Copepods are another of the many crustaceans that are excellent food sources for the smallest of aquarium inhabitants. Copepods may be found throughout the world in both fresh and marine waters, with more than 5,000 species having been described to date. One of the most commonly encountered species is Cyclops fuscus, which grows to 0.125 inches in length.

Copepods may be collected and cultured in the same manner as has been described for daphnia.