R.M. (1994) A dinoflagellate-like parasite in Alaskan spot shrimp
Pandalus platyceros and pink shrimp P. borealis. Diseases of Aquatic Organisms 18, 7176.
Meyers, T.R., Morado, J.F., Sparks, A.K., Bishop, G.H., Pearson, T., Urban, D. and Jackson, D. (1996) Distribution of bitter crab syndrome in Tanner crabs (Chionoecetes bairdi, C. opilio) from the Gulf of Alaska
and the Bering Sea. Diseases of Aquatic Organisms 26, 221227.
Mialhe, E., Bachre, E., Chagot, D. and Grizel, H. (1988a) Isolation and purification of the protozoan
Bonamia ostreae (Pichot et al. 1980), a parasite affecting the flat oyster Ostrea edulis L. Aquaculture 71,
293299.
Mialhe, E., Boulo, V., Elston, R., Hill, B., Hine, M., Montes, J., van Banning, P. and Grizel, H. (1988b)
Serological analysis of Bonamia in Ostrea edulis and Tiostrea lutaria using polyclonal and monoclonal
antibodies. Aquatic Living Resources 1, 6769.
Millar, R.H. (1963) Oysters killed by trematode parasites. Nature 197, 616.
Miller, R.J. (1985) Succession in sea urchin and seaweed abundance in Nova Scotia, Canada. Marine Biology
84, 275286.
Montes, J., Anadn, R. and Azevedo, C. (1994) A possible life cycle for Bonamia ostreae on the basis of
electron microscopy studies. Journal of Invertebrate Pathology 63, 16.
Montes, J., Ferro-Soto, B., Conchas, R.F. and Guerra, A. (2003) Determining culture strategies in populations
of the European flat oyster, Ostrea edulis, affected by bonamiosis. Aquaculture 220, 175182.
Morado, J.F. and Small, E.B. (1995) Ciliate parasites and related diseases of Crustacea: a review. Review in
Fisheries Science 3, 275354.
Morado, J.F., Sparks, A.K. and Reed, S.K. (1984) A coccidian infection of the kidney of the native littleneck
clam Protothaca staminea. Journal of Invertebrate Pathology 43, 207217.
Mourton, C., Boulo, V., Chagot, D., Hervio, D., Bachere, E., Mialhe, E. and Grizel, H. (1992) Interactions
between Bonamia ostreae (Protozoa: Ascetospora) and hemocytes of Ostrea edulis and Crassostrea gigas
(Mollusca: Bivalvia): in vitro system establishment. Journal of Invertebrate Pathology 59, 235240.
674
S.M. Bower
Moyer, M.A., Blake, N.J. and Arnold, W.S. (1993) An acetosporan disease causing mass mortality in the
Atlantic calico scallop, Argopecten gibbus (Linnaeus, 1758). Journal of Shellfish Research 12,
305310.
Mulvey, M. and Feng, S.Y. (1981) Hemolymph constituents of normal and Proctoeces maculatus infected
Mytilus edulis. Comparative Biochemistry and Physiology 70A, 119125.
Munford, J.G., DaRos, L. and Strada, R. (1981) A study on the mass mortality of mussels in the Laguna Veneta.
Journal of the World Mariculture Society 12, 186199.
Murrell, A., Kleeman, S.N., Barker, S.C. and Lester, R.J.G. (2002) Synonymy of Perkinsus olseni Lester &
Davis, 1981 and Perkinsus atlanticus Azevedo, 1989 and an update on the phylogenetic position of the
genus Perkinsus. Bulletin of the European Association of Fish Pathologists 22, 258265.
Nagasawa, K. and Nagata, M. (1992) Effects of Pectenophilus ornatus (Copepoda) on the biomass of cultured
Japanese scallop Patinopecten yessoensis. Journal of Parasitology 78, 552554.
Nagasawa, K., Takahashi, K., Tanaka, S. and Nagata, M. (1991) Ecology of Pectenophilus ornatus, a
copepod parasite of the Japanese scallop Patinopecten yessoensis. Bulletin of the Plankton Society of
Japan, Special Volume Proceedings of the Fourth International Conference on Copepoda 1991,
495502.
Ngo, T.T.T., Berthe, F.C.J. and Choi, K.-S. (2003) Prevalence and infection intensity of the ovarian parasite
Marteilioides chungmuensis during an annual reproductive cycle of the oyster Crassostrea gigas.
Diseases of Aquatic Organisms 56, 259267.
Norn, F., Moestrup, O. and Rehnstam-Holm, A.-S. (1999) Parvilucifera infectans Norn et Moestrup gen. et
sp. nov. (Perkinsozoa phylum nov.): a parasitic flagellate capable of killing toxic microalgae. European
Journal of Protistology 35, 233245.
Norton, J.H., Shepherd, M.A., Perkins, F.P. and Prior, H.C. (1993) Perkinsus-like infection in farmed
golden-lipped pearl oyster Pinctada maxima from the Torres Strait, Australia. Journal of Invertebrate
Pathology 62, 105106.
OIE (2003a) Bonamiosis (Bonamia exitiosus, B. ostreae and Mikrocytos roughleyi). In: Manual of Diagnostic
Tests of Aquatic Animals. Office International des Epizooties, Paris, pp. 230234.
OIE (2003b) Marteiliosis (Marteilia refringens and M. sydneyi). In: Manual of Diagnostic Tests for Aquatic
Animals. Office International des pizooties, Paris, pp. 240245.
Olson, R.E., Tiekotter, K.L. and Reno, P.W. (1994) Nadelspora canceri n. g., n. sp., an unusual
microsporidian parasite of the Dungeness crab, Cancer magister. Journal of Eukaryotic Microbiology
41, 349359.
Ords, M.C., Gomez-Leon, J. and Figueras, A. (2001) Histopathology of the infection by Perkinsus atlanticus
in three clam species (Ruditapes decussatus, R. philippinarum and R. pullastra) from Galicia (NW Spain).
Journal of Shellfish Research 20, 10191024.
Overstreet, R.M. (1975) Buquinolate as a preventive drug to control microsporidosis in the blue crab. Journal
of Invertebrate Pathology 26, 213216.
Overstreet, R.M. (1988) Microsporosis of blue crabs. In: Sindermann, C.J. and Lightner, D.V. (eds) Disease
Diagnosis and Control in North American Marine Aquaculture. Elsevier, Amsterdam, pp. 200203.
Paraso, M.C., Ford, S.E., Powell, E.N., Hofmann, E.E. and Klinck, J.M. (1999) Modeling the MSX parasite in
eastern oyster (Crassostrea virginica) populations. II. Salinity effects. Journal of Shellfish Research 18,
501516.
Pasharawipas, T., Flegel, T.W., Chaiyaroj, S., Mongkolsuk, S. and Sirisinha, S. (1994) Comparison of amplified RNA gene sequences from microsporidian parasites (Agmasoma or Thelohania) in Penaeus
merguiensis and P. monodon. Asian Fisheries Science 7, 169178.
Patterson, D.J. (2000) Changing views of protistan systematics: the taxonomy of protozoa an overview. In:
Lee, J.J., Leedale, G.F. and Bradbury, P. (eds) An Illustrated Guide to the Protozoa. Society of
Protozoologists, Allen Press, Lawrence, Kansas, pp. 29.
Pauley, G.B., Newman, M.W. and Gould, E. (1975) Serum changes in the blue crab, Callinectes sapidus,
associated with Paramoeba perniciosa, the causative agent of grey crab disease. Marine Fisheries
Review 37, 3438.
Payne, W.L., Gerding, T.A., Dent, R.G., Bier, J.W. and Jackson, G.J. (1980) Survey of the U.S. Atlantic coast
surf clam, Spisula solidissima, and clam products for anisakine nematodes and hyperparasitic protozoa.
Journal of Parasitology 66, 150153.
Paynter, K.T. and Burreson, E.M. (1991) Effects of Perkinsus marinus infection in the eastern oyster,
Crassostrea virginica: II. Disease development and impact on growth rate at different salinities. Journal of
Shellfish Research 10, 425431.
675
Penna, M.-S., Khan, M. and French, R.A. (2001) Development of a multiplex PCR for the detection of
Haplosporidium nelsoni, Haplosporidium costale and Perkinsus marinus in the eastern oyster
(Crassostrea virginica, Gmelin, 1971). Molecular and Cellular Probes 15, 385390.
Perkins, F.O. (1976) Ultrastructure of sporulation in the European flat oyster pathogen, Marteilia
refringens taxonomic implications. Journal of Protozoology 23, 6474.
Perkins, F.O. (1990) Phylum Haplosporidia. In: Margulis, L., Corliss, J.O., Melkonian, M. and Chapman, D.J.
(eds) Handbook of Protoctista. Jones and Bartlett Publishers, Boston, Massachusetts, pp. 1929.
Perkins, F.O. (1993) Infectious diseases of molluscs. In: Couch, J.A. and Fournie, J.W. (eds) Advances in
Fisheries Science: Pathobiology of Marine and Estuarine Organisms. CRC Press, Boca Raton, Florida,
pp. 255287.
Perkins, F.O. (1996) The structure of Perkinsus marinus (Mackin, Owen and Collier, 1950) Levine, 1978 with
comments on taxonomy and phylogeny of Perkinsus spp. Journal of Shellfish Research 15, 6787.
Perkins, F.O. (2000a) Class Perkinsasida Levine, 1978. In: Lee, J.J., Leedale, G.F. and Bradbury, P. (eds) An
Illustrated Guide to the Protozoa. Society of Protozoologists, Allen Press, Lawrence, Kansas,
pp. 200202.
Perkins, F.O. (2000b) Phylum Haplosporidia Caullery & Mesnil, 1899. In: Lee, J.J., Leedale, G.F. and
Bradbury, P. (eds) An Illustrated Guide to the Protozoa. Society of Protozoologists, Allen Press,
Lawrence, Kansas, pp. 13281341.
Perkins, F.O. and Castagna, M. (1971) Ultrastructure of the Nebenkrper or secondary nucleus of the parasitic amoeba Paramoeba perniciosa (Amoebida, Paramoebidae). Journal of Invertebrate Pathology 17,
186193.
Perkins, F.O. and Wolf, P.H. (1976) Fine structure of Marteilia sydneyi sp. n. haplosporidan pathogen of
Australian oysters. Journal of Parasitology 62, 528538.
Pernas, M., Novoa, B., Berthe, F., Tafalla, C. and Figueras, A. (2001) Molecular methods for the diagnosis of
Marteilia refringens. Bulletin of the European Association of Fish Pathologists 21, 200208.
Pestal, G.P., Taylor, D.M., Hoenig, J.M., Shields, J.D. and Pickavance, R. (2003) Monitoring the prevalence of
the parasitic dinoflagellate Hematodinium sp. in snow crabs Chionoecetes opilio from Conception Bay,
Newfoundland. Diseases of Aquatic Organisms 53, 6775.
Pichot, Y., Comps, M., Tig, G., Grizel, H. and Rabouin, M.A. (1980) Research on Bonamia ostreae gen. n.,
sp. n., a new parasite of the flat oyster Ostrea edulis L. Revue des Travaux de lInstitut des Pches
Maritimes 43, 131140 (in French).
Pixell Goodrich, H. (1956) Crayfish epidemics. Parasitology 46, 480483.
Powell, E.N., Klinck, J.M. and Hofmann, E.E. (1996) Modeling diseased oyster populations. II Triggering
mechanisms for Perkinsus marinus epizootics. Journal of Shellfish Research 15, 141165.
Powell, E.N., Klinck, J.M., Ford, S.E., Hofmann, E.E. and Jordan, S.J. (1999) Modeling the MSX parasite in eastern oyster (Crassostrea virginica) populations. III. Regional application and the problem of transmission.
Journal of Shellfish Research 18, 517537.
Pregenzer, C. (1983) Survey of metazoan symbionts of Mytilus edulis (Mollusca: Pelecypoda) in Southern
Australia. Australian Journal of Marine and Freshwater Research 34, 387396.
Ragone, L.M. and Burreson, E.M. (1993) Effect of salinity on infection progression and pathogenicity of Perkinsus
marinus in the eastern oyster, Crassostrea virginica (Gmelin). Journal of Shellfish Research 12, 17.
Ragone Calvo, L.M., Wetzel, R.L. and Burreson, E.M. (2001) Development and verification of a model for the
population dynamics of the protistan parasite, Perkinsus marinus, within its host, the eastern oyster,
Crassostrea virginica, in Chesapeake Bay. Journal of Shellfish Research 20, 231241.
Ray, S.M. (1966a) A review of the culture method for detecting Dermocystidium marinum, with suggested
modifications and precautions. Proceedings of the National Shellfisheries Association 54, 5569.
Ray, S.M. (1966b) Cyclohexamide: inhibition of Dermocystidium marinum in laboratory stocks of oysters.
Proceedings of the National Shellfisheries Association 56, 3136.
Reece, K.S., Bushek, D. and Graves, J.E. (1997a) Molecular markers for population genetic analysis of Perkinsus
marinus. Molecular Marine Biology and Biotechnology 6, 197206.
Reece, K.S., Siddall, M.E., Burreson, E.M. and Graves, J.E. (1997b) Phylogenetic analysis of Perkinsus based
on actin gene sequences. Journal of Parasitology 83, 417423.
Reece, K.S., Siddall, M.E., Stokes, N.A. and Burreson, E.M. (2003) Molecular phylogeny of the Haplosporidia
based on two independent gene sequences. Journal of Parasitology 90, 11111122.
Renault, T., Stokes, N.A., Chollet, B., Cochennec, N., Berthe, F., Gerard, A. and Burreson, E.M. (2000)
Haplosporidiosis in the Pacific oyster Crassostrea gigas from the French Atlantic coast. Diseases of
Aquatic Organisms 42, 207214.
676
S.M. Bower
Robledo, J.A.F., Coss, C.A. and Vasta, G.R. (2000) Characterization of the ribosomal RNA locus of
Perkinsus atlanticus and development of a polymerase chain reaction-based diagnostic assay. Journal
of Parasitology 86, 972978.
Rodrguez, F., Godoy, T. and Navas, J.I. (1994) Cross-infection with Perkinsus atlanticus in Ruditapes
decussatus, Ruditapes philippinarum and Venerupis pullastra. Bulletin of the European Association of
Fish Pathologists 14, 2427.
Rogier, H., Hervio, D., Boulo, V., Clavies, C., Hervaud, E., Bachre, E., Mialhe, E., Grizel, H., Pau, B. and
Paolucci, F. (1991) Monoclonal antibodies against Bonamia ostreae (Protozoa: Ascetospora), an
intrahaemocytic parasite of flat oyster Ostrea edulis (Mollusca: Bivalvia). Diseases of Aquatic Organisms
11, 135142.
Rosenfield, A., Buchanan, L. and Chapman, G.B. (1969) Comparison of the fine structure of spores of three
species of Minchinia (Haplosporida, Haplosporidiidae). Journal of Parasitology 55, 921941.
Roubal, F.R., Masel, J. and Lester, R.J.G. (1989) Studies on Marteilia sydneyi, agent of QX disease in the
Sydney rock oyster, Saccostrea commercialis, with implications for its life cycle. Australian Journal of
Marine and Freshwater Research 40, 155167.
Sanders, M.J. and Lester, R.J.G. (1981) Further observations on a bucephalid trematode infection in scallops
(Pecten alba) in Port Phillip Bay, Victoria. Australian Journal of Marine and Freshwater Research 32,
475478.
Scheibling, R.E. and Stephenson, R.L. (1984) Mass mortality of Strongylocentrotus droebachiensis
(Echinodermata: Echinoidea) off Nova Scotia, Canada. Marine Biology 78, 153164.
Sherburne, S.W. and Bean, L.L. (1991) Mortalities of impounded and feral Maine lobsters, Homarus
americanus H. Milne-Edwards, 1837, caused by the protozoan ciliate Mugardia (formerly Anophrys =
Paranophrys), with initial prevalence data from ten locations along the Maine coast and one offshore
area. Journal of Shellfish Research 10, 315326.
Shields, J.D. (1994) The parasitic dinoflagellates of marine crustaceans. Annual Review of Fish Diseases 4,
241271.
Shields, J.D., Scanlon, C. and Volety, A. (2003) Aspects of the pathophysiology of blue crabs, Callinectes
sapidus, infected with the parasitic dinoflagellate Hematodinium perezi. Bulletin of Marine Science
72, 519535.
Siddall, M.E., Stokes, N.A. and Burreson, E.M. (1995) Molecular phylogenetic evidence that the phylum
Haplosporidia has an alveolate ancestry. Molecular Biology and Evolution 12, 573581.
Siddall, M.E., Reece, K.S., Graves, J.E. and Burreson, E.M. (1997) Total evidence refutes the inclusion of
Perkinsus species in the phylum Apicomplexa. Parasitology 115, 165176.
Sindermann, C.J. (1990) Principal Diseases of Marine Fish and Shellfish. Vol. 2, Diseases of Marine Shellfish,
2nd edn. Academic Press, San Diego, California, 516 pp.
Sindermann, C.J. (1993) Disease risks associated with importation of nonindigenous marine animals. Marine
Fisheries Review 54, 110.
Sindermann, C.J. and Lightner, D.V. (eds) (1988) Disease Diagnosis and Control in North American Marine
Aquaculture. Elsevier, Amsterdam, 431 pp.
Singhas, L.S., West, T.L. and Ambrose. W.G. (1993) Occurrence of Echeneibothrium (Platyhelminthes,
Cestoda) in the calico scallop Argopecten gibbus from North Carolina. Fishery Bulletin 91, 179181.
Somers, I.F. and Kirkwood, G.P. (1991) Population ecology of the grooved tiger prawn, Penaeus semisulcatus,
in north-western Gulf of Carpentaria, Australia: growth, movement, age structure and infestation by the
bopyrid parasite Epipenaeon ingens. Australian Journal of Marine and Freshwater Research 42, 349367.
Sparks, A.K. (1985) Synopsis of Invertebrate Pathology Exclusive of Insects. Elsevier Science Publishers,
Amsterdam, 423 pp.
Sprague, V. (1979) Classification of the Haplosporidia. Marine Fisheries Review 41, 4044.
Sprague, V., Beckett, R.L. and Sawyer, T.K. (1969) A new species of Paramoeba (Amoebida, Paramoebidae)
parasitic in the crab Callinectes sapidus. Journal of Invertebrate Pathology 14, 167174.
Stephenson, M.F., McGladdery, S.E., Maillet, M. and Veniot, A. (2003) First reported occurrence of MSX in
Canada. Journal of Shellfish Research 22, 355 (abstract).
Stokes, N.A. and Burreson, E.M. (1995) A sensitive and specific DNA probe for the oyster pathogen
Haplosporidium nelsoni. Journal of Eukaryotic Microbiology 42, 350357.
Stokes, N.A. and Burreson, E.M. (2001) Differential diagnosis of mixed Haplosporidium costale and
Haplosporidium nelsoni infections in the eastern oyster, Crassostrea virginica, using DNA probes. Journal
of Shellfish Research 20, 207213.
677
Stokes, N.A., Siddall, M.E. and Burreson, E.M. (1995) Detection of Haplosporidium nelsoni (Haplosporidia:
Haplosporidiidae) in oysters by PCR amplification. Diseases of Aquatic Organisms 23, 145152.
Stokes, N.A., Flores Kraus, B.S., Burreson, E.M., Ashton-Alcox, K.A. and Ford, S.E. (1999) Searching for the
putative MSX intermediate host using molecular diagnostics. Journal of Shellfish Research 18, 334335
(abstract).
Svrdh, L. and Thulin, J. (1985) The parasite fauna of natural and farmed Mytilus edulis from the west coast of
Sweden, with special reference to Renicola roscovita. Meddelande Frn Havsfiskelaboratoriet Lysekil
312, 116.
Upton, S.J. (2000) Suborder Eimeriorina Lger, 1911. In: Lee, J.J., Leedale, G.F. and Bradbury, P. (eds) An Illustrated Guide to the Protozoa. Society of Protozoologists, Allen Press, Lawrence, Kansas, pp. 318369.
van Banning, P. (1979) Haplosporidian diseases of imported oysters, Ostrea edulis, in Dutch estuaries. Marine
Fisheries Review 41, 818.
van Banning, P. (1985a) Minchinia armoricana disease of the flat oyster. In: Sindermann, C.J. (ed.) Fiches
didentification des maladies et parasites des poissons, crustacs et mollusques. Vol. 17, Conseil
International pour lExploration de la Mer, Copenhagen, pp. 14.
van Banning, P. (1985b) Control of Bonamia in Dutch oyster culture. In: Ellis, A.E. (ed.) Fish and Shellfish
Pathology. Academic Press, London, pp. 393396.
van Banning, P. (1987) Further results of the Bonamia ostreae challenge tests in Dutch oyster culture.
Aquaculture 67, 191194.
van Banning, P. (1990) The life cycle of the oyster pathogen Bonamia ostreae with a presumptive phase in
the ovarian tissue of the European flat oyster, Ostrea edulis. Aquaculture 84, 189192.
van Banning, P. (1991) Observations on bonamiasis in the stock of the European flat oyster, Ostrea edulis, in
the Netherlands, with special reference to the recent developments in Lake Grevelingen. Aquaculture
93, 205211.
Villalba, A., Mourelle, S.G., Carballal, M.J. and Lpez, C. (1997) Symbionts and diseases of farmed mussels
Mytilus galloprovincialis throughout the culture process in the Ras of Galicia (NW Spain). Diseases of
Aquatic Organisms 31, 127139.
Warner, R.W. and Katkansky, S.C. (1969) Infestation of the clam Protothaca staminea by two species of
tetraphyllidian cestodes (Echeneibothrium spp.). Journal of Invertebrate Pathology 13, 129133.
Weir, G.O. and Sullivan, J.T. (1989) A fluorescence screening technique for microsporida in histological
sections. Transactions of the American Microscopical Society 108, 208210.
Wesche, S.J. (1995) Outbreaks of Marteilia sydneyi in Sydney rock oysters and their relationship with
environmental pH. Bulletin of the European Association of Fish Pathologists 15, 2327.
Wharton, W.G. and Mann, K.H. (1981) Relationship between destructive grazing by the sea urchin,
Strongylocentrotus droebachiensis, and the abundance of American lobster, Homarus americanus, on
the Atlantic coast of Nova Scotia. Canadian Journal of Fisheries and Aquatic Sciences 38, 13391349.
White, M.E., Powell, E.N., Ray, S.M. and Wilson, E.A. (1987) Host-to-host transmission of Perkinsus marinus
in oyster (Crassostrea virginica) populations by the ectoparasitic snail Boonea impressa (Pyramidellidae).
Journal of Shellfish Research 6, 15.
Whyte, S.K., Cawthorn, R.J. and McGladdery, S.E. (1994) Co-infection of bay scallops Argopecten irradians
with Perkinsus karlssoni (Apicomplexa, Perkinsea) and an unidentified coccidian parasite. Diseases of
Aquatic Organisms 18, 5362.
Wilhelm, G. and Mialhe, E. (1996) Dinoflagellate infection associated with the decline of Necora puber crab
populations in France. Diseases of Aquatic Organisms 26, 213219
Wolf, P.H. (1979) Diseases and parasites in Australian commercial shellfish. Haliotis 8, 7583.
Wolf, P.H., Winstead, J.T. and Couch, J.A. (1987) Proctoeces sp. (Trematoda: Digenea) in Australian oysters,
Saccostrea commercialis and Crassostrea amasa. Transactions of the American Microscopical Society
106, 379380.
Xue, Q. and Renault, T. (2000) Enzymatic activities in European flat oyster, Ostrea edulis, and Pacific oyster,
Crassostrea gigas, hemolymph. Journal of Invertebrate Pathology 76, 155163.
Yarnall, H.A., Reece, K.S., Stokes, N.A. and Burreson, E.M. (2000) A quantitative competitive polymerase
chain reaction assay for the oyster pathogen Perkinsus marinus. Journal of Parasitology 86, 827837.
Zabaleta, A.I. and Barber, B.J. (1996) Prevalence, intensity and detection of Bonamia ostreae in Ostrea edulis
L. in the Damariscotta River area, Maine. Journal of Shellfish Research 15, 395400.
18
Introduction
Vertebrates are distinguished from invertebrates by an internal skeleton of cartilage or
bone. The subphylum Vertebrata includes
the jawless fish (Agnatha), such as hagfish
and lamprey, the Placodermi, which are the
earliest group of jawed fish, the cartilaginous fish (Chondrichthyes), such as sharks
and rays, the bony fish (Osteichthyes), such
as sturgeon, trout, carp and Tilapia, the
amphibians, the reptiles, the birds and the
mammals. Fish are the oldest animal group
with an immune system showing clear similarities with the defence systems of mammals and birds. The defence system is
organized on two levels: (i) an innate (inborn)
defence system; and (ii) an acquired (adaptive) defence system. Protection based upon
innate immunity has a general character
and does not depend upon recognition of
distinctive molecular structures of the
invading organisms. Moreover, this component of the system can act rapidly (minutes
to hours) and is relatively temperature
independent. The acquired component is
characterized by specific antigen recognition and memory development. Specific
responses usually require between weeks
and months to build up adequate protection against pathogens. Moreover, the
appearance of specific receptors, such as
678
Lectins
Lectins (or natural agglutinins) in fish can
be detected as natural precipitins or
agglutinins. They are usually cross-linking
carbohydrate moieties on the surface of
xenogeneic erythrocytes or bacteria. They
are probably important in neutralizing
bacterial components (e.g. exotoxins) or in
immobilizing microorganisms and hence
will facilitate phagocytosis (Fletcher, 1982).
Fish lectins are not structurally related to Ig,
but resemble plant or invertebrate agglutinins.
Fish lectins have been found in coho salmon
(Oncorhynchus kisutch) eggs (Yousif et al.,
1995), rainbow trout (Oncorhynchus mykiss)
serum (Hoover et al., 1998) and mucus of
ayu (Plecoglossus altivelis) (Itami et al., 1993).
A mannose-binding lectin, isolated from
Atlantic salmon (Salmo salar) serum, has
been shown to opsonize a virulent Aeromonas
salmonicida strain and lectin-coated bacteria can induce macrophages to kill them
(Ottinger et al., 1999).
