New insights into the genetic diversity of the stone crayfish: taxonomic and conservation implications.

BACKGROUND: Austropotamobius torrentium is a freshwater crayfish species native to central and south-eastern Europe, with an intricate evolutionary history and the highest genetic diversity recorded in the northern-central Dinarides (NCD). Its populations are facing declines, both in number and size across its entire range. By extanding current knowledge on the genetic diversity of this species, we aim to assist conservation programmes. Multigene phylogenetic analyses were performed using different divergence time estimates based on mitochondrial and, for the first time, nuclear DNA markers on the largest data set analysed so far. In order to reassess taxonomic relationships within this species we applied several species delimitation methods and studied the meristic characters with the intention of finding features that would clearly separate stone crayfish belonging to different phylogroups. RESULTS: Our results confirmed the existence of high genetic diversity within A. torrentium, maintained in divergent phylogroups which have their own evolutionary dynamics. A new phylogroup in the Kordun region belonging to NCD has also been discovered. Due to the incongruence between implemented species delimitation approaches and the lack of any morphological characters conserved within lineages, we are of the opinion that phylogroups recovered on mitochondrial and nuclear DNA are cryptic subspecies and distinct evolutionary significant units. CONCLUSIONS: Geographically and genetically isolated phylogroups represent the evolutionary legacy of A. torrentium and are highly relevant for conservation due to their evolutionary distinctiveness and restricted distribution.

The Rhyacophila fasciata Group in Europe: Rhyacophila fasciata Hagen 1859 and formerly synonymized species (Trichoptera: Rhyacophilidae), with new description of Rhyacophila fasciata and Rhyacophila septentrionis McLachlan 1865 (stat. prom.).

The presence and distribution of Rhyacophila fasciata Hagen 1859 in Europe were revised, based on bibliographic study, collection specimens, and new material collected in different countries. The status of formerly synonymized species, Rhyacophila ferruginea (Scopoli 1763) and Rhyacophila septentrionis McLachlan 1865 was also assessed. The type of R. ferruginea is missing, the taxon is still unidentified, and thus we propose Rhyacophila ferruginea as a nomen dubium. Morphological features and genetic evidence revealed that R. septentrionis differs from R. fasciata, so we propose to change its status to status resurrectus. We therefore include new descriptions of the different stages (larva, pupa, male, and female) of R. fasciata and of R. septentrionis, together with a molecular analysis based on mitochondrial cytochrome oxidase I (mtCOI) and ecological notes. The species R. coppai Oláh 2020 NEW SYNONYM and R. soreda Coppa Oláh 2020 NEW SYNONYM are synonyms of R. sociata Navás 1916; the species R. kopasa Oláh Coppa 2020 NEW SYNONYM and R. rova Oláh Coppa 2020 NEW SYNONYM are synonyms of R. denticulata McLachlan 1879; the species R. matrensis Oláh Szczesny 2020 is probably a synonym of R. fasciata, so more study of this species is needed in order to confirm or deny that it is a valid species.