Members of the class crustacea. Includes amongst the aquatic crustaceans, shrimp, prawn, yabby, crab, lobster. Many of them are now farmed commercially in enclosed waters.
- parasitic c. — small crustaceans or copepods are common parasites on the gills of aquarium and pond fish where they appear as white spots. The gills become obstructed and the fish die of anoxia.