Lysozyme
This enzyme is found in fish mucus, serum
and eggs (Ellis, 1999) and is able to digest
the peptidoglycan layer of bacterial cell
walls. Lysozyme is produced by macrophages and neutrophilic granulocytes
(Murray and Fletcher, 1976) and is bactericidal even for serious pathogens such as
Aeromonas salmonicida and Aeromonas
hydrophila (Ellis, 1999).
679
C-reactive protein
In teleost fish, C-reactive protein (CRP) is
a serum component that increases rapidly
upon exposure to bacterial endotoxins
(Ingram, 1980) or experimental infection
with bacterial pathogens (Murai et al., 1990).
CRP reacts with polysaccharide structures
at the cell surface of microorganisms. It has
lectin-like properties and can act as an
opsonin to enhance phagocytosis or to
activate the complement system after binding to the bacterium Vibrio anguillarum
(Nakanishi et al., 1991). CRP from rainbow
trout (O. mykiss) was isolated and characterized as a 66 kDa glycoprotein that contains
two protein subunits (Murai et al., 1990).
Interferon
Interferon (IFN) is a cytokine that is produced by many cell types in response to
viral infections. It increases the resistance
of host cells to different viruses by inducing
the expression of proteins that inhibit the
translation of viral mRNA. IFN in teleosts is
species-specific, e.g. IFN produced by rainbow trout does not protect cyprinid cells
in vitro. In vivo synthesis of IFN during
a viral infection peaks after 23 days and
usually precedes the virus-neutralizing effects
of circulating antibodies, which appear 1 or
2 weeks later (De Kinkelin et al., 1977). It is
interesting that type I and type II IFN can be
distinguished in rainbow trout based upon
acid stability (pH 2) and relative temperature
resistance (60C) (Secombes, 1991). Today
IFN activity has been demonstrated in a
number of fish species, e.g. rainbow trout,
Atlantic salmon and halibut (Hippoglossus
hippoglossus L.) (Robertsen, 1999).
Complement
The complement system consists of a group
of protein and non-protein components that
are involved in both innate defence mechanisms and specific adaptive immunity. The
complement system can be activated along
two major routes: (i) the classical pathway,
680
Inflammation
Inflammation is a local reaction upon tissue
damage, e.g. caused by invading microorganisms. The initiation of inflammation
is highly complex and multifactorial. Many
soluble factors (clotting system, kinin system,
complement system) and cells (thrombocytes, granulocytes and macrophages) play
a role (Secombes, 1996). Characteristics of
the process include local vasodilatation and
an influx of granulocytes and monocytes/
macrophages. The massive influx of cells
confers some degree of protection by walling off an infected area from the rest of the
body. Histopathological studies in fish provide evidence for inflammatory responses
in bacterial, viral, fungal, protozoan and
metazoan parasitic infections (Roberts,
1978). Acute inflammation responses in bony
fish are comparable with those in mammals
(Finn and Nielsen, 1971). Granulocyte infiltration appears 1224 h after injection of
bacteria or Freunds complete adjuvant in
rainbow trout. The infiltrating cells (granulocytes and macrophages) increase in numbers till day 24. The macrophages are
stimulated to secrete interleukin-1 (IL-1)
and eicosanoids, which attract and activate
other leukocytes, including lymphocytes
(Secombes et al., 1999). These events can
be seen as an example of the interaction
between the innate and acquired immune
systems in fish.
Phagocytic cells
Macrophages and neutrophilic granulocytes
in fish are the principal phagocytic cells
(Secombes and Fletcher, 1992; Verburg-Van
Kemenade et al., 1994). These cells recognize
evolutionarily conserved epitopes present
on microorganisms, using so-called pattern
recognition receptors (PRRs). Different types
of PRRs have been described for fish, including Toll-like receptors (Bricknell and Dalmo,
2005). Upon stimulation through PRRs, these
cells phagocytize antigenic material and/or
exert cytotoxic activity. The killing of intracellular or extracellular pathogens is based
upon the release of a number of oxygen
radical species and nitric oxide (NO) (Campos-Perez et al., 2000; Saeij et al., 2002).
Phagocytosis of antigenic material by
macrophages is not only an activity of the
non-specific innate defence system but is
also the initial step in the specific adaptive
immune response (see Fig. 18.4). As in
mammals, we are probably dealing with
subpopulations of mononuclear phagocytes
that differ in function. In this respect, it is
interesting to note that macrophages from
immune fish are more active in phagocytosis than those from control animals.
This is probably due to opsonization of the
antigen by antibodies or to metabolic activation of the macrophages (Griffin, 1983).
Sakai (1984) has even suggested that salmonid
macrophages have Fc and C3 receptors on
their surface facilitating the binding and
subsequent phagocytosis of opsonized
material. Most macrophages from the hind
681
gut of carp bind purified Ig, which is an indication for Fc receptors on these cells
(Koumans-Van Diepen et al., 1994). This is
another example of cooperation between the
innate immune system (phagocytes) and the
acquired immune system (Ig molecules).
Non-specific cytotoxic cells
Studies in channel catfish (Ictalurus punctatus) reveal the presence of non-specific
cytotoxic cells (NCC) in these bony fish
(Graves et al., 1984). The monocyte-like NCC
show a clear in vitro lytic activity against
certain transformed mammalian cell lines.
NCC have been shown in the blood, spleen
and head kidney of several teleost fishes
(Manning, 1994). These cells are the teleost
equivalent of mammalian natural killer (NK)
cells (Evans and Jaso-Friedmann, 1992). They
are probably involved in killing protozoan
parasites and virus-infected cells.
system is well developed in fish. Bone marrow, the bursa of Fabricius, Peyers patches
and lymph nodes, which are present in birds
and/or mammals, are not found in fish. Most
observations indicate that the spleen of bony
fish is an erythropoietic and secondary lymphoid organ (Van Muiswinkel et al., 1991),
whereas the thymus is a primary lymphoid
organ, mainly involved in T-cell differentiation (Zapata et al., 1996). The kidney
(pronephros and mesonephros) is probably
analogous to mammalian bone marrow
(Lamers, 1985; Zapata et al., 1996). Therefore, it may function as a primary organ
(blood-cell formation, B-lymphocyte differentiation) but also as a secondary organ
(memory-cell and plasma-cell development).
682
Ig isotypes
Antibody repertoire
its high molecular weight and polymeric
structure. However, the mammalian IgM is a
pentamer with five structural units (H2L2)5.
The amino acid sequence of the four constant
domains in the H chain (CH) shows 24%
homology with the mouse chain (Ghaffari
and Lobb, 1989). Interestingly enough, the
variable heavy (VH) genes of channel catfish (I. punctatus) (Ghaffari and Lobb, 1989)
or rainbow trout (O. mykiss) (Matsunaga
et al., 1990) show much higher amino acid
sequence identity (4560%) with mammals
than the C domain genes. In other words, the
683
Fig. 18.3. Schematic presentation of Ig heavy-chain loci in germline DNA of cartilaginous fish, bony fish
and mammals. V, variable gene segment; D, diversity gene segment; J, joining gene segment; C, constant
gene segment. The V, D, J and C gene segments are recombined during B-cell development in bony fish and
mammals. In cartilaginous fish this process has taken place already at the early germ-line stage.
T-cell receptors
We know from molecular studies in mammals that Ig and TCRs are related protein
molecules that are characterized by an
extreme variation in antigen-binding sites
based upon rearrangements of V, J, C and
sometimes D region gene segments in the
genome of early B- or T-cells. In mammals,
two antigen-specific TCR types ( and )
are present. TCR- and chain gene
sequences have been described in teleosts
(Partula et al., 1996; Hordvik et al., 1999;
Wilson et al., 1998). The isolation of TCR-
chains in cartilaginous fish (Rast et al.,
1995), as well as CD3-like polypeptides in
sturgeons (Acipenser rhutenus) (B.Y. Alabyev,
684
Cytokines
Surprisingly, the apparently old and conserved cytokine system exhibits low degrees
of homology among vertebrate species
when its ligands are compared at the level
of amino acid sequences (approximately
30% homology between the human and
teleost forms of IL-1). On the other hand,
the secondary and tertiary structure of the
IL-1 molecule appears to be quite conserved.
Secombes et al. (1998) have shown that the
trout IL-1 sequence can be superimposed on
the human crystal structure for IL-1. It would
appear that, in an evolutionary context,
the conservation of the three-dimensional
structure is more important for cytokine
function than its primary sequence. In recent
years, a variety of cytokine sequences have
been elucidated for several fish species.
Fibroblast growth factor (FGF) and some CC
and CXC chemokines have been cloned
from a number of fish species (Secombes
et al., 1999; Laing and Secombes, 2004).
Several isoforms of the anti-inflammatory
cytokine transforming growth factor- (TGF-)
have been described for fish and isoforms of
the pro-inflammatory cytokines IL-1 and
tumour necrosis factor- (TNF-) sequences
have been published (Secombes et al.,
1999). The first teleost sequence for IL-1
was published for rainbow trout by Zou
et al. (1999), followed by the IL-1 sequence
for common carp (Fujiki et al., 2000), sea
bass (Dicentrarchus labrax) (Scapigliati
et al., 2001) and gilthead sea bream (Sparus
aurata) (Pelegrin et al., 2001). For both rainbow trout (Pleguezuelos et al., 2000) and
carp (Engelsma et al., 2001; Huising et al.,
2004), a second IL-1 sequence was found.
An explanation for the existence of two
related but distinct forms may be the
685
Cytokine receptors
In addition to the IL-1 sequences, the IL-1
receptors type I (Holland et al., 2000) and
type II (Sangrador-Vegas et al., 2000) were
published for rainbow trout. Elegant threedimensional models of IL-1 and IL-1
receptor type I from rainbow trout and sea
bass were predicted by comparison with
those available from humans and mice
(Scapigliati et al., 2004; Fig. 18.5). The multiple forms of IL-1 and the presence of both
types of receptors indicate that the complexity of the IL-1 system in teleost fish is
similar to that in mammals.
Cytokine function
A biological role for carp IL-1 is strongly
supported by the observation of a transient
in vivo expression of this interleukin during
days 14 of Trypanoplasma borelli infection (Saeij et al., 2003b). Functional aspects
of TNF- action in fish were demonstrated
using human recombinant TNF- in rainbow trout macrophages (Knight et al., 1998)
and assaying for hepatocyte serum amyloid
686
Humoral immunity
The kinetics of the humoral response in bony
fish have been studied in detail (Sailendri
and Muthukkaruppan, 1975; Rijkers, 1982;
Kaattari and Piganelli, 1996). It is important
to realize that, following immunization, the
length of the lag phase, exponential phase
and decay phase may be influenced by several factors, such as water temperature, type
of antigen, antigen dose, route of application, age and species involved (see also
sections on memory, vaccination and temperature). Injection of an optimal dose of
sheep red blood cells (SRBC) into carp
(24C) evokes peak numbers of antibody
(Ab)-forming cells in spleen and kidney
after 910 days (Rijkers et al., 1980a), but
Cellular immunity
Cellular immunity in fish has been studied
in vitro using mixed leukocyte reactions
(MLR), cytokine production and stimulation
of DNA synthesis by T-cell mitogens or
Fig. 18.6. A schematic representation of the primary and secondary humoral response in bony fish (from
Lamers, 1985, with permission).
687
Immunological Memory
An important feature of the immune system
is the capacity to develop immunological
memory. A first contact with an antigen
usually induces relatively short-lived effector
cells (activated Th, plasma cells or cytotoxic
T-cells). There are also long-lived memory
cells among the progeny of the original
non-primed lymphocytes. These memory
cells retain the capacity to be stimulated by
Fig. 18.7. Survival times of scale and skin allografts in different groups of fish. Dark columns: first-set
grafts; grey columns: second-set grafts. (From Manning and Nakanishi, 1996, with permission.)
688
Fig. 18.8. The development of memory B-cell populations in teleost fish (rainbow trout) and mammals
(rat). Note the difference in size of the memory pool between the trout and the rat. B, memory B cell;
B, B cell; P, plasma cell; Ag, antigen. (Slightly modified after Kaattari, 1992.)
689
690
Vaccination
General aspects
Fish farming has grown significantly during
the last 30 years. Fish like trout, Tilapia and
salmon are often kept at high population
densities. This increases the risk of dramatic
disease outbreaks. Although antibiotics can
be used for the treatment of bacterial diseases, this also has some drawbacks. Repeated
use can induce drug resistance in microorganisms or suppress the immune system of
fish (Rijkers et al., 1980c). Moreover, harmful residues may be present in the fish sold
for human consumption. Hence, it is not
surprising that there is an increasing interest in protecting fish by vaccination. There
are several reviews or books on fish vaccination (Lamers, 1985; Ellis, 1988; Gudding
Fig. 18.9. Section of a melano-macrophage centre (MMC) in the spleen of adult rosy barb (Barbus
conchonius). The dark staining (left) is characteristic for the pigment-containing macrophages in the MMC.
et al., 1997). In addition to the usual vaccination method by injection, new procedures for bath or immersion methods have
been developed. These impose less stress on
fish and are almost as effective as injection.
Oral vaccines
Oral vaccination usually evokes only minimal immune responses in the host. It is not
easy to explain this phenomenon. Stroband
and Van Der Veen (1981) showed that the
intestine in almost all fish is divided into
three different segments. The first or proximal segment is involved in the digestion
and absorption of lipids and proteins. The
second segment contains epithelial cells
with pinocytotic activity and the third segment or end-gut probably plays a role in
osmoregulation (Fig. 18.10). In a study by
Rombout and Van Den Berg (1989), it was
shown that the second gut segment is
important for antigen transport and antigen
processing by macrophages. Numerous
lymphoid cells are also present in this gut
segment (Rombout et al., 1989a). These
cells probably play a role in local (mucosal)
responses. Repeated oral administration of
bacterial antigen resulted in antibodies in
skin mucus and bile, but not in serum
(Rombout et al., 1989b). It is expected that
691
encapsulation of vaccines is needed to prevent digestion in the first part of the gut and
to ensure that the essential antigenic determinants reach the second gut segment in
a non-degraded and immunostimulatory
form (Joosten et al., 1995). This approach
should allow the development of new and
effective oral vaccines in the future.
DNA technology
In recent years, various vectors have been
used to produce large quantities of antigens
by recombinant DNA technology. In aquaculture, research on recombinant vaccines
has focused mainly on viral vaccines,
because traditional production of viruses
in cell culture systems is relatively expensive. Glycoproteins of viruses causing viral
haemorrhagic septicaemia (VHS) and infectious haematopoietic necrosis (IHN) in
rainbow trout elicit protective antibodies
(Lorenzen and Olesen, 1997). Genetic
immunization using naked DNA is the most
recent approach in vaccine development.
Intramuscular injection of plasmid DNA
containing genes encoding glycoproteins or
nucleocaspid protein in rainbow trout protected against challenge by VHS and IHN
(Lorenzen et al., 2002).
Fig. 18.10. Uptake of horseradish peroxidase by epithelial cells in the second intestinal segment of
20-day-old grasscarp larva (Ctenopharyngodon idella Val.). Note that the enzyme activity is absent in the
first (left) and third (right) segment of the gut. The circle in the lumen is an empty Artemia salina eggshell,
which was part of the food used. (Courtesy H.W.J. Stroband.)
692
Environmental Effects
Temperature
In cold-blooded animals such as fish, the
metabolic activity is directly influenced by
the ambient water temperature. The effects
of temperature on antibody synthesis have
been known for a long time (Bisset, 1948).
The summer flounder (Paralichthys dentatus)
needs water temperatures above 18C for
an effective Ab response against parasitic
haemoflagellates (Sypek and Burreson, 1983).
The relationship between temperature and
the humoral response in carp is shown in
Fig. 18.11 (Rijkers et al., 1980a). This relationship matches the effect of temperature
on allograft survival in goldfish (Carassius
auratus) (Hildemann and Cooper, 1963).
Avtalion (1981) studied the effects of temperature on antibody production in carp
and Tilapia against bovine serum albumin
and hapten-carriers. They showed that
Stress
It is obvious that several human activities
affect fish welfare, e.g. commercial and sports
fisheries, aquaculture, ornamental fish keeping and scientific research. Tissue damage,
physical exhaustion and severe oxygen deficit can occur during handling or capture.
Moreover, pain and stress can be expected
when a fish is killed. It is inevitable that
fish are exposed to stress induced by aquaculture practices such as crowding, transport, handling and impaired water quality.
In fishes, as in mammals, the stress response
comprises activation of the sympathetic nervous system, as well as of the hypothalamus
pituitaryinterrenal (HPI) axis; the interrenal
tissue in the head kidney of fish contains
the equivalents (cortisol-producing cells and
chromaffin cells) of the mammalian adrenals
(Wendelaar Bonga, 1997). In response to
hypothalamic release of corticotrophinreleasing hormone (CRH) and thyrotrophinreleasing hormone (TRH), the pituitary
enhances synthesis of Pro-opiomelanocortin
POMC and release of its cleavage products.
Adrenocorticotrophic hormone (ACTH) is a
potent stimulator of cortisol production by
the interrenal steroid-producing cells. Cortisol
has both glucocorticoid and mineralocorticoid
actions in fish (the type of response to
cortisol is receptor-dependent).
Endocrine-immune interactions
As the head kidney combines glucocorticoid
and catecholamine production with important immune features, e.g. lymphopoiesis
and antibody production, the potential for
paracrine modulation of immune responses
by stress hormones is indicated. Effects of
cortisol on the immune system of fish are
generally similar to those in mammals.
Numerous studies suggest that prolonged
stress causes lymphocyte depletion in
peripheral blood and lymphoid organs
(Zapata et al., 1992). Circulating lymphocyte populations decrease in number while
neutrophilic granulocytes remain constant
or increase (Ellsaesser and Clem, 1986;
Ainsworth et al ., 1991). Lymphocyte
693
694
Fig. 18.12. Interaction between the stress response and the immune response in fish. During the stress
response, neuropeptides, including corticotrophin-releasing hormone (CRH) and thyrotrophin-releasing
hormone (TRH), control the release of pituitary hormones involved in the regulation of cortisol (ACTH,
adrenocorticotrophic hormone; MSH, melanophore-stimulating hormone). The head kidney of fish
contains equivalents (e.g. cortisol-producing interrenal cells) of the mammalian adrenal. High levels of
cortisol may affect the expression of cytokine genes in cells of the immune system. Cytokines (e.g. IL-1,
interleukin-1; IL-6, interleukin-6; TNF, tumour necrosis factor) play an important role in the regulation
of the immune response, but are also known to interact with the hypothalamuspituitaryinterrenal (HPI)-axis.
Administration of IL-1 in experimental fish can activate CRH neurons and stimulates the release of CRH,
illustrating immuneneuroendocrine interaction (J. Metz, G. Flik and S.E. Wendelaar Bonga, personal
communication).
Moreover, an association has been established between certain MHC alleles and the
susceptibility for specific diseases in birds
and mammals (De Vries et al., 1979;
Svejgaard et al., 1982). The increasing
knowledge of the MHC in fish will certainly
be important for our ideas about regulation
of the immune response in fish (see also the
section on antigen recognition and presentation). Several examples of genetic differences in disease resistance in fish have been
described (Chevassus and Dorson, 1990;
Houghton et al., 1991; Wiegertjes et al.,
1993), but well-defined genetic markers are
still scarce. In a study with captive-bred chinook salmon (Oncorhynchus tshawytscha), it
was shown that outbred and/or heterozygous (MHC genes) animals were usually
more resistant to V. anguillarum, IHN virus
and the parasite that causes whirling disease than inbred or homozygous fish (Arkush
et al., 2002). Only a few studies have
addressed the functional aspects of MHC
molecules in fish. Grimholt et al. (2003)
showed a significant association between
resistance to disease (infectious salmon
anaemia virus (ISAV) and A. salmonicida)
Conclusions
During the last 2030 years, considerable
progress has been made in describing and
understanding the immune system of fish.
Antigenic stimulation in fish evokes responses that are comparable to those in
warm-blooded vertebrates. An effective
innate immune system is present and
acquired immune responses show the
expected characteristics of specificity and
memory. However, an isotype switch or
affinity maturation in Ig is usually absent.
There are clear influences of environmental
factors, such as temperature and stress
conditions. Our knowledge of the immune
system of fish can be used for evaluation of
the health status of fish under different
conditions, but can also be used for vaccination and breeding for disease resistance
in aquaculture.
695
References
Abruzzini, A.F., Ingram, L.O. and Clem, L.W. (1982) Temperature-mediated processes in teleost immunity:
homeoviscous adaptation in teleost lymphocytes. Proceedings of the Society for Experimental Biology
and Medicine 169, 1218.
Agius, C. (1980) Phylogenetic development of melano-macrophage centres in fish. Journal of Zoology,
London 191, 1113.
Ainsworth, A.J., Dexiang, C. and Waterstrat, P.R. (1991) Changes in peripheral blood leukocyte percentages
and function of neutrophils in stressed channel catfish. Journal of Aquatic Animal Health 3, 4147.
Ardelli, B.F. and Woo, P.T.K. (1997) Protective antibodies and anamnestic response in Salvelinus fontinalis to
Cryptobia salmositica and innate resistance of Salvelinus namaycush to the hemoflagellate. Journal of
Parasitology 83, 943946.
Arkoosh, M.R. and Kaattari, S.L. (1991) Development of immunological memory in rainbow trout (Oncorhynchus mykiss). I. An immunochemical and cellular analysis of the B cell response. Developmental and
Comparative Immunology 15, 279293.
Arkush, K.D., Giese, A.R., Mendonca, H.L., McBride, A.M., Marty, G.D. and Hedrick, P.W. (2002) Resistance
to three pathogens in the endangered winter-run chinouk salmon (Oncorhynchus tshawscha): effects of
inbreeding and major histocompatibility complex genotypes. Canadian Journal of Fisheries and Aquatic
Sciences 59, 966975.
Arnold, R.E. and Rice, C.D. (2000) Channel catfish, Ictalurus punctatus, leukocytes secrete immunoreactive
adrenal corticotropin hormone (ACTH). Fish Physiology and Biochemistry 22, 303310.
Avtalion, R.R. (1981) Environmental control of the immune response in fish. Critical Reviews on Environmental Control 11, 163188.
Bingulac-Popovic, J., Figueroa, F., Sato, A., Talbot, W.S., Johnson, S.L., Gates M., Postlewait, J.H. and
Klein, J. (1997) Mapping of MHC class I and class II regions to different linkage groups in the zebrafish,
Danio rerio. Immunogenetics 46, 129134.
Bisset, K.A. (1948) The effect of temperature upon antibody production in cold blooded vertebrates. Journal of
Pathology and Bacteriology 60, 8792.
Boesen, H.T., Pedersen, K., Larsen, J.L., Koch, C. and Ellis, A.E. (1999) Vibrio anguillarum resistance to rainbow trout (Oncorhynchus mykiss) serum: the role of lipopolysaccharide. Infection and Immunity 67,
294301.
Borysenko, M. and Hildemann, W.H. (1970) Reactions to skin allografts in the horned shark, Heterodontus
francisci. Transplantation 10, 545557.
Bricknell, I. and Dalmo, R.A. (2005) The use of immunostimulants in fish larval culture. Fish and Shellfish
Immunology 19, 457472.
Campos-Perez, J.J., Ellis, A.E. and Secombes, C.J. (2000) Toxicity of nitric oxide and peroxynitrite to bacterial
pathogens of fish. Diseases of Aquatic Organisms 43, 109115.
Carlson, R.E., Anderson, D.P. and Bodammer, J.E. (1993) In vivo cortisol administration suppresses the
in vitro primary immune response of winter flounder lymphocytes. Fish and Shellfish Immunology 3,
299312.
Caspi, R.R. and Avtalion, R.R. (1984) Evidence for the existence of an IL-2 like lymphocyte growth promoting
factor in bony fish, Cyprinus carpio. Developmental and Comparative Immunology 8, 5166.
Chevassus, B. and Dorson, M. (1990) Genetics of resistance to disease in fishes. Aquaculture 85, 83107.
Chiller, J.M., Hodgins, H.O. and Weiser, R.S. (1969) Antibody response in rainbow trout (Salmo gairdneri) II.
Studies on the kinetics of development of antibody-producing cells and on complement and natural
hemolysin. Journal of Immunology 102, 12021207.
De Kinkelin, P., Baudouy, A.M. and Le Berre, M. (1977) Raction de la truite fario (Salmo trutta, L. 1766) et
arc-en-ciel (Salmo gairdneri Richardson, 1836) linfection par un nouveau rhabdovirus. Comptes
Rendus de lAcadmie des Sciences Paris 248, 401404.
De Vries, R.R.P., Meera Khan, P., Bernini, L.F., Van Loghem E. and Van Rood, J.J. (1979) Genetic control of
survival to epidemics? Journal of Immunogenetics 6, 271287.
Douglas, S.E., Gallant, J.W., Gong, Z. and Hew, C. (2001) Cloning and developmental expression of a family
of pleurocidin-like antimicrobial peptides from winter flounder, Pleuronectes americanus (Walbaum).
Developmental and Comparative Immunology 25, 137147.
Du Pasquier, L. (1982) Antibody diversity in lower vertebrates Why is it so restricted? Nature 296, 311313.
Ellis, A.E. (ed.) (1988) Fish Vaccination. Academic Press, London.
Ellis, A.E. (1999) Immunity to bacteria in fish. Fish and Shellfish Immunology 9, 291308.
696
Ellsaesser, C.F. and Clem, L.W. (1986) Haematological and immunological changes in channel catfish
stressed by handling and transport. Journal of Fish Biology 28, 511521.
Engelsma, M.Y., Stet, R.J.M. and Verburg-van Kemenade, B.M.L. (2001) EMBL/Genbank accession numbers:
AJ401030; AJ401031.
Espelid, S., Lkken, G.B., Steiro, K. and Bgwald, J. (1996) Effects of cortisol and stress on the immune system
in Atlantic salmon (Salmo salar L.). Fish and Shellfish Immunology 6, 95110.
