zooplanctones

Zooplancton is a collective term for the heterotrophic plankton that drift in the Earth's oceans, seas, and freshwater bodies. These organisms are part of the planktonic community, which includes both phytoplankton (photosynthetic algae) and zooplankton. Zooplankton are not capable of swimming against currents and are therefore carried by water movements. Their size can range from microscopic zooflagellates, less than 0.02 mm, to large jellyfish, which can be several meters long.

The composition of zooplankton varies greatly depending on the environment and depth. In marine ecosystems, common zooplankton include copepods, krill, and larval stages of fish and invertebrates. Freshwater zooplankton communities often feature rotifers, cladocerans, and copepods. These organisms play a crucial role in aquatic food webs, serving as a primary food source for many larger animals, including fish, whales, and seabirds. They also contribute to nutrient cycling within the water column.

Zooplankton are broadly divided into two categories: meroplankton, which are planktonic for only part of their life cycle (e.g., larval stages), and holoplankton, which spend their entire lives in the plankton. Their distribution and abundance are influenced by factors such as temperature, salinity, nutrient availability, and water currents. Monitoring zooplankton populations can provide valuable insights into the health and productivity of aquatic ecosystems.