Sea Star is another name for starfish. Actually, these creatures aren't fish at all, but echinoderms, members of the same club as sea urchins and sand dollars. Echinoderm comes from the Greek words for "hedgehog skin". These animals have platelike skeletons covered with spiny, tough skin.
Sea stars are born symmetrical, their right and left sides are identical. But as they mature, they develop into 5 similar parts rather than two. Most sea stars reproduce by releasing their swimming young into the sea to make their own way. The blood star, however makes a pouch with her arms and protects her young until they are fully formed and ready for release.
Sea stars move by adjusting the water pressure going to each of their hundreds of suction bottomed "tube feet". This makes the feet move and thus propels the sea star along. The water is taken in through a tiny hole in the upper part of the body called a madreporite.
One of the sea star's favorite food is bi-valve mollusks such as oysters or clams. The star pries open the shell by using it's sucker feet and then literally turns it's stomach inside out, inserting the stomach inside the shell of the mollusk through the mouth. The stomach releases enzymes that turn the inside of the mollusk into liquid, and the liquid is guided into the star's mouth by tiny cilia on the arms.
The star's liking for oysters actually helped increase populations at one time. Oyster fisherman, fearing that the sea stars were taking more than their fair share of the oyster crop, would break any sea stars they brought up into pieces and throw them back into the water, thinking to kill the creature. Little did they know that sea stars have amazing regeneration qualities. If as little as one arm and one fifth of the central dish remain intact, the star can recover and be good as new. So the fishermen, by breaking up the stars, and throwing them into the sea, actually increased the sea star population. One sea star, if divided properly can become five sea stars. Silly fishermen. | 
