1. Class: Asteroidea
Sea Stars

2. 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

4. 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

5. 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

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