Callinectes Sapidus, commonly known as the blue crab, is a species of crab that is widely used in seafood cuisine across the world. There are multiple synonyms for Callinectes Sapidus, such as the Atlantic blue crab, Maryland blue crab, Chesapeake blue crab, and the Atlantic crab. The blue crab has a hard shell, which is typically blue in color, and can grow up to 9 inches in length. They are often found in the shallow waters of the Atlantic and Gulf coasts, where they feed on small fish, mollusks, and other crustaceans. The blue crab is considered a delicacy in many countries, due to their sweet and delicate flavor.