Class: Asteroidea Sea Stars

General Information All are ocean-dwelling Carnivores & Scavengers Tidal pools, deep-ocean seafloors, near the shore… Carnivores & Scavengers They eat: slow-moving/sedentary mollusks and dead organisms Some eat live coral, causing major destruction to the coral reefs Ex: the Crown of Thorns Wide range of colors and sizes

Skeleton & Movement Skeleton Water Vascular System Sea stars have a CaCO3 endoskeleton made of tiny plates called ossicles, like sea urchins These ossicles are connected by muscles and connective tissue to form a network that makes the arms extremely flexible These ossicles are where the spines (if any) attach Water Vascular System System is similar to sea urchins Ambulacral Groove – this is a groove that runs up the underside (ventral or oral side) of the echinoderm

Feeding & Digestion Like urchins the mouth is under the body and the anus is at the top Sea Stars have NO TEETH! So how do they prey on other animals? They push their stomach out of the body, spread it out over the food and digest it! Ex: Eating a mollusk (like a clam or oyster) Attach suction-cupped tube feet to each side of the shells and pull apart steadily until it opens (even 0.1mm is enough room); then push stomach into the clam and digest it

The (kind of) Immortal Sea Star Sea Stars can regenerate arms and sometimes a whole body! Diagram Time! 