Genome-wide nuclear data confirm two species in the Alpine endemic land snail s.l. (Gastropoda, Hygromiidae).

The Austrian endemic land snail species (formerly ) occurs in the Northeastern Calcareous Alps at high elevations. Two morphologically highly similar subspecies   and have been described. First analyses of mitochondrial and nuclear marker sequences indicated a high genetic divergence between them. In the present study, we aimed to assess gene flow between the two subspecies which should help to re-evaluate their taxonomic status. Sequence data and amplified fragment length polymorphism (AFLP) markers of 255 specimens covering the whole distribution range were analyzed. A clear geographic separation was found within the potential contact zone, the Haller Mauern mountain range. Samples of all western sites were part of the clade representing and almost all samples from the eastern sites clustered with . However, within two sampling sites of the eastern Haller Mauern, a few individuals possessed a sequence matching the clade whereas at the locus they were heterozygous possessing the alleles of both taxa. Contrary to the results indicating historical and/or ongoing hybridization, AFLP analyses of 202 individuals confirmed a clear separation of the two taxa congruent with the mitochondrial data. Although they occur on the same mountain range without any physical barrier, no indication of ongoing gene flow between the two taxa was found. Thus, we conclude that the two taxa are separate species and .