Trout Salmo spp. complex in Serbia and adjacent regions of the western Balkans: reconstruction of evolutionary history from external morphology P. SIMONOVIC ´ *, S. MARIC ´ AND V. NIKOLIC ´ Faculty of Biology, University of Belgrade, Studentski trg 16, 11000 Belgrade, Serbia and Montenegro (Received 23 February 2005, Accepted 19 March 2007) The multivariate phenetic approach to the classification of Salmo spp. samples from Serbia and adjacent regions of western Balkans for 22 continuous external morphological characters suggests the occurrence of the following distinct stocks: West Danubian (Crno Osoje Stream and upper Zeta River) Salmo taleri, marble trout Salmo marmoratus (Trebusˇcˇ ica River), hatchery-reared Atlantic Salmo trutta, Mlava River drainage (Mlava and Krupaja rivers and Buk Stream) trout Salmo cf. trutta, Velika Morava River system (Godljevacˇa, Bela and Resava rivers) trout S. cf. trutta, Ohrid Lake belvica Salmo ohridana and Aegean coastal drainage Salmo macedonicus (Bozˇica River). In contrast to the phenetic similarity, the phylogenetic reconstruc- tion places the Lake Ohrid belvica as part of an unresolved polytomy with other trout groups. Salmo cf. trutta in the Mlava River appears to form the basal group for the trout species in the region. The position of marble trout implies its independent and more recent origin from the West Danubian trout stock. # 2007 The Authors Journal compilation # 2007 The Fisheries Society of the British Isles Key words: Balkans; phenetics; phylogenetics; Salmo stocks; trout. INTRODUCTION Problems in the understanding of the taxonomy of trout Salmo spp. are asso- ciated with the complex and incompletely described evolutionary history of the taxa within various parts of their recent distribution ranges. This evolutionary history, and hence taxonomy, has been shaped by several geological events (e.g. mountain orogeny, glaciation events, marine regressions, changes in river catchments and drainages) (Karaman, 1924, 1927, 1932, 1933, 1938). The tax- onomic status of those trout, which have rather uniform ecological character- istics throughout the Balkan Peninsula, however, is still unclear. Karaman (1927) stated that isolation of trout populations dating from the Tertiary (e.g. Lake Ohrid trout taxa) is a consequence of mountain chain genesis (e.g. Dinarid Alps), whereas the post-Pleistocene isolation of trout within drainages *Author to whom correspondence should be addressed. Tel.: þ381 11 187266; fax: þ381 11 638500; email: pedja@bf.bio.bg.ac.yu Journal of Fish Biology (2007) 70 (Supplement C), 359–380 doi:10.1111/j.1095-8649.2007.01516.x, available online at http://www.blackwell-synergy.com 359 # 2007 The Authors Journal compilation # 2007 The Fisheries Society of the British Isles