Crustaceans of which there are between 4,000 and 8,000 species, both saltwater and freshwater. Crabs are hard–shelled, though soft–shelled (just moulted) blue crabs are a delicacy in America, China and Venice. Crab meat is sweet, delicate and versatile and food lovers compare it to lobster. Buy live crabs from reputable sources as they are highly perishable. Never buy a dead uncooked crab. Look for lively crabs that feel heavy for their size. Crabs with worn barnacles and feet will not have just moulted—these crabs will have more meat. Cooked crabs are also highly perishable, so buy with care. Make sure they smell fresh and are undamaged and their legs and feet are drawn into the body (if they were dead when cooked, their legs will be looser). Crab meat is also available frozen, tinned and in vacuum–sealed plastic bags.