Croatian Journal of Fisheries (Dec 2003)
ON THE ORIGIN OF THE BALKAN PENINSULA SALMONIDS
Abstract
This paper puts forward the knowledge of the immigration itineraries of the ancestors of five extant salmonid species on Balkan Peninsula which are the following: Acantholingua ohridana (Steindachner, 1892), Hucho hucho (Linnaeus, 1758), Salmo trutta Linnaeus, 1758, Salmothymus obtusirostris Heckel, 1851 and Thymallus thymallus (Linnaeus, 1758). The thesis for the migration itineraries is based on the anatomical, molecular and zoogeographical facts recently published. These latest facts complement or reject the previous thesis that considered the origin of separate species, which in this paper are analyzed together. A new position on the origin of some S. trutta populations inhabiting the Mediterranean Sea watershed is proposed. The new thesis is that they did not inhabit it from the west, through the Atlantic Ocean and Gibraltar, but from the North, through the branches of the former Sarmatian Sea, using the continental way. A. ohridana and S. obtusirostris, the only endemic Balkanean salmonids, have developed here from the mutual ancestor with the extant Siberian Brachymystax lenok (Pallas, 1773). This ancestor came first, together with the S. trutta lineage known as »marmorata«. Using the same migration way, the T. thymallus population of Soča River, the North.West boundary of Balkan Peninsula remained restricted at that corner of Adriatic Sea watershed. In the Black Sea watershed (the Danube River flow extension on Balkan Peninsula) the distribution of T. thymallus coincides with the distribution of H. hucho. The thesis which has been proposed for this, largest contemporary Balkan Peninsula salmonid fish was that it came here last, after the connections between the Mediterranean Sea basin and once existent Sarmatian Sea disappeared. This occurred after the end of the last glaciations. This has been concluded on the basis of the exclusion of the areas of the »marmorata« lineage of S. trutta (Mediterranean Sea watershed) and H. hucho (Black Sea watershed). Their extensions touch just at the water-separation between the Mediterranean Sea and the Black Sea on the Dinarid Mountains. The idea for this thesis originates from the distribution of the small cobitid Cobitis elongata Heckel & Kner, 1858 given in the work of K a r ama n, S., (1952). The thesis that the endemic salmonids came in the Adriatic Sea watershed through the Adriatic.Pannonian connection is supported by the zoogeographical distribution of some mutual marine, brachic or freshwater fish species for Adriatic Sea itself or the Adriatic Sea watershed and Ponto.Caspian depression (Black Sea and Caspian Lake). These fish belong to the families Acipenseridae and Cobitidae, some endemic Cyprinidae representatives from the Adriatic Sea watershed belong to widely extended genera in the central Europe, mainly in the Danube river flow.
