DNA barcoding provides new insights on the distribution, systematics and conservation of the freshwater genus Pelasgus (Cypriniformes: Cyprinidae) in Greece

The freshwater ichthyofauna of Greece is characterized by high diversity and endemism and faces various conservation challenges. Despite significant efforts, mainly with traditional assessment methods, the precise taxonomic status and geographic range of some of the currently acknowledged fish species remain insufficiently explored. Here, the results of the first comprehensive DNA barcoding survey of the genus Pelasgus are presented, covering its entire known range in Greece. Two hundred and forty COI sequences (retrieved from collected samples, museum specimens and the GenBank) were analysed to determine the number of putative species and delineate their current distribution. Data support the existence of seven haplogroups, corresponding to the currently valid Pelasgus species. Analysis of museum samples of the critically endangered species P. epiroticus from its type locality (now extinct there) uncovers its presence in contemporary samples from a neighbouring aquatic system (Zaravina Lake) and from aquatic systems well outside its native range (possibly as a result of past translocations) for the first time. A subgroup of P. epiroticus haplotypes was also identified in North-western Greece in regions previously believed to host P. thesproticus or P. stymphalicus . Based on the above, hotspots for further Pelasgus taxonomic investigations are identified and conservation actions are discussed.