First molecular characterization of invasive alien populations of Pelophylax kurtmuelleri (Gayda, 1940) and new records from Italy

Many introduced species cause harm to the environment through predation, hybridization, transmission of pathogens and competition for food and breeding sites. In Italy, the Balkan Frog Pelophylax kurtmuelleri (Gayda, 1940) is a naturalized alien species since 1941 when seven pairs of this species were collected from Southern Albania and released in Western Liguria. Since the 70s, P. kurtmuelleri has spread in Liguria and Piedmont, and it has been recently observed in the Oltrepi, Pavese area (Lombardy). The taxonomic identification of individuals based on morphological characters is difficult because the species highly resembles the Marsh frog P. ridibundus. Moreover, other green frogs occur in Italy, which reproduce by hybridogenetic mechanisms. We used mitochondria1 markers (16S, ND3) to assess the real status of Italian populations ascribed to P. kurtmuelleri, checking also new records from Emilia-Romagna and Sardinia. We tracked the natural expansion of invasive populations and checked for multiple origins of non-native water frogs in northern Italy. Finally, we tested the role of P. kurtmuelleri as a vector of pathogens by screening populations for chytndiomycosis specific gene markers.