![]() Sea stars range in size from three-fourths of an inch (2 cm) up to three and a half feet (one meter) in diameter.To eat shellfish, they use their powerful suckers to pry open a clam or oyster shell, then push their stomach out through their mouth and insert it inside the shell where they digest and absorb the soft inner tissues leaving an empty shell behind. This feature allows sea stars to consume a variety of prey larger than their mouth. Their stomach can be extended out through their mouth to engulf and digest prey. Sea stars are ravenous carnivores with a special adaptation for consuming prey outside their bodies. The arms can bend and twist allowing sea stars to move over irregular surfaces, grasp prey or even flip themselves over. During locomotion the tiny tube feet perform a coordinated “grip and pull” action. A network of water vessels in each arm draws in water and channels it to the tube feet enabling them to move. ![]() The tube feet are used for locomotion, feeding, respiration and sensory functions. Along the groove there are 2-4 rows of small tubular projections called tube feet tipped with muscular suction cups. Sea stars have a groove extending from the mouth into each arm. ![]() Regeneration is a slow process and may require a year for complete reformation. ![]() Regeneration is possible because each of the arms contains parts of the vital organs including the digestive tract and reproductive organs. Some species of sea star have the ability to regenerate lost arms or even regenerate a whole new sea star from a single arm attached to a portion of the central disc. ![]()
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