From Greek plēusis - swimming, plēō - I swim.

An aggregate of hydrobionts with part of their bodies in the water and part above its surface; free-swimming members of the pleuston are moved by the wind.

These are large or medium-sized airborne pelagic organisms floating under the action of wind on the water surface or in a semi-submerged state. Pleuston organisms are characterized by low specific gravity, gas reservoirs, release of frothy floats, etc.

Fixtures for holding on the surface of water:

Gas chambers (e.g., Physalia physalis);

release of frothy floats (e.g., Janthina);

reliance on the surface film of water (e.g., Glaucus atlanticus).