Echinoderms
Echinoderms are deuterostomes. Almost all are marine. The body wall has spines or plates of calcium
carbonate.
Echinoderms are deuterostomes. Almost all are marine. The body wall has spines or plates of calcium
carbonate.Echinoderm means spiny skinned animal. They include Crinoids (sea lilies and feather stars), sea stars , sea urchins , heart urchins, sand dollars , brittle stars , and sea cucumbers . Adults are radially symmetrical with some bilateral features. Larvae are bilateral. A decentralized nervous system permits responses to be made in all directions.
The unique water vascular system operates the tube feet by contracting the ampulla on each one. Collectively the tube feet achieve a suction useful in locomotion and prey capture. Sea stars can evert their stomachs when feeding.
This animation (Audio - Important) illustrates the function of water vascular system.
Water-vascular system video (Audio - Not Important) taken at the Monterey Bay Aquarium.
REVIEW: A water-vascular system is characteristic of the
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