Some Starfish Have 40 Arms, and Other Facts About the Sea Creatures

Starfish (or sea stars) are beautiful marine animals found in a variety of colors, shapes, and sizes. All starfish resemble stars, and though the most common have only five arms, some of these animals can grow up to 40 arms. The amazing sea creatures—part of a group of animals known as echinoderms—travel using their tube feet. They can regenerate lost limbs and swallow large prey using their unusual stomachs. Sea Stars Are Not Fish Although sea stars live underwater and are commonly called "starfish," they are not true fish. They do not have gills, scales, or fins like fish do. Sea stars also move quite differently from fish. While fish propel themselves with their tails, sea stars have tiny tube feet to help them move along. Because they are not classified as fish, scientists prefer to call starfish "sea stars." Sea Stars Are Echinoderms Sea stars belong to the phylum Echinodermata. That means they are related to sand dollars, sea urchins, sea cucumbers, andsea lilies. Overall, this p...