Which is the largest crab in the world and how big is it?

Crabs belong to the class of animals that are known as crustaceans, i.e. the creatures that have their skeletons on outside of the body rather than inside. There are hundreds of crab species. Most are found in oceans and on seashores, the largest of which are the giant spider crabs that inhabit seabed off the coast of Japan. (See photograph.) Usually, adult males have a heart-shaped main body measuring 25.4 x 30.4 cms. (10" x 12") and a biting claw span of about 1.83-2.13 metres (6-7 feet long). Adult females are smaller. The largest known specimen was a male which had a leg-span of 3.3 metres (10.1 feet) and a shell measuring 33.5 x 30.5 cms (13.18" x 12"), but even bigger examples have been reliably reported. One outsized individual preserved in a Bangladesh museum, has a claw-span of 3.45 metres (11’ 4") and a measurement of 3.7 metres (12’ 1.5") has been quoted for another male which weighed 6.35 kilograms. The maximum size attained by this curious-looking creature has not yet been established. Most reports remain unverified by scientists. For example one enormous crab caught in a fish

erman’s net off Honshu Island of Japan in November, 1921 reputedly had a claw-span of 5.79 metres (19 feet) and weighed 18.14 kilograms. Because of their cumbersome structure the giant spider crabs can only move about in the very still waters found at depths of more than 300 metres. Here these long-legged crabs are often disguised by the algae, barnacles and sea anemones that attach themselves to these slow-moving crustaceans. On dry land such crabs are completely helpless and cannot move at all. Much less moving, they find it impossible to stand erect.