Mesodorylaimus aethiopicus sp. nov. (Nematoda: Dorylaimida), a new species from soil in Bale, Ethiopia

During a nematological survey in the Bale Mountains National Park (Ethiopia), an undescribed species belonging to the genus Mesodorylaimus was found. M. aethiopicus sp. nov. is characterised by having a medium-sized body 1483–1858 μm long, the lip region weakly angular and offset by a slight depression, a medium-sized odontostyle (14–17 μm long), a longitudinal vulva slit positioned at mid-body, absence of pars refringens vaginae, a well-developed pars dilatata oviductus, a relatively long female tail (133.5–162.5 μm), male spicules 56.0–63.5 μm long and regularly spaced 12–14 ventromedian supplements. The new species was morphologically compared to eight species of the genus Mesodorylaimus and two species of the genus Calcaridorylaimus with similar body length and tail length values. In molecular phylogenetic studies, using the sequences of 18S rDNA and 28S rDNA, close relationships of M. aethiopicus with representatives of the genera Mesodorylaimus and Calcaridorylaimus were shown. However, the sequences of species with a similarity above 99% for the 18S rRNA gene and above 98% for the 28S rRNA gene were absent in GenBank.