(MIV) Echinodermata Phylum Lesson

Echinodermata Phylum

The phylum Echinodermata consists of sea stars, sea urchins, sand dollars and sea cucumbers just to name a few. These organisms demonstrate radial symmetry. Their body parts are symmetrical across five planes as a disc, sphere or cylinder. Echinoderms use a water vascular system for locomotion as the move to feed on worms, mollusks, corals, sponges, crustaceans, and fish. image of sea urchin

image of sea star Sea stars have tube feet which allow them to move to capture their prey. When they have located a food source, they invert their stomachs and place it over the food and digest the food externally. Sea urchins live on firm surfaces and scrape food such as algae from the surface of a rock. Sand dollars feed on detritus found in the sediment.

Watch the following video of a starfish preying upon a mussel.

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