Inventory of the inland-water Phallodrilinae (Clitellata: Naididae), with descriptions of a new genus and five new species from groundwaters of southern Europe

An inventory of the Phallodrilinae (Clitellata, Naididae) recorded in inland waters worldwide is provided. One new genus and five new species are described from groundwaters of southern Europe, Cantabrodrilus pilarae gen. nov., sp. nov., Aberrantidrilus sketi sp. nov., Gianius camachoae sp. nov., Gianius inermis sp. nov. and Gianius parvogenitalis sp. nov., bringing the total number of genera and named species recorded in inland waters to 10 and 30, respectively (representing about 30% and 10% of the currently known Phallodrilinae genera and species, respectively).

Three genera are now known exclusively from freshwaters, Aberrantidrilus Martin, Phallobaikalus Martínez-Ansemil and Cantabrodrilus Martínez-Ansemil gen. nov. . Twenty-two of the species found in inland waters (73%) have been reported from the Mediterranean basin. The number of non-marine Phallodrilinae species is increasing considerably in parallel with intensified sampling in karst environments.

The identification of the oligochaetes collected from 633 groundwater samples in southern Europe shows that the Phallodrilinae were present in 5.4% of the samples, with an average relative abundance of 1.1% of the total oligochaete fauna.