They are most commonly found in soft sediments rich in organic matter, and several species characteristically live in sites that receive organic pollution. Like all aquatic oli gochaetes, tubificids respire cutaneously, but a unique feature of this family is that some species can tolerate anoxic conditions. Most tubificids are deposit feeders, subsisting on organic detritus and its associated microflora. The Naididae is an ecologically diverse family of worms common in both running and standing waters. Many naidids are sediment dwellers, like the tubificids, but other species are characteristically found among aquatic plants.
Sexual reproduction is rare in most species.
R eproduction occurs predominantly by paratomy. These large worms are found in standing and running waters, and are ecologically somewhat similar to tubificids. Because of taxonomic difficult ies, very little work has been done on the ecology of freshwater enchytraeids in North America. References Kellogg, L.L. 1994. Monitor's Guide to Aquatic Macroinvertebrates.