Esteve-Gassent, M.D., Nielsen, M.E. and Amaro, C. (2003) The kinetics of antibody production in mucus and
serum of European eel (Anguilla anguilla L.) after vaccination against Vibrio vulnificus: development of a
new method for antibody quantification in skin mucus. Fish and Shellfish Immunology 15, 5161.
Evans, D.L. and Jaso-Friedmann, L. (1992) Non-specific cytotoxic cells as effectors of immunity in fish. Annual
Review of Fish Disease 2, 109121.
Fnge, R. (1982) A comparative study of lymphomyeloid tissue in fish. Developmental and Comparative
Immunology 6 (suppl. 2), 2333.
Fiebig, H., Gruhn, R. and Ambrosius, H. (1977) Studies on the control of IgM antibody synthesis III. Preferential formation of anti-DNP antibodies of high functional affinity in the course of the immune response in
carp. Immunochemistry 14, 721726.
Finn, J.P. and Nielsen, N.O. (1971) The inflammatory response in rainbow trout. Journal of Fish Biology 3,
463478.
Fletcher, T.C. (1982) Non-specific defence mechanisms of fish. Developmental and Comparative Immunology 6 Suppl. 2, 123132.
Frommel, D., Litman, G.W., Finstad, J. and Good, R.A. (1971) The evolution of the immune response XI.
The immunoglobulins of the horned shark, Heterodontus francisci: purification, characterization and
structural requirements for antibody activity. Journal of Immunology 106, 12341243.
Fujiki, K., Shin, D.H., Nakao, M. and Yano, T. (2000) Molecular cloning and expression analysis of carp
(Cyprinus carpio) interleukin-1 beta, high affinity immunoglobulin E Fc receptor subunit and serum
amyloid A. Fish and Shellfish Immunology 10, 229242.
Ghaffari, S.H. and Lobb, C.J. (1989) Cloning and sequence analysis of channel catfish heavy chain cDNA
indicate phylogenetic diversity within the IgM immunoglobulin family. Journal of Immunology 142,
13561365.
Ghaffari, S.H. and Lobb, C.J. (1991) Heavy chain variable region gene families evolved early in phylogeny:
immunoglobulin complexity in fish. Journal of Immunology 146, 10371046.
Graves, S.S., Evans, D.L., Cobb, D. and Dawe, D.L. (1984) Non-specific cytotoxic cells in fish (Ictalurus
punctatus) I. Optimum requirements for target cell lysis. Developmental and Comparative Immunology
8, 293302.
Griffin, B.R. (1983) Opsonic effect of rainbow trout (Salmo gairdneri) antibody on phagocytosis of Yersinia
ruckeri by trout leukocytes. Developmental and Comparative Immunology 7, 253260.
Grimholt, U., Drabls, F., Jrgensen, S., Hyheim, B. and Stet, R.J.M. (2002) The major histocompatibility
class I locus in Atlantic salmon (Salmo salar L.): polymorphism, linkage and protein modeling.
Immunogenetics 54, 570581.
Grimholt, U., Larsen, S., Nordmo, R., Midtlyng, P., Kjoeglum, S., Storset, A., Saeb and Stet, R.J.M. (2003)
MHC polymorphism and disease resistance in Atlantic salmon (Salmo salar); facing pathogens with
single expressed major histocompatibility class I and class II loci. Immunogenetics 55, 210219.
Grondel, J.L. and Harmsen, E.G.M. (1984) Phylogeny of interleukins: growth factors produced by leukocytes
of the cyprinid fish, Cyprinus carpio L. Immunology 52, 477482.
Gudding, R., Lillehaug, A., Midtlyng, P.J. and Brown, F. (eds) (1997) Fish Vaccinology. Karger, Basle,
Switzerland.
Hansen, J.D., Srassburger, P., Thorgaard, G.H., Young, W.P. and Du Pasquier, L. (1999) Expression, linkage,
and polymorphism of MHC-related genes in rainbow trout, Oncorhynchus mykiss. Journal of Immunology
163, 774786.
Hardie, L.J., Fletcher, T.C. and Secombes, C.J. (1995) Effect of temperature on macrophage activation and
the production of macrophage activating factor by rainbow trout, Oncorhynchus mykiss, leucocytes.
Developmental and Comparative Immunology 18, 5766.
Harrell, L.W., Etlinger, H.M. and Hodgins, H.O. (1975) Humoral factors important in resistance of salmonid
fish to bacterial disease I. Serum antibody protection of rainbow trout (Salmo gairdneri) against vibriosis.
Aquaculture 6, 211219.
Hashimoto, K., Nakanishi, T. and Kurosawa, Y. (1990) Isolation of carp genes encoding major histocompatibility antigens. Proceedings of the National Academy of Sciences USA 87, 68636867.
697
Hildemann, W.H. and Cooper, E.L. (1963) Immunogenesis of homograft reactions in fishes. Federation
Proceedings 22, 11451151.
Hinds, K.R. and Litman, G.W. (1986) Major reorganization of immunoglobulin VH segmental elements
during vertebrate evolution. Nature 320, 546549.
Hinds-Frey, K.R., Nishikata, H., Litman, R.T. and Litman, G.W. (1993) Somatic variation precedes extensive
diversification of germline sequences and combinatorial joining in the evolution of immunoglobulin
heavy chain diversity. Journal of Experimental Medicine 178, 815824.
Hirono, I., Nam, B., Kurobe, T. and Aoki, T. (2000) Molecular cloning, characterization and expression of
TNF cDNA and gene from Japanese flounder Paralichthys olivaceus. Journal of Immunology 165,
44234427.
Holland, J., Pottinger, T.G., Cunningham, C. and Secombes, C.J. (2000) Oncorhynchus mykiss partial mRNA
for interleukin-1 receptor type 1 (IL-1R1) gene. EMBL/Genbank accession number: AJ295296.
Hoover, G.J., El-Mowafi, A., Simko, E., Kocal, T.E., Ferguson, H.W. and Hayes, M.A. (1998) Plasma proteins
of rainbow trout (Oncorhynchus mykiss) isolated by binding to lipoplysacchatide from Aeromonas
salmonicida. Comparative Biochemistry and Physiology Part B, 120, 559569.
Hordvik, I., Jacob, A.L.J., Charlemagne, J. and Endresen, C. (1996) Cloning of T-cell receptor chain cDNAs
from Atlantic salmon (Salmo salar). Immunogenetics 45, 914.
Hordvik, I., Theverajan, J., Samdal, I., Bastani, N. and Krossoy, B. (1999) Molecular cloning and phylogenetic
analysis of the Atlantic salmon immunoglobulin D gene. Scandinavian Journal of Immunology 50,
202210.
Houghton, G., Wiegertjes, G.F., Groeneveld, A. and Van Muiswinkel, W.B. (1991) Differences in resistance
of carp Cyprinus carpio L., to atypical Aeromonas salmonicida. Journal of Fish Diseases 14,
333341.
Huising, M.O., Stet, R.J.M., Savelkoul, H.F.J. and Verburg-Van Kemenade, B.M.L. (2004) The molecular
evolution of the interleukin-1 family of cytokines: IL-18 in teleost fish. Developmental and Comparative
Immunology 28, 395413.
Iger, Y. and Wendelaar Bonga, S.E. (1994) Cellular aspects of the skin of carp exposed to acidified water. Cell
and Tissue Research 275, 481492.
Ingram, G. (1980) Substances involved in the natural resistance of fish to infection. A review. Journal of Fish
Biology 16, 2360.
Itami, T., Ishida, Y., Endo, F., Kawazoe, N. and Takahashi, Y. (1993) Haemagglutinins in the skin mucus of
ayu. Fish Pathology 28, 4147.
Joosten, P.H.M., Aviles-Trigueros, M. and Rombout, J.H.W.M. (1995) Oral vaccination of juvenile carp
(Cyprinus carpio) and gilthead bream (Sparus aurata) with bioencapsulated Vibrio anguillarum bacterin.
Fish and Shellfish Immunology 5, 289299.
Jrgensen, J.B., Lunde, H., Jensen, L., Whitehead, A.S. and Robertsen, B. (2000) Serum amyloid A transcription in Atlantic salmon (Salmo salar L.) hepatocytes is enhanced by stimulation with macrophage
factors, recombinant human IL-1 beta, IL-6 and TNF alpha or bacterial lipopolysaccharide. Developmental and Comparative Immunology 24, 553563.
Kaastrup, P., Nielson, B., Hrlyck, V. and Simonsen, M. (1988) Mixed lymphocyte reactions (MLR) in rainbow trout, Salmo gairdneri, sibling. Developmental and Comparative Immunology 12, 801808.
Kaattari, S.L. (1992) Fish B lymphocytes defining their form and function. Annual Review of Fish Diseases 2,
161180.
Kaattari, S.L. and Piganelli, J.D. (1996) The specific immune system: humoral defense. In: Iwama, G and
Nakanishi, T. (eds) The Fish Immune System. Organism, Pathogen and Environment. Academic Press,
London, pp. 207254.
Klein, J. and Horejsi, V. (1999) Immunology, 2nd edn. Blackwell Publishing, Oxford, UK.
Knight, J., Stet, R.J.M. and Secombes, C.J. (1998) Modulation of MHC class II expression in rainbow trout
Oncorhynchus mykiss macrophages by TNF alpha and LPS. Fish and Shellfish Immunology 8, 545553.
Kokubu, F.K., Hinds, K., Litman, R., Shamblott, M.J. and Litman, G.W. (1987) Extensive families of constant
region genes in a phylogenetically primitive vertebrate indicate an additional level of immunoglobulin
complexity. Proceedings of the National Academy of Sciences USA 84, 58685872.
Koumans-Van Diepen, J.C.E., Van De Lisdonk, M.H.M., Taverne-Thiele, J.J., Verburg-Van Kemenade, B.M.L.
and Rombout, J.H.W.M. (1994) Characterization of immunoglobulin-binding leucocytes in carp
(Cyprinus carpio L.). Developmental and Comparative Immunology 18, 4556.
Kuroda, N., Figueroa, F., OHuigin, C. and Klein, J. (2002) Evidence that the separation of MHC class II from
class I loci in the zebrafish, Danio rerio, occurred by translocation. Immunogenetics 54, 418430.
698
Laing, K.J. and Secombes, C.J. (2004) Chemokines. Developmental and Comparative Immunology 28,
443460.
Laing, K.J., Wang, T.H., Zou, J., Holland, J., Hong, S.H., Bols, N., Hirono, I., Aoki, T. and Secombes, C.J.
(2001) Cloning and expression analysis of rainbow trout Oncorhynchus mykiss tumour necrosis
factor-alpha. European Journal of Biochemistry 268, 13151322.
Lamers, C.H.J. (1985) The reaction of the immune system of fish to vaccination. PhD thesis, Wageningen
University, Wageningen, The Netherlands.
Lamers, C.H.J. and De Haas, M.J.H. (1985) Antigen localization in the lymphoid organs of carp (Cyprinus
carpio). Cell and Tissue Research 242, 491498.
Lamers, C.H.J., De Haas, M.J.H. and Van Muiswinkel, W.B. (1985) Humoral response and memory formation
in carp after injection of Aeromonas hydrophila bacterin. Developmental and Comparative Immunology
9, 6575.
Le Morvan-Rocher, C., Troutaud, D. and Deschaux, P. (1995) Effects of temperature on carp leukocyte
mitogen-induced proliferation and nonspecific cytotoxic activity. Developmental and Comparative
Immunology 19, 8795.
Lobb, C.J. and Clem, L.W. (1981a) Phylogeny of immunoglobulin structure and function X. Humoral
immunoglobulins of the sheepshead, Archosarchus probatocephalus. Developmental and Comparative
Immunology 5, 271282.
Lobb, C.J. and Clem, L.W. (1981b) The metabolic relationships of the immunoglobulins in fish serum,
cutaneous mucus and bile. Journal of Immunology 127, 15251529.
Lobb, C.J. and Olson, M.O.J. (1988) Immunoglobulin heavy chain isotypes in a teleost fish. Journal of
Immunology 141, 12361245.
Lobb, C.J., Olson, M.O. and Clem, L.W. (1984) Immunoglobulin light chain classes in a teleost fish. Journal of
Immunology 132, 19171923.
Lorenzen, N. and Olesen, N.J. (1997) Immunization with viral antigens: viral haemorrhagic septicaemia.
In: Gudding, R., Lillehaug, A., Midtlyng, P.J. and Brown, F. (eds) Fish Vaccinology. Karger, Basle,
Switzerland, pp. 201209.
Lorenzen, N., Lorenzen, E., Einer-Jensen, K. and LaPatra (2002) DNA vaccines as a tool for analysing
protective immune response against rhabdoviruses in rainbow trout. Fish and Shellfish Immunology 12,
439453.
McLarney, W. (1987) The Freshwater Aquaculture Book. Hartley and Marks, Point Roberts, Washington.
McL. Press, C., Dannevig, B.H. and Landsverk, T. (1994) Immune and enzyme histochemical phenotypes of
lymphoid and nonlymphoid cells within the spleen and head kidney of Atlantic salmon (Salmo salar L.).
Fish and Shellfish Immunology 4, 7993.
Manning, M.J. (1994) Fishes. In: Turner, R.J. (ed.) Immunology: a Comparative Approach. John Wiley & Sons,
New York, pp. 69100.
Manning, M.J. and Nakanishi, T. (1996) The specific immune system: cellular defenses. In: Iwama, G and
Nakanishi, T. (eds) The Fish Immune System. Organism, Pathogen and Environment. Academic Press,
London, pp. 159205.
Marchalonis, J.J., Schluter, S.F., Bernstein, R.M., Shen, S. and Edmundson, A.B. (1998) Phylogenetic
emergence and molecular evolution of the immunoglobulin family. Advances in Immunology 70,
417506.
Marsden, M.J., Hamdani, S.H. and Secombes, C.J. (1995) Proliferative responses of rainbow trout,
Oncorhynchus mykiss, leukocytes. Veterinary Immunology and Immunopathology 5, 199210.
Matsunaga, T. and Tormnen, V. (1990) Evolution of antibody and T-cell receptor V genes the antibody repertoire might have evolved abruptly. Developmental and Comparative Immunology 14, 18.
Matsunaga, T., Chen, T. and Trmnen, V. (1990) Characterization of a complete immunoglobulin
heavy-chain variable region germ-line gene of rainbow trout. Proceedings of the National Academy of
Sciences USA 87, 77677771.
Maule, A.G. and Schreck, C.B. (1990) Glucocorticoid receptors in leucocytes and gill of juvenile coho
salmon (Oncorhynchus kisutch). General and Comparative Endocrinology 77, 448455.
Miller, N.W. and Clem, L.W. (1984) Temperature-mediated processes in teleost immunity: differential effects
of temperature on catfish in vitro antibody responses to thymus-dependent and thymus-independent
antigens. Journal of Immunology 133, 23562359.
Miller, N.W., Sizemore, R.C. and Clem, L.M. (1985) Phylogeny of lymphocyte heterogeneity: the cellular
requirements for in vitro anitbody responses of channel catfish leukocytes. Journal of Immunology 134,
28842888.
699
Miller, N.W., Bly, J.E., Van Ginkel, F.W. and Clem, L.W. (1987) Phylogeny of lymphocyte heterogeneity:
identification and separation of functionally distinct subpopulations of channel catfish lymphocytes with
monoclonal antibodies. Developmental and Comparative Immunology 11, 739747.
Murai, T., Kodama, H., Naiki, M., Mikami, T. and Isawa, H. (1990) Isolation and characterization of rainbow
trout C-reactive protein. Developmental and Comparative Immunology 14, 4958.
Murray, C.K. and Fletcher, T.C. (1976) The immunohistochemical localization of lysozyme in plaice
(Pleuronectes Platessa L.) tissues. Journal of Fish Biology 9, 329334.
Nakanishi, T., Kodama, H., Murai, T., Mikami, T. and Izawa, H. (1991) Activation of rainbow trout complement
by C-reative protein. American Journal of Veterinary Research 52, 397401.
Nanoka, M., Natsume-Sakai, S. and Takahashi, M. (1981) The complement system of rainbow trout (Salmo
gairdneri) II. Purification and characterization of the fifth component (C5). Journal of Immunology 126,
14951498.
Nanoka, M., Iwaki, M., Nakai, C., Nozaki, M., Kaidoh, T., Nonaka, M., Natsuume-Sakai, S. and Takahashi, M.
(1984) Purification of a major serum protein of rainbow trout (Salmo gairdneri) homologous to the third
component of mammalian complement. Journal of Biological Chemistry 259, 63276333.
Naruse, K., Shima, A. and Nonaka, M. (2000) MHC gene organization in the bony fish, medaka. In:
Kasahara, M. (ed.) Major Histocompatibility Complex: Evolution, Structure and Function. Springer
Verlag, Berlin/Heidelberg, Germany, pp. 91109.
Nikoskelainen, S., Bylund, G. and Lilius, E.-S. (2004) Effect of environmental temperature on rainbow trout
(Oncorhynchus mykiss) innate immunity. Developmental and Comparative Immunology 28, 581592.
Nossal, G.J.V., Austin, C.M. and Ada, G.L. (1965) Antigens in immunity. VII. Analysis of immunological
memory. Immunology 9, 333348.
Ottaviani, E., Franchini, A. and Franceshi, C. (1998) Presence of immunoreactive corticotropin-releasing
hormone and cortisol molecules in invertebrate haemocytes and lower and higher vertebrate thymus.
Histochemistry Journal 30, 6167.
Ottinger, C.A., Johnson, S.C., Ewart, K.V., Brown, L.L. and Ross, N.W. (1999) Enhancement of antiAeromonas salmonicida activity in Atlantic salmon (Salmo salar) macrophages by a mannose-binding
lectin. Comparative Biochemistry and Physiology Part C 123, 5359.
Partula, S., De Guerra, A., Fellah, J.S. and Charlemagne, J. (1996) Structure and diversity of TCR alpha-chain
in a teleost fish. Journal of Immunology 157, 207212.
Pelegrn, P., Garcia-Castillo, J., Mulero, V. and Meseguer, J. (2001) Interleukin-1 isolated from a marine fish
reveals up-regulated expression in macrophages following activation with lipopolysaccharide and
lymphokines. Cytokine 16, 6772.
Perey, D.Y.E., Finstad, J., Pollara, B. and Good, R.A. (1968) Evolution of the immune response VI. First and
second set homograft rejections in primitive fishes. Laboratory Investigation 19, 591598.
Pilstrm, L., Lundqvist, M.L. and Wermenstam, N.E. (1998) The immunoglobulin light chain in poikilothermic
vertebrates. Immunological Reviews 166, 123132.
Pleguezuelos, O., Zou, J., Cunningham, C. and Secombes, C.J. (2000) Cloning, sequencing, and analysis of
expression of a second IL-1 gene in rainbow trout (Oncorhynchus mykiss). Immunogenetics 51,
10021011.
Rast, J.P., Haire, R.N., Litman, R.T., Pross, S. and Litman, G.W. (1995) Identification and characterization of
T-cell antigen receptor-related genes in phylogenetically diverse vertebrate species. Immunogenetics 42,
204212.
Rijkers, G.T. (1980) The immune system of cyprinid fish. PhD thesis, Wageningen University, Wageningen,
The Netherlands.
Rijkers, G.T. (1982) Kinetics of humoral and cellular immune reactions in fish. Developmental and Comparative Immunology 6, Suppl. 2, 93100.
Rijkers, G.T. and Van Muiswinkel, W.B. (1977) The immune system of cyprinid fish. The development of
cellular and humoral responsiveness in the rosy barb (Barbus conchonius). In: Solomon, J.B. and
Horton, J.D. (eds) Developmental Immunobiology. Elsevier/North-Holland, Amsterdam, pp. 233240.
Rijkers, G.T., Frederix-Wolters, E.M.H. and Van Muiswinkel, W.B. (1980a) The immune system of cyprinid
fish. Kinetics and temperature dependence of antibody producing cells in carp (Cyprinus carpio). Immunology 41, 9197.
Rijkers, G.T., Frederix-Wolters, E.M.H. and Van Muiswinkel, W.B. (1980b) The immune system of cyprinid
fish. The effect of antigen dose and route of administration on the development of immunological
memory in carp (Cyprinus carpio). In: Manning, M.J. (ed.) Phylogeny of Immunological Memory.
Elsevier/North-Holland, Amsterdam, pp. 93102.
700
Rijkers, G.T., Teunissen, A.G., Van Oosterom, R. and Van Muiswinkel, W.B. (1980c) The immune system of
cyprinid fish. The immunosuppressive effect of the antibiotic oxytetracycline in carp (Cyprinus carpio L.).
Aquaculture 19, 177189.
Roberts, R.J. (ed.) (1978) Fish Pathology. Baillire Tindall, London.
Robertsen, B. (1999) Modulation of the non-specific defence of fish by structurally conserved microbial
polymers. Fish and Shellfish Immunology 9, 269290.
Rombout, J.H.W.M. and Van Den Berg, A.A. (1989) Immunological importance of the second gut segment of
carp. I. Uptake and processing of antigens by epithelial cells and macrophages. Journal of Fish Biology
35, 1322.
Rombout, J.H.W.M., Blok, L.J., Lamers, C.H.J. and Egberts, E. (1986) Immunization of carp (Cyprinus carpio)
with a Vibrio anguillarum bacterin: indications for a common mucosal immune system. Developmental
and Comparative Immunology 10, 341351.
Rombout, J.H.W.M., Bot, H.E. and Taverne-Thiele, J.J. (1989a) Immunological importance of the second gut
segment in carp II. Characterization of mucosal leucocytes. Journal of Fish Biology 35, 167178.
Rombout, J.H.W.M., Bot, H.E. and Taverne-Thiele, J.J. (1989b) Immunological importance of the second gut
segment of carp III. Systemic and/or mucosal immune responses after immunization with soluble or
particulate antigen. Journal of Fish Biology 35, 179186.
Rombout, J.H.W.M., Taverne, N., Van de Kamp, M. and Taverne-Thiele, A.J. (1993) Differences in mucus and
serum immunoglobulin of carp (Cyprinus carpio L.). Developmental and Comparative Immunology 17,
309317.
Saeij, J.P.S., Van Muiswinkel, W.B., Groeneveld, A. and Wiegertjes, G.F. (2002) Immune modulation by fish
kinetoplastid parasites: a role for nitric oxide. Parasitology 124, 7786.
Saeij, J.P.J., Stet, R.J.M., De Vries B.J., Van Muiswinkel, W.B. and Wiegertjes, G.F. (2003a) Molecular and
functional characterization of carp TNF: a link between TNF polymorphism and trypanotolerance?
Developmental and Comparative Immunology 27, 2941.
Saeij, J.P.J., De Vries, B. and Wiegertjes, G.F. (2003b) The immune response of carp to Trypanoplasma borreli:
kinetics of immune gene expression and polyclonal lymphocyte activation. Developmental and Comparative Immunology 27, 859874.
Sailendri, K. and Muthukkaruppan, V. (1975) The immune response of the teleost, Tilapia mossambica to soluble and cellular antigens. Journal of Experimental Zoology 191, 371381.
Sakai, D.K. (1984) Opsonization by fish antibody and complement in immune phagocytosis by peritoneal
exudate cells isolated from salmonid fish. Journal of Fish Diseases 7, 2938.
Sangrador-Vegas, A., Martin, S.A.M., ODea, P.G. and Smith, T.J. (2000) Cloning and characterization of
the rainbow trout (Oncorhynchus mykiss) type II interleukin-1 receptor cDNA. European Journal of
Biochemistry 267, 70317037.
Scapigliati, G., Buonocore, F., Bird, S., Zou, J., Pelegrn, P., Falasca, C., Prugnoli, D. and Secombes, C.J.
(2001) Phylogeny of cytokines: molecular cloning and expression analysis of sea bass Dicentrarchus
labrax interleukin-1. Fish and Shellfish Immunology 11, 711726.
Scapigliati, G., Costantini, S., Clonna, G., Facchiano, A., Buonocore, F., Bossu, P., Cunningham, C.,
Holland, J.W. and Secombes, C.J. (2004) Modelling of fish interleukin-1 and its receptor. Developmental and Comparative Immunology 28, 429441.
Secombes, C.J. (1991) The phylogeny of cytokines. In: Thomson, A.W. (ed.) The Cytokine Handbook.
Academic Press, London, pp. 387412.
Secombes, C.J. (1996) The nonspecific immune system: cellular defenses. In: Iwama, G. and Nakanishi, T. (eds)
The Fish Immune System. Organism, Pathogen and Environment. Academic Press, London, pp. 63103.
Secombes, C.J. and Fletcher, T.C. (1992) The role of phagocytes in the protective mechanism of fish. Annual
Review of Fish Disease 2, 5371.
Secombes, C.J., Manning, M.J. and Ellis, A.E. (1982) The effect of primary and secondary immunization on the
lymphoid tissues of the carp, Cyprinus carpio L. Journal of Experimental Zoology 220, 277287.
Secombes, C.J., Van Groningen, J.J.M. and Egberts, E. (1983) Separation of lymphocyte subpopulations in carp,
Cyprinus carpio L. by monoclonal antibodies: immunohistochemical studies. Immunology 48, 165175.
Secombes, C.J., Zou, J., Daniels, D.G., Cunningham, C., Koussounadis, A. and Kemp, G. (1998) Rainbow
trout cytokine and cytokine receptor genes. Immunological Reviews 166, 333340.
Secombes, C.J., Zou, J., Laing, K., Daniels, D.G. and Cunningham, C. (1999) Cytokine genes in fish.
Aquaculture 172, 93102.
Sheldon, W.M. and Blazer, V.S. (1991) Influence of dietary lipid and temperature on bactericidal activity of
channel catfish macrophages. Journal of Aquatic Animal Health 3, 8793.
701
Stet, R.J.M., Van Erp, S.H.M., Hermsen, T., Sltmann, H.A. and Egberts, E. (1993) Polymorphism and
estimation of the number of MhcCyca Class I and Class II genes in laboratory strains of the common carp
(Cyprinus carpio L.). Developmental and Comparative Immunology 17, 141156.
Stet, R.J.M., Johnestone, R. and Parham, P. (1997) The unMHC of teleostean fish: segregation analyses in
common carp and Atlantic salmon. Hereditas 127, 169170.
