Oligoketo (Oligochaeta)anelidoen filum-eko izen berekoklaseko metazooez esaten da. Gorputz biribil luzexka eta eraztunez eratua izaten dute, hankarik edo beste luzakinik gabea. Hiru ordena biltzen dira klase honetan, lunbrikulidoak, moniligastridoak eta haplotaxidoak.Zizarea da klase honetako animaliarik ezagunena.
- RandiellidaeErséus & Strehlow, 1986
- Naididae / TubificidaeVejdovsky, 1884 (tartean NaidinaeEhrenberg, 1831)
- NarapidaeRighi, 1983
- OpistocystidaeCernosvitov, 1936
- DorydrilidaeCook, 1971
- ParvidrilidaeErséus, 1999
- PhreodrilidaeBeddard, 1891
- PropappidaeCoates, 1986
- HaplotaxidaeMichaelsen, 1900
- TiguassuidaeBrinkhurst, 1988
- LumbriculidaeVejdovsky, 1884
- EnchytraeidaeVejdovsky, 1879
- MoniligastridaeClaus, 1880
- AlluroididaeMichaelsen, 1900
- SyngenodrilidaeSmith & Green, 1919
- GlossoscolecidaeMichaelsen, 1900
- TumakidaeRighi, 1995
- AiloscolecidaeBouché, 1969 (tartean KomarekionidaeGates, 1974)
- SparganophilidaeMichaelsen, 1918
- MicrochaetidaeMichaelsen, 1900
- TritogeniidaePlisko, 2013
- LumbricidaeClaus, 1876 (tartean DiporodrilinaeBouché, 1970; EiseniinaeOmodeo, 1956; SpermophorodrilinaeOmodeo & Rota, 1989; PostandrilinaeQiu & Bouché, 1998; AllolobophorinaeKvavadze, 2000 and HelodrilinaeKvavadze, 2000)
- KynotidaeBrinkhurst & Jamieson, 1971
- HormogastridaeMichaelsen, 1900 (tartean VignysinaeBouché, 1970 and XaninaeDiaz Cosinet al., 1989)
- LutodrilidaeMcMahan, 1978
- CriodrilidaeVejdovsky, 1884 (tartean BiwadrilidaeBrinkhurst & Jamieson, 1971)
- AlmidaeDuboscq, 1902
- OcnerodrilidaeBeddard, 1891 (tartean MalabariinaeGates, 1966)
- AcanthodrilidaeClaus, 1880 (tartean DiplocardiinaeMichaelsen, 1900)
- OctochaetidaeMichaelsen, 1900 (tartean BenhamiinaeMichaelsen, 1895/7)
- ExxidaeBlakemore, 2000
- MegascolecidaeRosa, 1891 (tartean PontodrilinaeVejdovsky, 1884; PlutellinaeVejdovsky, 1884 and ArgilophilinaeFender & McKey-Fender, 1990)
- EudrilidaeClaus, 1880
