The Class Ophiuroidea ("snake-tail form") contains forms known as brittle stars and basket stars. They are called brittle stars because their arms (which are long and slender) break off easily when seized by a predator, but are easily regenerated. The animals are quite mobile, moving with a writhing, serpent-like motion in search of prey and particulate matter that they collect with their arms and tube feet.  Although they have a sac-like stomach in the central disc, there is no intestine or anus!

Note: These brittle stars are resting on a coral colony, and the yellow organism located in the lower left hand corner of the picture is a polychaete worm known as a feather duster or Christmas tree worm!