Invertebrates

Also known as the sand crab, the Atlantic ghost crab is a sand-colored crustacean with a distinct pair of white claws. Ghost crabs are active on coastal beaches in the Chesapeake Bay region from spring through autumn.

Barnacles are small, grayish-white crustaceans that live on rocks, pilings, boat hulls and other hard surfaces throughout the Chesapeake Bay.

Also known as the Atlantic mud crab, the black-fingered mud crab is muddy brown in color with stout, black-tipped claws. It can be found on oyster reefs and along the muddy bottoms of marshes.

The blue crab is a swimming crustacean with bright blue claws and an olive green shell. It is one of the most recognizable species in the Chesapeake Bay.

The Chinese mitten crab is a light brown crustacean with a distinct pair of hairy, white-tipped claws. Native to East Asia, the invasive species has been reported in small numbers in the Chesapeake Bay.

The common grass shrimp has a delicate, nearly transparent body with a distinctive serrated “horn” over the eyes. It lives in shallow waters throughout the Chesapeake Bay and its rivers.

Also known as the portly spider crab or the nine-spined spider crab, the common spider crab is a long-legged and slow-moving crustacean that covers itself in algae and small debris as a defense against predators. 

The deer tick—named for its preferred host, the white-tailed deer—can carry and transmit to humans the bacteria that causes Lyme disease. Ticks are most active in late spring and summer. 

The devil crayfish is a brownish red crustacean that resembles a miniature lobster. They typically have red-tipped claws. They can be found burrowing in forested areas where the water table is near the surface.

Fairy shrimp are relatively large and slow-moving crustaceans that live in vernal pools throughout the Chesapeake Bay watershed.

Fiddler crabs are small crustaceans with a distinctive enlarged claw. They live on beaches, mud flats and marshes throughout the Chesapeake Bay.

Hermit crabs are small crustaceans that lack a shell and must “borrow” one from another animal. They live on beaches, mud flats and shallow waters throughout the lower Chesapeake Bay.

The horseshoe crab is a primitive-looking arthropod with a hard, brownish-green exoskeleton and a spike-like tail. It visits the Chesapeake Bay’s sandy beaches each spring and summer to spawn.

The mantis shrimp is a crustacean with a flattened, segmented body and praying mantis-like claws. It burrows within muddy flats along the shoreline of the middle and lower Chesapeake Bay.

The marsh crab is a small shore crab that lives in salt and brackish marshes in the middle and lower Chesapeake Bay.