Japanese spider crab

 

The Japanese spider crab has the greatest leg span of any arthropod, reaching 3.8 metres (12 ft) from claw to claw. The body may grow to a size of 40 cm or 16 in (carapace width) and the whole crab can weigh up to 41 pounds (19 kg).The males have the longer chelipeds; females have much shorter chelipeds, which are shorter than the following pair of legs.Apart from its outstanding size, the Japanese spider crab differs from other crabs in a number of ways. The first pleopods of males are unusually twisted, and its larvae appear primitive. The crab is orange, with white spots along the legs. It is reported to have a gentle disposition "in spite of its ferocious appearance".

Japanese spider crabs are mostly found off the southern coasts of the Japanese island of Honshū, from Tokyo Bay to Kagoshima Prefecture. Outlying populations have been found in Iwate Prefecture and off Su-ao in Taiwan. Adults can be found at depths of up to 600 m (2,000 ft), or as shallow as 50 m (160 ft). They like to inhabit vents and holes in the deeper parts of the ocean.