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![crustacean](/images/sized/images/uploads/sd/Crustacean-266x200.jpg)
Emperor shrimp (Periclimenes imperator) on Sea cucumber (Bohadschia argus). Credit: Wikimedian Nhobgood Nick Hobgood.
crustacean:
A class of joint-legged animals with a hard outer covering. Most crustaceans, including crabs, shrimps, lobsters, and barnacles, live in water. Some, such as wood lice, are land dwellers.