title: Differentiation in theTrochulus hispiduscomplex and related taxa (Pulmonata: Hygromiidae): morphology, ecology and their relation to phylogeography.
abstract: In this study we investigated the morphology and ecology of representatives of the taxonomically ambiguous genusTrochulus. The main focus was on theT. hispiduscomplex, which comprises several genetically highly divergent mitochondrial clades, as determined in a parallel molecular genetic study. We analysed shell morphology and anatomical traits and asked whether the clades are differentiated in these characters. In addition, the related speciesT. oreinosandT. striolatuswere investigated and compared with theT. hispiduscomplex. Finally, we compared the ecological requirements of the taxa. Among the genetic clades of theT. hispiduscomplex there was no clear morphological differentiation and geographic populations could not be distinguished based on their morphology. The investigated characters of the genital anatomy did not allow discrimination of any of theT. hispidusclades and were not even diagnostic for the group as a whole. The morphotype ofT. sericeusis present in all clades and thus cannot be assigned to a genetic group or any specific population. Thus, our morphological data do not provide evidence that any of the mitochondrialT. hispidusclades represent separate species. Concerning interspecific delimitation, theT. hispiduscomplex was clearly differentiated fromT. striolatusandT. oreinosby shell morphological and anatomical characters, e.g. sculpture of shell surface and details of the penis. Finally, the habitat ofT. oreinosis different from those of the other two species. In contrast to the lack of correspondence between genetic and morphological differentiation within theT. hispiduscomplex, related species display intraspecific morphological differentiation corresponding with mitochondrial clades: withinT. striolatusthere was a slight morphological differentiation between the subspeciesT. s. striolatus,T. s. juvavensisandT. s. danubialis. The two subspecies ofT. oreinoscould be discriminated by a small but consistent difference in the cross-section of the penis. The unequal levels of intraspecific differentiation are caused by different evolutionary histories as a consequence of disparities in ecological demands, dispersal ability and use of glacial refugia: both theT. hispiduscomplex andT. striolatusare fast-spreading, euryoecious organisms which are able to (re-)colonize habitats and survive under different climate conditions. While theT. hispiduscomplex probably survived the Pleistocene in several glacial refugia, forT. striolatusone glacial refugium is suggested.Trochulus oreinosdiffers from the other taxa, as it is a slow disperser with a narrow ecological niche. We suggest that its subspecies spent at least the last glaciation in or close to the presently inhabited areas.
authors.affiliation: 3rd Zoological Department , Museum of Natural History Vienna , Burgring 7, 1010 Vienna , Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Duda
authors.affiliation: Central Research Laboratories , Museum of Natural History Vienna , Burgring 7, 1010 Vienna , Austria.
authors.forename: Luise
authors.initials: L
authors.lastname: Kruckenhauser
authors.affiliation: 3rd Zoological Department , Museum of Natural History Vienna , Burgring 7, 1010 Vienna , Austria.
authors.forename: Helmut
authors.initials: H
authors.lastname: Sattmann
authors.affiliation: Central Research Laboratories , Museum of Natural History Vienna , Burgring 7, 1010 Vienna , Austria ; Department of Integrative Zoology , University of Vienna , Althanstraße 14, 1090 Vienna , Austria.
authors.forename: Josef
authors.initials: J
authors.lastname: Harl
authors.affiliation: 3rd Zoological Department , Museum of Natural History Vienna , Burgring 7, 1010 Vienna , Austria ; Central Research Laboratories , Museum of Natural History Vienna , Burgring 7, 1010 Vienna , Austria.
authors.forename: Katharina
authors.initials: K
authors.lastname: Jaksch
authors.affiliation: Central Research Laboratories , Museum of Natural History Vienna , Burgring 7, 1010 Vienna , Austria ; Department of Integrative Zoology , University of Vienna , Althanstraße 14, 1090 Vienna , Austria.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Haring