The major aim of this project was to elucidate the phylogeography of the hairy snail Trochulus hispidus with emphasis on Alpine populations, to investigate the morphological variation within Austrian populations of T. hispidus including the ill-described and problematic taxon T. sericeus, and to revise the taxonomic state of the East-Alpine endemic Trochulus oreinos and its subspecies. Analyses of the mitochondrial genes for cytochrome c oxidase subunit I (COI), 12S rRNA (12S) and 16S rRNA (16S) revealed nine distinct mitochondrial clades (showing p-distances up to 19% in COI), all of them comprising individuals with a T. hispidus phenotype. Moreover, T. hispidus appears paraphyletic in the phylogenetic tree with respect to several other morphologically well defined Trochulus species (T. clandestinus, T. villosus, T. villosulus and T. striolatus) which form well-supported monophyletic groups. The results of a parallel morphometric investigation did not reveal any differentiation between the nine T. hispidus clades.
Two congeners of T. hispidus were investigated in more detail: T. striolatus and T. oreinos. Concerning T. oreinos (formerly treated as a subspecies of T. hispidus) morphological investigations reconfirmed its status as a separate species characterized by some distinct diagnostic traits like differences in hair morphology. Furthermore, we identified several characters like shell measurements and structures that distinguish the two species by trend, although there are overlaps in some cases. The two geographically and genetically well separated subspecies of T. oreinos (oreinos and scheerpeltzi) show only weak morphological differentiation. Genetic analyses revealed the two T. oreinos subspecies as distantly related sister groups, clearly separated from T. hispidus. The deep divergences between the three taxa is also reflected in high divergences in nuclear marker sequences which implies that they represent old lineages. Differences are also found in habitat preferences: While T. oreinos is restricted to rocky high alpine areas, especially Carex firma meadows with patchy structures, T. hispidus is distributed over a wider altitudinal range in moist areas and scrubby perennial herb vegetation near water bodies. Within T. striolatus there is a slight morphological differentiation between the subspecies T. s. striolatus, T. s. juvavensis and T. s. danubialis, which are not clearly separated at the genetic level.
For more information on our phylogenetic, morphological, anatomical and ecological investigations and on presumed glacial refugia read our publications and see below. Our results were also presented at several scientific meetings.
Currently, potential gene flow between the two subspecies of T. o. oreinos and T. o. scheerpeltzi in their contact zone is analysed by Sonja Bamberger in the course of her master thesis (in collaboration with Andreas Tribsch, University of Salzburg). For this task she is utilizing AFLP markers. The results, together with all information gathered from our previous investigations, shall lead to a conclusive decision whether the two taxa should be elevated to species level.