The Aeolosomatidae and Potamodrilidae are represented by minute annelid worms living in freshwater habitas. Both taxa are made up of only a few species, the Potamodrilidae consists of only a single species, Potamodrilus fluviatilis.
The Aeolosomatidae are about 0.3 -10 mm long and 0.04 – 0.06 mm in diameter while Potamodrilus fluviatilis is about 1.3 mm long and up to 0.11 mm in diameter. Aeolosomatidae comprises 3 genera: Aelosoma, Rheomorpha, Hystricosoma. Most of species are found in phytal regions and on the detritus-rich bottoms of freshwater habitats.
