Panopeus herbstii: the black-fingered mud crab or sometimes common mud crab.
One of the reasons everyone touts oysters as one of the foundational species of the Chesapeake can be seen here in this picture.
This little guy, a common mud crab, is a frequent hitchhiker in the oyster shells we pull up off the bottom on our Ecology Cruises here at the Chesapeake Bay Maritime Museum, and is one of the many animals you find as you rummage through the catch in an oyster dredge. In addition to filtering water, the reef habitat created by oysters acts as an ‘apartment building’, providing little nooks and crannies for all sorts of tiny and intricate layers of life. Worms, mussels, barnacles with wavering 'feet’ extending from their shell trapdoors, skilletfish pillowed in their own eggs, naked goby fish, bryzoans extending their lacy mesh; all forms of life abound on an oyster reef tenement. Even dead oysters provide nourishment and shelter for all manner of small, weird creatures.
So remember- even on the iciest days this winter, when the surface looks frozen and lifeless, below all these animals go about their business, thriving in the water that holds just enough salt to keep the oyster bar humming.