Phylum: Echinodermata

Characteristics  “echino” = spiny “derma” = skin “derma” = skin Spiny skin, internal skeleton, water vascular system, tube feet and 5 part radial symmetry Spiny skin, internal skeleton, water vascular system, tube feet and 5 part radial symmetry They are the most complex invertebrate phylum because they have skin, an anus and the larvae show bilateral symmetry. They are the most complex invertebrate phylum because they have skin, an anus and the larvae show bilateral symmetry. Reproduction: Usually separate sexes. External fertilization. Reproduction: Usually separate sexes. External fertilization.

Water Vascular System – a system of internal tubes which aid in respiration, circulation and movement.

5 main groups of Echinoderms 1. Sea Urchins/Sand dollars large internal plates that form a box around internal organs large internal plates that form a box around internal organs Dead sand dollar Live sand dollar Sea Urchin

2. Brittle Stars  Will shed an arm if attacked. Filter feeders and detritivores.

3. Sea Cucumbers warty, moving, pickles. May eviscerate (vomit) up part of intestines/stomach if threatened. warty, moving, pickles. May eviscerate (vomit) up part of intestines/stomach if threatened.

carnivores, can regenerate as long as central ring is present. carnivores, can regenerate as long as central ring is present. 4. Sea Stars

5. Sea Lilies/Feather Stars Sea lily Feather star