Neustonic

Neustonic refers to organisms that live in the neuston, which is the uppermost layer of a body of water, specifically the surface film and the few millimeters immediately below it. This habitat is characterized by unique physical conditions, including high light intensity, fluctuating temperatures, and exposure to atmospheric conditions like wind and UV radiation. Organisms found in the neuston are often adapted to float or drift at the surface.

The neuston can be divided into two layers: the epineuston, which lives on the surface of the water, and the hyponeuston, which lives just below the surface. Epineustonic organisms, such as certain types of bacteria, algae, and some insects like water striders, are often equipped with adaptations that allow them to remain buoyant or to utilize surface tension. Hyponeustonic organisms, which may include larval forms of fish and invertebrates, as well as plankton, are typically found within a few millimeters of the surface, benefiting from the light and potential food sources found there.

The neuston plays a significant role in aquatic ecosystems, acting as a platform for primary production and serving as a food source for other organisms. It is a dynamic environment, influenced by factors such as wave action, currents, and the presence of dissolved organic matter. Research into the neuston is important for understanding microbial ecology, the dispersal of aquatic organisms, and the impacts of pollution on surface waters.