Callinectes sapidus (from the Greek calli- = "beautiful", nectes = "swimmer", and Latinsapidus = "savory"), the blue crab, Atlantic blue crab, or regionally as the Chesapeake blue crab, is a species of crab native to the waters of the western Atlantic Ocean and the Gulf of Mexico, and introduced internationally.Callinectes sapidus is a decapod crab of the swimming crab family Portunidae. The genus Callinectes is distinguished from other portunid crabs by the lack of an internal spine on the carp