The sea spider has a small, narrow body. It usually has four pairs of long, thin legs attached to the abdomen. Attached to the head there are usually three other pairs of appendages—a pair called chelicerae, used for grasping food; a pair of sensory projections called palps; and a pair of egg-carrying legs (sometimes underdeveloped or absent in the female). The female lays round masses of eggs on the egg-carrying legs of the male, which carries the eggs until they hatch.