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Phylum Echinodermata

Like cnidarians and comb jellies, echinoderms are radially symmetrical. However, this is a secondary characteristic of adult echinoderms; their planktonic larvae are bilaterally symmetrical. Most echinoderms develop pentamerous radial symmetry (symmetry based on five parts). Along with an organ system level of organization, echinoderms have an internal skeleton and a water vascular system. The Phylum Echinodermata is exclusively marine. The mouth of most echinoderms is on the bottom, which then is the oral surface.The water vascular system is a network of water-filled canals that end in muscular extensions called tube feet. Tube feet are used for attachment, locomotion, and receiving chemical and mechanical stimuli.

Click on the links below to learn more about different classes of echinoderms that are found in the intertidal of the Gulf of California. To go back to the Gallery of Marine Life, click here.

To take a practice quiz on the Phylum Echinodermata, click here.


page last updated on 7/15/03

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