Atlantic Mud Crab

Panopeus herbstii is small, growing to about a width 6.4 cm, with black-tipped claws of unequal size. P. herbstii has a strong exoskeleton, with very thick and strong claws. The shell is mostly a dull gray and dark brown color with the belly of the crab being a lighter white.

Panopeus herbstii is found along the Atlantic coast of North America, from Boston, Massachusetts to Santa Catarina, Brazil and on Bermuda. It is the most common xanthid crab on the east coast of the United States. It is found on muddy bottoms and oyster beds, where it takes refuge under stones and shells or among sponges and weeds, but it is rarely seen in the open. Its habitat often being in oyster beds allows for easier access to prey and feeding.

It feeds mainly on young clams, oysters, barnacles, and periwinkles; it cracks open their shells with its strong claws. They are also an interspecific cannibalism species as they eat other crabs. Mud crabs are especially fond of hermit crabs, which are grasped by the legs and pulled out of their protective shells. Like most mud crabs, it is a scavenger. Young P. herbstii are an important food source to other marine animals.