Four New Earthworm Species from the Highlands of Cameroon with Description of a New Genus Okudrilus gen. n. (Oligochaeta: Eudrilidae & Acanthodrilidae)

Examining a small collection of earthworms from the highlands of Cameroon resulted in clarifying the taxonomic status of Eminoscolex franzi Zicsi & Csuzdi, 1986 stat. n. and discovering a new eudrilid genus Okudrilus gen. n. containing three new species: O. monticolus, O. sulcatus and O. nyosensis spp. n. The new genus is similar to Metascolex Michaelsen, 1903; however, it differs from it in the position of the gizzard, the structure of the ovo-spermathecal system and furthermore in the presence of penial setae. It also resembles Vomia Segun, 1976 but differs from it in the metandric condition of the male genitalia and the long backward running vesicles. Apart from the new eudrilid taxa the material also contained a new acanthodrilid species, Dichogaster (Diplothecodrilus) asymmetrica sp. n., characterised by the asymmetric position of its spermathecal duct-ampulla junction. All members of this new genus were collected in North West Region, with O. monticolus endemic to the summit grasslands of Mount Oku, and is possibly threatened by climate change, and soil degradation through overgrazing and fire.