Crabs

Crabs are 10-legged animals that walk sideways. There are almost 5,000 different species of crabs; about 4,500 are true crabs, plus about 500 are hermit crabs (hermit crabs don't have a very hard shell and use other animals' old shells for protection). Most crabs live in the oceans, but many, like the robber crab, live on land.
The Biggest Crabs: The biggest crab is the Japanese Spider crab (Macrocheira kaempferi), which lives on the floor of the north Pacific Ocean; it has a 12 ft leg span. The biggest land crab is the Coconut crab ,which lives on islands in the Pacific Ocean. It has a leg span up to 2.5 ft.
Many crabs are omnivores,others are carnivores,and some are herbivores.
Crabs are invertebrates, animals without a backbone. They have an exoskeleton (also called a carapace), an outer shell that both protects them from predators and provides support. These crustaceans have ten jointed legs, two of which have large, grasping claws (called pincers or chelipeds). They have a flattened body, two feelers,and two eyes located at the ends of stalks.
Marine crabs breathe underwater using gills, which are located in a two cavities under the carapace. True land crabs have enlarged, modified cavities that act like lungs so that the land crabs can breathe air.
The earliest unambiguous crab fossils date from the Jurassic, although the Carboniferous Imocaris, known only from its carapace is thought to be a primitive crab. The radiation of crabs in the Cretaceous and afterwards may be linked either to the break-up of Gondwana or to the concurrent radiation of bony fish, the main predators of crabs.
About 850 species of crab are freshwater or (semi-)terrestrial species; they are found throughout the world's tropical and semi-tropical regions. They were previously thought to be a closely related group, but are now believed to represent at least two distinct lineages, one in the Old World and one in the New World. Well, this is all I can tell you about crabs, marine-lovers. See you in the next poest!
~~~~~~Megan~~~~~~