A new earthworm species within a controversial genus: Eiseniona gerardoi sp. n. (Annelida, Lumbricidae) - description based on morphological and molecular data.

The morphological and anatomical simplicity of soil dwelling animals, such as earthworms, has limited the establishment of a robust taxonomy making it sometimes subjective to authors' criteria. Within this context, integrative approaches including molecular information are becoming more popular to solve the phylogenetic positioning of conflictive taxa. Here we present the description of a new lumbricid species from the region of Extremadura (Spain), Eiseniona gerardoi sp. n. The assignment to this genus is based on both a morphological and a phylogenetic study. The validity of the genus Eiseniona, one of the most controversial within Lumbricidae, is discussed. A synopsis of the differences between the type species and the west-European members of the genus is provided.