Genetic differentiation of coregonid populations in Subarctic areas
Sendek, Dmitry S.; Ivanov, Eugenie V.; Khodulov, Vladimir V.; Novoselov, Alexander P.; Matkovsky, Andrej K.; Ljutikov, Anatoly A.
A population genetics study of coregonid fish species from the Russian Arctic using 30 enzyme loci demonstrated that Siberian endemic species (Coregonus peled (Gmelin 1789) and C. muksun (Pallas 1814)) as well as species with distributions limited by the Holarctic at the edges of western North America and Eastern Europe (broad whitefish C. nasus (Pallas 1776) and Arctic cisco C. autumnalis (Pallas 1776)) are rather homogeneous along the whole Arctic shoreline. In contrast, circumpolar coregonid species (European whitefish C. lavaretus (Linneaus 1758) and the vendance complex of European cisco C. albula, C. sardinella (Valenciennes 1848)) feature stronger genetic divergence among populations in the same region and patterns of genetic diversity showed a significant consistency across species with minimal variations identified between the species from the farthest Eastern European population (the Pechora River) and the outermost eastern populations of Eastern Siberia (the Kolyma and the Indigirka Rivers). It was hypothesised that modern populations of whitefishes and ciscoes from Eastern Sibirian and Eastern European Subarctic shores are the remains of a former more or less integral fauna of these species which may have developed differently during the Pleistocene in Siberia and adjacent areas, perhaps by large-scale merging of periglacial lakes and their discharges via desalinated segments of the sea or during the course of the ice regression period via merging of the lower sections of neighbouring rivers. In the Late Pleistocene, a relatively homogeneous fauna of whitefishes and ciscoes of the Arctic area was fragmented as a result of the advance of the glaciers and the ousting of the fauna of the Arctic fishes to its southern periphery with postglacial colonisation by the forms of those species that evolutionarily could have been established in the region of Lake Baikal and adjacent mountainous territories. Postglacial expansion of these forms towards the Subarctic coast coincided with the recovery of the flow of the largest Siberian rivers (Ob, Yenisei and Lena) with the hydrographic network of upstream sections having been changed drastically as a result of complicated geological processes that took place in the south of Siberia.