Starfish

Starfish are relatives of sea urchins and sea cucumbers, with a body plan organized around a central disc. Rows of tube feet use the water vascular system to assist movement, attachment and feeding. Some species prey on mussels or other shellfish, while others use different foods. Lost arms can often regrow, though the ability to form a whole animal varies. Their familiar star shape does not imply that every species has exactly five arms.