Genetic architecture of trout from Albania as revealed by mtDNA control region variation

Major European peninsulas are known to have played a central role in the survival of animal and plants during ice-age maxima and have received a high degree of attention in terms of conservation of endemic taxa [1,2]. Compared with the Iberian and Italian peninsulas, the biodiversity and rich level of phenotypic variability present in the Balkan Peninsula have only recently been investigated by molecular techniques (e.g. [3-5]). As one of the 17 biodiversity hotspots of the world [6], this peninsula harbours numerous endemic taxa [4], including members of the genus Salmo (subsequently referred to as Balkan trout), which are especially diverse in this region. Many studies on the morphology and phenotypes of the fish of the Balkans were undertaken during the last century (e.g. [7,8]) and found high levels of endemism among Balkan trout. As a consequence, given the benefit of availability of modern molecular techniques, a number of recent studies have focused on revisiting Balkan trout taxonomy, population structure and demographic history [9-14]. However, much remains to be done, as the status of several nominal species and populations of Balkan trout remains unresolved, mainly as a result of the region's geographical, political and cultural isolation [15].Considerable variation in external morphology of Balkan trout was reported in early studies [16,17], giving rise to many taxonomic units (see [18] for review). Recent molecular studies of trout from Bosnia-Herzegovina, Montenegro and FYROM [10,13,14] have confirmed this diversity. However, little clear association between phenotype and genotype has been found, and some well-established taxonomic groups, such as S. marmoratus [10], have been found not to be associated with detected genetic assemblages.Several Salmo taxa have been reported to inhabit Albanian rivers and neighbouring drainages in FYROM and Greece. Examples include S. farioides, proposed by Karaman [17], and S. ohridanus, S. letnica, S. letnica lumi, S.