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SYNOPTIC DESCRIPTION OF THE PHYLUM ECHINODERMATA

SYNOPTIC DESCRIPTION OF THE PHYLUM ECHINODERMATA

EUKARYA>UNIKONTA>OPISTHOKONTA>ANIMALIA>BILATERIA>DEUTEROSTOMATA>ECHINODERMATA
PHYLUM ECHINODERMATA LINKS

Description of Phylum

Hierarchical Description

The following information came from Margulis and Schwartz (1998), Buchsbaum (1938), Barnes (1980), Barnes (1984), Brusca and Brusca (2003), Hickman (1973), Nielsen (2001), Storer and Usinger (1965), Colbert and Morales (1991), Ruppert et al. (2004), Pechenik (2005), and Tudge (2000).
  • I. SYNONYMS: echinoderms.
  • II. NUMBER: >6,000 species known.
  • III. PHYLUM CHARACTERISTICS:
    • A. Structure
      • Symmetry: 5-rayed symmetry; unsegmented.
      • Body Cavity: Eucoelomate; schizocoelic in forms with direct development and enterocoelic in forms with a larval stage. One pouch forms water vascular system (text with tooltip) The water vascular system is a series of internal tubes through which water circulates and provides hydraulic force for movement. The water vascular system connects to the outside by a pore called a madreporite. .
      • Body Covering: Covered by thin epithelium and endoskeletal elements.
      • Support: Endoskeletal (text with tooltip) An endoskeleton is an internal skeleton made by mesodermal tissue. elements and water vascular system.
      • Digestive System: Mobile forms with ventral mouth and dorsal anus; sessile forms with dorsal mouth.
      • Circulatory System: Circumesophageal ring with 5 arm elements. Blood colorless; main circulation with the body cavity.
      • Locomotion: Moves by hydrostatic control of tube feet (text with tooltip) Tube feet are extentions of the surface of echinoderms. They usually function in attachment and locomotion. They may also function as respiratory and sensory structures. or by movement of skeletal elements.
      • Excretory System: Absent.
      • Nervous System: No brain. Circumesophagial ring.
      • Endocrine System:
      • Respiratory System Absorption through body surface, papillate extensions of the water vascular system or coelom.
    • B. Reproduction:
      • Reproductive System: Sexes separate. Gonads (text with tooltip) The term is derived from a Greek root meaning offshoot or offspring (gonos, γόνος). Gonads are sex glands in animals. Ovaries produce eggs and testis produce sperm. in multiples of 5. Fertilization external.
      • Development: Eggs cleave radially. Direct development or ciliated larva.
      • Larval types:
      • Crinoids: Vitellaria
      • Asteroids: Bipinnaria
      • Ophuroids: Ophiopluteus
      • Echinoids: Pluteus (or Echinopluteus)
      • Holothuroids: Auricularia
    • C. Ecology: Sluggish benthic marine animals; filter-feeders, grazers and predators.
LITERATURE CITED

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.

Brusca, R. C. and G. J Brusca. 2003. Invertebrates. Sinauer Associates, Inc. Sunderland, Mass.

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

Colbert, E. H. and M. Morales. 1991. Evolution of the Vertebrates, A History of the Backboned Animals Through Time. WILEY-LISS, Inc. New York.

Delsuc, F., H. Brinkmann, D. Chourrout, and H. Philippe. 2006. Tunicates and not cephalochordates are the closest living relatives of vertebrates. Nature. 439: 965-968.

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

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. 2001. Animal Evolution: Interrelationships of the Living Phyla. 2nd Edition. Oxford University Press. Oxford.

Pechenik, J. A. 2005. Biology of the Invertebrates. McGraw-Hill. New York.

Putnam, N. H., T. Butts, D. E. K. Ferrier, R. F. Furlong, U. Hellsten, T. Kawashima, M. Robinson-Rechavi, E. Shoguchi, A. Terry, J.-K. Yu, E. Benito-Gutiérrez, I. Dubchak, J. Garcia-Fernàndez, J. J. Gibson-Brown, I. V. Grigoriev, A. C. Horton, P. J. de Jong, J. Jurka, V. V. Kapitonov, Y. Kohara, Y. Kuroki, E. Lindquist, S. Lucas, K. Osoegawa, L. A. Pennacchio, A. A. Salamov, Y. Satou, T. Sauka-Spengler, J. Schmutz, T. Shin-I, A. Toyoda, M. Bronner-Fraser, A. Fujiyama, L. Z. Holland, P. W. H. Holland, N. Satoh, and D. S. Rokhsar. 2008. The amphioxus genome and the evolution of the chordate karyotype. Nature. 453: 1064-1071.

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.

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.

Wray, G.A. 1999. Echinodermata, Spiny-skinned animals: sea urchins, starfish, and their allies. In: Tree of Life Web Project. http://tolweb.org/Echinodermata. Accessed 22 January 2010.
By Jack R. Holt and Carlos A. Iudica. Last revised: 02/06/2013
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