Topic: feather star

feather star common name of a class of echinoderms that, as juveniles, are attached to the sea bottom by a stalk with rootlike branches; the mouth side faces upward. In the adult stage they break away from the stalk and move about freely. Feather stars have water-vascular (ambulacral) systems, similar to those in other echinoderms, that extend into the branched arms on the body, or crown. Some can swim by undulating movements of the arms. Feather stars creep about by means of projections at the base of the crown, called cirri, which can grasp bottom objects. They are marine animals, like all... Read more