Species New to Science: Holocephali

Showing posts with label Holocephali. Show all posts

Friday, August 23, 2024

[Ichthyology • 2024] Harriotta avia • A New rhinochimaerid (Chimaeriformes: Rhinochimaeridae) described from the Southwest Pacific

Harriotta avia

Finucci, Didier, Ebert, Green & Kemper, 2024

Australasia Narrow-nosed Spookfish || DOI: 10.1007/s10641-024-01577-4

x.com/BritFinucci

Abstract

Harriotta avia sp. nov., a new species of long-nose chimaera (Holocephali: Chimaeriformes: Rhinochimaeridae), is described from specimens collected off New Zealand in the Southwest Pacific Ocean. The species is distinguished from its congeners by a combination of the following characters: elongated, narrow and depressed snout up to 56% BDL; long, slender trunk; beak-like vomerine tooth plate; large eye, length 8–12% BDL and height 5–7% BDL; long dorsal spine reaching slightly beyond apex of the dorsal fin; and slender rod-like pelvic claspers. The skin is deciduous, and uniform chocolate brown when intact. Harriotta avia sp. nov. is also distinguished from other Harriotta species based on DNA sequence divergence of the NADH2 gene. Harriotta avia sp. nov. is reported from the New Zealand-Australian region. Conclusions here show that Harriotta raleighana, a presumed globally distributed species, likely comprises several species and the genus Harriotta warrants a revision with specimens representing all ocean basins.

Keywords: Holocephali, Integrated Taxonomy, Morphology, Genetics, New Zealand, Australia

Harriotta avia sp. nov.

Etymology: The species name is derived from the Latin noun avia (grandmother), in memory of June Thomas who proudly supported her granddaughter’s (BF) science career. The proposed English common name is the Australasia Narrow-nosed Spookfish.

Brittany Finucci, Dominique Didier, David A. Ebert, Madeline E. Green and Jenny M. Kemper. 2024. Harriotta avia sp. nov. – A New rhinochimaerid (Chimaeriformes: Rhinochimaeridae) described from the Southwest Pacific. Environmental Biology of Fishes. DOI: 10.1007/s10641-024-01577-4

x.com/BritFinucci/status/1826727153633009947

Saturday, March 9, 2024

[Ichthyology • 2024] Chimaera supapae (Holocephali: Chimaeriformes: Chimaeridae) • A New Species of Chimaera from the Andaman Sea of Thailand

Chimaera supapae

Ebert, Krajangdara, Fahmi & Kemper, 2024

Raffles Bulletin of Zoology. (72);

twitter.com/LostSharksGuy

Abstract

A new species of shortnose chimaera is described from a single specimen collected at 772–775 m depth in the Andaman Sea (07.54° N; 96.99° E) off Thailand. The species is distinguished from its congeners by the combination of the following characteristics: massive head with short snout; eyes relatively large, horizontally oval, eye length 32.2% head length; thin body with a relatively long trunk 40% body length (BDL), deciduous skin; uniformly dark brown; preopercular and oral lateral line canals sharing a common branch; posterior margin of pectoral fins slightly convex; long dorsal spine 27% BDL, longer than the first dorsal fin. The new species is morphologically close to Chimaera macrospina from Australia but differs in the length of the ventral caudal lobe, snout-vent length, and pectoral fin anterior margin length. It can be distinguished from C. macrospina and other Chimaera species based on the DNA sequence divergence of the mitochondrial ND2 gene.

Key words. Chondrichthyes, eastern Indian Ocean, SE Asia, morphology, genetics, taxonomy

Lateral view of Chimaera supapae, new species, holotype (PMBC 30399),
immature male, 508 mm TL, 276 mm BDL (Before preservation).

Chimaera supapae, new species

Andaman shortnose chimaera

Diagnosis. Chimaera supapae can be distinguished from all other chimaeroids by the following combination of characters: massive head with a short snout; eyes relatively large, horizontally oval, eye length 32.2% head length; thin and relatively long trunk 40% BDL, deciduous skin; uniformly dark brown, without any spots or stripes; preopercular and oral lateral line canals sharing a common branch; posterior margin of pectoral fins slightly convex; long dorsal spine 27 % BDL, longer than first dorsal fin.

