Japanese spider crab (Macrocheira kaempferi) has the largest leg span among arthropods. In Japanese, it is named as taka-ashi-gani, which means “tall legs crab”. It is also called Giant spider crab and it is a docile creature.
Like its name, it looks like a spider with its spherical-shaped body. It has an orange appearance and its legs are speckled with white marks. Its bumpy carapace camouflages with the rocky background. The eyestalks are short and located at the front. The larva has transparent body with no legs.
The size of its leg span measures 18 feet. The width of its carapace is 40 centimeters and weighs around 42 pounds. In comparison to female crabs, the male crabs have much larger claws (chelipeds).
The lifespan of the Japanese spider crab is the longest among crabs and it can live up to 100 years.
For breeding, these crabs go down as deep as 164 feet. Normally, they stay at a temperature range of 50 to 55 °F. The larvae develop from 54 to 72 days.
Japanese spider crabs are distributed mostly across the southern shores of Japan, off Kyushu and Konshu Islands in the Pacific. They are also present off southern shores in the Eastern Taiwan.
The adult spider crabs are found at a depth range of 164 to 1,968 feet and inhabiting ocean floors in holes and vents.
It is an omnivorous animal and so it eats both animals and plants. It also scavenges carrion.
In Japan, it is considered as a delicacy and are caught using trawling nets.
It is preyed upon by predators like octopuses.