Tags: Crustacean.
Crustaceans (Crustacea) form a very large group of arthropods usually treated as a subphylum which includes such familiar animals as crabs lobsters crayfish shrimp krill and barnacles. The 67000 described species range in size from Stygotantulus stocki at 0.1 mm (0.004 in) to the Japanese spider crab with a leg span of up to 3.8 m (12.5 ft) and a mass of 20 kg (44 lb). Like other arthropods crustaceans have an exoskeleton which they moult to grow.
