The giant spider crab is the largest known species of crab and may live up to 100 years. Populations of this species of crab have diminished over recent years and there are many efforts to protect them.
The Japanese spider crab has the greatest leg span of any arthropod, reaching 10-12ft, claw to claw. The body may grow to a size of 16 in and the whole crab can weigh up to 42 lb — second only to the American lobster among all living arthropod species. The Japanese spider crab is an omnivore, consuming both plant matter and animals. It also sometimes acts as a scavenger consuming dead animals. Some have been known to scrape the ocean floor for plants and algae while others pry open the shells of mollusks.