Marine Biology

Plankton

Plankton are divided into phytoplankton, which include photosynthesizing species such as algae, and zooplankton, which are consumer species. Zooplankton consist largely of copepods (tiny crustaceans). Although plankton generally drift with ocean currents, some plankton have limited mobility. For example, certain zooplankton species move towards the water surface at night to feed, when there is less danger of predation, and return to deeper waters during the day. This type of migration is termed vertical migration. Although most planktonic species are small, some are large, such as Sargassum and jellyfish.