The Japanese spider crab is the largest living arthropod, reaching 13 feet in arm span. It is an omnivorous scavenger feeding on decaying animal and plant matter. Found in the cold, deep waters off the coast of Japan, the Japanese spider crab is known to breed between the months of January and April each year. Females of this species can carry up to 1.5 million eggs each season. The exact life span of these giant crustaceans is unknown, but it is believed that they can live more than 50 years, with some reports suggesting that they can survive for more than 100 years.