DNA barcoding reveals cryptic diversity in Antarctic species of Orchomene sensu lato (Crustacea: Amphipoda: Lysianassoidea)

Recent molecular analyses revealed that several so-called “circum-Antarctic” benthic crustacean species appeared to be complexes of cryptic species with restricted distributions. In this study we used a DNA barcoding approach based on mitochondrial cytochrome oxidase I gene sequences in order to detect possible cryptic diversity and to test the circumpolarity of some lysianassoid species. In the majority of the studied species, a genetic homogeneity was found even among specimens from remote sampling sites which indicates a possible circum-Antarctic and eurybathic distribution. In four investigated species (Orchomenella (Orchomenopsis) acanthurus, Orchomenella (Orchomenopsis) cavimanus, Orchomenella (O.) franklini and Orchomenella (O.) pinguides), genetically divergent lineages and possible cryptic taxa were revealed. Results might be explained by the different dispersal and gene flow capability of these amphipods as well as by the generally insufficient knowledge on the biodiversity of the fauna of Southern Ocean related to species identification.