Stet, R.J.M., Kruiswijk, C.P. and Dixon, B. (2003) Major histocompatibility lineages and immune gene
function in teleost fishes: the road not taken. Critical Reviews in Immunology 23, 441471.
Stolen, J.S. and Mkela, O. (1975) Carrier preimmunization in the anti-hapten response of a marine fish.
Nature 254, 718719.
Stroband, H.W.J. and Van Der Veen, F.H. (1981) Localization of protein absorption during transport of food in the
intestine of the grass carp, Ctenopharyngodon idella (Val.). Journal of Experimental Zoology 218, 149156.
Svejgaard, A., Platz, P. and Ryder, L.P. (1982) HLA and disease: 1982 a review. Immunological Reviews 70,
193218.
Sypek, J.P. and Burreson, M. (1983) Influence of temperature on the immune response of juvenile summer
flounder, Paralichthys dentatus, and its role in the elimination of Trypanoplasma bullocki infections.
Developmental and Comparative Immunology 7, 277286.
Tomonaga, S., Kobayashi, K., Hagiwara, K., Yamaguchi, K. and Awaya, K. (1986) Gut associated lymphoid
tissue in elasmobranchs. Zoological Science 3, 2329.
Tonegawa, S. (1983) Somatic generation of antibody diversity. Nature 302, 575581.
Van Muiswinkel, W.B., Lamers, C.H.J. and Rombout, J.H.W.M. (1991) Structural and functional aspects of the
spleen in bony fish. Research in Immunology 142, 362366.
Verburg-Van Kemenade, B.M.L., Groeneveld, A., Van Rens, B.T.T.M. and Rombout, J.H.W.M. (1994)
Characterization of macrophages and neutrophilic granulocytes from the pronephros of carp (Cyprinus
carpio). Journal of Experimental Biology 187, 143158.
Verburg-Van Kemenade, B.M.L., Nowak, B., Engelsma, M.Y. and Weyts, F.A.A. (1999) Differential effects of
cortisol on apoptosis and proliferation of carp B-lymphocytes from head kidney, spleen and blood. Fish
and Shellfish Immunology 9, 409415.
Verlhac, V., Sage, M. and Deschaux, P. (1990) Cytotoxicity in carp, Cyprinus carpio, leucocytes induced
against TNP-modified autologous spleen cells and influence of acclimatization temperature. Developmental and Comparative Immunology 14, 475480.
Wendelaar Bonga, S.E. (1997) The stress response in fish. Physiological Reviews 77, 591625.
Weyts, F.A.A. (1998) Corticosteroids and interleukin-1. Messengers for communication between the endocrine and immune system of carp. PhD thesis, Wageningen University, Wageningen, The Netherlands.
Wiegertjes, G.F., Daly, J.G. and Van Muiswinkel, W.B. (1993) Disease resistance of carp, Cyprinus carpio L.:
identification of individual genetic differences by bath challenge with atypical Aeromonas salmonicida.
Journal of Fish Diseases 16, 569576.
Wilson, M.R. and Warr, G.W. (1992) Fish immunoglobulins and the genes that encode them. Annual Review
of Fish Diseases 2, 201221.
Wilson, M.R., Bengten, E., Miller, N.W., Clem, L.W., Du Pasquier, L. and Warr, G.W. (1997) A novel chimeric Ig heavy chain from a teleost fish shares similarities to IgD. Proceedings of the National Academy of
Sciences USA 94, 45934597.
Wilson, M.R., Zhou, H., Bengten, E., Clem, L.W., Stuge, T.B., Warr, G.W. and Miller, N.W. (1998) T-cell
receptors in channel catfish. Structure and expression of TCR and genes. Molecular Immunology 35,
545557.
Woo, P.T.K. (1992) Immunological responses of fish to parasitic organisms. Annual Review of Fish Diseases 2,
339366.
Yano, T. (1996) The non-specific immune system: humoral defense. In: Iwama, G and Nakanishi, T. (eds) The
Fish Immune System. Organism, Pathogen and Environment. Academic Press, London, pp. 105157.
Yousif, A.N., Albright, L.J. and Evelin, T.P.T. (1995) Interaction of coho salmon, Oncorhynchus kisutch, egg
lectin with the pathogen A. salmonicida. Diseases of Aquatic Organisms 21, 193199.
Zapata, A.G., Varas, A. and Torroba, M. (1992) Seasonal variations in the immune system of lower
vertebrates. Immunology Today 13, 142147.
Zapata, A.G., Chiba, A. and Varas, A. (1996) Cells and tissues of the immune system of fish. In: Iwama, G. and
Nakanishi, T. (eds) The Fish Immune System. Organism, Pathogen and Environment. Academic Press,
London, 162.
Zou, J., Grabowski, P.S., Cunningham, C. and Secombes, C.J. (1999) Molecular cloning of interleukin 1 from
rainbow trout Oncorhynchus mykiss reveals no evidence of an ICE cut site. Cytokine 11, 552560.
19
1Institute
Introduction
Much progress has been made in recent
years, particularly in the identification of
cytokines and chemokines; however, the
immune system of fin fish is still not as well
characterized as that of more recently evolved
vertebrates, such as mammals. Although the
chapter will focus on teleosts and cartilaginous fishes, much of what is discussed
will be done with reference to the more
well-defined immune system of mammals.
The immune system has two basic components that respond to foreign antigens:
(i) the humoral response, involving production of immunoglobulins (antibodies) by
plasma cells; and (ii) the cell-mediated
response, mediated by T-lymphocytes. In
addition, there are also cell populations
responsible for non-specific and specific
immune defences and they include lymphocytes, monocytes/macrophages, granulocytes and thrombocytes. The lymphocytes
are classified as immunoglobulin positive
B-cells and immunoglobulin-negative T-cells.
Other cell types include mast cells, nonspecific cytotoxic cells and dendritic cells.
In addition, the tissues of the spleen and
kidney of fish also contain a distinct population of cells, known as melanomacrophages.
All of the cell types described are generally
702
703
Until recently, macrophages have been considered to be the primary cell type serving
as an antigen-presenting cell. In mammals,
mononuclear phagocytes originate in the
bone marrow, circulate for a short time in
the blood as monocytes and then move into
tissues, where they develop into macrophages. Tissue macrophages (fixed or wandering) are derived primarily from blood
monocytes, but they may also form by proliferation in the tissues as well. When in
other tissues, macrophages are often called
alveolar phagocytes (lungs), microglia (central nervous system), reticular cells (bone
marrow and lymphoid organs) or Kupffer
cells (liver).
In mammals, macrophages have a
unique surface glycoprotein, known as F4/80
(160 kDa) (Hirsch et al., 1981). They are larger
than B- or T-cells and are characterized by a
large number of lysosomes. Mammalian
macrophages also have receptors for class II
major histocompatibility complex (MHC)
antigens, FcRs, complement (C3b) and
lymphokines. In contrast to T-cells, macrophages do not possess specific antigen
receptors but they bind, ingest and degrade
virtually any type of antigenic material.
They produce some of the major components
of complement, interferons, prostaglandins
and cytokines, such as interleukin-1 (IL-1)
(see later section). In the nurse shark
(Nebrius ferrugineus), the neutrophil, not the
macrophage, carries the receptor for Fc
(McKinney and Flajnik, 1997). The FCR falls
704
705
Granulocytic cells
Granulocytes are leukocytes that are characterized by the presence of cytoplasmic granules. This group is subdivided into three
types in mammals, based on the nature of
the granules present: (i) basophils, containing basophilic granules; (ii) eosinophils,
Thrombocytes (platelets)
Platelets in the blood of fish may be small
cytoplasmic fragments with diameters less
than half that of a red blood cell. In mammals, they are derived from large megakaryocytes in the bone marrow and possess
small granules, surface receptors (FcRs) for
IgG and IgE and class I MHC antigens. Platelets are not only important for blood clotting
(as producers of thromboplastin), but they are
also critically involved in hypersensitivity
reactions and the inflammatory process. This
cell type releases permeability-increasing substances, such as histamine, following aggregation and degranulation. Platelets can be
induced to aggregate and degranulate by
platelet-activating factor, immune complexes and complement components (C3a
and C5a). Platelet-activating factor is produced by a variety of cells, for example,
basophils and mast cells, following interaction
with allergens or immune complexes and
complement factors.
706
having eosinophilic granules; and (iii) neutrophils, which lack specific granules. In mammals they develop in the bone marrow, but
development in fish is variable. Granulopoiesis in cartilaginous fishes occurs in the
spleen and lymphomyeloid tissues (epigonal
organ and organ of Leydig), while the spleen
and kidney are the granulopoietic organs in
bony fishes. In some elasmobranchs, granulopoiesis aggregates are found in the central nervous system. Human eosinophils, basophils
and mast cells share a number of recruitment
pathways with one another and with other
cell types. However, each also possesses
unique adhesion and migration responses,
which may contribute to their preferential
accumulation. The behaviour of these cell
types is not identical, however. All three are
linked to allergic reactions and yet their localization within a given tissue can be distinct.
Neutrophils
The granular cytoplasm in neutrophils does
not stain well with either acidic or basic dyes
at neutral pH. In mammals, mature neutrophils are characterized by distinct lobed
nuclei and are commonly referred to as
polymorphonuclear neutrophils (PMNs). The
percentage of circulating neutrophils in fish
is generally smaller than in mammals (60%),
because they tend to have larger numbers of
circulating lymphocytes. The PMNs in mammals are derived from pluripotent stem cells,
as are the other blood cells, but in fish the
head kidney is the major haemopoietic
organ. The main function of neutrophils is
phagocytosis of foreign, aberrant or dead
cells, as well as pinocytosis of immune complexes. In mammals, neutrophils also exhibit
antibody-dependent cell-mediated cytotoxicity (ADCC) and are capable of rapid activation
and mobilization in response to chemotactic
stimuli, such as bacterial products or activated
components of complement (C5a). Once activated, a variety of receptors (Fc, C3b, C3d
and C5a) is displayed. During the early
stages of inflammation, as a result of
infection and/or immune complexes, neutrophils are the most prominent cell type at
the inflammatory site and bind, ingest or
lyse the foreign target (Miller et al., 1998).
707
708
Lymphoid cells
Lymphocytes occur in large numbers in the
lymph of the thoracic duct in mammals.
Similarly, lymphocytes in fish are numerous
in lymph, particularly in lymph of the neural lymphatic duct. A lymphatic system has
been described for most teleosts, although in
some fishes the presence of a true lymphatic
system has been challenged (Vogel, 1985).
Lymphocytes are ovoid cells and,
depending on the species of fish, they range
in size (8 to 12 m in diameter). As in mammals, fish have T-cells and B-cells and they
are morphologically indistinguishable using
light microscopy. However, both classes of
lymphocytes have characteristically large
nuclei, which fill almost the entire cell (Figs
9.2 and 9.3, L). Lymphocytes are mobile cells
and they circulate throughout the body. In
mammals, approximately 2030% of circulating lymphocytes are antigen-reactive B-cells,
6575% are T-cells and fewer than 5% are
null cells. In contrast, fish have 12 103
lymphocytes/mm3, while mammals have a
much lower number, at about 2 103 lymphocytes/mm3 (Ellis, 1986). The lymphocytes
of S. auratus have different sizes, with
small microvilli on the cell surface and
scanty cytoplasm (Zuasti and Ferrer, 1989).
With the use of immunological assays,
cell separation techniques and the development of distinct clonal leukocyte cell
709
710
B-lymphocytes
Plasma cells
711
712
713
714
Cytokines
These are secreted by stimulated immunocompetent cells (e.g. macrophages) and they
encompass regulatory proteins, commonly
called growth factors (CSF), interleukins,
lymphokines, monokines and interferons
(IFN). Classifications of cytokines in higher
vertebrates have been based on the structural motifs they adopt. The largest group
of cytokines has an antiparallel 4--helical
bundle structure and is subdivided into
short-chain or long-chain helical bundles.
Short-chain cytokines include IL-2, IL-3,
IL-4, IL-5, IL-7, IL-9, IL-13 and IFN- and
large-chain cytokines include IL-6, IL-12,
IL-11, IL-10 and IFN/. Another group of
cytokines are classified as having long-chain
-sheet structures. In mammals, these
include the tumour necrosis factor (TNF)
family of cytokines (i.e. TNF-, TNF-, CD40,
CD27 and Fas ligands) (Nicola, 1994). Fish
cytokines have adopted this categorization
(Secombes et al., 2001).
Cytokines regulate the intensity and
duration of an immune response by stimulating or inhibiting the proliferation of various
immune cells or their secretion of antibodies
or other cytokines. To date, cytokines with
activities similar to IFN, IL-1, IL-2, 1 L-4,
chemokines, macrophage migration inhibition factor (MIF), macrophage-activating
factor (MAF) and CSF have been described
from rainbow trout (O. mykiss), carp
(C. carpio), Atlantic salmon (Salmo salar),
715
716
Interferons
Interferons are divided into two major
groups, type I and type II. Members of the
type I IFN family have homology to each
other, bind to the same cell surface receptors
and have overlapping functions (Oritani
et al., 2001). The type I interferon family is
comprised of IFN-, IFN-, IFN- and IFN-.
IFN- and IFN- are produced by leucocytes, while IFN- is a fibroblast product.
Although only small amounts of IFN are
produced under normal healthy conditions,
these can be dramatically increased during
a viral infection. Some growth factors and
cytokines also induce IFN-/ production.
IFN-/ affects proliferation, differentiation
and function of various cell types in the
immune system. For example, type I IFNs
suppress the antigen-specific or mitogeninduced proliferation of CD4+ and CD8 +
T-lymphocytes, while they induce IL-15
production in macrophages and IL-15 can
enhance T-cell growth. In contrast, IFN-/
has been reported to augment the lytic activity of NK cells and cytotoxic T-lymphocytes.
Enhanced expression of cell-surface antigens
of the MHC represents one important mechanism for IFNs influence on immunity.
IFN-/ further modulates the immune system functions by influencing the production
of pro-inflammatory cytokines, such as IL-1,
TNF- and IL-8. Expression of the nitric
oxide synthetase gene in macrophages is also
IFN-sensitive (see Oritani et al., 2001).
An IFN gene has been cloned and characterized from the zebrafish (D. rerio).
Treatment with the known IFN inducer,
polyinosinic acid-polycytidylic acid (poly(I)-poly-(C)), increases IFN mRNA transcripts
in zebrafish. Also, a putative IFN from
puffer (F. rubripes) was present when the
zebrafish IFN was used to BLAST (basic
local alignment search tool) the puffer
genome (Altmann et al., 2003). Fish are
known to produce substances that exhibit
IFN activity, but IFN has not been cloned or
purified (Renault et al., 1991). However,
IFN-induced genes have been cloned from
several species of fish. Following viral infection or exposure to double-stranded RNA,
catfish cells produce a soluble factor that
717
718
References
Abelli, L., Baldassini, M.R., Mastrolia, L. and Scapigliati, G. (1999) Immunodetection of lymphocyte subpopulations
involved in allograft rejection in a teleost, Dicentrarchus labrax (L.). Cellular Immunology 191, 152160.
Accolla, R.S., Auffray, C., Singer, D.S. and Guardiola, J. (1991) The molecular biology of MHC genes.
Immunology Today 12, 9799.
Agius, C. and Roberts, R.J. (2003) Melano-macrophage centres and their role in fish pathology. Journal of Fish
Diseases 26, 499509.
Alabyev, B.Y., Najakshin, A.M., Mechetina, L.V. and Taranin, A.V. (2000) Cloning of a CXCR4 homolog in
chondrostean fish and characterization of the CXCR4-specific structural features. Developmental and
Comparative Immunology 24, 765770.
719
Altmann, S.M., Mellon, M.T., Distel, D.L. and Kim, C.H. (2003) Molecular and functional analysis of an
interferon gene from the zebrafish, Danio rerio. Journal of Virology 77, 19922002.
Arkoosh, M.R. and Kaattari, S.L. (1991) Development of immunological memory in rainbow trout
(Oncorhynchus mykiss). I. An immunochemical and cellular analysis of the B cell response. Developmental and Comparative Immunology 15, 279293.
Ashwell, J.D. and Klusner, R.D. (1990) Genetic and mutational analysis of the T-cell antigen receptor. Annual
Review of Immunology 8, 139167.
Banchereau, J., Briere, F., Caux, C., Davoust, J., Lebecque, S., Liu, Y.J., Pulendran, B. and Palucka, K. (2000)
Immunobiology of dendritic cells. Annual Review of Immunology 18, 767811.
Barreda, D.R., Neuman, N.F. and Belosevic, M. (2000) Flow cytometric analysis of PKH26-labeled goldfish
kidney-derived macrophages. Developmental and Comparative Immunology 24(4), 395406.
Belcourt, D.R., Okawara, Y., Fryer, J.N. and Bennett, H.P. (1995) Immunocytochemical localization of
granulin-1 to mononuclear phagocytic cells of the teleost fish Cyprinus carpio and Carassius auratus.
Journal of Leukocyte Biology 57, 94100.
Bielek, E. (1988) Ultrastructural analysis of leucocyte interaction with tumour targets in a teleost, Cyprinus
carpio L. Developmental and Comparative Immunology 12 (4), 809821.
Bielek, E., Bigaj, J., Chadzinska, M. and Plytycz, B. (1999) Depletion of head kidney neutrophils and cells with
basophilic granules during peritoneal inflammation in the goldfish, Carassius auratus. Folia Biologica
(Krakow) 47, 3342.
Bodammer, J.E. (1986) Ultrastructural observations on peritoneal exudate cells from the striped bass. Veterinary Immunology and Immunopathology 12, 127140.
Bunton, T.E., Baksi, S.M., George, S.G. and Frazier, J.M. (1987) Abnormal hepatic copper storage in a teleost
fish (Morone americana). Veterinary Pathology 24, 515524.
Buonocore, F., Prugnoli, D., Falasca, C., Secombes, C.J. and Scapigliati, G. (2003) Peculiar gene organisation and incomplete splicing of sea bass (Dicentrarchus labrax L.) interleukin-1beta. Cytokine 21,
257264.
Butterworth, A.E. and David, J.R. (1981) Eosinophil function. New England Journal of Medicine 304,
154156.
Caspi, R.R. and Avtalion, R.R. (1984) Evidence for the existence of an IL-2-like lymphocyte growth promoting factor in a bony fish, Cyprinus carpio. Developmental and Comparative Immunology 8, 5160.
Christiansen, J.L., Grzybowski, J.M. and Kodama, R.M. (1996) Melanomacrophage aggregations and their age
relationships in the yellow mud turtle, Kinosternon flavescens (Kinosternidae). Pigment Cell Research 9,
185190.
Columbo, M., Horowitz, E.M., Botana, L.M., MacGlashan, D.W., Jr, Bochner, B.S., Gillis, S., Zsebo, K.M.,
Galli, S.J. and Lichtenstein, L.M. (1992) The human recombinant c-kit receptor ligand, rhSCF, induces
mediator release from human cutaneous mast cells and enhances IgE-dependent mediator release from
both skin mast cells and peripheral blood basophils. Journal of Immunology 149, 599608.
Daffern, P.J., Pfeifer, P.H., Ember, J.A. and Hugli, T.E. (1995) C3a is a chemotaxin for human eosinophils but
not for neutrophils. I. C3a stimulation of neutrophils is secondary to eosinophil activation. Journal of
Experimental Medicine 181, 21192127.
Daniels, G.D. and Secombes, C.J. (1999) Genomic organisation of rainbow trout, Oncorhynchus mykiss
TGF-beta. Developmental and Comparative Immunology 23, 139147.
Daniels, G.D., Zou, J., Charlemagne, J., Partula, S., Cunningham, C. and Secombes, C.J. (1999) Cloning of
two chemokine receptor homologs (CXC-R4 and CC-R7) in rainbow trout Oncorhynchus mykiss. Journal
of Leukocyte Biology 65, 684690.
Denburg, J.A. (1999) Bone marrow in atopy and asthma: hematopoietic mechanisms in allergic inflammation.
Immunology Today 20, 111113.
Dinarello, C.A. (1997) Interleukin-1. Cytokine Growth Factor Reviews 8, 253265.
Ellis, A.E. (1986) The function of teleost fish lymphocytes in relation to inflammation. International Journal of
Tissue Reaction 8, 263270.
Engelsma, M.Y., Stet, R.J., Saeij, J.P. and Verburg-van Kemenade, B.M. (2003) Differential expression and
haplotypic variation of two interleukin-1 beta genes in the common carp (Cyprinus carpio L.). Cytokine
22, 2132.
Evans, D.L., Leary, J.H., 3rd and Jaso-Friedmann, L. (2001) Nonspecific cytotoxic cells and innate immunity:
regulation by programmed cell death. Developmental and Comparative Immunology 25, 791805.
Fehniger, T.A., Cooper, M.A. and Caligiuri, M.A. (2002) Interleukin-2 and interleukin-15: immunotherapy for
cancer. Cytokine Growth Factor Reviews 13, 169183.
720
Ferri, S. and Sesso, A. (1981) Ultrastructural study of Kupffer cells in teleost liver under normal and experimental conditions. Cell and Tissue Research 220, 387391.
Fournier-Betz, V., Quentel, C., Lamour, F. and LeVen, A. (2000) Immunocytochemical detection of Ig-positive
cells in blood, lymphoid organs and the gut associated lymphoid tissue of the turbot (Scophthalmus
maximus). Fish and Shellfish Immunology 10, 187202.
Fridman, R., Kibbey, M.C., Royce, L.S., Zain, M., Sweeney, M., Jicha, D.L., Yannelli, J.R., Martin, G.R. and
Kleinman, H.K. (1991) Enhanced tumor growth of both primary and established human and murine tumor
cells in athymic mice after coinjection with Matrigel. Journal of the National Cancer Institute 83, 769774.
Fujiki, K., Shin, D.H., Nakao, M. and Yano, T. (1999) Molecular cloning of carp (Cyprinus carpio) CC
chemokine, CXC chemokine receptors, allograft inflammatory factor-1, and natural killer cell enhancing
factor by use of suppression subtractive hybridization. Immunogenetics 49, 909914.
Fujiki, K., Shin, D.H., Nakao, M. and Yano, T. (2000a) Molecular cloning of carp (Cyprinus carpio) leucocyte
cell-derived chemotaxin 2, glia maturation factor beta, CD45 and lysozyme C by use of suppression
subtractive hybridisation. Fish and Shellfish Immunology 10, 643650.
Fujiki, K., Shin, D.H., Nakao, M. and Yano, T. (2000b) Molecular cloning and expression analysis of carp
(Cyprinus carpio) interleukin-1 beta, high affinity immunoglobulin E Fc receptor gamma subunit and
serum amyloid A. Fish and Shellfish Immunology 10, 229242.
Fujiki, K., Gauley, J., Bols, N.C. and Dixon, B. (2003) Genomic cloning of novel isotypes of the rainbow trout
interleukin-8. Immunogenetics 55, 126131.
Ghanmi, Z., Rouabhia, M. and Deschaux, P. (1993) Zinc (Zn2+) and fish immune response effect on carp
IL2-like production and activity. Ecotoxicology and Environmental Safety 25, 236243.
Gleich, G.J. and Loegering, D.A. (1984) Immunobiology of eosinophils. Annual Review of Immunology 2,
429459.
Gogal, R.M., Jr, Smith, B.J., Robertson, J.L., Smith, S.A. and Holladay, S.D. (1999) Tilapia (Oreochromis
niloticus) dosed with azathioprine display immune effects similar to those seen in mammals, including
apoptosis. Veterinary Immunology and Immunopathology 68, 209227.
Grondel, J.L. and Harmsen, E.G. (1984) Phylogeny of interleukins: growth factors produced by leucocytes of
the cyprinid fish, Cyprinus carpio L. Immunology 52, 477482.
Gudding, R., Lillehaug, A. and Evenson, O. (1999) Recent developments in fish vaccinology. Veterinary
Immunology and Immunopathology 72(12), 203212.
Hagiwara, K., Kobayashi, K., Kajii, T. and Tomonaga, S. (1985) J-chain-like component in 18-S immunoglobulin of the skate Raja kenojei, a cartilaginous fish. Molecular Immunology 22, 775778.
Haire, R.N., Miracle, A.L., Rast, J.P. and Litman, G.W. (2000) Members of the Ikaros gene family are present in
early representative vertebrates. Journal of Immunology 165, 306312.
Hardie, L.J., Chappell, L.H. and Secombes, C.J. (1994) Human tumor necrosis factor alpha influences rainbow
trout Oncorhynchus mykiss leucocyte responses. Veterinary Immunology and Immunopathology 40, 7384.
Harms, C.A., Kennedy-Stoskopf, S., Horne, W.A., Fuller, F.J. and Tompkins, W.A. (2000) Cloning and sequencing hybrid striped bass (Morone saxatilis M. chrysops) transforming growth factor-beta (TGF-beta), and
development of a reverse transcription quantitative competitive polymerase chain reaction (RT-qcPCR)
assay to measure TGF-beta mRNA of teleost fish. Fish and Shellfish Immunology 10, 6185.
Hart, P.H. (1997) Regulation of the inflammatory response in asthma by mast cell products. Immunology and
Cell Biology 79, 149153.
Herbert, D.R., Nolan, T.J., Schad, G.A. and Abraham, D. (2002) The role of B cells in immunity against larval
Strongyloides stercoralis in mice. Parasite Immunology 24, 95101.
Herzenberg, A.M., Lien, J. and Magil, A.B. (1996) Monoclonal heavy chain (immunoglobulin G3) deposition
disease: report of a case. American Journal of Kidney Disease 28, 128131.
Hirono, I., Nam, B.H., Kurobe, T. and Aoki, T. (2000) Molecular cloning, characterization, and expression of
TNF cDNA and gene from Japanese flounder Paralichthys olivaceus. Journal of Immunology 165,
44234427.
Hirono, I., Nam, B.H., Enomoto, J., Uchino, K. and Aoki, T. (2003) Cloning and characterisation of a cDNA
encoding Japanese flounder Paralichthys olivaceus IgD. Fish and Shellfish Immunology 15, 6370.
