Rohan, Michaela, Nori, and Lauren

 Seastars  Brittlestars  Sea urchins  Sand dollars  Sea Cucumbers  Crinoids

 Echinoderms have three germ layers. ◦ Ectoderm (Outer) ◦ Endoderm (Inner) ◦ Mesoderm (Middle)

 Sea Stars, Crinoids, Brittle Stars, and Sea Urchins have radial symmetry.  Sea Cucumbers do not have distinct radial symmetry, but they are bilateral.  Most echinoderms are bilateral as larvae, but as adults become radial.

 The water vascular system includes a ring like canal in the center that extends to the five radial canals which pump water into the external tube feet.  The tube feet act as suction cups as water is squeezed through them along with adhesive chemicals.  Water can flow in or out of the surrounding area through the Madreporite.  Tube feet can be used for locomotion, feeding and or gas exchange.

 They have a unique water vascular system.  External tube feet used for locomotion.  These feet are hydraulically controlled.

 Soft flimsy stomach with digestive fluids to break down nutrients.  The mouth is located on the underside of the most echinoderms.  They have a mouth, a cardiac stomach, a pyloric stomach, small intestines, and an anus near the mouth.

 Echinoderms have no distinct head or brain, therefore they have not endured a change in symmetry other than from larvae to adult.  Although they do not have a distinct head, they have a fairly defined nervous system.

 They have no segmentation  Although there is no segmentation, they are prickly with skelatal bumps and spines.

 Advanced invertebrates with five appendages that point outward

 Echinoderms have no true heart.  They have an open and reduced circulatory system that consists of a central ring and radial vessels.  Their blood lacks respiratory pigment.

 Echinoderms use the bumps and spines on their surface to take in oxygen.  They have a gill like structure and a poor respiratory system.

 Most species of Echinoderms are separate male and female individuals which involve the fertilization of eggs with spermatozoa.  Other species such as sea stars and sea cucumbers can produce asexually through budding. This means they can regenerate body parts by splitting apart or breaking off single appendages to create a whole new animal.  Fission is to split in two and create a new body.

 Echinoderms are found at every depth of the ocean from the intertidal zone to the abyssal zone.  They are found in sand, rubble, and coral reefs as well as cold and tropical waters.