Crab

The typical crab is thought of as a creature which scuttles sideways across the sea bottom or beach; and many crabs answer to this description. However, there are also swimming crabs and land crabs, and the range of sizes and configurations is huge. The tiny oyster (pea) crab is the size of a pea, whereas the giant Japanese spider crab may measure 3.6 m (12') from claw tip to claw tip. The constant feature is possession of two claws and eight walking or swimming legs or ‘feet’, and that the whole creature is, like other crustaceans, contained within a hard exoskeleton which serves as protective armour except at those times when it has to be shed, as its occupant grows, and replaced by a new and larger one.