Hirsch, S., Austyn, J.M. and Gordon, S. (1981) Expression of the macrophage-specific antigen F4/80
during differentiation of mouse bone marrow cells in culture. Journal of Experimental Medicine 154,
713725.
Hitoshi, Y., Yamaguchi, N., Mita, S., Sonoda, E., Takaki, S., Tominaga, A. and Takatsu, K. (1990) Distribution of IL-5 receptor-positive B cells. Expression of IL-5 receptor on Ly-1(CD5)+ B cells. Journal of
Immunology 144, 42184225.
721
Holland, J.W. and Rowley, A.F. (1998) Studies on the eosinophilic granule cells in the gills of the rainbow
trout, Oncorhynchus mykiss. Comparative Biochemistry and Physiology C Pharmacology, Toxicology
and Endocrinology 120(2), 321328.
Huising, M.O., Stolte, E., Flik, G., Savelkoul, H.F. and Verburg-van Kemenade, B.M. (2003) CXC chemokines
and leukocyte chemotaxis in common carp (Cyprinus carpio L.). Developmental and Comparative
Immunology 27, 875888.
Hyder, S.L., Cayer, M.L. and Pettey, C.L. (1983) Cell types in peripheral blood of the nurse shark: an approach
to structure and function. Tissue and Cell 15, 437455.
Inoue, Y., Haruta, C., Usui, K., Moritomo, T. and Nakanishi, T. (2003) Molecular cloning and sequencing of
the banded dogfish (Triakis scyllia) interleukin-8 cDNA. Fish and Shellfish Immunology 14, 275281.
Jansson, E., Gronvik, K.O., Johannisson, A., Naslund, K., Westergren, E. and Pilstrom, L. (2003) Monoclonal
antibodies to lymphocytes of rainbow trout (Oncorhynchus mykiss). Fish and Shellfish Immunology 14,
239257.
Jaso-Friedmann, L., Leary, J.H., 3rd and Evans, D.L. (2001) The non-specific cytotoxic cell receptor (NCCRP-1):
molecular organization and signaling properties. Developmental and Comparative Immunology 25,
701711.
Kantor, A.B. (1991) The development and repertoire of B-1 cells (CD5 B cells). Immunology Today 12, 389391.
Kay, A.B. (1985) Eosinophils: role in asthma, allergy and parasite immunity. New England Regional Allergy
Proceedings 6, 341345.
Khamidov, D.K.H. and Nishanbaev, K.N. (1975) A comparative electron microscopic study of the peripheral
blood leukocytes of vertebrates. Arkhiv anatomii, gistologii i embriologii 69, 7683.
Kobayashi, K., Hara, A., Takano, K. and Hirai, H. (1982) Studies on subunit components of immunoglobulin
M from a bony fish, the chum salmon (Oncorhynchus keta). Molecular Immunology 19, 95103.
Laing, K.J., Grabowski, P.S., Belosevic, M. and Secombes, C.J. (1996) A partial sequence for nitric oxide synthase
from a goldfish (Carassius auratus) macrophage cell line. Immunology and Cell Biology 74, 374379.
Laing, K.J., Wang,T., Zou, J., Holland, J., Hong, S., Bols, N., Hirono, I., Aoki, T. and Secombes, C.J. (2001)
Cloning and expression analysis of rainbow trout Oncorhynchus mykiss tumour necrosis factor-alpha.
European Journal of Biochemistry 268, 13151322.
Laing, K.J., Zou, J.J., Wang, T., Bols, N., Hirono, I., Aoki, T. and Secombes, C.J. (2002) Identification and
analysis of an interleukin 8-like molecule in rainbow trout Oncorhynchus mykiss. Developmental and
Comparative Immunology 26, 433444.
Lally, J., Al-Anouti, F., Bols, N. and Dixon, B. (2003) The functional characterisation of CK-1, a putative CC
chemokine from rainbow trout (Oncorhynchus mykiss). Fish and Shellfish Immunology 15, 411424.
Lambrecht, B.N., Salomon, B., Klatzmann, D. and Pauwels, R.A. (1998) Dendritic cells are required for the
development of chronic eosinophilic airway inflammation in response to inhaled antigen in sensitized
mice. Journal of Immunology 160, 40904097.
Lee, E.Y., Park, H.H., Kim, Y.T. and Choi, T.J. (2001) Cloning and sequence analysis of the interleukin-8 gene
from flounder (Paralichthys olivaceus). Gene 274, 237243.
Lindenstrom, T., Buchmann, K. and Secombes, C.J. (2003) Gyrodactylus derjavini infection elicits IL-1beta
expression in rainbow trout skin. Fish and Shellfish Immunology 15, 107115.
Liu, K., Catalfamo, M., Li, Y., Henkart, P.A. and Weng, N.P. (2002) IL-15 mimics T cell receptor crosslinking
in the induction of cellular proliferation, gene expression, and cytotoxicity in CD8+ memory T cells.
Proceedings of the National Academy of Sciences of the USA 99, 61926197.
Liu, L., Chong, S.W., Balasubramaniyan, N.V., Korzh, V. and Ge, R. (2002) Platelet-derived growth factor
receptor alpha (pdgfr-alpha) gene in zebrafish embryonic development. Mechanisms in Development
116, 227230.
Long, Q., Quint, E., Lin, S. and Ekker, M. (2000) The zebrafish scyba gene encodes a novel CXC-type
chemokine with distinctive expression patterns in the vestibulo-acoustic system during embryogenesis.
Mechanisms in Development 97, 183186.
Long, S., Wilson, M., Bengten, E., Bryan, L., Clem, L.W., Miller, N.W. and Chinchar, V.G. (2004) Identification of a cDNA encoding channel catfish interferon. Developmental and Comparative Immunology 28,
97111.
McCumber, L.J. and Clem, L.W. (1976) Esterification of J chain and its effect on electrophoretic mobility in
sodium dodecyl sulfate polyacrylamide gels. Biochimia et Biophysica Acta 446, 536541.
McEwen, B.J. (1992) Eosinophils: a review. Veterinary Research Communications 16, 1144.
McKinney, E.C. and Flajnik, M.F. (1997) IgM-mediated opsonization and cytotoxicity in the shark. Journal of
Leukocyte Biology 61, 141146.
722
Mathew, J.A., Guo, Y.X., Goh, K.P., Chan, J., Verburg-van Kemenade, B.M. and Kwang, J. (2002) Characterisation of a monoclonal antibody to carp IL-1beta and the development of a sensitive capture ELISA. Fish
and Shellfish Immunology 13, 8595.
Meseguer, J., Esteban, M.A., Garcia Ayala, A., Lopez Ruiz. A. and Agulleiro, B. (1990) Granulopoiesis in the
head-kidney of the sea bass (Dicentrarchus labrax L.): an ultrastructural study. Archives of Histology and
Cytology 53, 287296.
Meseguer, J., Lopez-Ruiz, A. and Angeles Esteban, M. (1994) Cytochemical characterization of leucocytes
from the seawater teleost, gilthead seabream (Sparus aurata L.). Histochemistry 2, 3744.
Mestecky, J., Kulhavy, R., Schrohenloher, R.E., Tomana, M. and Wright, G.P. (1975) Identification and
properties of J chain isolated from catfish macroglobulin. Journal of Immunology 115, 993997.
Middleton, D., Curran, M. and Maxwell, L. (2002) Natural killer cells and their receptors. Transplantation
Immunology 10, 147164.
Miller, N., Wilson, M., Bengten, E., Stuge, T., Warr, G. and Clem, W. (1998) Functional and molecular
characterization of teleost leukocytes. Immunological Reviews 166, 187197.
Miller, N.W. and Clem, L.W. (1984) Temperature-mediated processes in teleost immunity: differential effects
of temperature on catfish in vitro antibody responses to thymus-dependent and thymus-independent
antigens. Journal of Immunology 133, 23562359.
Mukaida, N., Harada, A. and Matsushima, K. (1998) Interleukin-8 (IL-8) and monocyte chemotactic and
activating factor (MCAF/MCP-1), chemokines essentially involved in inflammatory and immune reactions. Cytokine and Growth Factor Reviews 9, 923.
Nakanishi, T. and Ototake, M. (1999) The graft-versus-host reaction (GVHR) in the ginbuna crucian carp,
Carassius auratus langsdorfii. Developmental and Comparative Immunology 23, 1526.
Nam, B.H., Yamamoto, E., Hirono, I. and Aoki, T. (2000) A survey of expressed genes in the leukocytes of
Japanese flounder, Paralichthys olivaceus, infected with Hirame rhabdovirus. Developmental and
Comparative Immunology 24, 1324.
Nam, B.H., Hirono, I. and Aoki, T. (2003) The four TCR genes of teleost fish: the cDNA and genomic DNA
analysis of Japanese flounder (Paralichthys olivaceus) TCR alpha-, beta-, gamma-, and delta-chains.
Journal of Immunology 170, 30813090.
Neumann, N.F., Fagan, D. and Belosevic, M. (1995) Macrophage activating factor(s) secreted by mitogen
stimulated goldfish kidney leukocytes synergize with bacterial lipopolysaccharide to induce nitric
oxide production in teleost macrophages. Developmental and Comparative Immunology 19,
473482.
Neumann, N.F., Barreda, D.R. and Belosevic, M. (2000) Generation and functional analysis of distinct
macrophage sub-populations from goldfish (Carassius auratus L.) kidney leukocyte cultures. Fish and
Shellfish Immunology 10, 120.
Nicola, N.A. (1994) Guidebook to Cytokines and Their Receptors. Sambrook & Tooze Publications, Oxford, UK.
Nie, P. and Hoole, D. (2000) Effects of Bothriocephalus acheilognathi on the polarization response of
pronephric leucocytes of carp, Cyprinus carpio. Journal of Helminthology 74, 253257.
Ogata, K., An, E., Shioi, Y., Nakamura, K., Luo, S., Yokose, N., Minami, S. and Dan, K. (2001) Association
between natural killer cell activity and infection in immunologically normal elderly people. Clinical and
Experimental Immunology 124, 392397.
Oritani, K., Kincade, P.W., Zhang, C., Tomiyama, Y. and Matsuzawa, Y. (2001) Type I interferons and limitin:
a comparison of structures, receptors, and functions. Cytokine Growth Factor Reviews 12, 337348.
Partula, S., de Guerra, A., Fellah, J.S. and Charlemagne, J. (1995) Structure and diversity of the T cell antigen
receptor beta-chain in a teleost fish. Journal of Immunology 155, 699706.
Qin, Q.W., Ototake, M., Noguchi, K., Soma, G., Yokomizo, Y. and Nakanishi, T. (2001) Tumor necrosis factor
alpha (TNFalpha)-like factor produced by macrophages in rainbow trout, Oncorhynchus mykiss. Fish
and Shellfish Immunology 11, 245256.
Ravetch, J.V. (1997) Fc receptors. Current Opinion in Immunology 9, 121125.
Renault, T., Torchy, C. and De Kinkelin, P. (1991) Spectrophotometric method for titration of trout interferon,
and its application to rainbow trout fry experimentally infected with viral haemorrhagic septocaemia
virus. Diseases of Aquatic Organisms 10, 2329.
Rijkers, G.T., Frederix-Wolters, E.M. and van Muiswinkel, W.B. (1980) The immune system of cyprinid fish.
Kinetics and temperature dependence of antibody-producing cells in carp (Cyprinus carpio).
Immunology 41(1), 9197.
Ruiz, J., Leary, J.H., 3rd and Jaso-Friedmann, L. (2001) Phosphorylation-induced activation of tilapia nonspecific
cytotoxic cells by serum cytokines. Diseases of Aquatic Organisms 46, 129137.
723
Saeij, J.P., Stet, R.J., de Vries, B.J., van Muiswinkel, W.B. and Wiegertjes, G.F. (2003) Molecular and functional
characterization of carp TNF: a link between TNF polymorphism and trypanotolerance? Developmental
and Comparative Immunology 27, 2941.
Saito, H., Shimizu, H., Mita, H., Maeda, Y. and Akiyama, K. (1996) Histamine augments VCAM-1 expression
on IL-4- and TNF-alpha-stimulated human umbilical vein endothelial cells. International Archives of
Allergy and Immunology 111, 126132.
Sangrador-Vegas, A., Lennington, J.B. and Smith, T.J. (2002) Molecular cloning of an IL-8-like CXC
chemokine and tissue factor in rainbow trout (Oncorhynchus mykiss) by use of suppression subtractive
hybridization. Cytokine 17, 6670.
Scapigliati, G., Bird, S. and Secombes, C.J. (2000) Invertebrate and fish cytokines. European Cytokine
Network 11, 354361.
Scapigliati, G., Romano, N., Buonocore, F., Picchietti, S., Baldassini, M.R., Prugnoli, D., Galice, A., Meloni, S.,
Secombes, C.J., Mazzini, M. and Abelli, L. (2002) The immune system of sea bass, Dicentrarchus labrax,
reared in aquaculture. Developmental and Comparative Immunology 26, 151160.
Seaman, M.S., Wang, C.R. and Forman, J. (2000) MHC class Ib-restricted CTL provide protection against
primary and secondary Listeria monocytogenes infection. Journal of Immunology 165, 51925201.
Secombes, C.J., Clements, K., Ashton, I. and Rowley, A.F. (1994) The effect of eicosanoids on rainbow
trout, Oncorhynchus mykiss, leucocyte proliferation. Veterinary Immunology and Immunopathology 42,
367378.
Secombes, C.J., Wang, T., Hong, S., Peddie, S., Crampe, M., Laing, K.J., Cunningham, C. and Zou, J. (2001)
Cytokines and innate immunity of fish. Developmental and Comparative Immunology 25, 713723.
Sepulcre, M.P., Pelegrin, P., Mulero, V. and Meseguer, J. (2002) Characterisation of gilthead seabream
acidophilic granulocytes by a monoclonal antibody unequivocally points to their involvement in fish
phagocytic response. Cell and Tissue Research 308, 97102.
Sire, M.F. and Vernier, J.M. (1995) Partial characterization of eosinophilic granule cells (EGCs) and
identification of most cells of the intestinal lamina propria in rainbow trout (Oncorhynchus mykiss). Biochemical and cytochemical study. Biol Cell 85(1), 3541.
Steinman, R.M. (1991) The dendritic cell system and its role in immunogenicity. Annual Review of Immunology
9, 271296.
Stuge, T.B., Yoshida, S.H., Chinchar, V.G., Miller, N.W. and Clem, L.W. (1997) Cytotoxic activity generated
from channel catfish peripheral blood leukocytes in mixed leukocyte cultures. Cellular Immunology 177,
154161.
Szakal, A.K., Kosco, M.H. and Tew, J.G. (1989) Microanatomy of lymphoid tissue during humoral immune
responses: structure function relationships. Annual Review of Immunology 7, 91109.
Tafalla, C., Aranguren, R., Secombes, C.J., Castrillo, J.L., Novoa, B. and Figueras, A. (2003) Molecular characterisation of sea bream (Sparus aurata) transforming growth factor beta1. Fish and Shellfish Immunology 14,
405421.
Tonegawa, S. (1983) Somatic generation of antibody diversity. Nature 302, 575581.
Townsend, A. and Bodmer, H. (1989) Antigen recognition by class I-restricted T lymphocytes. Annual Review
of Immunology 7, 601624.
Vallejo, A.N., Jr and Ellis, A.E. (1989) Ultrastructural study of the response of eosinophil granule cells to
Aeromonas salmonicida extracellular products and histamine liberators in rainbow trout Salmo gairdneri
Richardson. Developmental and Comparative Immunology 13, 133148.
van Ewijk, W. (1991) T-cell differentiation is influenced by thymic microenvironments. Annual Review of
Immunology 9, 591615.
van Ginkel, F.W., Miller, N.W., Cuchens, M.A. and Clem, L.W. (1994) Activation of channel catfish B cells by
membrane immunoglobulin cross-linking. Developmental and Comparative Immunology 18, 97107.
Verburg-van Kemenade, B.M., Weyts, F.A., Debets, R. and Flik, G. (1995) Carp macrophages and neutrophilic
granulocytes secrete an interleukin-1-like factor. Developmental and Comparative Immunology 19,
5970.
Vethaak, A.D., Jol, J.G., Meijboom, A., Eggens, M.L., Rheinallt, T., Wester, P.W., van de Zande, T., Bergman, A.,
Dankers, N., Ariese, F., Baan, R.A., Everts, J.M., Opperhuizen, A. and marquenie, J.M. (1996) Skin and
liver diseases induced in flounder (Platichthys flesus) after long-term exposure to contaminated sediments in large-scale mesocosms. Environmental Health Perspective 4, 12181229.
Vogel, W.O. (1985) The caudal heart of fish: not a lymph heart. Acta Anatomica (Basle) 121, 4145.
Warr, G.W. and Marchalonis, J.J. (1987) Nonpermeant covalent labels in analytical studies of lymphocyte
membrane proteins. Methods in Enzymology 150, 399418.
724
Weinheimer, P.F., Mestecky, J. and Acton, R.T. (1971) Species distribution of J chain. Journal of Immunology
107, 12111212.
Weiss, J. (1979) Occurrence and ultrastructure of mast cells in the hypothalamus of teleost fishes. Zeitschrift
fur mikroskopisch-anatomische Forschung 93, 147160.
Williams, H., Brenner, S. and Venkatesh, B. (2002) Identification and analysis of additional copies of the
platelet-derived growth factor receptor and colony stimulating factor 1 receptor genes in fugu. Gene
295, 255264.
Wilson, M.R. and Warr, G.W. (1992) Fish immunoglobulins and the genes that encode them. Annual Review
of Fish Diseases Vol. 2, 201221.
Woodhead, A.D., Pond, V. and Dailey, K. (1983) Aging changes in the kidneys of two poeciliid fishes, the
guppy Poecilia reticulatus and the Amazon molly P. formosa. Experimental Gerontology 18, 211221.
Zhang, H., Thorgaard, G.H. and Ristow, S.S. (2002) Molecular cloning and genomic structure of an
interleukin-8 receptor-like gene from homozygous clones of rainbow trout (Oncorhynchus mykiss).
Fish and Shellfish Immunology 13, 251258.
Zou, J., Secombes, C.J., Long, S., Miller, N., Clem, L.W. and Chinchar, V.G. (2003) Molecular identification
and expression analysis of tumor necrosis factor in channel catfish (Ictalurus punctatus). Developmental
and Comparative Immunology 27, 845858.
Zuasti, A. and Ferrer, C. (1989) Haemopoiesis in the head kidney of Sparus auratus. Archives of Histology and
Cytology 52, 249255.
20
Introduction
Molecular genetic techniques have in the
last 15 years gained widespread use in the
study of fish parasites. These techniques
have been particularly effective in unravelling the complex life histories of various
parasitic forms, and have played a key role
in determining the precise taxonomic relationships between parasite species that are
difficult to ascertain using traditional morphological techniques. In some instances,
these studies have provided key insights into
evolutionary biology as a whole. In addition,
molecular tools have contributed to our
understanding of the cellular biology of parasites, and have proved indispensable in the
more practical realm of disease diagnosis and
vaccine development.
The present chapter focuses primarily
on the use of two methods, namely, the
polymerase chain reaction (PCR) and DNA
sequencing, in the analysis of fish parasites.
This emphasis reflects the widespread use
of these techniques in diagnostics, epidemiology and systematics. Specific applications are described for Myxozoa, Microspora,
Ciliates, kinetoplastids, Icthyosporea and
helminths. Along with PCR and DNA
sequence analysis (which rely on DNADNA
interactions in solution), solid-phase hybridization methods are also discussed, with
particular emphasis on in situ hybridization
as a means of identifying parasites in host
725
726
T.G. Clark
727
Fig. 20.2. Organization of ribosomal RNA loci. Small subunit (18S) and large subunit (28S) rRNA genes are
separated by internally transcribed spacer regions (ITS1 and ITS2). The rDNA genes are expressed as a single
large transcript that extends from the externally transcribed spacer region (ETS) just proximal to the small
subunit gene, through the end of the large subunit gene. The transcript is processed into separate 18S, 5.8S
and 28S rRNAs, which are then incorporated into the ribosome. The variable region at the proximal end of
the large subunit gene (D1/D2), as well as the intergeneic non-transcribed spacer regions (IGS1 and IGS2)
are sometimes used as targets for phylogenetic analyses.
728
T.G. Clark
Fig. 20.3. (Top panel) SSU rRNA gene primer map for C. shasta. Predicted amplicon sizes for different
combinations of the primers (Cs1, Cs2, R, Cs3, Cs4, Cs5, 18SUNIF and 18SUNIR are shown in base pairs.
Bottom panel shows specificity of different primer pairs for C. shasta DNA. Amplicons of the predicted size
were obtained with DNA from C. shasta spores (lanes a, d, g, j and m), but not rainbow trout (lanes b, e, h,
k and n) or Henneguya salminicola (c, f, i, l and o). Primer pairs were Cs1Cs5 (lanes ac); Cs1Cs3 (lanes
df); Cs2Cs5 (lanes gi); RCs4 (lanes jl); and rCs5 (lanes mo). (From Palenzuela et al., 1999 with
permission from Diseases of Aquatic Organisms.)
729
730
T.G. Clark
Microspora
The microsporidia are an extremely interesting group of intracellular parasites that
infect vertebrate and invertebrate hosts
(Chapter 7). More than 150 species are known
to infect fishes (Lom and Nilsen, 2003).
Microsporidia may cause either destruction
of the host cell cytoplasm or hypertrophy
and the formation of an enlarged host cell/
parasite complex referred to as a xenoma. In
fish, microsporidia are found in different
host tissues, including gills, muscle, nerve,
blood, gonads, liver and intestine, where
they cause severe disease. Although morphological criteria have been used to classify the microsporidia, SSU rDNA sequence
analyses have been far more informative in
respect of phylogenetic relationships within
this group. While a detailed phylogenetic
tree for microsporidia is still emerging,
sequence data are available for 12 of the 15
microsporidian genera known to infect fish.
SSU sequence comparisons suggest that
these cluster into five taxonomic groups,
four of which form a single clade. The outlying group (Nucleospora) is only distantly
related and probably represents an entirely
different taxonomic order (Nilsen, 2000).
Supporting this argument is the fact that
SSU ribosomal genes from Nucleospora
salmonis and species belonging to the main
clade share only 60% sequence identity
overall (Lom and Nilsen, 2003).
The high degree of conservation of SSU
sequences sometimes obscures relationships
between closely related species within the
individual microsporidian group. However,
ITS regions (which vary in length by a factor of 10 among different microsporidia), as
well as protein-coding genes, often provide
the necessary data to resolve the relationships between individual species (Lom and
Nilsen, 2003). Interestingly, within the
principal clade of microsporidia infecting
teleosts, a number of species appear to be
specific for hosts other than fish (including
crustaceans, insects and humans). If this
host specificity can be verified, similarities
in the SSU sequences between fish-specific
parasites and the non-fish species would
suggest that the switch to non-fish hosts is a
fairly recent event (Lom and Nilsen, 2003).
At the higher taxonomic level, initial
studies of SSU rDNA sequences suggested
that microsporidia evolved early in the
eukaryotic lineage and were considered to
be primitive protozoans (Vossbrinck et al.,
1987). Nevertheless, accumulating data from
both SSU and protein-coding genes, including tubulin (Edlind et al., 1996; Keeling and
Doolittle, 1996), HSP70 (Germot et al., 1997;
Hirt et al., 1997; Peyretaillade et al., 1998)
and RNA polymerase II (Cheney et al., 2001),
have indicated that the microsporidia are
related to fungi and have evolved more
recently than previously thought.
Apart from their use in phylogenetic
studies, PCR-based analyses of SSU rDNAs
have been useful as diagnostic tools for the
detection of microsporidian infections in
fishes. Single and nested PCR tests have
been developed for Microsporidium seriolae
(Bell et al., 1999), Pleistophora anguillarum
(Hung et al., 1998), Loma salmonae (Docker
et al., 1997), and N. salmonis (Barlough et al.
1995; Gresoviac et al., 2000). These tests are
731
Ciliates
SSU rDNA sequence analysis has been
applied to the two most important parasitic
ciliates of commercially raised fish, namely,
Ichthyophthirius multifiliis, the causative
agent of white-spot disease in freshwater
fish, and Cryptocaryon irritans, its saltwater
counterpart (Chapter 4). These species were
long considered to be taxonomically related
because of their similar life cycles and
morphologies. Nevertheless, rDNA sequence
analysis has indicated that I. multifiliis and
C. irritans are highly diverged. I. multifiliis
is one of two genera within the group
Ophryoglenina that is sister to the tetrahymenines (class Oligohymenophorea)
(Wright and Lynn, 1995). C. irritans, on the
other hand, is only distantly related and is
in a different class, the Prostomatea (order
Prorodontida) (Diggles and Adlard, 1995;
Wright and Colorni, 2002). Analysis of
rDNA sequences from individual isolates of
Cryptocaryon from Australia (Diggles and
732
T.G. Clark
Fig. 20.4. Riboprinting. Specific primers (in this example for SSU rDNA) are used to amplify regions
of DNA by PCR. PCR products are then digested with a given restriction endonuclease. Sequence
polymorphisms among individual organisms, strains or species are manifested as different patterns of bands
on agarose gels. (From Clark, 1997. With permission from Journal of Eukaryotic Microbiology.)
Kinetoplastids
The kinetoplastids (Chapter 3) are a group of
flagellated protozoa (phylum Euglenozoa)
that share a common structural feature, the
kinetoplast, which lies within the single
mitochondrion at the base of the flagellum(a).
This structure comprises a network of circular DNA molecules containing genes for
mitochondrial proteins. However, unlike
standard protein coding genes, those within
the kinetoplast undergo an unusual process of post-transcriptional RNA editing in
order that their sequences can be translated in an appropriate fashion (Maslov
et al., 1994; Vickerman and Coombs,
1999). The kinetoplastids consist of two or
more suborders, the most widely recognized being Trypanosomatina, a group of
exclusively parasitic forms that have a single flagellum (including the well-known
Trypanosoma and Leishmania species), and
Bodonina, which include free-living heterotrophic, ectocommensal and parasitic forms
with two flagella. A number of species
within each group are parasitic on/in
Ichthyosporea (Mesomycetozoea)
Molecular genetic analyses have been
instrumental in the classification of
Ichthyosporea, a discrete taxon consisting
733
734
T.G. Clark
encoding elongation factor 1- from Ichthyosporea, animals and fungi do not provide a
clear picture of the relationships between
these organisms, they clearly group all three
within a separate clade, known formally as
the Opisthokonta (Ragan et al., 2003).
