l>Sea Star
A sea star rests top top a barnacle-covered rock.E. Zabel, courtesy of sdrta.net

Sea Star (Asterias forbesii)

Alternate typical name: Forbes Sea Star, Starfish. Color: Brownish purple to orange through lighter underside. Size: as much as 12 inches across when mature. Habitat: Rocky shores, tide pools, dock pilings, only bottom. Seasonal appearance: every year.

You are watching: How do most starfish get their food


Sea stars room not fish as their nickname "starfish" suggests. They belong come a team of animals called echinoderms, which method "spiny skin." castle are pertained to brittle stars, sea urchins, sea cucumbers, and sand dollars. Sea stars have 5 arms, or rays, associated to a small round body. Sea stars detect irradiate with 5 purple eyespots at the finish of every arm. The bright orange period in the facility of the human body is dubbed the madreporite. This body organ pumps water into the sea star"s body. This pumping activity creates suction in ~ the finish of numerous tube feet, located in combine rows top top the underside of the arms.

Life history and Behavior

Sea stars use suction in the tube feet because that movement and also feeding. They wrap their bodies roughly quahogs and other bivalves, utilizing the suction native their pipe feet to pull shells apart. As soon as the prey is opened, the sea star pushes the stomach out of that body and also into the bivalve, secreting enzymes the digest the prey"s soft human body tissues. The liquefied bivalve is then absorbed into the stomach. Sea stars feeding often, and their size depends on the lot of food castle eat, no on their age.

Sea stars are eaten by bottom-dwelling fish and also crabs, and by sea gulls once low tides leaving the sea stars exposed. Rebirth will happen as lengthy as one 5th of the sea star"s body continues to be intact. Sea stars breed in the spring, producing as many as 2,500,000 eggs. Females will feel plump and also spongy when their arms space filled v eggs.

Special Notes

Sea stars space integral members of maritime ecosystems, back they complete directly with commercial and recreational fishermen. One sea star can devour end 50 young clams in a week. once their population grows, sea stars deserve to consume entire beds that shellfish. In 1929, one oyster company removed much more than 10 million sea stars from 11,000 acre of oyster beds in Narragansett Bay. Sea stars are harvested through a device resembling a large mop, i m sorry is dragged follow me the bottom. The sea stars affix themselves come the mop strands and are hauled board fishing boats. As soon as harvested, sea stars are ground up and sold because that fertilizer and poultry feed.

See more: What System Do Spiracles Open Into On A Grasshopper Is Specialized For Movement?

Adapted native The Uncommon overview to typical Life top top Narragansett Bay. Conserve The Bay, 1998.