Variability of microsatellite DNA and genetic differentiation of populations in the resident form of Dolly Varden Salvelinus malma krascheninnikovi from Sakhalin

Variability in 11 microsatellite loci is followed for nine populations of the resident southern form of Dolly Varden Salvelinus malma krascheninnikovi from Sakhalin. In all studied populations, the level of genetic differentiation is significant with global values of F _st and R _st 0.182 and 0.329, respectively. On the NJ tree, two clusters are separated significantly: the former is represented by the populations from southwestern Sakhalin (the Novoselka River basin), and the latter includes all populations from southern and eastern Sakhalin. Abrupt size variations (bottleneck events) are suggested for several studied populations, and 50% reductions of allelic richness and average heterozygosity are observed in two lacustrine populations of the Novoselka River basin in comparison to the riverine populations of this basin. The results suggest an occurrence of a comparatively recent gene flow between the populations of resident Dolly Varden from Sakhalin and absence of reproductive isolation between the anadromous and resident forms. The degradation of the majority of Dolly Varden populations can be expected in the near future, and conservation projects should be developed.