Pleuston

Pleuston are the organisms that live in the thin surface layer existing at the air-water interface of a body of water as their habitat. Examples include some cyanobacteria, some gastropods, the ferns Azolla and Salvinia and the seed plants Lemna, Wolffia, Pistia, Eichhornia crassipes and Hydrocharis. Some fungi and fungi-like protists may be also found.The term Neuston is used either:Plankton (organisms that float or drift within the water) are distinguished from nekton (organisms that swim, powerfully, in the water), and benthos (organisms on the bottom of a body of water).