Japanese Spider Crab

The Japanese Spider Crab is the largest living arthropod; fully grown it can reach a leg span of almost 4 m (13 ft), a body size of up to 37 cm(15 inches) and a weight of up to 20 kg (44 pounds). The crab's natural habitat is on the bottom of the Pacific Ocean (some 300–400 m deep) around Japan, where it feeds on dead animals and shellfish. It is believed to have a life expectancy of up to 100 years.

Because it is a particularly old species of crab, it is often referred to as a "living fossil".

for more info on the Japanese Spider Crab click on these:

http://en.wikipedia.org/wiki/Japanese_spider_crab

http://www.vincelewis.net/spider.html

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