Phylum Porifera
Phylum Porifera
Phylum Porifera
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canal systems lined with flagellated cells for filter
feeding. Sponges are exclusively aquatic organisms.
All adults are stationary (sessile) and attached to
shells, corals, rocks or any other submerged suitable
substratum, and hence, they depend on the current of
water for their metabolism. They are generally
asymmetrical creatures with some exceptions. They
can reproduce asexually by budding, fragmentation
and regeneration, and gemmule formation and
sexually by fertilization forming free-swimming ciliated
larvae.
PHYLUM The taxonomy of the sponges is mostly based
PORIFERA on the details of their endoskeleton (internal
skeleton). It is considered to be one of the most
useful diagnostic tools for identifying and classifying
sponges. The skeleton consists of calcareous or
siliceous crystalline spicules, spongin fibers made-up
of protein, or a combination of both. The ratio of the
skeletal elements and the shapes, sizes, and
composition of the spicules contribute greatly to the
variety of forms and texture of the sponges.
Phylum Porifera
Class Calcispongiae (Calcarea): The members of this class have spicules made-
up of calcium carbonate. They are needle-shaped, three or four rayed. These
sponges also exhibit all three types of canal systems (asconoid, syconoid,
leuconoid). All are marine dwellers.
Ex . Grantia (Scypha, Sycon), Leucosolenia
Materials
hand lens
compound light microscope
prepared slides of : Leucosolenia (w.m.), Grantia (x.s), spicules
preserved specimens of : Euplectella, Spongia, Carteriospongia
Procedure
Obtain the prepared slides and preserved specimens of sponges and study their
morphology. Label the photographs in the Activity Sheet.
Morphology of Some Representative Species
References
Barnes, R.S. K., P. Calow and P.J. W. Olive. 1993. The Invertebrates – A New
Synthesis. 2nd edition. Blackwell Science Ltd. pp.49-52
Engemann, J.G. and R.W. Hegner. 1981. Invertebrate Zoology. 3rd edition.
MacMillan Publishing Co., Inc. pp. 157-189.
Hickman, C.P., F.M. Hickman and L. Kats. 1997. Laboratory Studies in Integrated
Principles of Zoology. 9th edition. The McGraw-Hill Companies, Inc. pp. 242-
250.
II. Guide Questions
1. Differentiate the three types of canal systems. Which canal system is the most
efficient and why?
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3. Why is this phylum considered just above the protozoan level of organization?
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