An edible, bluish swimming crab (Callinectes sapidus) that has a wide distribution along the Atlantic and Gulf coasts of North America. Any member of a genus (Callinectes) of decapods, particularly C. sapidus and C. hastatus, common edible crabs of the western Atlantic coast prized as delicacies. Their usual habitats are muddy shores, bays, and estuaries. The blue crab shell, greenish on top and dingy white below, is about 3 in. (15-18 cm) long. The legs are bluish. The chelae, or pincers, are large and somewhat unequal in size, and the fifth pair of legs is flattened for swimming. Blue crabs are scavengers