The Nile Soft-shell Turtle, Trionyx triunguis, of Israel and Turkey: Two genetically indistinguishable populations?

Abstract

Whereas the Nile Soft-shelled Turtle, Trionyx triunguis, used to be found in most of the east Mediterranean rivers, today only three major subpopulations remain: two in Turkey and one in Israel. The management of small subpopulations should rely on their genetic relatedness, and so this study examined the AFLP and cytochrome b genetic diversity of 58 T. triunguis specimens from the Alexander River in Israel and from Dalaman’s Lake Kükürtlü in southwestern Turkey. The four selective primer pairs for AFLPs yielded 339 distinct loci. We found the populations to be highly polymorphic (>88%) and the level of gene diversity (He) relatively low (0.11). Indeed, using our methods, the two populations were found to be genetically identical (I=1.0). Our study further demonstrates a high identity of the mitochondrial gene cytochrome b DNA sequence with a Liberian (West Africa) specimen of T. triunguis. These results support previous preliminary genetic studies and observations which showed that this species travels around in the Mediterranean Sea. However, we suggest that the results are evidence of previous large populations and of past connections with the African populations, and that the dams on the Nile are probably preventing this gene flow today.