MICROSATELLITE POLYMORPHISM WITHIN TWO LAKE BAIKAL OILFISH SPECIES (COMEPHORUS LACEPEDE, 1801)
Intraspecific genetic polymorphism of a Baikal Lake endemic, big Baikal oilfish (Comephorus baicalensis Pallas, 1776), was evaluated based on microsatellite analysis. The obtained results have compared to the results received earlier for a little Baikal oilfish (C. dybowski Korotneff, 1905). Six microsatellite loci designed for the European sculpin, Cottus gobio, were used. Big Baikal oilfish samples were tested from the three Baikal trenches (southern, middle, northern). Average values of F<sub>ST</sub> and R<sub>ST</sub>indexes between the samples did not exceed 0,02 that point to weak intraspecific genetic differentiation. Big Baikal oilfish had the smaller allele variety, the greater deficit of heterozygotes and presence of low-molecular alleles in comparison with little Baikal oilfish. The values of genetic differentiation were equaled F<sub>ST</sub> = 0,138 and R<sub>ST</sub> = 0,244 for all loci between cumulative samples of little and big Baikal oilfish. Analysis of microsatellite polymorphism has showed that both a big and little Baikal oilfishes are represented by single populations. The factor promoting panmixia within the Baikal oilfish species is apparently a passive transfer of juvenile and adult fishes by water currents.
