Longest marine crustacean

The longest marine crustacean (although not the heaviest) is the taka-ashi-gani or giant spider crab (Macrocheira kaempferi) found off the south-eastern coast of Japan. A specimen with a claw-span of 3.7 m (12 ft 18 in) weighed 18.6 kg (41 lb). The crab has an average body size of 25.4 x 30.5 cm (10 x 12 in) and an average leg span of 2.43 x 2.74 m (8-9 ft). The largest specimen ever found had a leg span of 3.69 m (12 ft 1.5 in) and weighed 18.6 kg (41 lb).

The giant spider crab lives at the bottom of the ocean at depths of 30–50 m (98–164 ft). It feeds on other crustaceans, worms and molluscs. It was discovered in 1836. Specimens have a lifespan of 50+ years. The heaviest marine crustacean is the American or North Atlantic lobster (Homarus americanus).