Copepod

Copepod, small crustacean of subclass Copepoda. Of great ecological importance, copepods serve as food for many species of fish. Although there are freshwater copepods, most of the 7,500 known species are marine forms. They are found both at the surface and at great depths of the sea. While most copepods reproduce sexually, some do so by parthenogenesis (the female's eggs produce new copepods without being fertilized).

See also: Plankton.