The giant spider crab has the largest leg span of all known species of crab and may live up to 100 years. The Japanese name for this species is taka-ashi-gani literally translating to “tall legs crab.” Their armored exoskeletons help protect them from predators. Like all crustaceans, the spider crab must occasionally moult its armour in order to grow. The process of shedding their old exoskeleton can take hours and leaves its soft unprotected new exoskeleton extremely vulnerable to predation. The new exoskeleton will harden in about two weeks.
Spider crabs are considered a prized delicacy in many parts of Japan. They are caught using small trawling nets. Harvesting of the crab is forbidden during the spring, when crabs move to shallower water to reproduce. Populations of this species of crab have diminished over recent years and there are many efforts to protect them.