Gastrotrichs

Gastrotrichs live in a diverse range of habitats. They can be found in freshwater, marine, and a few semi-terrestrial environments, though they are more abundant in freshwater and marine environments.  In semi-terrestrial environments, they live in a film of water surrounded by grains of soil. Because they are so small, they usually live in interstitial spaces between particles of sediment. They are also a part of the benthic community, and are usually attached to underwater plants or submerged objects, which makes them sessile organisms. They have adhesive tubes all over their body allowing them to attach to surfaces. They also have a short life cycle that can span from 3-21 days depending on the species.