Analyses of the mtDNAs of the Holozoa
provide additional, interesting information
regarding the evolution of the genome
structure of this organelle. While Metazoa
have relatively uniform compact (1319 kb)
mitochondrial genomes, consisting of closed
circular DNAs present as monomers and
concatenated oligomers, mtDNAs in other
eukaryotic clades (including plants, fungi
and protozoa) vary greatly in terms of their
size and overall structures. Interestingly,
the circular mtDNAs of choanoflagellates
are up to four times as large as those in
Metazoa and have roughly twice the number of protein-coding genes. Mitochondrial
DNAs of Ichthyosporea are even larger (up
to ten times the size), and consist of several
hundred linear chromosomes that share
elaborate terminal repeat structures (Burger
et al., 2003). The differences in mtDNA
structure within various branches of the
Holozoa would clearly suggest that compaction of the mitochondrial genomes seen in
animals occurred at or near the time of
emergence of a multicellular body plan.
Helminths
Nucleotide sequence analyses of rDNA and
protein-coding genes have been widely
applied in epidemiological and phylogenetic studies of parasitic helminths of fish.
These approaches are particularly useful in
uncovering cryptic or sibling species whose
members are more or less morphologically
similar. In addition, they relate to important
issues in parasite evolution, including the
idea that host switching plays a role in the
speciation of at least some taxa. Examples
of the use of these techniques are summarized briefly below, with primary emphasis
on species that have an impact on wild and
commercial fisheries.
Monogenean parasites (Chapter 9)
belonging to the genus Gyrodactylus have
been classified into 400 species on morphological grounds, although the true
number may exceed 20,000 (Zietara and
Lumme, 2002). A number of these species
are pathogenic to fishes and have serious
effects on wild populations, particularly
those of Norwegian Atlantic salmon. Genetic
markers that can distinguish species and/or
intraspecific (i.e. strain) differences that
relate to pathogenicity have long been
sought. Because of its economic impact,
considerable emphasis has been placed on
Gyrodactylus salaris. The parasite has been
identified in rivers and streams across
Northern Europe, where it infects both
Atlantic salmon (Salmo salar L.), and
farmed rainbow trout. Disease outbreaks in
specific locations have suggested that
pathogenic strains of G. salaris may exist.
However, pathogenicity has not been linked
to any particular morphological trait(s).
Indeed, while intraspecific differences in
host adaptation appear to exist, the genus as
a whole is morphologically quite similar. At
the molecular level, neither SSU nor ITS
rDNA sequence analysis has been particularly useful for discriminating strains.
For example, ITS sequences are identical
between G. salaris isolates obtained from
different host species across a wide geographical range and fail to discriminate
G. salaris from Gyrodactylus thymalli, its
avirulent sister group that is specific for
European grayling (Thymallus thymallus)
(Cunningham, 1997; Zietara and Lumme,
2002). However, analyses of the intergenic
spacer (IGS) regions of rDNA, as well as the
mitochondrial cytochrome c oxidase I (COI)
gene, have been far more revealing (Sterud
et al., 2002; Cunningham et al., 2003;
Hansen et al., 2003; Meinil et al., 2004).
While these studies have failed to yield markers for pathogenic strains, they provide considerable insight into the phylogeny of
G. salaris and its sister group G. thymalli,
and suggest an interesting hypothesis
regarding mechanisms of speciation within
the genus. Analysis of IGS rDNA sequences
of Gyrodactylus collected at different locations from different types of fish show clear
differences in the number and sequence of
individual 23 bp repeats within the two
735
736
T.G. Clark
genetic analysis. A number of anisakid species (in particular, Anisakis simplex) are
recognized as zoonotic agents in humans
who consume undercooked seafood. Simple PCR-based assays that can be used to
detect and distinguish species of anisakids
infecting marine and freshwater fishes,
mammals and fish-eating birds have now
been developed (Zhu et al., 1998; DAmelio
et al., 2000; Kijewska et al., 2002). These
assays rely on RFLPs in a region of the
rDNA containing ITS1, the 5.8S rRNA gene,
ITS2 and 70 bp of the 28S rRNA gene.
Upon amplification of this region with
broadly specific primers spanning the ITS1
and ITS2 domains of anisakid rDNA, batteries of restriction enzymes generate discrete
patterns of fragments from different parasite
species, including possible cryptic species
of A. simplex (Zhu et al., 1998; DAmelio
et al., 2000; Kijewska et al., 2002). These
types of PCR-RFLP assays will undoubtedly
be extremely useful in future diagnostic and
epidemiological studies of marine and
freshwater ascarids.
737
738
T.G. Clark
Fig. 20.5. RAPD PCR analysis of Ichthyophthirius multifiliis. DNA from individual (cloned) parasites
collected from rainbow trout following a natural outbreak of white spot disease in upstate New York was
amplified,using a single pair of random PCR primers (lanes 110). The infection was passaged on channel
catfish and individual parasites were again harvested and analysed by RAPD PCR with the same set of
random primers (lanes 1119). While DNA fingerprints from parasites collected from the initial infection
on rainbow trout were quite varied, the patterns generated with parasites taken from channel catfish were
largely homogeneous. The lane on the extreme right represents a DNA size standard.
to the probe. Following hybridization, signals generated by the probe are used to
detect and localize the pathogen (where the
probe is labelled with a fluorochrome, the
method is referred to as fluorescence in situ
hybridization (FISH)).
ISH techniques for the detection of
fish parasites have been applied to both
Myxozoa and Microsporea. Antonio et al.
(1998) used them to detect M. cerebralis in
fixed tissues of rainbow trout and its intermediate host, T. tubifex. Three different
oligonucleotide primers intended originally
for PCR amplification of M. cerebralis SSU
rDNA were end-labelled with the steroid
hapten digoxigenin (DIG) and hybridized
to fixed tissue sections that had been
dewaxed and proteinase K-treated to expose
parasite DNA. After high-stringency washing,
probes were detected using alkaline
phosphatase-conjugated anti-DIG antibodies
and appropriate colorimetric (NBT/BCIP)
739
740
T.G. Clark
Gene Cloning
The isolation of genes encoding specific
proteins has become an indispensable tool
for studying the biology of living species
and is often a key step in the development
of therapeutic and prophylactic reagents
against pathogens. Procedures for gene purification generally take one of two routes. The
first involves construction and plating of
libraries of genomic or complementary
DNA (cDNA) from the pathogen, followed
by the identification and isolation of clones
of interest by hybridization with specific
nucleic acid probes (or by cross-reactivity
with antibody probes in the case of expression libraries). The alternative approach
involves amplification of known (or suspected) protein-coding regions by PCR,
using genomic DNA as the template and
degenerate oligonucleotide primers that target conserved regions of coding sequence.
Once desired genes have been isolated, corresponding protein products can be synthesized using any of a number of heterologous
protein expression systems (e.g. Escherichia coli (Swartz, 2001), yeast (Gellissen,
2000), Tetrahymena (Gaertig et al., 1999),
insect (Jarvis et al., 1996) and mammalian
tissue culture cells (Fussenegger et al.,
1999)). The resulting recombinant products
can then be used for a variety of purposes,
ranging from X-ray crystallography and
drug design to the development of recombinant subunit vaccines. In systems that
allow reverse genetics, gene isolation often
permits one to conduct functional assays of
specific proteins by knocking out the corresponding gene in vivo, using either
targeted deletion via homologous recombination (Gong and Rong, 2003) or interfering
RNA technology (RNAi) (Zanmore, 2002).
The creation of knockout strains can also
serve in the construction of rationally attenuated vaccine strains, particularly in cases
where gene deletion results in altered virulence (Kit et al., 1985; Charles and Dougan,
1990; Uzonna et al., 2004).
Along with conventional gene isolation
methods, robotic systems are now available
that permit high-throughput sequencing of
large numbers of cloned inserts from DNA
libraries. This approach has opened up an
entirely new method for gene discovery, in
which computational methods can be applied
on a genome-wide scale. High-throughput,
single-pass sequencing of cloned cDNAs (to
create expressed sequence tags (ESTs)) (Gill
and Sanseau, 2000) offers further opportunities, along with microarrays (Freeman,
2003), to examine patterns of gene expression at different stages of parasite life cycles
or in response to changes in environmental
conditions. High-throughput methods are
particularly useful in systems that do not
allow straightforward genetics, and they
offer a powerful approach towards the discovery of novel targets for diagnosis, drug
treatment and vaccine development. While
the application of genomics to fish disease
is still in its infancy, a number of pilot EST
projects are under way for a diverse group
of parasitic agents that affect wild and
farm-raised fish. These include Clonorchis
sinensis (a digenean trematode that is an
important zoonotic agent in China, Korea
and South East Asia) (Lee et al., 2003),
741
742
T.G. Clark
743
744
T.G. Clark
adjuvant was reported to provide significant protection in terms of parasite load and
overall mortality (although the challenge
dose itself killed fewer than half the fish)
(He et al., 1997). This result is clearly interesting and deserves further investigation,
particularly in light of studies indicating
that protection afforded by purified subunit
antigens is serotoype-specific. As shown by
Wang et al. (2002), channel catfish injected
with i-antigens purified directly from the
parasite confer protection against only
those strains from which the antigens are
obtained. Similarly, passive protection using
i-antigen-specific mouse monoclonal antibodies is serotype-specific, with the conformational epitopes recognized by these
antibodies being unique to a given serological strain (Clark and Dickerson, 1997). In
the studies of He et al. (1997), the parasite
strain used for challenge was undefined, as
was the nature of the epitope(s) associated
with the recombinant fusion protein.
Recently, paralogous surface antigen
genes have been isolated from a different
I. multifiliis strain (G5), representing a distinct i-antigen serotype (namely, D) (Lin
et al., 2002b). These genes, designated
IAG52A[G5] and IAG52B[G5], encode surface antigens of 468 and 460 amino acids,
respectively. As with the 48 kDa protein
from the G1 isolate, the serotype D proteins
are predicted to contain hydrophobic signal
peptides at their N- and C-termini and a
series of imperfect tandem repeats of ~ 80
amino acids each spanning their length.
Antibodies against affinity-purified i-antigens
of serotype D recognize a broad band of
52/55 kDa on Western blots, which resolves
into four or more spots on two dimensional
gels. Along with IAG48, the IAG52A and
IAG52B genes have recently been cloned
and expressed in Tetrahymena thermophila,
a non-pathogenic, freshwater ciliate that is
taxonomically related to Ichthyophthirius
(Shang et al., 2002; T.G. Clark, Y. Bisharyan
and D.M. Cassidy-Hanley, unpublished).
Following their expression, T. thermophila
cell lines are rapidly immobilized by specific antibodies against the parasite proteins
in a manner almost identical to that seen
with I. multifiliis (T.G. Clark, Y. Bisharyan
745
Conclusions
Over the past 15 years, molecular genetics
techniques have proved exceedingly useful
in studies of fish parasites and have revealed
novel aspects of the biology, evolution and
life styles of these organisms. In many
instances, such studies have gone beyond
fish parasites and shed important light on
evolutionary biology as a whole. In more
practical terms, molecular cloning techniques provide sensitive and specific methods for diagnosing parasite infections of
fish. They have contributed significantly
towards our understanding of the epidemiology of parasite disease, and are beginning
to play a role in the development of efficacious vaccines for the prevention of parasitic infections in farm-raised fish. Despite
this explosion of new information, continued
studies at the molecular level will be needed
to unravel species differences and the precise evolutionary relationships among and
between taxa for a variety of parasite lineages. One would imagine that molecular
approaches will continue to be applied in
the arena of vaccine development, since these
offer the best hope for protecting farmraised fish against a number of the most
important disease-causing agents of commercial aquaculture. Finally, the bioinformatics
revolution spawned by genomic and
proteomics-based approaches to biology
have begun to find their way into the study
of fish parasites and will almost certainly
provide the next wave of understanding of
these complex and fascinating organisms.
746
T.G. Clark
References
Aguero, F., Campo, V., Cremona, L., Jager, A., Di Noia, J.M., Overath, P., Sanchez, O. and Frasch, A.C.
(2002) Gene discovery in the freshwater fish parasite Trypanosoma carassii: identification of
trans-sialidase-like and mucin-like genes. Infection and Immunity 70, 71407144.
Altschul, S.F., Gish, W., Miller, W., Myers, E.W. and Lipman, D.J. (1990) Basic local alignment search tool.
Journal of Molecular Biology 215, 403410.
Andree, K.B., Gresoviac, S.J. and Hedrick, R.P. (1997) Small subunit ribosomal RNA sequences unite alternate
actinosporean and myxosporean stages of Myxobolus cerebralis the causative agent of whirling disease
in salmonid fish. Journal of Eukaryotic Microbiology 44, 208215.
Andree, K.B., MacConnell, E. and Hedrick, R.P. (1998) A nested polymerase chain reaction for the detection
of genomic DNA of Myxobolus cerebralis in rainbow trout Oncorhynchus mykiss. Diseases of Aquatic
Organisms 34, 145154.
Andree, K.B., Szekely, C., Molnar, K., Gresoviac, S.J. and Hedrick, R.P. (1999a) Relationships among members of the genus Myxobolus (Myxozoa: Bilvalvidae) based on small subunit ribosomal DNA sequences.
Journal of Parasitology 85, 6874.
Andree, K.B., el Matbouli, M., Hoffman, R.W. and Hedrick, R.P. (1999b) Comparison of 18S and ITS-1 rDNA
sequences of selected geographic isolates of Myxobolus cerebralis. International Journal of Parasitology
29, 771775.
Antonio, D.B., Andreee, K.B., McDowell, T.S. and Hedrick, R.P. (1998) Detection of Myxobolus cerebralis in
rainbow trout and oligochaete tissues by using a nonradioactive in situ hybridization (ISH) protocol.
Journal of Aquatic Animal Health 10, 338347.
Arkush, K.D., Mendoza, L., Adkison, M.A. and Hedrick, R.P. (2003) Observations on the life stages of
Sphaerothecum destruens n. sp., a mesomycetozoean fish pathogen formally referred to as the rosette
agent. Journal of Eukaryotic Microbiology 50, 430438.
Barlough, J.E., McDowell, T.S., Bigornia, L., Slemenda, S.B., Pieniazek, N.J. and Hedrick, R.P. (1995) Nested
polymerase chain reaction for detection of Enterocytozoon salmonis genomic DNA in chinook salmon
Onchorhynchus tschawytscha. Diseases of Aquatic Organisms 29, 1723.
Bartholomew, J.L., Whipple, M.J., Stevens, D.G. and Fryer, J.L. (1997) The life cycle of Ceratomyxa
shasta, a myxosporean parasite of salmonids, requires a freshwater polychaete as an alternate host.
Journal of Parasitology 83, 859868.
Bartoli, P., Jousson, O. and Russell-Pinto, F. (2000) The life cycle of Monorchis parvus (Digenea: Monorchiidae)
demonstrated by developmental and molecular data. Journal of Parasitology 86, 479489.
Bell, A.S., Yokoyama, H., Aoki, T., Takahashi, M. and Maruyama, K. (1999) Single and nested polymerase
chain reaction assays for the detection of Microsporidium seriolae (Microspora), the causative agent of
Beko disease in yellowtail Seriola quinqueradiata. Diseases of Aquatic Organisms 37, 127134.
Brooks, D.R. and McLennan, D.A. (1993) Parascript: Parasites and the Language of Evolution. Smithsonian
Instituition Press, Washington, DC.
Burger, G., Forget, L., Zhu, Y., Gray, M.W. and Lang, B.F. (2003) Unique mitochondrial genome architecture
in unicellular relatives of animals. Proceedings of the National Academy of Sciences (USA) 100,
892897.
Callahan, H.A., Litaker, R.W. and Noga, E.J. (2002) Molecular taxonomy of the suborder Bodonina (Order
Kinetoplastida), including the important fish parasite, Ichthyobodo necator. Journal of Eukaryotic
Microbiology 49, 119128.
Canning, E.U. and Okamura, B. (2004) Biodiversity and evolution of the Myxozoa. Advanced Parasitology 56,
43131.
Canning, E.U., Tops, S., Curry, A., Wood, T.S. and Okamura, B. (2002) Ecology, development and pathogenicity of Buddenbrockia plumatellae Schroder, 1910 (Myxozoa, Malacosporea) (syn. Tetracapsula
bryozoides) and establishment of Tetracapsuloides n. gen. for Tetracapsula bryosalmonae. Journal of
Eukaryotic Microbiology 49, 280295.
Charles, I. and Dougan, G. (1990) Gene expression and the development of live enteric vaccines. Trends in
Biotechnology 8, 117121.
Chenchik, A., Zhu, Y., Diatchenko, L., Li, R., Hill, J. and Siebert, P. (1998) Generation and use of
high-quality cDNA from small amounts of total RNA by SMART PCR. In: Siebert, P. and Larrick, J.
(eds) RT-PCR Methods for Gene Cloning and Analysis (Bio Techniques Books, Massachusetts).
pp. 305319.
747
Cheney, S.A., Lafranchi-Tristem, N.J., Bourges, D. and Canning, E.U. (2001) Relationships of microsporidian
genera, with emphasis on the polysporous genera, revealed by sequences of the largest subunit of RNA
polymerase II (RPB1). Journal of Eukaryotic Microbiology 48, 111117.
Clark, C.G. (1997) Riboprinting: a tool for the study of genetic diversity in microorganisms. Journal of
Eukaryotic Microbiology 44, 277283.
Clark, T.G. and Dickerson, H.W. (1997) Antibody-mediated effects on parasite behavior: evidence of a novel
mechanism of immunity against a parasitic protist. Parasitology Today 13, 477480.
Clark, T.G., McGraw, R.A. and Dickerson, H.W. (1992) Developmental expression of surface antigen genes
in the parasitic ciliate, Ichthyophthirius multifiliis. Proceedings of the National Academy of Sciences
(USA) 89, 63636367.
Clark, T.G., Lin, T.-L. and Dickerson, H.W. (1995) Surface immobilization antigens of Ichthyophthirius
multifiliis: their role in protective immunity. Annual Review of Fish Diseases 5, 113131.
Clark, T.G., Lin, T.L., Jackwood, D.A., Sherrill, J., Lin, Y. and Dickerson, H.W. (1999) The gene for an abundant parasite coat protein predicts tandemly repetitive metal binding domains. Gene 229, 91100.
Clark, T.G., Gao, Y., Gaertig J., Wang, X. and Cheng, G. (2001) The I-antigens of Ichthyophthirius multifiliis
are GPI-anchored proteins. Journal of Eukaryotic Microbiology 48, 332337.
Cribb, T.H., Anderson, G.R., Adlard, R.D. and Bray, R.A. (1998) A DNA-based demonstration of a three-host
life-cycle for the Bivesiculidae (Platyhelminthes: Digenea). International Journal for Parasitology 28,
17911795.
Cribb, T.H., Chisholm, L.A. and Bray, R.A. (2002) Diversity in the Monogenea and Digenea: does lifestyle
matter? International Journal of Parasitology 32, 321328.
Cunningham, C.O. (1997) Species variation within the internal transcribed spacer (ITS) region of
Gyrodactylus (Monogenea: Gyrodactylidae) ribosomal RNA genes. Journal of Parasitology 83,
215219.
Cunningham, C.O. and Mo, T.A. (1997) Random amplified polymorphic DNA (RAPD) analysis of three
Norwegian Gyrodactylus salaris populations. Journal of Parasitology 83, 311314.
Cunningham, C.O., Collins, C.M., Malmberg, G. and Mo, T.A. (2003) Analysis of ribosomal RNA intergenic
spacer (IGS) sequences in species and populations of Gyrodactylus (Platyhelminthes: Monogenea) from
salmonid fish in northern Europe. Diseases of Aquatic Organisms 57, 237246.
DAmelio, S., Mathiopoulos, K.D., Santos, C.P., Pugachev, O.N., Webb, S.C., Picanco, M. and Paggi, L.
(2000) Genetic markers in ribosomal DNA for the identification of members of the genus Anisakis
(Nematoda: Ascaridoidea) defined by polymerase-chain-reaction-based restriction fragment length polymorphism. International Journal of Parasitology 30, 223226.
Das, M., Harvey, I., Chu, L.L., Sinha, M. and Pelletier, J. (2001) Full-length cDNAs: more than just reaching
the ends. Physiological Genomics 6, 5780.
Desdevises, Y., Morand, S., Jousson, O. and Legendre, P. (2002) Coevolution between Lamellodiscus
(Monogenea: Diplectanidae) and Sparidae (Teleostei): the study of a complex hostparasite system.
Evolution: International Journal of Organic Evolution 56, 24592471.
Diggles, B.K. and Adlard, R.D. (1995) Taxonomic affinities of Cryptocaryon irritans and Ichthyophthirius
multifiliis inferred from ribosomal RNA sequence data. Diseases of Aquatic Organisms 22, 3943.
Diggles, B.K. and Adlard, R.D. (1997) Intraspecific variation in Cryptocaryon irritans. Journal of Eukaryotic
Microbiology 44, 2532.
Docker, M.F., Devlin, R.H., Richard, J., Khattra, J. and Kent, M.L. (1997) Sensitive and specific polymerase
chain reaction assay for detection of Loma salmonae. Diseases of Aquatic Organisms 29, 4148.
Donnelly, J.J., Ulmer, J.B., Shiver, J.W. and Liu, M.A. (1997) DNA vaccines. Annual Review of Immunology
15, 617648.
Dykova, I., Fajer, A. and Fiala, I. (2002) Kudoa dianae sp. n. (Myxosporea: Multivalvulida), a new parasite of
bullseye puffer, Sphoeroides annulatus (Tetraodontiformes: Tetraodontidae). Folia Parasitologica (Praha)
49, 1723.
Dzikowski, R., Levy, M.G., Poore, M.F., Flowers, M.F. and Paperna, I. (2003) Genetic and morphologic differentiation of Bolbophorus confusus and B. levantinus (Digenea: Diplostomatidae), based on rDNA SSU
polymorphism and SEM. Diseases of Aquatic Organisms 57, 231235.
Edlind, T.D., Li, J., Visvesvara, G.S., Vodkin, M.H., McLaughlin, G.L. and Katiyar, S.K. (1996) Phylogenetic analysis of beta-tubulin sequences from amitochondrial protozoa. Molecular Phylogenetics and
Evolution 5, 359367.
Eszterbauer, E. (2002) Molecular biology can differentiate morphologically indistinguishable myxosporean
species: Myxobolus elegans and M. hungaricus. Acta Veterinaria Hungarica 50, 5962.
748
T.G. Clark
Ferrier, D.E.K. and Holland, P.W.H. (2001) Ancient origin of the Hox gene cluster. Nature Reviews, Genetics
2, 3338.
Finnerty, J.R. (2001) Cnidarians reveal intermediate stages in the evolution of Hox clusters and axial complexity.
American Zoologist 41, 608620.
Frasca, S., Jr, Linfert, D.R., Tsongalis, G.J., Gorton, T.S., Garmendia, A.E., Hedrick, R.P., West, A.B. and Van
Kruiningen, H.J. (1999) Molecular characterization of the myxosporean associated with parasitic
encephalitis of farmed Atlantic salmon Salmo salar in Ireland. Diseases of Aquatic Organisms 35,
221233.
Freeman, T. (2003) Platform technologies for microarray analysis. Briefings in Functional Genomics and
Proteomics 2, 46.
Frohman, M.A. (1990) RACE: rapid amplification of cDNA ends. In: Innis, M.A., Gelfand, D.J., Sninsky, J.J.
and White, T.J. (eds) PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego,
California, pp. 2838.
Fussenegger, M., Bailey, J.E., Hauser, H. and Mueller, P.P. (1999) Genetic optimization of recombinant
glycoprotein production by mammalian cells. Trends in Biotechnology 17, 3542.
Gaertig, J., Gao, Y., Tishgarten, T., Clark, T.G. and Dickerson, H.W. (1999) Surface display of a parasite antigen in the ciliate Tetrahymena thermophila. Nature Biotechnology 17, 462465.
Gellissen, G. (2000) Heterologous protein production in methylotrophic yeasts. Applied Microbiology and
Biotechnology 54, 741750.
Germot, A., Philippe, H. and Le Guyader, H. (1997) Evidence for loss of mitochondria in Microsporidia from a
mitochondrial-type HSP70 in Nosema locustae. Molecular Biochemical Parasitology 87, 159168.
Gilbert, M.A. and Granath, W.O., Jr (2001) Persistent infection of Myxobolus cerebralis, the causative agent of
salmonid whirling disease, in Tubifex tubifex. Journal of Parasitology 87, 101107.
Gill, R.W. and Sanseau, P. (2000) Rapid in silico cloning of genes using expressed sequence tags (ESTs).
Biotechnology Annual Reviews 5, 2544.
Gong, M. and Rong, Y.S. (2003) Targeting multi-cellular organisms. Current Opinion in Genetics and
Development 13, 215220.
Graham, G. (1997) Riboprinting: a tool for the study of genetic diversity in microorganisms. Journal of
Eukaryotic Microbiology 44, 277283.
Gresoviac, S.J., Khattra, J.S., Nadler, S.A., Kent, M.L., Devlin, R.H., Vivares, C.P., De La Fuente, E. and
Hedrick, R.P. (2000) Comparison of small subunit ribosomal RNA gene and internal transcribed spacer
sequences among isolates of the intranuclear microsporidian Nucleospora salmonis. Journal of
Eukaryotic Microbiology 47, 379387.
Hansen, H., Bachmann, L. and Bakke, T.A. (2003) Mitochondrial DNA variation of Gyrodactylus spp.
(Monogenea, Gyrodactylidae) populations infecting Atlantic salmon, grayling, and rainbow trout in
Norway and Sweden. International Journal for Parasitology 33, 14711478.
