Aeolosoma

Aeolosoma is a genus of minute annelid worms, variously attributed either to oligochaetes or polychaetes. Unlike most polychaetes, they reside in freshwater environments in various parts of the world. 
"Aeolosoma" are transparent worms, very thin and of he length of 1.5-2mm. They usually reproduce asexually. Only one species, "Aeolosoma singulare", is known to reproduce sexually.
"Aeolosoma" feed on microalgae, microorganisms and detritus. Their mouth acts like a small vacuum cleaner, which helps them suck up their food into there system.