The Japanese Giant Spider Crab has a leg span of up to 3.5 m from claw to claw, including 37 cm for the body itself, and weighs 20kg. It is the largest living arthropod.
Adult specimens’ carapaces do not vary greatly in size – it is the claws that go on growing. The species can live for up to 100 years.
It is a relatively placid species, spending most of its time searching the ocean floor for animal remains, molluscs and shellfish.
Unlike other spider crabs, this species does not need to cover its carapace with seaweed or sponges in order to go on its way unseen; its impressive size is enough to keep predators away. Adults live at depths of up to 600 metres, while the young frequent shallower waters (50 metres).
In spring, after mating, the female lays more than a million eggs. It is edible and is subject to small scale fishing on the part of the Japanese.
The male has the longer chelipeds (first pair of legs ending in pincers); the female’s are shorter than its other legs.
