Oligochaeta

Oligoketo (Oligochaeta) anelidoen filum-eko izen bereko klaseko 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.

 Familiak 

 Randiellidae Erséus & Strehlow, 1986
 Naididae / Tubificidae Vejdovsky, 1884 (tartean Naidinae Ehrenberg, 1831)
 Narapidae Righi, 1983
 Opistocystidae Cernosvitov, 1936
 Dorydrilidae Cook, 1971
 Parvidrilidae Erséus, 1999
 Phreodrilidae Beddard, 1891
 Propappidae Coates, 1986
 Haplotaxidae Michaelsen, 1900
 Tiguassuidae Brinkhurst, 1988
 Lumbriculidae Vejdovsky, 1884
 Enchytraeidae Vejdovsky, 1879
 Moniligastridae Claus, 1880
 Alluroididae Michaelsen, 1900
 Syngenodrilidae Smith & Green, 1919
 Glossoscolecidae Michaelsen, 1900
 Tumakidae Righi, 1995
 Ailoscolecidae Bouché, 1969 (tartean Komarekionidae Gates, 1974)
 Sparganophilidae Michaelsen, 1918
 Microchaetidae Michaelsen, 1900
 Tritogeniidae Plisko, 2013
 Lumbricidae Claus, 1876 (tartean Diporodrilinae Bouché, 1970; Eiseniinae Omodeo, 1956; Spermophorodrilinae Omodeo & Rota, 1989; Postandrilinae Qiu & Bouché, 1998; Allolobophorinae Kvavadze, 2000 and Helodrilinae Kvavadze, 2000)
 Kynotidae Brinkhurst & Jamieson, 1971
 Hormogastridae Michaelsen, 1900 (tartean Vignysinae Bouché, 1970 and Xaninae Diaz Cosin et al., 1989)
 Lutodrilidae McMahan, 1978
 Criodrilidae Vejdovsky, 1884 (tartean Biwadrilidae Brinkhurst & Jamieson, 1971)
 Almidae Duboscq, 1902
 Ocnerodrilidae Beddard, 1891 (tartean Malabariinae Gates, 1966)
 Acanthodrilidae Claus, 1880 (tartean Diplocardiinae Michaelsen, 1900)
 Octochaetidae Michaelsen, 1900 (tartean Benhamiinae Michaelsen, 1895/7)
 Exxidae Blakemore, 2000
 Megascolecidae Rosa, 1891 (tartean Pontodrilinae Vejdovsky, 1884; Plutellinae Vejdovsky, 1884 and Argilophilinae Fender & McKey-Fender, 1990)
 Eudrilidae Claus, 1880

 Erreferentziak 

 Kanpo estekak