Hanson, L.A., Lin-Danjuan, Pote, L.M.W. and Shivaji, R. (2001) Small subunit rRNA gene comparisons of four
actinosporean species to establish a polymerase chain reaction test for the causative agent proliferative
gill disease in channel catfish. Journal of Aquatic Animal Health 13, 117123.
He, J., Yin, Z., Xu, G., Gong, Z., Lam, T.J. and Sin, Y. M. (1997) Protection of goldfish against Ichthyophthirius
multifiliis by immunization with a recombinant vaccine. Aquaculture 158, 110.
Hedrick, R.P., Baxa, D.V., DeKinkelin, P. and Okamura, B. (2004) Malacosporean-like spores in urine of rainbow trout react with antibody and DNA probes to Tetracapsuloides bryosalmonae. Parasitology
Research 92, 8188.
Heppell, J. and Davis, H.L. (2000) Application of DNA vaccine technology to aquaculture. Advanced Drug
Delivery Reviews 43, 2943.
Herr, R.A., Ajello, L., Taylor, J.W., Arseculeratne, S.N. and Mendoza, L. (1999) Phylogenetic analysis of
Rhinosporidium seeberis 18S small-subunit ribosomal DNA groups this pathogen among members of
the protoctistan Mesomycetozoa clade. Journal of Clinical Microbiology 37, 27502754.
Hirt, R.P., Healy, B., Vossbrinck, C.R., Canning, E.U. and Embley, T.M. (1997) Identification of a mitochondrial HSP70 homologue in Vairimorpha necatrix: molecular evidence that microsporidia once contained
mitochondria. Current Biology 7, 14.
Hollar, L., Lukes, J. and Maslov, D.A. (1998) Monophyly of endosymbiont containing trypanosomatids:
phylogeny versus taxonomy. Journal of Eukaryotic Microbiology 45, 293297.
Hung, H.W., Lo, C.F., Tseng, C.C., Peng, S.E., Chou, C.M. and Kou, G.H. (1998) The small subunit ribosomal
RNA gene sequence of Pleistophora anguillarum and the use of PCR primers for diagnostic detection of
the parasite. Journal of Eukaryotic Microbiology 45, 556560.
749
Huyse, T. and Volckaert, F.A. (2002) Identification of a host-associated species complex using molecular and
morphometric analyses, with the description of Gyrodactylus rugiensoides n. sp. (Gyrodactylidae,
Monogenea). International Journal of Parasitology 15, 907919.
Jarvis, D.L., Weinkauf, C. and Guarino, L.A. (1996) Immediate early baculovirus vectors for foreign gene
expression in transformed or infected insect cells. Protein Expression and Purification 8, 191203.
Johnson, S.C., Ewart, K.V., Osborne, J.A., Delage, D., Ross, N.W. and Murray, H.M. (2002) Molecular cloning
of trypsin cDNAs and trypsin gene expression in the salmon louse Lepeophtheirus salmonis (Copepoda:
Caligidae). Parasitology Research 88, 789796.
Jones, S.R., Prosperi-Porta, G., Dawe, S.C. and Barnes, D.P. (2003) Distribution, prevalence and severity of
Parvicapsula minibicornis infections among anadromous salmonids in the Fraser River, British Columbia,
Canada. Diseases of Aquatic Organisms 54, 4954.
Keeling, P.J. and Doolittle, W.F. (1996) Alpha-tubulin from early-diverging eukaryotic lineages and the evolution of the tubulin family. Molecular Biology and Evolution 13, 12971305.
Kelley, G.O., Adkison, M.A., Leutenegger, C.M. and Hedrick, R.P. (2003) Myxobolus cerebralis: identification
of a cathepsin Z-like protease gene (MyxCP-1) expressed during parasite development in rainbow trout,
Oncorhynchus mykiss. Experimental Parasitology 105, 201210.
Kent, M.L., Khattra, J., Hervio, D.M.L. and Devlin, R.H. (1998) Ribosomal DNA sequence analysis of isolates
of the PKX mysosporean and their relationship to members of the genus Sphaerospora. Journal of
Aquatic Animal Health 10, 1221.
Kent, M.L., Andree, K.B., Bartholomew, J.L., El-Matbouli, M., Desser, S.S., Devl, R.H., Feist, S.W., Hedrick, R.P.,
Hoffmann, R.W., Khattra, J., Hallett, S.L., Lester, Longshaw, M., Palenzeula, O., Siddall, M.E. and Xiao, C.
(2001) Recent advances in our knowledge of the Myxozoa. Journal of Eukaryotic Microbiology 48,
395413.
Kiesling, T.L., Wilkinson, E., Rabalais, J., Ortner, P.B., McCabe, M.M. and Fell, J.W. (2002) Rapid identification of
adult and naupliar stages of copepods using DNA hybridization methods. Marine Biotechnology 4, 3039.
Kijewska, A., Rokicki, J., Sitko, J. and Wegrzyn, G. (2002) Ascaridoidea: a simple DNA assay for identification of
species infecting marine and freshwater fish, mammals, and fish-eating birds. Experimental Parasitology
101, 3539.
Kit, S., Kit, M. and Pirtle, E.C. (1985) Attenuated properties of thymidine kinase-negative deletion mutant of
pseudorabies virus. American Journal of Veterinary Research 46, 13591367.
Knoll, A.H. (1992) The early evolution of eucaryotes: a geological perspective. Science 256, 622627.
Lang, B.F., OKelly, C., Nerad, T., Gray, M.W. and Burger, G. (2002) The closest unicellular relatives of animals.
Current Biology 12, 17731778.
Lee, J.S., Lee, J., Park, S.J. and Yong, T.S. (2003) Analysis of the genes expressed in Clonorchis sinensis adults
using the expressed sequence tag approach. Parasitology Research 91, 283289.
Leiro, J., Iglesias, R., Ubeira, F.M. and Samartin, M.L. (2001) Non-isotopic detection of Tetramicra brevifilum
(Microspora) DNA in turbot tissues. Journal of Parasitology 87, 14881490.
Levy, M.G., Flowers, J.R., Poore, M.F. and Mullen, J.E. (2002) Morphologic, pathologic, and genetic investigations of Bolbophorus species affecting cultured channel catfish in the Mississippi delta. Journal of
Aquatic Animal Health 14, 235246.
Lin, Y. (2002) Development of a DNA vaccine against the fish parasite Ichthyophthirius multifiliis. PhD
dissertation, Cornell University, Ithaca, New York.
Lin, Y., Cheng, G., Wang, X. and Clark, T.G. (2002a) The use of synthetic genes for the expression of ciliate
proteins in heterologous systems. Gene 288, 8594.
Lin, Y., Lin, T.L., Wang, C.C., Wang, X., Klobfleisch, R., Stieger, K. and Clark, T.G. (2002b) Variation in
primary sequence and tandem repeat copy number among i-antigens of Ichthyophthirius multifiliis.
Molecular and Biochemical Parasitology 120, 93106.
Lom, J. and Nilsen, F. (2003) Fish microsporidia: fine structural diversity and phylogeny. International Journal
for Parasitology 33, 107127.
Luo, H.Y., Nie, P., Zhang, Y.A., Wang, G.T. and Yao, W.J. (2002) Molecular variation of Bothriocephalus
acheilognathi Yamaguti, 1934 (Cestoda: Pseudophyllidea) in different fish host species based on ITS
rDNA sequences. Systematic Parasitology 52, 159166.
Martn-Snchez, J., Diaz, M., Artacho, M.E. and Valero, A. (2003) Molecular arguments for considering
Hysterothylacium fabri (Nematoda: Anisakidae) a complex of sibling species. Parasitology Research 89,
214220.
Maslov, D.A., Avila, H.A., Lake, J.A. and Simpson, L. (1994) Evolution of RNA editing in kinetoplastid
protozoa. Nature 365, 345348.
750
T.G. Clark
Maslov, D.A., Lukes, J., Jirku, M. and Simpson, L. (1996) Phylogeny of trypanosomes as inferred from the
small and large subunit rRNAs: implications for the evoluation of parasitism in the trypanosomatid
protozoa. Molecular Biochemical Parasitology 75, 197205.
Maslov, D.A., Podlipaev, S.A. and Lukes, J. (2001) Phylogeny of the Kinetoplastida: taxonomic problems and
insights into the evolution of parasitism. Memorias do Instituto Oswaldo Cruz 96, 397402.
Meinil, M., Kuusela, J., Zietara, M.S. and Lumme, J. (2004) Initial steps of speciation by geographic isolation
and host switch in salmonid pathogen Gyrodactylus salaris (Monogenea: Gyrodactylidae). International
Journal for Parasitology 34, 515526.
Mendoza, L., Taylor, J.W. and Ajello, L. (2002) The class Mesomycetozoea: a heterogeneous group of microorganisms at the animalfungal boundary. Annual Review of Microbiology 56, 315344.
Morris, D.J., Adams, A. and Richards, R.H. (2000) In situ hybridization identifies the gill as a portal of entry of
PKX (phylum Myxozoa), the causative agent of proliferative kidney disease in salmonids. Parasitology
Research 86, 950956.
Nilsen, F. (2000) Small subunit ribosomal DNA phylogeny of microsporidia with particular reference to genera
that infect fish. Journal of Parasitology 86, 128133.
Okamura, B., Anderson, C.L., Longshaw, M., Feist, S.W. and Canning, E.U. (2001) Patterns of occurrence and
18S rDNA sequence variation of PKX (Tetracapsula bryosalmonae), the causative agent of salmonid
proliferative kidney disease. Journal of Parasitology 87, 379385.
Olson, P.D., Ruhnke, T.R., Sanney, J. and Hudson, T. (1999) Evidence for host-specific clades of
tetraphyllidean tapeworms (Platyhelminthes: Eucestoda) revealed by analysis of 18S ssrDNA. International
Journal of Parasitology 29,14651476.
Overstreet, R.M., Curran, S.S., Pote, L.M., King, D.T., Blend, C.K. and Grater, W.D. (2002) Bolbophorus
damnificus n. sp. (Digenea: Bolbophoridae) from the channel catfish Ictalurus punctatus and American
white pelican Pelecanus erythrorhynchos in the USA based on life-cycle and molecular data. Systematic
Parasitology 52, 8196.
Palenzuela, O., Trobridge, G. and Bartholomew, J.L. (1999) Development of a polymerase chain reaction
diagnostic assay for Ceratomyxa shasta, a myxosporean parasite of salmonid fish. Diseases of Aquatic
Organisms 36, 4551.
Palenzuela, O., Redondo, M.J. and Alvarez-Pellitero, P. (2002) Description of Enteromyxum scophthalmi gen.
nov., sp. nov. (Myxozoa), an intestinal parasite of turbot (Scophthalmus maximus L.) using morphological and ribosomal RNA sequence data. Parasitology 124, 369379.
Peyretaillade, E., Broussolle, P., Peyret, P., Duffieux, F., Metenier, G., Gouy, M. and Vivars, C.P. (1998)
Microsporidia, amitochondrial protists, possess a 70-kDa heat shock protein gene of mitochondrial
evolutionary origin. Molecular and Biochemical Parasitology 15, 683689.
Pomport-Castillon, C., Romestand, B. and De Jonckheere, J.F. (1997) Identifcation and phylogenetic relationships of microsporidia by riboprinting. Journal of Eukaryotic Microbiology 44, 540544.
Pote, L.M., Hanson L.A. and Shivaji, R. (2000) Small subunit ribosomal RNA sequences link the cause
proliferative gill disease in channel catfish to Henneguya n. sp. (Myxozoa: Myxosporea). Journal of
Aquatic Animal Health 12, 230240.
Poulin, R. (2002) The evolution of monogenean diversity. International Journal of Parasitology 32, 245254.
Pugovkin, D., Felleisen, R. and Wahli, T. (2001) A PCR-based method for the detection of Tetrahymena corlissi
contaminations in Ichthyophthirius multifiliis in vitro cultures. Bulletin of the European Association of Fish
Pathologist 21, 222227.
Ragan, M.A., Goggin, C.L., Cawthorn, R.J., Cerenius, L., Jamieson, A.V., Plourde, S.M., Rand, T.G., Soderhall, K.
and Gutell, R.R. (1996) A novel clade of protistan parasites near the animalfungal divergence. Proceedings
of the National Academy of Sciences (USA) 93, 1190711912.
Ragan, M.A., Murphy, C.A. and Rand, T.G. (2003) Are Ichthyosporea animals or fungi? Bayesian phylogenetic
analysis of elongation factor 1alpha of Ichthyophonus irregularis. Molecular Phylogenetics and Evolution
29, 550562.
Raynard, R.S., Bricknell, I.R., Billingsley, P.F., Nisbet, A.J., Vigneau, A. and Sommerville, C. (2002)
Development of vaccines against sea lice. Pest Management Sciences 58, 569575.
Rognlie, M.C. and Knapp, S.E. (1998) Myxobolus cerebralis in Tubifex tubifex from a whirling disease
epizootic in Montana. Journal of Parasitology 84, 711713.
Sambrook, J., Fritsch, E.F. and Maniatis, T. (1989) In: Nolan, C. (ed.) Molecular Cloning: A Laboratory Manual.
Cold Spring Harbor Press, Plainview, New York.
Snchez, J.G., Speare, D.J. and Markahm, R.J.E. (1999) Nonisotopic detection of Loma salmonae (Microspora) in
rainbow trout (Oncorhynchus mykiss) gills by in situ hybridization. Veterinary Pathology 36, 610 612.
751
Snchez, J.G., Speare, D.J., Markahm, R.J.E., Wright, G.M. and Kibenge, F.S.B. (2001) Localization of the initial
developmental stages of Loma salmonae in rainbow trout (Oncorhynchus mykiss). Veterinary Pathology
38, 540546.
Saulnier, D. and de Kinkelin, P. (1997) Polymerase chain reaction primers for investigations on the causative
agent of proliferative kidney disease of salmonids. Journal of Fish Diseases 20, 467470.
Saulnier, D., Bremont, M. and de Kinkelin, P. (1996) Cloning, sequencing and expression of a cDNA encoding an antigen from the myxosporean parasite causing the proliferative kidney disease of salmonid fish.
Molecular and Biochemical Parasitology 83, 153161.
Schaefer, B.C. (1995) Revolution in rapid amplification of cDNA ends: new strategies for polymerase chain
reaction cloning of full-length cDNA ends. Analytical Biochemistry 20, 255273.
Schisle, G.J., Bergersen, E.P., Walker, P.G., Wood, J. and Epp, J.K. (2001) Comparison of single-round polymerase chain reaction (PCR) and pepsintrypsin digest (PTD) methods for detection of Myxobolus
cerebralis. Diseases of Aquatic Organisms 45, 109114.
Shang, Y., Song, X., Bowen, J., Corstanje, R., Gao, Y., Gaertig, J. and Gorovsky, M.A. (2002) A robust inducible
repressible promoter greatly facilitates gene knockouts, conditional expression, and overexpression of
homologous and heterologous genes in Tetrahymena thermophila. Proceedings of the National Academy of Sciences (USA) 99, 37343739.
Shaw, R.W., Hervio, D.M., Devlin, R.H. and Adamson, M.L. (1997) Infection of Aulorhynchus flavidus (Gill)
Osteichthyes: Gasterosteiformes) by Kudoa thyrsites (Gilchrist) (Myxosporea: Multivalvulida). Journal of
Parasitology 83, 810814.
Sicard, M., Desmarais, E. and Lambert, A. (2001) Molecular characterization of Diplozoidae populations
on 5 species of Cyprinidae: new data on parasite specificity. Comptes Rendus de lAcadmie des
Sciences-Series III 324, 709717.
Sogin, M.L. and Silberman, J.D. (1998) Evolution of the protists and protistan parasites from the perspective of
molecular systematics. International Journal of Parasitology 28, 1120.
Sterud, E., Mo, T.A., Collins, C.M. and Cunningham, C.O. (2002) The use of host specificity, pathogenicity,
and molecular markers to differentiate between Gyrodactylus salaris Malmberg, 1957 and G. thymalli
Zitnan, 1960 (Monogenea: Gyrodactylidae). Parasitology 124, 203213.
Swartz, J.R. (2001) Advances in Escherichia coli production of therapeutic proteins. Current Opinion in
Biotechnology 12, 195201.
Swofford, D.L.G., Olsen, J., Waddel, P.J. and Hillis, D.M. (1996) Phylogenetic inference. In: Hilllis, D.M.,
Mortiz, C. and Mable, B.K. (eds) Molecular Systematics, 2nd edn. Sinauer Associates, Sunderland,
Massachusetts, pp. 407514.
Uzonna, J., Spath, G.F., Beverley, S.M. and Scott, P. (2004) Vaccination with phosphoglycan-deficient
Leishmania major protects highly susceptible mice from virulent challenge without inducing a strong
Th1 response. Journal of Immunology 172, 37933797.
Van de Peer, Y., Baldauf, S.L., Doolittle, W.F. and Meyer, A. (2000) An updated and comprehensive rRNA
phylogeny of (crown) eukaryotes based on rate calibrated evolutionary distance. Journal of Molecular
Evolution 51, 565576.
Verneau, O., Renaud, F. and Catzeflis, F. (1997a) Evolutionary relationships of sibling tapeworm species
(Cestoda) parasitizing teleost fishes. Molecular Biology and Evolution 14, 630636.
Verneau, O., Catzeflis, F.M. and Renaud, F. (1997b) Molecular relationships between closely related species
of Bothriocephalus (Cestoda: Platyhelminthes). Molecular Phylogenetics and Evolution 7, 201207.
Vickerman, K. and Coombs, G.H. (1999) Protozoan paradigms for cell biology. Journal of Cell Science 112,
27972798.
Vossbrinck, C.R., Maddox, J.V., Fiedman, S., Debrunner-Vossbrinck, B.A. and Woese, C.R. (1987) Ribosomal
RNA sequence suggests microsporidia are extremely ancient Eukaryotes. Nature 326, 411414.
Wang, X., Clark, T.G., Noe, J. and Dickerson, H.W. (2002) Immunization with Ichthyophthirius multifiliis immobilization antigens elicits serotype-specific protection. Fish and Shellfish Immunology 13, 337350.
Whipps, C.M., Adlard, R.D., Bryant, M.S., Lester, R.J., Findlay, V. and Kent, M.L. (2003) First report of three
Kudoa species from eastern Australia: Kudoa thyrsites from mahi mahi (Coryphaena hippurus), Kudoa
amamiensis and Kudoa minithyrsites n. sp. from sweeper (Pempheris ypsilychnus). Journal of Eukaryotic
Microbiology 50, 215219.
Wilcox, J.N. (1993) Fundamental principles of in situ hybridization. Journal of Histochemistry and
Cytochemistry 41, 17251733.
Wright, A.D.G. and Colorni, A. (2002) Taxonomic re-assignment of Cryptocaryon irritans, a marine fish parasite.
European Journal of Protistology 37, 375378.
752
T.G. Clark
Wright, A.D. and Lynn, D.H. (1995) Phylogeny of the fish parasite Ichthyophthirius and its relatives
Ophryoglena and Tetrahymena (Ciliophora, Hymenostomatia) inferred from 18S ribosomal RNA
sequences. Molecular Biology and Evolution 12, 285290.
Wright, A.D.G. and Lynn, D.H. (1997) Maximum ages of ciliate lineages estimated using a small subunit
rRNA molecular clock: crown eukaryotes date back to the Paleoproterozoic. European Journal of
Protistology 148, 329341.
Yambot, A.V., Song, Y.L. and Sung, H.H. (2003) Characterization of Cryptocaryon irritans, a parasite isolated
from marine fishes in Taiwan. Diseases of Aquatic Organisms 54, 147156.
Zanmore, P.D. (2002) Ancient pathways programmed by small RNAs. Science 296, 12651269.
Zhu, X., Gasser, R.B., Podolska, M. and Chilton, N.B. (1998) Characterisation of anisakid nematodes with
zoonotic potential by nuclear ribosomal DNA sequences. International Journal of Parasitology 28,
19111921.
Zietara, M.S. and Lumme, J. (2002) Speciation by host switch and adaptive radiation in a fish parasite genus
Gyrodactylus (Monogenea, Gyrodactylidae). Evolution: International Journal of Organic Evolution 56,
24452458.
Glossary
Abdomen: The part of the crustacean body that lies behind the genital segments; the last
genital segment normally corresponds to the last thoracic segment.
Abiotic factors: Physical factors which affect the development/survival of an organism.
Abscess: A localized collection of pus in a cavity formed by disintegration of issues.
Acanthella: An acanthocephalan larva that lacks a proboscis and develops from an
acanthor in the intermediate host.
Acanthor: An acanthocephalan larva that develops from a zygote and is infective to the
intermediate host.
Accessory cell: A cell required for, but not actually mediating, a specific immune response;
often used to describe antigen-presenting cells (APC; see below).
Accessory filaments: Fibrillar structures, such as striated lamella, that may form part of the
support in cells; accessory filaments are distinct from microtubules.
Acetabulum: The ventral sucker in trematodes.
Aclid organ: A structure with large, tissue-cutting spines which is located anteriorly on the
acanthor.
Acquired (adaptive) immunity: A series of host defences against a parasite which are characterized by extreme specificity and immunological memory; the defences are mediated by antibody and/or T-cells.
Adenoma: A tumour which consists of glandular tissues.
Adhesion: A pathological condition which results in connective tissue proliferation within
and around an organ.
Affinity: The strength of interaction or binding between an antibody binding site and an
antigenic determinant.
Agarose gel electrophoresis: A method for separating DNA or RNA fragments (in an electric
field) of different lengths, based on their differential rates of migration in an agarose gel.
Agglutinate: The aggregation of organisms or particles into clumps; this may be due to the
reaction of specific antibodies against surface antigenic determinants on the organism.
Agglutinin: Any substance, not necessarily antibody, which is capable of forming bridges
between antigenic determinants on contiguous cells to form visible clumps.
Alae: Lateral cuticular expansions along the body of some nematodes.
Allograft: A tissue transplant (graft) between two genetically non-identical members of a
species.
Alternative complement pathway: The activation of complement through involvement of
properdin factor D, properdin factor B, C3b, C3 and then progressing as in the classical
pathway.
753
754
Glossary
Glossary
755
756
Glossary
Glossary
757
Definitive host: The host in which the parasite usually undergoes sexual reproduction.
Degenerate primer: A set of oligonucleotides, each coding for the same region of a protein, but differing at the third position of codons. Degenerate primers are used to
amplify genes from related organisms based on regions of conserved sequence within
proteins.
Delayed-type hypersensitivity (DTH): A T-cell-mediated reaction to an antigen, which
takes 2448 h to develop fully in an animal, and which involves the release of lymphokines and the recruitment of monocytes and macrophages. Also called cell-mediated
immunity.
Dermatitis: The inflammation of the skin.
Determinant: Part of the antigen molecule that binds to an antibody-combining site or to a
receptor on T-cells.
Diadromous: The life history of fish with both freshwater and marine phases.
Diapedesis: The movement of haemocytes through intact epithelium (i.e. through the gut
or mantle) and thus, are voided from the body.
Digestive gland: Part of the digestive tract of molluscs that extends from the midgut and is
composed of numerous ducts and blind tubules. Forms a discrete organ that functions
in nutrient acquisition.
Digitiform: Finger-like.
Dimorphic: Existing in two morphologically different forms.
Dinospore: A unicellular, haploid, motile, parasitic stage that resembles a free-living
dinoflagellate. The dinospore is covered by thecal armour and may contain pigment,
starch, lipid and a stigma.
Diplokaryon: Two closely apposed nuclei with their membranes adhering to each other in
a binucleated cell.
Diplomond: A flagellate with one or two karyomastigonts, each with one to four flagella
and accessary organelles; duplozoic individuals have bilateral symmetry.
Diplozoic: Having two karyomastigonts.
Disporic: A small sporogonic plasmodium or pseudoplasmodium which produces only
one spore.
Disporoblastic sporogony: A process of spore production in which two sporoblasts arise
from one sporont.
DNA polymerase: An enzyme that catalyses the synthesis of DNA strands. PCR (polymerase
chain reaction) reactions utilize DNA polymerase enzymes from thermophilic bacteria,
which can withstand denaturation at the high temperatures required for DNA strand
separation.
DNA probes: Segments of DNA from an organism which are used to identify homologous
segments of DNA from another organism. These probes are usually used for rapid identification of parasites.
DNA sequencing: A method of determining the primary nucleotide sequence of a DNA
molecule.
Domain: A compact segment of an immunoglobulin molecule, made up of about 110 amino
acids around an SS bond, and encoded by a unique segment of DNA surrounded by
non-translated sequences.
Dropsy: The abnormal accumulation of serous fluid in cellular tissue or the body cavity.
Ductus ejaculatorus: The functional penis in flatworms.
Dyplasia: The regressive change in adult cells.
Dysmea: Difficulty in breathing.
Ecchymosis: A small haemorrhagic spot, larger than a petechia, in the skin or mucus
membrane.
Ecdysis: The shedding of the nematode cuticle following moulting.
758
Glossary
Glossary
759
Expression library: A DNA library in which cloned gene fragments (inserts) are expressed
as proteins in a bacterial cell host. Expression of the DNA is driven by a promoter
element in the cloning vector which is either constitutively active or induced by the
conditions of cell culture.
Extracellular: Situated or occurring outside a cell.
Extrasporogonic: A phase of the development cycle which occurs parallel to the sporogonic
phase.
Extravascular: Situated or occurring outside a vessel.
Extrusion apparatus: An elaborate apparatus that serves for injection of the sporoplasm of
a microsporidia into the host cell.
Fab: A fragment of an antibody containing the antigen-binding site generated by cleavage
of the antibody with the enzyme papain.
Fc: A fragment of an antibody without antigen-binding sites generated by cleavage with
papain; the Fc fragment contains the C-terminal domains of the heavy immunoglobulin chain.
Fibroblastic response: The response characterized by intensive hyperplasia of fibroblasts.
Fibroblasts: A type of connective tissue cell which is responsible for synthesis of collagen.
Fibrosis: The proliferation of connective tissues which consists of a high proportion of
fibroblasts.
