Genetic differences and similarities in the introduced population of European beaver (Castor fiber L., 1785) in the Kirov and Novosibirsk regions of Russia

Potential factors were analyzed that affected the formation of gene pools of two introduced beaver populations founded in the 1940s-1950s by releasing beavers from Voronezh oblast and Belarus into rivers of the Kirov and Novosibirsk oblasts. The populations from these two regions were shown to differ in four allozyme loci (Ahd-2, Gpi, Es-5, and Dia-2). Within Kirov oblast, the samples from three tributaries of the Vyatka River differed in three other loci (Ck-1, Gp-9, and Trf). It is suggested that these features of the allele distribution at these loci are explained by the history of the introduced populations, hybridization between beavers from Voronezh oblast and Belarus, and founder effect during the subsequent artificial and spontaneous migration. Generally, genetic differences between the populations in all studied loci were very small: D = 0.02 between populations from different regions and D = 0.01 between populations from the tributaries of third-order rivers of the Kirov oblast. At the same time, disequilibrium was detected for ten polymorphic loci in the combined sample from the populations of Kirov oblast, which indicates the existence of interpopulation heterogeneity at the level of local populations of fourth- and fifth-order rivers. The unexpected finding of a genetic similarity between one studied individual of Tuvinian beaver subspecies (Castor fiber tuvinicus) and C. f. orientoeuropeas was recorded.