Etymology. The epithet supapae is named to honor the late Professor Supap Monkolprasit (1934–2013), for her extensive work on the cartilaginous fishes of Thailand. She was the Dean of Faculty of Fisheries, Kasetsart University, Thailand during the years 1991–1995, but devoted her entire life to the study of cartilaginous fishes in Thailand.

Distribution. Known only from the type location ___ in the Andaman Sea off Thailand, eastern Indian Ocean at 772–775 m depth (Fig. 1).

David A. EBERT, Tassapon KRAJANGDARA, FAHMI and Jenny M. KEMPER. 2024. Chimaera supapae (Holocephali: Chimaeriformes: Chimaeridae), A New Species of Chimaera from the Andaman Sea of Thailand. Raffles Bulletin of Zoology. (72); 84–90.

twitter.com/LostSharksGuy/status/1765246529793593825

Friday, March 8, 2024

[PaleoIchthyology• 2024] Cosmoselachus mehlingi • A New operculate symmoriiform chondrichthyan (Symmoriiformes: Falcatidae) from the Late Mississippian Fayetteville Shale (Arkansas, United States)

Cosmoselachus mehlingi

Bronson, Pradel, Denton & Maisey, 2024

sciencepress.mnhn.fr/en/periodiques/geodiversitas/46/4

twitter.com/AMNH

twitter.com/Kimi_Chap

We describe a new genus of symmoriiform chondrichthyan from the Late Mississippian Fayetteville Shale of Arkansas, United States, and include this fossil in a phylogenetic analysis of chondrichthyans. This taxon possesses elongate cartilaginous rays extending from the gill arches, forming an operculate structure that covers at least two of the branchial arches farther posteriorly. Although presence of a ‘hyoid operculum’ has been postulated in at least two unrelated Paleozoic sharks (e.g., Triodus, Tristychius), subsequent investigations failed to corroborate those claims. The new fossil therefore provides the first evidence of an endoskeletal operculum formed by elongate, fused pharyngeal arch rays in a chondrichthyan.

KEYWORDS: Chondrichthyes, Symmoriiformes, operculum, CT scanning, phylogeny, new genus, new species

An artist’s reconstruction of the new shark-like species Cosmoselachus mehlingi.

amnh.org

Class CHONDRICHTHYES Huxley, 1880

Order SYMMORIIFORMES Maisey, 2007

Family Falcatidae Zangerl, 1990

Genus Cosmoselachus n. gen.

Cosmoselachus mehlingi

Etymology: Cosmoselachus mehlingi n. gen., n. sp. is named in honor of American Museum of Natural History Senior Museum Specialist Carl Mehling, nickname “Cosm”, therefore “Cosm” -oselachus, in recognition of his contributions toward the acquisition and identification of numerous fossil chondrichthyans, as well as his indefatigable enthusiasm for all unusual vertebrates and many years of service to paleontology.

Allison W. Bronson, Alan Pradel, John S. S. Denton and John G. Maisey. 2024. A New operculate symmoriiform chondrichthyan from the Late Mississippian Fayetteville Shale (Arkansas, United States). GEODIVERSITAS. 46(4); 101-117.

sciencepress.mnhn.fr/en/periodiques/geodiversitas/46/4

twitter.com/AMNH/status/1765859348192915697

twitter.com/Kimi_Chap/status/1765729274294645095

Thursday, February 9, 2017

[Ichthyology • 2017] Hydrolagus erithacus • A New Species of Chimaerid (Chimaeriformes: Chimaeridae) from the southeastern Atlantic and southwestern Indian oceans

Hydrolagus erithacus

Walovich, Ebert & Kemper, 2017

DOI: 10.11646/zootaxa.4226.4.4

Abstract

A new species of chimaerid, Hydrolagus erithacus sp. nov., is described from nine specimens collected from the southeast Atlantic and southwest Indian oceans from depths of 470–1,000 meters. This species is distinguished from all other Hydrolagus species based on the following characteristics: head bulky, relatively large, followed by stocky body; head and body height from about pectoral fin origin to pelvic fin origin similar, then tapering rapidly to filamentous tail; first dorsal fin spine height about equal to, or slightly less than first dorsal fin apex height; second dorsal fin up to 81% of total body length and uniform in height; trifurcate claspers forked for approximately 20% of total length; robust frontal tenaculum nearly uniform in width, prepelvic tenaculae with five to seven medial spines, and a uniform black coloration with robust, non-deciduous skin. Comparison of mitochondrial NADH2 gene sequences with other morphologically similar Hydrolagus species suggests that H. erithacus is a distinct species.

