Does Islander Invasive Fish Species Acquire Genetic Variation? The Case of Gokceada Island, the Westernmost Part of Turkey

Geographical barriers to invasive species dispersion are being acceleratingly annihilated by human actions through deliberately or accidentally introductions as species were translocated of their region to the new environment across the world. Molecular markers could be useful to comprehend invasion scenarios of non-native species within this context. The aim of this study was to elucidate genetic diversity and dispersal patterns of non-native species (Carassius gibelio, Gambusia holbrooki and Pseudorasbora parva) from the westernmost part of Turkey, Gokceada Island using mitochondrial COI marker. The present results discover three main findings: (i) a total of 13 haplotypes from COI was detected of which 11 were unique; (ii) high genetic diversity was determine for all non-native species (h = 0.680 and pi = 0.0023 for C. gibelio, h = 0.776 and pi = 0.0027 for G. holbrooki, and h = 0.479 and pi = 0.0262 for P. parva); (iii) non-native species may have entered Turkey first from over Europe (i.e., invasive zone) after being introduced from their native distribution areas and then into Gokceada Island from the mainland (i.e., Anatolia) through common stocking practices. The results of the present study indicated that non-native species were translocated or still being introduced to the Island. If the findings of this study are evaluated by public associations, the management activities can be better arranged on non-native species for the Island.