Facts on the Japanese Giant Spider Crab

The Japanese giant spider crabs are a scary sight because of their enormous size. However, they are harmless to humans and are actually fragile and susceptible to attacks from other species. Since they are only found in one place in the world, more are starting to be captured so they can be viewed in aquariums around the world.

  1. Appearance

    • Japanese giant spider crabs have eight long legs and two giant feeding arms. The large legs and small body make it look like a giant spider, hence the name. The feeding arms have pinchers on the ends of them, and in males, the feeding arms will actually become longer than the legs they have. The feeding arms of females are much shorter than their legs. The body is mostly red and has white spots on the legs. The two eyes are located on front of the body, and they have two horns between their eyes. The horns will become shorter overtime.

    Size

    • Like the name suggests, Japanese giant spider crabs are huge. It is the legs that actually make them look big, because when the legs are spread out, the crab can measure 12 feet across. The body is much smaller and can reach a maximum length of 15 inches. The weight of these crabs may reach about 40 Ibs. Marine biologists believe that the Japanese giant spider crabs can live to be about 100 years old, a major reason why they can reach huge sizes.

    Location

    • Japanese giant spider crabs are only known to live in one location, the seafloor of the Pacific Ocean around Japan. They can live in water depths between 150 and 1,000 feet, in places where the water is cold and dark. The normal depth for these species is about 650 feet, but if females have to lay their eggs, they will travel to water at about 150 feet in depth. The most common time the Japanese giant spider crabs are caught is in the spring, when females lay eggs.

    Feeding and Other Facts

    • The Japanese giant spider crab is the largest arthropod in existence today. Arthropods include spiders, insects, crabs and shrimp. This crab is a scavenger, so it feeds mostly on decaying animals and plants, but it can pry open mollusk shells with its giant claws to feed on them. After molting, these crabs will eat their own shell to regain important nutrients. Since they live in such deep waters, they are hard to catch and therefore not often fished commercially.