Keywords: Pisces, Chimaera, ghost shark, taxonomy, NADH2 gene

FIGURE 1. Photograph of the Hydrolagus erithacus holotype, SAIAB 200578, mature male, 1290 mm TL, 790 mm BDL. Scale bar = 5 cm.

Hydrolagus erithacus sp. nov

Common Name: Robin’s Ghostshark

Hydrolagus sp. nov. (Big black chimaera): Compagno 1999: 120.

Etymology. The species name erithacus derives from the avian genus of the robin (Aves: Passeriformes: Muscicapidae: Erithacus Cuvier, 1800). Named after Robin Leslie of South African Department of Agriculture, Forestry and Fisheries (DAFF), a fanatic birder, in recognition of his help and support on this project, and his overall contribution to Chondrichthyan research in southern Africa.

Kristin Walovich holds the 50th described species of ghost shark, Hydrolagus erithacus, on record. The animal's nose is usually pointy, but it became crooked during its preservation.

Kristin A. Walovich, David A. Ebert and Jenny M. Kemper. 2017. Hydrolagus erithacus sp. nov. (Chimaeriformes: Chimaeridae), A New Species of Chimaerid from the southeastern Atlantic and southwestern Indian oceans. Zootaxa. 4226(4); 509–520. DOI: 10.11646/zootaxa.4226.4.4

A new species of chimaerid, Hydrolagus erithacus sp. nov., is described from nine specimens collected from the southeast Atlantic and southwest Indian oceans from depths of 470–1,000 meters.

shark-references.com/species/view/Hydrolagus-erithacus

facebook.com/sharkreferences/photos/1343922852294482

Smile! New Bucktoothed Ghost Shark Species Discovered

https://shar.es/192FtT via @LiveScience

Friday, January 6, 2017

[PaleoIchthyology • 2017] Dwykaselachus oosthuizeni • A Symmoriiform Chondrichthyan Braincase and the Origin of Chimaeroid Fishes

Reconstruction of Dwykaselachus oosthuizeni, a type of symmoriid shark now known to be an early chimaera.

Illustration: Kristen Tietjen DOI: 10.1038/nature20806

Chimaeroid fishes (Holocephali) are one of the four principal divisions of modern gnathostomes (jawed vertebrates). Despite only 47 described living species, chimaeroids are the focus of resurgent interest as potential archives of genomic data and for the unique perspective they provide on chondrichthyan and gnathostome ancestral conditions. Chimaeroids are also noteworthy for their highly derived body plan. However, like other living groups with distinctive anatomies, fossils have been of limited use in unravelling their evolutionary origin, as the earliest recognized examples already exhibit many of the specializations present in modern forms. Here we report the results of a computed tomography analysis of Dwykaselachus, an enigmatic chondrichthyan braincase from the ~280 million year old Karoo sediments of South Africa. Externally, the braincase is that of a symmoriid shark and is by far the most complete uncrushed example yet discovered. Internally, the morphology exhibits otherwise characteristically chimaeroid specializations, including the otic labyrinth arrangement and the brain space configuration relative to exceptionally large orbits. These results have important implications for our view of modern chondrichthyan origins, add robust structure to the phylogeny of early crown group gnathostomes, reveal preconditions that suggest an initial morpho-functional basis for the derived chimaeroid cranium, and shed new light on the chondrichthyan response to the extinction at the end of the Devonian period.

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Michael I. Coates, Robert W. Gess, John A. Finarelli, Katharine E. Criswell and Kristen Tietjen. 2017. A Symmoriiform Chondrichthyan Braincase and the Origin of Chimaeroid Fishes. Nature. DOI: 10.1038/nature20806

280 million-year-old fossil reveals origins of chimaeroid fishes http://phy.so/402728253 via @physorg_com

Origins of Elusive 'Ghost Shark' Revealed https://shar.es/1DOoHR via @LiveScience

Dwykaselachus oosthuizeni Oelofsen, 1986