Most aquatic earthworms may be found in lakes and ponds or slow currents in streams and rivers.
Many species are typical of terrestrial earthworms in their habits of deposit-feeding and utilizing the organic fraction of mud for their nutrient source.
Oligochaeta are tolerant to pollution and can tolerate very low levels of oxygen.
As they can be easily captured, they are a source of food for macroinvertebrates and fish.