They are primarily gill-breathing arthropods of freshwater and saltwater. Larger crustaceans callde decapods include crabs and crayfish which serves as second intermediate hosts of the lung fluke Pargfonimus westermani.
Copepods are tiny, simple aquatic organsims that lack carapace (shell covering some or all of the dorsal part of an animal), have one pair of maxillae (one of the paired appendages immediately behind the mandibles of arthropods) and have five pairs of biramous swimming legs.
Treatment, Prevention and Control:
Prevention requires attention to public health measures such as chlorination and filtration of water and thorough cooking of all fish. Infected victims are abstained from bathing in water used for drinking. In addtion, suspected water should be avoided.