The Atlantic blue crab (also known as the Chesapeake Blue Crab) is a common species along the east coast of the United States and in the Gulf of Mexico and lives as far south as Argentina. It is named for its blue color (in life) and is a favorite seafood species throughout its range. This species is the target of one of the largest U.S. crab fisheries outside of Alaska. When cooked, Atlantic blue crabs are bright red.
The Atlantic blue crab lives on soft bottom habitats from estuaries to shallow shelves. Along with other crabs, prawns, and lobsters, Atlantic blue crabs are decapods; they have ten legs. They are covered with a spiny exoskeleton that provides them some protection from potential predators, but at different stages of its lifecycle, the species is preyed upon by many species of fishes and some other invertebrates. Atlantic blue crabs are omnivorous and will eat just about anything that they find, plant or animal, dead or alive. Like in all decapods, the Atlantic blue crab’s shell really is a skeleton on the outside of its body. The exoskeleton does not expand, and therefore individuals must molt (=shed) it regularly in order to grow bigger. Before molting, an individual begins building a new, larger skeleton inside the existing one. As it gets too big to be contained, it splits open the outer shell, and the new exoskeleton hardens. During this process, the new exoskeleton can be soft for some time, and the crab is vulnerable to predation. In the seafood industry, so-called “soft shelled crabs” are Atlantic blue crabs that have recently molted. When marketed in this way, they are often eaten whole, in sandwiches and other dishes.
This species reproduces via internal fertilization, and the females only have to mate once in their lifetime. They have the ability to store sperm and will retain enough sperm for several clutches of eggs after the initial mating. The females brood the fertilized eggs under their abdomens until they hatch and the larvae enter the plankton.
The Atlantic blue crab is the target of a large fishery in the U.S. The most significant fisheries for this species occur in the Chesapeake Bay and the Gulf of Mexico. In recent decades, populations have declined as a combined result of fishing and several disease outbreaks that have inflicted this species. The conservation status is not currently known, but managers have recently placed stronger regulations on fisheries that target Atlantic blue crabs. Recent surveys imply that populations may be rebounding in some places.
Oceana joined forces with Sailors for the Sea, an ocean conservation organization dedicated to educating and engaging the world’s boating community. Sailors for the Sea developed the KELP (Kids Environmental Lesson Plans) program to create the next generation of ocean stewards. Click here or below to download hands-on marine science activities for kids.