Sand Dollar Shell Pin

A sand dollar shell looks like a round white coin, which is where it gets its name. When they're alive they're actually a dark color, covered with short dark spines. These spines are moveable, and the sand dollar uses them both to move around on sea bottom and to push small pieces of food to its mouth. Just as the starfish has five arms, most sand dollars have a pattern of five sets of pores on them. Those are used to move sea water into the sand dollar's body, which is then pumped to aid in movement.