The Japanese spider crab (Macrocheira kaempferi) is a marine crab that lives in waters @ Japan. It has the largest leg span (up to 12') of any arthropod & weighs up to 42 lbs. Adults live at depths of 500-2,000 ft. They like to inhabit vents in deeper parts of the ocean, consuming both plants & animals. Adults migrate up to @ 160 ft to breed. Females carry fertilized eggs attached to abdominal appendages till they hatch into tiny planktonic larvae & drift as plankton at the ocean’s surface.