Sea Star

You probably know sea stars as starfish, the name sea stars are commonly known by. But sea stars aren’t really fish. Sea stars, like sea urchins and sand dollars, do not have backbones, which makes them part of a group called invertebrates. Fish have backbones, which makes them vertebrates. Got it? Most sea stars sport spiny skin and five arms, although some can grow as many as 50 arms. The arms are covered with pincerlike organs and suckers that allow the animal to slowly creep along the ocean floor. Light-sensitive eyespots on the tips of the arms help the sea star find food. Favorites on the menu include mollusks such as clams, oysters, and snails. The sea star eats by attaching to prey and extending its stomach out through its mouth. Enzymes from the sea star’s stomach digest the prey. The digested material enters the sea star’s stomach. Tiny organisms can be swallowed whole. Sea stars occupy every type of habitat, including tidal pools, rocky shores, sea grass, kelp beds, and coral reefs. Some sea stars even live in sands as deep as 20,530 feet (9,000 meters). Sea stars aren’t social creatures, but they will congregate in large groups during certain times of the year to feed.

At Friday Harbor Labs, scientists give sea stars a chance to shine

Starfish do not have arms, but a five-pointed head, study says

Meet the Tiny Killer Causing Millions of Sea Stars to Waste Away

National Marine Sanctuary Foundation

Northern Pacific Sea Star » Marine Biosecurity Porthole

Sea stars wash up on Port Aransas beach. 'There's more than I've

Common Sea Star

Absurd Creature of the Week: The Two-Foot-Wide Sea Star That's

Wild Side: Ochre sea star, Coastal Life

Sea Stars—Starfish—PNW Ocean Life—Species Identification — Edmonds

Sea Star Wasting Syndrome

Seeking Sea Stars (U.S. National Park Service)