Grube, 1850
The subclass (formerly treated also as a class, or an order) consists of 25-30 families, while its division into orders and suborders by different authors has been rather vague. In this guide, they are divided into the orders of Tubificida, Enchytraeida, Lumbriculida, Branchiobdellida, Haplotaxida and Lumbricida. The subclass is paraphyletic since not including the leeches (Hirudinea) arisen from it as an advanced group.
In NWE known 13 families, with a total of 184 species.
Description
Clitellate annelids, mostly equipped with four bundles of chaetae per segment beginning from II. Testes usually in 1-2 pairs, always located before ovarial segment(s). Differing from the leeches (other clitellates) in presence of well-developed body cavity and chaetae; mouth not developed as sucker. Differing from the various polychaete annelids (including the Aeolosomatidae etc.), in presence of dorsal pharyngeal pad, regular position of testes in front of ovaries, lack of parapodia and paired head appendages, etc.
Distribution
Cosmopolitan.
Ecology
In soil, and in freshwater and marine environments; mostly free-living but a few predatory, commensal or parasitic groups known.
Reproduction
Mostly sexual, with eggs laid in cocoons. Different ways of asexual reproduction in some groups.
Literature
Grube, 1850: 281, 345; Grube, 1851; Beddard, 1895; Michaelsen, 1900; Stephenson, 1930; Brinkhurst and Jamieson, 1971; Chekanovskaya, 1981; Hrabe, 1981; Kasprzak, 1981; Jamieson, 1988.