Neuston

The term neuston used in Limnology and Océanographie indicates the whole of the organizations related to water surface, i.e. with the Interface water-atmosphere.

Categories

Built starting from the radical Greek old neust- , which corresponds to the idea “to swim” or “to float”, the term “neuston” itself was introduced by the limnologist Einar Christian Leonard Naumann (1891-1934) in 1917. In the original definition, were taken into account only the organizations in contact with the surface Tension of film of surface, which they are above or in lower part; the term widened and diversified only later.

This category of watery organizations since then summer subdivided in several subcategories whose definitions are likely to vary according to the authors and the disciplines. In particular, the uses often diverge between limnology (fresh water) and oceanography.

The first subdivision related to the position of the organizations compared to surface itself. Thus, the épineuston corresponds it to those which live above surface, the hyponeuston referring to those which occupy the surface layer of the liquid element, immediately under surface. Its Antonyme is infraneuston .

Another important category, the pleuston , does not achieve the unanimity concerning its definition. The term is built starting from the Greek radical pleust- which means to sail, to float. In the seamen circle, it almost always applies to the living beings which float on the surface and whose displacements are passive, i.e. controlled by the currents or the winds. A whole community of aquatic animals perfectly adapted to this lifestyle have floats which can exceed surface and act as veil.

For many limnologists, the neuston would represent only the fraction of small size, even microscopic, of the organizations related to surface whereas the pleuston would correspond to the organizations of big size. Another classification based on the size distinguishes the piconeuston , whose size can be lower than 2 μm, from the microneuston and the macroneuston whose certain representatives can measure one meter and more.

The neuston can also be categorized according to the types of organizations which compose it. One can thus speak about bactérioneuston , the bacterial fraction of the neuston, phytoneuston (vegetable), of zooneuston (animal) or of ichthyoneuston (fish).

Species concerned