noun
- the aggregate of animal or animallike organisms in plankton, as protozoans.
noun
- the animal constituent of plankton, which consists mainly of small crustaceans and fish larvaeCompare phytoplankton
1901, from comb. form of Greek zoion “animal” (see zoo) + plankton.
- Plankton that consists of tiny animals, such as rotifers, copepods, and krill, and of microorganisms once classified as animals, such as dinoflagellates and other protozoans.