Application of molecular genetics and geometric morphometrics to taxonomy and conservation of cave beetles in central Italy

Abstract

Integration of molecular genetic techniques and geometric morphometrics represent a valuable tool in the resolution of taxonomic uncertainty and the identification of significant units for conservation. We combined mitochondrial DNA cytochrome c oxidase subunit II gene sequence data and geometric morphometric analysis to examine taxonomic status and identify units for conservation in four species of the hypogean beetle Duvalius (Coleoptera, Trechinae) using mainly museum specimens collected in central Italy. Previous taxonomic studies based on morphological traits described several subspecies often inhabiting geographically distinct caves. Phylogenetic analysis identified two well supported monophyletic lineages and a number of different clades with relatively small genetic differences, suggesting a short divergence time in line with known geological history of the study area. Geometric morphometrics, on the other hand, recovered a high level of distinctiveness among specimens. Both genetic and morphometric analyses did not entirely corroborate former taxonomic nomenclature, suggesting possible rearrangements and the definition of evolutionary significant units. Beetles of the genus Duvalius are protected by regional laws and the majority of taxa considered in this study inhabit caves located outside protected areas. Our study advocates the importance of devoting protection efforts to networks of cave ecosystems rather than single locations or species.