Mole crab - Definition and Overview

Mole crabs (Emerita talpoida) are oval-shaped crustaceans. The scientific name for a mole crab is Emerita talpoida. Although like the true crabs they belong to the order Decapoda, they are classified in a different infraorder, Anomura (the true crabs are in the infraorder Brachyura).

Mole crabs are the color of rippled sand at the water's edge. Mole crabs are very small. They can only reach about 35 mm. It can be hard to tell a male from a female when they are young. When they mature, it becomes an easier task because females are larger. A male may reach 20 mm when a female can reach up to 35 mm.

Mole crabs have no claws. They have ten legs and four antennae. When a mole crab is completely covered with sand, its first two antennae reach above the sand to allow it to breathe. The second two antennae are feathery. They are used to filter tiny animals such as plankton and organic debris. Mole crabs also eat the tentacles of Portuguese man o' war. As soon as a tentacle is spotted, the mole crab grabs it and winds it around its leg like yarn. By eating the tentacles, mole crabs help people who walk along beaches to not get stung.

Mole crabs live under sand near the shore break. They start off as free little larvae. Mole crabs live from two to three years, but most don't make it to their reproductive age. The female that make it to their reproductive age carry bright orange colored eggs under their telson during the summer months. Mole crabs are eaten by some fish and shorebirds.

Their known range is from Cape Cod to Texas, and they have also been found in Mexico