Genetic differentiation and shell morphology of Trochulus oreinos (Wagner, 1915) and T. hispidus (Linnaeus, 1758) (Pulmonata: Hygromiidae) in the northeastern Alps

Abstract

<i>Trochulus oreinos oreinos</i> and <i>T. oreinos scheerpeltzi</i> are two land snail taxa endemic to the Northeastern Austrian Alps, which have been regarded as subspecies of the highly variable, widespread land snail <i>T. hispidus</i>. We analysed these three taxa morphologically and genetically to evaluate whether a delimitation between them is possible and, if so, to resolve their phylogenetic relationships. Shell morphological results revealed high similarity between the two <i>T. oreinos</i> taxa, and that they are clearly separated from <i>T. hispidus</i>. Additionally, the <i>T. oreinos</i> subspecies concur with respect to their habitat preferences, as they are both restricted to rocky high alpine areas, whereas the local form of <i>T. hispidus</i> is distributed over a wider altitudinal range in moist areas and scrubby perennial herb vegetation near water bodies. While the morphological and ecological results allow clear differentiation between <i>T. hispidus</i> and <i>T. oreinos</i> only, analyses of the mitochondrial cytochrome <i>c</i> oxidase subunit I and 16S rRNA genes revealed high sequence divergences between all three taxa, which indicates that they represent old lineages. The two <i>T. oreinos</i> taxa appear as distantly related sister groups, well separated from <i>T. hispidus</i>. Whether <i>T. o. oreinos</i> and <i>T. o. scheerpeltzi</i> should be considered as species cannot be decided at the current state of knowledge.