The common brittle star lives up to its name: it is very brittle. Particularly the arms are very breakable, but fortunately should one fall off, they regenerate just like other starfish. Brittle stars have a relatively small body and long arms. They can have all kinds of beautiful colors. Using their roughly spined arms, they filter plankton out of the seawater. Common brittle stars are very sensitive to cold winters; their numbers can decrease strongly after a severe winter.