부산대학교 도서관

Species discovery and validation methods were used to delimit the species of a cryptic species complex. Species boundaries were inferred from multiple lines of evidence arising from mitochondrial and nuclear DNA sequencing and ecological niche modelling. Phylogenetic relationships among species were assessed by Bayesian inference and maximum-likelihood procedures. The approach was applied to the terrestrial gastropod genus Pyramidula. By examining 211 specimens collected from the Western Palaearctic region, we here identified nine putative species for this region. So far, descriptions of the morphospecies of this genus had been based exclusively on shell characters. Hence, we also studied the variation of shell characters to assess their utility to differentiate the species defined and to examine whether shell shape in Pyramidula is influenced by environmental factors. Our findings indicate that although shell characters serve to discriminate between some putative species, they are not sufficient as unique taxonomic characters and other lines of evidence are needed. According to our ecological niche modelling results, shell shape may be influenced by environmental factors. [ABSTRACT FROM AUTHOR]