Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (= short, ουρά/οura = tail), or where the reduced abdomen is entirely hidden under the thorax. They are generally covered with a thick exoskeleton, and armed with a single pair of chelae (claws). 6,793 species are known. Crabs are found in all of the world's oceans. Additionally, many crabs live in freshwater and on land, particularly in tropical regions. Crabs… (More on Crab)