planktonPlankton - a set of small freshwater and marine organisms that inhabit the water column. The composition of the plankton are algae (blue-green, green, diatoms and other), bacteria, protozoa, coelenterates, crustaceans and other Plankton are divided into phytoplankton (plant organisms) and zooplankton (animal organisms). Some representatives of zooplankton are intermediate hosts of worms. So, for example, copepods are the first intermediate hosts lentetsov - infect freshwater fish (last infect humans); crustaceans, intermediate hosts the worm is infecting humans if swallowed with water. Plankton is the food for various aquatic animals. Cm. also the Simplest.