Genetic prospective of a local invader: the strange pattern of Pontastacus leptodactylus population structure in Greece and Turkey based on microsatellite DNA.

Background: The combination of the increasing demand of freshwater crayfish exports, the reduced population sizes due to overfishing, the crayfish plague epidemics and the habitat degradation, have led to unrecorded translocations of Pontastacus leptodactylus in Greek lakes.

Methods And Results: In the present study, the genetics of five narrow clawed crayfish (P. leptodactylus) populations were studied, namely three translocated populations inhabiting in Northern Greece, one native Greek population from Evros river and one potential progeny source population from Turkey. Nine microsatellite loci previously designed for the specific species were investigated, in order to assess the levels of genetic diversity and further to confirm the origin of these translocated populations some decades after the translocation events. Our results confirmed that the source population for the translocated Greek population is the Turkish lake Eğirdir. Further, despite the low values of the number of alleles, heterozygosity, and F the populations were generally diverse, providing evidence for local adaptation.

Conclusions: The low values of F for the translocated populations in combination with the high values of gene flow, possibly indicate the existence of re-introducing events. Apart from the translocated populations, high levels of genetic diversity and heterozygosity were observed in Evros population, suggesting it as a possible unit for future conservation purposes both as a donor population for reintroduction purposes as well as a unique gene pool protection source. To the best of our knowledge this is the first study dealing with the genetic composition of Greek P. leptodactylus populations from Nothern Greece, operating as a first step towards the development of proper management practices for restocking events and monitoring of translocated populations.