Latin Hydrobiontes; from Ancient Greek ὕδωρ - water + biont.

Living organisms (animals, plants, and bacteria) that live permanently or temporarily (insect larvae, amphibians) in the water column and bottom sediments of water bodies and streams. Hydrobiota are divided into bottom dwellers (benthic organisms) and water column dwellers (pelagic organisms).

Hydrobionts are marine and freshwater organisms that permanently live in the aquatic environment. Hydrobionts also include organisms living in water for part of their life cycle, for example, most representatives of amphibians, mosquitoes, dragonflies, etc. There are marine and freshwater hydrobionts, as well as those living in the natural or artificial environment, which are of industrial importance and have not become such. Industrial fishing, aquaristics and similar activities deal with hydrobionts.

Diversity of hydrobionts:

Pelagic organisms (plants or animals that live in the water column or on the surface).

Neuston - a set of microorganisms living at the surface film of water at the boundary of the aqueous and air environments.

Pleistons are plant or animal organisms that live on the surface of the water, or semi-submerged in the water.

Rheophiles are animals that have adapted to living in flowing waters.

Nekton - a set of aquatic actively swimming organisms capable of resisting the force of the current.

Plankton are heterogeneous, mostly small organisms that drift freely in the water column and are unable to resist the current.

Benthos (a set of organisms living on the ground and in the ground of the bottom of water bodies).