Sea Star

photo by Andrew McKinlay CC BY-NC
Ochre Sea Star


Sea Stars, often known as Starfish, can be found in all the world's oceans. Look for them in tidal pools, along rocky shores at low tide, or around docks. Most Sea Stars have 5 arms evenly distributed around a central disc, but some have up to 40 arms. A tough, spiny skin on their upper surface protects them from predators. The lower surface is soft with rows of tiny tube feet that use suction to stay in one place or move. Size varies, but many are 5-10 in across. They are often very colorful to scare off predators or fit in with their surroundings. Sea Stars found along the coast of the Pacific Northwest are purple, orange, or brownish-red. There is even more color variation in other parts of the world.

Most or all of the Sea Star's vital organs are in their arms, including an eye at the tip of each arm that can detect light and dark. If they lose an arm, they can regrow it, and some Sea Stars can regrow their entire body. They use seawater instead of blood to transport oxygen around their body.

Sea Stars are closely related to Sea Urchins and Sand Dollars that also have radially symmetrical bodies.

Did you know? If their prey is too big to be swallowed, Sea Stars will push their stomach out of their mouth and around their prey, breaking down the soft flesh, and swallowing it.

See Also: Barnacle, Blue Mussel, Clam, Crab, Harbor Seal, River Otter, Sand Dollar, Sea Anemone, Sea Jelly, Sea Lion, Sea Otter, Sea Urchin