1. One of the family Harpacticidae, tiny copepod crustacea.
2. A tiny crustacean that lives among plankton and is an important food source for many fish. It is native to oceans and lakes. Subclass: Copepoda.

Copepods are minute free-living, freshwater and marine crustaceans (shell-covered); usually having six pairs of limbs on the thorax. Some are abundant in plankton and others parasitic on fish.