Review of Criodrilidae (Annelida: Oligochaeta) including Biwadrilus from Japan.

Abstract

Palaearctic family Criodrilidae Vejdovsky, 1884 is briefly reviewed and revised to reabsorb Biwadrilidae Brinkhurst & Jamieson, 1971, monotypic for lacustrine/limnic Biwadrilus bathybates (Stephenson, 1917) based on examination of new Lake Biwa material from recent earthworm surveys. Comparison is with type species: Criodrilus lacuum Hoffmeister, 1845. Synonymy in Criodrilus of monotypic genus Hydrilus Qiu & Bouché, 1998 from Algeria is accepted but with provisional restoration of its type as Criodrilus ghaniae (Qiu & Bouché, 1998) comb. nov., if indeed it belongs in the Criodrilidae. Another recent taxon Guarani camaqua Rodríguez & Lima, 2007 from rice fields of Rio Grande do Sul, Brazil is syn. nov. of Criodrilus lacuum at species and genus level since its characteristics are easily embraced within interspecific variability. Moreover, the prior taxon, C. lacuum, was already known from its type-locality. Distribution, ecology and species associations of the criodrilids are briefly summarised including a report of C. lacuum maintained in a laboratory culture for >42 years (T. Timm pers. comm.). A key to species is provided.

Keywords

• Oligochaeta
• Criodrilidae
• Criodrilus
• Biwadrilus
• Hydrilus
• Guarani
• new synonyms