Fingerling: A young salmonid fish which is older than a fry, and is approximately finger
size.
Flagllar pocket: An elongate tubular in-tucking of the body surface from which emerges a
flagellum.
Flame cells: Cilia bearing cells in flatworms that have excretory and/or osmoregulatory
functions.
Flashing: An erratic swimming behaviour in fishes.
Formalin: A 37% solution of formaldehyde.
Freunds complete adjuvant: A water-in-oil emulsion with killed mycobacteria; addition
of an antigen to the emulsion significantly increases the production of antibody
against the antigen.
Friable: Easily pulverized.
Funis: One of three bands of microtubular ribbons in Hexamita and Spironucleus; the
ribbon (M3) originates at kinetosome R, and passes from a nucleus posteriorly along
the flagellar pocket.
Gamogony: Part of sexual reproduction; it generally precedes fertilization of macrogametes
by microgametes.
Gastritis: The inflammation of the stomach.
Gastroderm: The epithelium lining the gastric lumen.
Genome: The complete set of genetic material of a living organism. In eukaryotes, the genome
can be further subdivided into the DNA within individual cellular compartments such
as the nucleus, mitochondria and other plastid organelles.
Genomic DNA library: A collection of individually cloned DNA fragments, typically in a
bacterial plasmid or phage vector. Genomic DNA libraries represent the sum of all
DNA present within the genome, while cDNA libraries represent the mRNA transcripts being expressed by a cell at the time RNA was extracted.
Genomics: The study of the genome of a particular organism, especially the sequence and
organization of its genes.
Germinal cells: Non-differentiated cells in a larval trematode, which serve as a source of
cells for the next larval generation.
760
Glossary
Germ line: Refers to genes in germ cells as opposed to those in somatic cells; that is, genes
in their unrearranged state rather than those rearranged for production of proteins.
Gliosis: The disease condition associated with the presence of glioma (neuroglial tumour)
or with the development of neuroglia tissue.
Glomerulitis: The inflammation of the glomeruli of the kidney, with proliferative or
necrotizing changes of the endothelial or epithelial cells or thickening of the basement
membrane.
Glycocalyx: The glycoprotein and polysaccharide covering that surrounds many cells.
Golgi complex: The internal reticular apparatus in the cell cytoplasm which is involved in
the secretory process.
Gonopore: The external opening of the reproductive system of a crustacean.
Graft: A piece of transplanted tissue.
Granulation tissues: Newly formed tissues (proliferating fibroblasts, endothelial cells,
histiocytes and macrophages) involved in the healing of various types of lesions and in
the reparative stage of inflammation.
Granulocytes: Granular leucocytes (eosinophils, basophils and neutrophils).
Granuloma: A lesion resembling a tumour which results from chronic inflammation and
consisting primarily of aggregation of macrophages, epithelioid cells and some connective tissue elements.
Granulomatous inflammation: The type of inflammation characterized by the exudate
composed of macrophages, epithelioid and giant cells and by connective tissue
formation.
Haematophagous: Feeding on blood or lymph.
Haematuria: The presence of blood in the urine.
Haemodilution: The increase of fluid content in the blood with resulting decrease in concentration of its red blood cells.
Haemorrhage: Internal bleeding and subsequent clotting caused by the rupture of blood
vessels.
Hamuli: Large sclerites that occur in pairs which are located centrally in the haptor of
monogeneans.
Haplokinety: Paroral membrane of exceptional length which is around the epistomial disc
in peritrichous ciliates.
Haplotype: A particular combination of closely linked genes on a chromosome inherited
from one individual.
Hapten: A substance that cannot initiate an immune response in an animal unless it is
bound to a carrier because of its small size.
Haptor: The posterior and principal organ of attachment used by monogeneans.
Heavy chain (H chain): The larger of the two types of chains that comprise a normal immunoglobulin molecule.
Helper T-cells: A class of T-cells that helps to trigger B-cells to produce antibodies against
thymus-dependent antigens. Helper T-cells also help to generate cytotoxic T-cells.
Hepatomegaly: The enlargement of the liver.
Hepatopancreas: A part of the digestive tract in crustacea that extends from the midgut and
is composed of numerous ducts and blind tubules.
Hermaphrodites: Organisms with both male and female genital systems.
Herniation: Protrusion of part of a membrane-covered organ through a defect or opening.
Heteroxenous parasite: A parasite that requires more than one host to complete its cycle.
Histocompatibility: The ability of transplanted tissues to get along with host tissues; these
antigens are collectively referred to as histocompatibility antigens.
Histiocyte: A type of cell with phagocytic macrophage-like properties; found in connective
tissues.
Glossary
761
762
Glossary
Glossary
763
764
Glossary
Glossary
765
766
Glossary
Oligonucleotide primers: Short single strands of DNA used to initiate the DNA polymerase
chain reaction on the template for the synthesis of the complementary strand.
Omnivorous: An animal with diverse diet.
Oncomiracidium: The free-swimming or crawling infection stage of monogeneans.
Oocyst: A one-to-three-layered wall or membrane-bound sack surrounding a sporont or
sporocysts.
Oostegite: Thoracid plates that extend under a female isopod to form a marsupium in
which the eggs are carried.
Ootype: A central chamber in the digenean female system which connects the oviduct, the
seminal receptacle, the vaginal and the vitelline ducts.
Operculum: A cup-like opening of the egg of flatworms.
Opsonin: A factor which binds to particles or parasites and increases their susceptibility to
phagocytosis.
Opsonization: The coating of bacteria (or protozoans) with antibody and/or complement,
which leads to enhanced phagocytosis of the microorganisms by phagocytic cells.
Oral kinety: Any kinety associated with the oral region in ciliates.
Oral vaccination: The immunization of an animal in which the vaccine is mixed with food.
Osmolarity: The concentration of osmotically active particles in solution.
Osmoregulation: The adjustment of internal osmotic pressure in an organism in relation to
changes in the external osmotic environment.
Oviparous: An organism that lays eggs.
Palintomy: Rapid binary fissions typically within a cyst and essentially without intervening growth.
Pansporoblast: A spore-producing formation within a polysporic plasmodium. It originates by the union of two generative cells (the pericyte and the sporogonic cell). The
pericyte gives rise to the pansporoblast envelope while the sporogonic cell divides to
produce the sporoblast cells.
Papillae: Small conical projections on the body surface.
Paraoral membrane: A ciliary organelle at the right border of the buccal cavity in ciliates. It
consists of two rows of kinetosomes, of which only the outer one is ciliated.
Parasome: An organelle-like structure beside the nucleus of Paramoeba sp., which may be
a discrete organism of unknown taxonomic affinities and is not an organelle of the
amoeba.
Paratenic host: A transport host in which the larval stage of a parasite undergoes no development and its only function is to transfer the parasite to the next host.
Paraxial rod: An electron-dense ribbon or rod along the axoneme in the flagellar membrane.
Paresthesia: Morbid or abnormal sensation such as burning, prickling.
PAS reaction: The Periodic-Acid-Schiff (PAS) reaction used for specific staining of glycogen, neutral mucin, basement membranes and fungi.
Pathognomonic: Specifically distinctive or characteristic of a disease or pathological condition; a sign or indicant on which a diagnosis can be made.
Pectinelle: One of an equatorial band of short oblique rows of up to about six closely
apposed cilia. It is used for locomotion in telotrochs of peritrichous ciliates; in adult
ciliates the cilia are usually resorbed.
Pellicle: The cortex of the ciliate cell; it is composed of an outer cell membrane subtended
with flat pellicular alveoli with underlying fibrous layer, the epiplasm.
Penmiculus: A modified membranelle, with kinetosomes slightly more apart, forming
sometimes more than three rows (up to seven) across.
Pentamer: A molecule consisting of five (sub)units.
Performatorium: A cortical structure at the anterior of theronts and trophonts, used for
penetration of epithelium and feeding.
Glossary
767
768
Glossary
Polypeptide: A peptide which on hydrolysis yields more than two amino acids.
Polysporic: A plasmodium which produces several spores.
Postoral kinety: A kinety which runs from the buccal cavity on the central side of a ciliate.
Pranzia: The larval stage of a gnathid isopod.
Precipitin: An antibody or other substance which reacts with a soluble antigen to form a
precipitate.
Precocious: An animal attaining maturity at early age (larval age).
Premunition: The resistance to infection against the same or closely related pathogen after an
acute infection has become chronic. The protection lasts as long as the infection persists.
Prepatent period: The period after infection but before the causative agent can be found
using the usual diagnostic techniques.
Presporogonic: A sequence of development which precedes sporogony.
Prevalence: The percentage of animals in a population which are infected at any one time
by a particular organism.
Primary lymphoid organs: Organs in which the maturation of T- and B-lymphocytes takes
place and antigen-specific receptors are first acquired.
Primary responses: The immune response to a first encounter with an antigen. The primary response is generally small, has a long induction phase or lag period, consists
primarily of IgM antibodies and generates immunological memory.
Primer: An oligodeoxynucleotide used to prime DNA synthesis reactions in PCR or DNA
sequencing protocols. The free 3 hydroxyl group of the terminal deoxyribose sugar
initiates DNA strand synthesis.
Primordia: The earliest discernible indication of an emerging organ or part of it.
Proboscis: A muscular, protrusible feeding organ in rhynchobdellid leeches.
Proboscis sheath: The space surrounding the proboscis when it is retracted.
Proceroid: The first larval stage of many cestodes which develop inside the body cavity of
the invertebrate (first) intermediate host.
Productive inflammation: See Proliferative inflammation.
Progenetic: Larval stage that attains sexual maturity and produces eggs.
Prohaptor: A non-sclerotized anterior organ of attachment used by monogeneans.
Proliferative inflammation: An inflammation which is characterized by a pronounced
multiplication of fibroblasts: histiocytes and endothelial cells.
Pronephros: The primary kidney which is incorporated into the head kidney in adult fish.
Prostate gland: A gland which provides the supporting medium for male gametes.
Protandry: A type of hermaphroditism in which the individual first functions as a male
and then as a female.
Protease: A general term for proteolytic enzymes.
Protista: Single-cell (or very few-celled and, therefore, still microscopic) eukaryotic
microorganisms which diversified to give rise to animal, plant and fungal evolutionary
lines.
Protonephridium: An organ for osmoregulation and excretion; it consists of flame cells
connected to a tubule complex that opens to the exterior.
Pseudocyst: A cyst-like structure surrounded by a dense fibrous capsule. It does not possess an inner lining and the formation of a pseudocyst follows necrotic changes.
Pseudopodium: A temporary cytoplasmic projection of an organism which is used for feeding and/or for locomotion.
Pulsatile vesicles: Blister-like lateral appendages on the urosome of some piscicolid
leeches; they are part of the coelomic system, and contract/expand to circulate
coelomic fluid.
Pyknotic: The degeneration of a cell in which the nucleus shrinks and the chromalin condenses to a solid amorphous mass.
Pyriform: Pear-shaped.
Glossary
769
Raceway: An elongated earth pond or cement lined container with constant water flow.
Rapid amplification of cDNA ends (RACE): A method to obtain sequence information from
the 5 and 3 ends of cDNA molecules. Starting with the sequence of a partial cDNA,
this method allows one to obtain the full-length sequence of an RNA transcript by PCR.
Random amplified polymorphic DNA (RAPD): DNA fragments generated by PCR using
pairs of random oligodeoxynucleotide primers. Patterns of bands generated with given
sets of primers can be diagnostic for a given organism, strain or species, and can be
used as a tool in genotype analysis.
Receptaculum seminis: A sac for storing received spermatozoans in the female genital system of trematodes.
Recurrent: Directed towards the posterior end.
Redia: The third larval stage of digeneans.
Regressive changes: A pathological process which is related to metabolic disorders and
includes dystrophic (degenerative) changes and necrosis.
Repair: A process to reestablish anatomical and functional integrity of tissues after an
injury or inflammation.
Respiratory burst: Oxygen-dependent increase in metabolic activity within phagocytic
cells usually stimulated by bacteria or parasites.
Restriction endonuclease: An enzyme that recognizes specific sequences within duplex
DNA and cleaves (digests) the double strand, leaving either blunt ends or overhangs,
which can act as sticky ends for DNA cloning. Digestion of genomic DNA with these
enzymes creates a unique pattern of fragments for any given endonuclease.
Restriction fragment length polymorphism (RFLP): DNA fragments of different lengths
after the DNA has been cleaved by restriction endonucleases at specific sites.
Rete system: A series of canals associated with the musculature in the body wall in an
acanthocephala.
Reticuloendothelial system (or mononuclear phagocyte system): A network of phagocytic
cells primarily in the reticular connective tissues of lymphoid and other organs.
Retina: The sensory lining on the back of an eye.
Rhizocyst: A nail-like organelle which projects from the attachment disc of some parasitic
dinoflagellates, e.g. Piscinoodinium; the organelle penetrates the host cells to provide
anchorage for the parasite.
Rhizoids: Modified cytoplasmic projections which arise from the basal end of some parasitic dinoflagellates, e.g. Amyloodinium, Crepidoodinium; these projections attach to
or penetrate host cells to provide anchorage.
Rhynchi: Anterior tentacles or fimbriae in bucephalid digeneans.
Ribosomal DNA (rDNA): A region of the genome that contains the genes for ribosomal RNA.
Ribosomal RNA (rRNA): A structural unit of the ribosome. Ribosomal RNA is expressed in
the nucleus as a large primary transcript that is processed to form 18S and 28S RNAs
that associate with the small (40S) and large (60S) subunits of eukaryotic ribosomes,
respectively.
Ribosomes: Intracytoplasmic granules which are rich in RNA and function in protein
synthesis.
RNA interference (RNAi): A method for suppressing the expression of specific genes in
eukaryotic cells using double-stranded RNA.
Rootlet fibril: See Striated lamella.
Sagenogenetosomes: Complex pit-like structures in the cell surface of the Labyrinthomorpha; they are presumed responsible for production of the ectoplasmic net which is
involved in movement and nutrient acquisition.
Sanguiniferous: Blood feeders.
Second set rejection: Accelerated rejection of an allograft in an already immune recipient.
770
Glossary
Glossary
771
772
Glossary
Tolerance: Diminished or absent capacity to respond to a specific antigen; it is usually produced as a result of contact with that antigen under non-immunizing conditions.
Tomites: Cells within the tomont which result from serial binary division.
Tomont: A cyst-like structure formed by the trophont following detachment from the host;
it supports binary division of the tomites and their maturation.
Torus (pl. tori): Rounded swelling.
Trachelosome: The neck region of a piscicolid leech that includes clitellar and preclitellar
segments.
Transcript: An RNA molecule copied from genomic DNA (often synonymous with messenger RNA).
Trophont: The feeding and growing stage of a dinoflagellate or a ciliate which differentiates into the reproductive tomont following detachment.
Trophozoite: A vegetative (feeding) stage in the life cycle of a parasitic protist that may
undergo asexual multiplication (fission).
Trunk: The body of many parasitic copepods; formed from fused and enlarged genital
segments and may also incorporate other thoracic segments.
Trypomastigote: The elongated developmental stage of a trypanosome in which the
flagellum arises posterior to the nucleus and emerges laterally to form a long undulating membrane along the body to the anterior end.
Tumour necrosis factor (TNF-a): Secreted by macrophages in response to inflammation
and infection; cytotoxic to tumour cells but not to normal cells.
Ulcer: The excavation of the surface of an organ or tissue produced by sloughing of necrotic
inflammatory tissue.
Ulceration: A pathological condition which is usually associated with the skin or mucosal
surfaces; it involves lesions with erosion of surface epithelia, and inflammation with
infiltration of leucocytes.
Urosome: The main body region of a piscicolid leech between the clitellum and caudal
sucker.
Urticaria: An allergic condition marked by red wheals.
Uveitis: Inflammation of the uvea the iris, ciliary body and choroid considered together.
Vaccination: Originally referred to immunization against smallpox with the less virulent
cowpox (Vaccinia) virus; it is now used for any immunization against a pathogen.
Vaccine: An antigen preparation which consists of either whole cells or extracts of cells
and is used to immunize animals.
Vacuolated: Containing spaces or cavities in the cytoplasm of a cell.
Valvogenic cell: One of the cells in a sporoblast in Myxosporea which differentiates into
the shell valve.
Vascularization: The increase in supply of blood to a tissue; this is either by increasing
blood volume (dilation of blood vessels) or the development of new blood vessels.
Vas efferens: Proximal sperm-carrying duct.
Vector (molecular biology): A vehicle for cloning genes, most often consisting of plasmid
or bacteriophage DNA that has been modified to accept foreign DNA inserts.
Ventriculus: The posterior glandular part of the oesophagus, this structure is characteristic
of many ascaridoid mematodes.
Vesicle: A small circumscribed elevation on the epidermis which contains serous fluid.
Vestibulum: A depression of the body surface which leads to the cytostome and is
equipped with ciliature of somatic origin; if it is in the shape of a groove, it is called a
vesticular groove.
VH genes: Genes which code for the variable region of a heavy chain in immunoglobulins.
Glossary
773
Virulence: The capacity of a parasite to cause disease in an animal; the damage may be
modified by the defence mechanism of the host.
Vitellaria: Yolk glands.
Vitreous humour: The posterior chamber of the eye.
Viviparous: The bearing of live young.
Western immunoblotting: A technique to identify specific antigens in a mixture by separation on polyacrylamide gels, blotting onto mitrocellulose, and labelling with radiolabelled or enzyme-labelled antibodies.
Xanthochromic: Yellow in colour.
Xenoma: A symbiotic complex formed by a hypertrophic host cell and an intracellular
parasite which proliferates in its cytoplasm.
Yearling: A one-year-old salmonid fish.
Zooplankton: Animal-like organisms which float or drift almost passively at sea or in other
large water bodies.
Index
776
Amyloodinium continued
life cycle and morphology 24, 25(fig),
26(fig)
parasite nutrition and physiology 3637
prevention and control 3839
taxonomy and systematics 20, 22
anaemia
in arthropod infections 503, 526
in cryptobiosis 63(fig), 79, 80
in monogenean infections 311313
in nematode infections 428
pernicious anaemia in humans with
tapeworms 603
in sea lice infestation 490
in trypanosomiasis 97, 99
Anarhichas spp. 216
Ancistrus cirrhosus 217
Ancylodiscoides vistulensis 300, 325
Anelasama spp. 533534
angelfish
hexamitid infections 4849, 55
Angiostrongylus cantonensis 662
Anguilla spp. 32, 218, 265, 581
arthropod infections 509510
digenean infections 350
immune response 376
monogenean infections 300, 311, 315(fig),
324325, 326
nematode infections 419(fig), 427, 431,
436
Anguillicola spp. 436
pathology 427, 429, 431
Anguilliocola spp. 419(fig), 4121(fig), 423(fig),
424(fig)
Anilocra spp. 520, 521, 522, 523, 524
Anisakis spp. 421(fig), 424425, 436, 613
application of molecular techniques 737
pathology 427(fig), 429, 430
zoonoses see zoonoses, fish-borne
Anisostremus virginicus 32
Annelida 657659
see also leeches
Anoplodiscus tai 301, 329
anorexia: as beneficial symptom 79, 85
antibiotics 88
antibodies
drug-conjugated 8990
humoral response 686
structure and repertoire 681683
apical complex 185
Apicomplexa
adelid parasites (coccidia sensu lato)
191193
pathogenicity 195
coccidia
development 185189
infection of fish 190191
Index
Index
777
778
Index
Index
cytotoxicity
non-specific 618, 711713
specific 686687, 705, 711712
779
780
farming, fish
effects of arthropods 512, 527, 474,
477478
effects of cryptobiosis 8587
effects of leeches 570571
effects of sea lice 480481, 483, 484
Fessisentis friedi 445
Flabellifera 528530
see also Cymothoidae
flatworms see digeneans; monogeneans;
tapeworms
flounders
ichthybodosis 62, 63
trypanosomiasis 92, 9394, 98, 99
flukes, blood see Sanguinicola spp.
Fluta alba: source of zoonoses 608
formalin 38, 39, 62, 144
fumagillin 274
Index
Fundulus grundis 32
Furnestia echeneis 301, 326
Index
781
782
Index
Index
783
784
Index
monopisthocotyleans vs.
polyopisthocotyleans 298, 302,
304, 306
muscular system 304305
opithaptor 301302, 303(fig)
reproductive system 306
sensory and nervous systems 304,
305(fig)
tegument 302303
pathogenicity
effects of feeding 312313
effects of gland secretions 316
effects of opithaptor 313314, 316
prevention and control
biological control 317
chemical control 317319
physical methods 317
regulatory measures 320
vaccination 319
wild vs. cultured fish 316317
zoosanitary measures 320
reproduction and life cycle 307309
species causing disease in aquaculture
Acolpenteron ureterocetes 324
Allobivagina spp. 334
Ancylodiscoides vistulensis 325
Anoplodiscus tai 329
Benedenia spp. 331
Dactylogyrus spp. 321324
Dawestrema cycloancistrium 325
Dermophthirius spp. 330
Diplectanum spp. 326
Discocotyle sagittata 333
Entobdella soleae 331332
Fumestia echeneis 326
Gyrodactylus spp. 326328
Heteraxine heterocerca 334
Heterobothrium okamotoi 332
Microcotyle spp. 333
Neobenendia spp. 330331
Neoheterobothrium hirame 331333
Pseudodactylogyrus spp. 324325
Tetraonchus spp. 325326
vectors for other pathogens 316
in vitro culture and propagation 312
Monorchis parvus 361
Moravecia australiensis 433
Morone spp. 32, 261, 572, 585
arthropod infections 467468, 476477
hybrids 348
Mothocya spp. 520, 521(fig), 522, 526, 527, 528
mucus 133, 135136
as chemoattractant 310, 487
initiates monogenean egg hatching 309
Mugardia spp 638639
Mugil cephalus 252, 470, 600
Mugil subviridis 530(fig)
Index
785
786
Index
Index
Penaeus spp.
microsporidian infections 629631
Penella spp. 495, 497(fig), 499, 503, 535
Peniculisa spp. 500(fig)
Peniculus spp. 497
Pennellidae (Lernaeocera branchialis and other
species)
economic significance 495
host immunity 502
host range, distribution and seasonality
496497
morphology and life cycle 496(fig),
497500
nutrition and physiology 504505
pathology 501502, 502504
prevention and control 505
systematics 497
Penniculisa shiinoi 499
Perca spp. 163, 259
acanthocephalan infections 458
digenean infections 348
diplostomiasis 375
source of zoonoses 603
tapeworm infections 401
perch 163
Percopsis omiscomaycus 255
peritrichs, sessiline see sessiline peritrichs
Perkinsiella amoeba 2
Perkinsus marinus
diagnosis, prevention and control 635636
effects on oyster industry 632
in vitro propagation 634635
morphology and life cycle 633634
pathology 634
Perkinsus spp. 636638
Peroderma spp. 497(fig), 501, 502
Phagicola nana 369(fig), 371
phagocytes 680681, 702703
Philometra spp. 418(fig), 420(fig), 422(fig), 424,
425, 4258, 429, 432433
Philometroides spp. 432, 436
Philonema spp. 429
phototaxis 486, 487
Phoxinus phoxinus 348349
Phrixocephalus spp. 497(fig), 500501, 502
Pimelodus masculatus 704
Pimephales promelas 221, 259, 348, 373(fig)
Pirenella conica 346(fig), 349350, 351
Piscicola geometra 68, 7172, 569, 570, 574,
578580, 583
Piscicola punctata 571
Piscicola salmositica 68, 71, 570, 571572, 574,
582583, 584585
Piscinoodinium 16, 19
asymptomatic infection 40
clinical signs and pathology 3435
host attachment mechanism 28(fig)
787
host range 19
life cycle and morphology 2829
prevention and control 3940
taxonomy and systematics 2223
Plagiorhyncus cylindraceus 455
plaice see Pleuronectes spp.
plankton: as source of digenean infection 348
Planorbella trivolis 349, 351
plasma cells 710711
Platichthys flesus (flounder) 495, 498
Platybdella olriki 600
Platycephalus fuscus 356(fig)
platyhelminths see digeneans; monogeneans;
tapeworms
Platypoecilus maculates 60
Plecoglossus altivelis 214, 351, 600
Pleistophora spp. 205, 206, 207(fig)
gonadal infections 221223
host tissue reaction 210213
life cycle of P. hyphessobryconis 212(fig)
muscle infections 216217
Pleuronectes spp. (plaice, flounders)
digenean infections 346
ichthybodosis 62
immunity 376
microsporidia infections 215
tagged with Myxobolus aeglefini 231
trypanosomiasis 92, 98, 99
Pneumatophoros japonicus: source of zoonoses
611
Poecilia gillii 347
Poecilia latipinna 32, 140, 300
Poecilia reticulata 60, 328329, 428
Pollachius spp. 268(fig), 269
Polydactylus sexfilis 39
Polydora spp. 657659
Polysporoplasma sparis 265266
Pomacentrus spp. 520
Pomphorhyncus spp. 444445, 453454, 455,
456
porkfish 32
Posthodiplostomum minimum 347, 373(fig)
potassium permanganate 144, 479500
Proctoeces maculatus 660661
Prokinetoplastina 59
proliferative gill disease 249
proliferative kidney disease 247248, 260262,
274, 729730
Propyxidium tectiformis 171
Prosorhynchus squamatus 659660
proteases
Cryptobia 70, 71(fig), 7273, 7475, 79
hexamitid 53
neutralization 81
Proteocephalus spp. 393, 394, 396, 399, 400,
401
Proteorhinus marmoratus 173
788
salinity
in control of disease 3940, 62, 143144,
147
effect of temperature on tolerance 27
and outbreaks of amoebic gill disease 5
Salmincola spp. see Lernaepodidae
Salmo gairdneri (previous name for O. mykiss)
see Oncorhynchus mykiss (rainbow
trout)
Salmo salar
amoebic gill disease see amoebic gill
disease
arthropod infections 480, 489(fig), 490,
491, 511, 525(fig)
Hexamita salmonis infection 48, 55
ichthybodosis 59, 63
immunity 8184, 490, 703(fig)
Index
Index
789
790
Index
Index
791