Phylogeography of stream-dwelling trout in the Republic of Macedonia and a molecular genetic basis for revision of the taxonomy proposed by S. Karaman

Abstract

To evaluate whether molecular data support the distinctiveness of Salmo macedonicus (Karaman, 1924) and Salmo pelagonicus Karaman, 1938, and to examine a possible impact of non-native trout translocated from the Drim drainage on the indigenous trout of the Vardar drainage, 187 individuals from 15 populations sampled across both drainages were studied by analysing the complete mitochondrial DNA control region and 12 microsatellite DNA loci. On the basis of both marker systems, the analysed populations were divided into two main genetic groups: I, native populations of the Drim drainage, along with some introduced populations of the Vardar drainage, and II, native Vardar populations, along with some populations exhibiting introgressed genotypes. The populations assigned to group I correspond taxonomically to Salmo farioides Karaman, 1938, among which those from the Drim were indigenous and those detected in the Vardar drainage were introduced. Four native Vardar populations from group II indicated two distinct clusters whose distribution matched the proposed range of S. macedonicus (two populations from the upper Vardar system) and S. pelagonicus (two populations from the Crna Reka system). Based upon the results of the study, some conservation genetic guidelines are proposed to help propagate and sustain the non-introgressed native trout populations.