How big is the Japanese spider crab?

The Japanese spider crab is the largest known species of crab, with a leg span that can reach up to 12 feet (3.7 meters) or more. Their body can grow to about 15 inches (38 centimeters) across. These crabs are found in the waters around Japan, typically at depths of around 150 to 300 meters. Despite their intimidating size, they are known to be relatively gentle.