Starfish, sometimes called sea stars, are found in all of the world's oceans, even in the icy Arctic Ocean. They are a kind of ocean invertebrate, which means they lack backbones. All starfish have at least five arms, but some have more. Many kinds of starfish can regrow arms that are bitten off by predators. Starfish can be dull or colorful and come in many different sizes. Scientists believe there are more than 1,500 types of starfish.


Starfish attack and eat other invertebrates. Some starfish, however, are harmful to undersea communities because they eat special kinds of coral or fish. Starfish are rarely eaten by humans because their bodies are bony and taste bad. Humans often use them as ornaments or collectibles.