Did You Know? Sea Stars

Photo by Amanda Gregory

Sea stars are echinoderms (which means “spiny skin”), and also known as asteroids because of their membership in the class Asteroidea.

Quick Facts

◆ Sea stars can have anywhere from 5 to 40 arms, and have hundreds of tube feet for mobility, feeding, and circulation. ◆ They have red spots at the end of each limb which enable them to detect intensity of light. ◆ Their prey includes – well, almost anything – but especially mussels, oyster and clams. ◆ Sea stars are a keystone species; if their numbers diminish, the whole food web is affected. ◆ They live not only in tropical waters, but also in polar oceans.

SEA STARS

Asterias Forbesi

Compiled by Neva Parsons

There's no such thing as starfish! Sea stars are not fish - they have no gills, scales or fins. They're related to sand dollars and sea urchins.

Strange but True! Although the ability to regrow legs is a little odd, check out these other strange facts: ◆ A sea star's stomach actually exits its body to consume food, then reenters when finished feeding. ◆ Sea stars “breathe” using diffusion when water passes over their bodies. (Look it up!) ◆ They can reproduce sexually, or asexually. ◆ They’re not stupid, but are they are brainless – they literally have no brain, but they have a keen sense of smell. ◆ Sea stars are bloodless – they filter sea water through their nervous system (called a nerve net) to extract nutrients.