Periphyton - aquatic organisms that live on living and dead substrates in the water column (pilings, cormorants, vessels, etc.).

From Ancient Greek περιφύω - to grow around, to fatten - ecotopic grouping of hydrobionts (plants, animals, microorganisms), leading mainly attached way of life on the water-solid substrates of different origin (stones, rocks, higher aquatic plants, animal covers, submerged large debris, piles, ship bottoms, etc.).

Microbiocenoses and biocenoses arising from the "fouling" by algae and many animals (e.g. barnacles, bivalves, hydroids, in particular freshwater hydra, bryozoans, sea acorns, ascidians, polychaetes, etc.) of underwater rocks, piles, tree trunks, sea and river vessels. Organisms belonging to these cenoses belong to several life forms.