Malacostracans · Decapoda · Inachidae

Giant Spider Crab

Macrocheira kaempferi

Not Evaluated

It has not yet been assessed against the IUCN criteria. See full glossary

The Japanese spider crab is a species of decapod crustacean of the infraorder Brachyura. It belongs to the group of the spider crabs, characterised by their triangular carapace and their long legs; measured from the tip of one leg to the tip of another, it can be considered the longest arthropod that has ever existed, at more than 4 metres, beating Arthropleura at 3 metres long.

Weight

up to 19 kg

Size

up to 3.8 m

Diet

Omnivore

Combines animal and plant food depending on availability.

Sighting difficulty

Unknown

OceanOmnivore Ocean Crustacean

5countries 3parks 2dive sites1same family

Fun facts

GeneralThe largest arthropod in the world: 3.8 m from leg tip to leg tip.
récordIt has the greatest leg span of any living arthropod known, over 3.7 metres between the tips of its outstretched front legs.
It has the greatest leg span of any living arthropod: up to 3.7 or 3.8 metres from claw to claw.
The body, by contrast, is modest: the carapace does not exceed about 40 cm. Almost all its size is in the legs.
By mass it is the second-heaviest living arthropod, at up to 19 kg, behind only the American lobster.
Males have much longer claws than females, longer than the rest of their legs.
Recent work on its larvae and its DNA has moved it out of the family Inachidae and into one of its own, Macrocheiridae.
It is the target of a small-scale fishery that has made conservation measures necessary.