The following information came from  Barnes (1984), Bergquist (2001), Brusca and Brusca (2003), Hickman (1973), Nielsen (2001), Storer and Usinger (1965), and Tudge (2000).  
I. SYNONYMS: Porifera was defined by Grant in 1836.  Sponges.


II. NUMBER: >10,000 species known.



A. Structure

Symmetry: Generally none. Symmetry may be radial.

Body Cavity: Not present in a strict sense.  Body of a mesohyl containing amoebocytes, spicules, and mesenchyme.  Organization of the animal based on an interconnected tubular system lined wholly or in part by choanocytes follows three basic body plans: asconoid, synconoid, and leuconoid.  

Body Covering: Exterior of the animal covered with epidermis-like cells called pinacoderm (strictly they are not epidermis because they lack a basement membrane).  Inner portion of animal porous with tubes lined with choanocytes.

Support: Support by spicules of calcium carbonate or silica. Sometimes with an organic matrix.

Digestive System: Animal is a filter-feeder. Particles are trapped and taken into choanocytes.

Circulatory System: None.

Locomotion: Adults are sessile. Some have larvae that move by ciliated epithelium.

Excretory System: None.

Nervous System: None.

Endocrine System: None.

B. Reproduction:

Reproductive System: No special organs. Eggs and sperm are produced. Asexual reproduction occurs; freshwater forms produce over wintering asexual structures called gemmules.

Development: Some with a planktonic larva that resembles a blastula.  

C. Ecology: Found mainly in marine environments. One freshwater group.



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Barnes, R. D. 1980. Invertebrate Zoology. Saunders College/Holt, Rinehart and Wilson, Philadelphia.

Barnes. R. S. K. 1984a. Kingdom Animalia. IN: R. S. K. Barnes, ed. A Synoptic Classification of Living Organisms. Sinauer Associates, Inc., Sunderland, MA. pp. 129-257.

Bergquist, P.R. 2001. The Porifera. In: Anderson, D.T., ed. Invertebrate Zoology. Oxford University Press. Oxford, UK. pp. 11-27.

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Buchsbaum, R. 1938. Animals Without Backbones, An Introduction to the Invertebrates. The University of Chicago Press. Chicago.

Hickman, C. P. 1973. Biology of the Invertebrates. The C. V. Mosby Company. Saint Louis.

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Leys, S. P. 2003. The significance of syncytial tissues for the position of the Hexactinellida in the Metazoa. Integrative and Comparative Biology. 43:19-27.

Margulis, L. and K. Schwartz. 1998. Five Kingdoms, an Illustrated Guide to the Phyla of Life on Earth. 3rd Edition. W. H. Freeman and Company.  New York.

Nielsen, C. 2008. Six major steps in animal evolution: are we derived from sponge larvae? Evolution and Development. 10(2): 241-257.

Reiswig, H.M. and G.O. Mackie. 1983. Studies on hexactinellid sponges. III. The taxonomic status of Hexactinellida within the Porifera. Philosophical Transactions of the Royal Society of London, B. 301:419-428.

Rokas, A., N. King, J. Finnerty, and S. B. Carroll. 2003. Conflicting phylogenetic signals at the base of the metazoan tree. Evolution and Development. 5:346-359.

Ruppert, E. E., R. S. Fox, and R. D. Barnes. 2004. Invertebrate Zoology: A Functional Evolutionary Approach. Seventh Edition. Thomson, Brooks/Cole. New York. pp. 1-963.

Sperling, E.A., D. Pisani, and K.J. Peterson. 2007. Poriferan paraphyly and its implications for Precambrian palaeobiology. In: Vickers-Rich, P. and P. Komarower, eds. The Rise and Fall of the Ediacaran Biota.  Geological Society, London, Special Publications. 286: 355-368.

Storer, T. I. and R. L. Usinger. 1965. General Zoology. 4th Edition. McGraw-Hill Book Company. New York.

Tudge, C. 2000. The Variety of Life, A Survey and a Celebration of all the Creatures That Have Ever Lived. Oxford University Press. New York.


By Jack R. Holt and Carlos A. Iudica.  Last revised: 01/26/2010