Genetic monitoring of sturgeon fishes under the conditions of artificial reproduction in the Astrakhan region

Abstract

When carrying out activities aimed at maintaining the number of sturgeon through the release of juveniles into the natural habitat, a competent genetic approach is necessary. This, first of all, will allow an assessment of the genetic diversity of the breeding stock and the degree of kinship of fish producers, to exclude the genetic degeneration of the population due to inbreeding. The aim of the work was to carry out genetic monitoring of Russian sturgeon and beluga from brood stocks of the scientific and experimental complex of aquaculture “BIOS” of the Volga-Caspian branch of VNIRO in the period 2020–2022. Genotyping of the producers was carried out according to five nuclear markers and a fragment of the control region of mitochondrial DNA. Crossing shemes of sturgeons from broodstocks were formed taking into account the coefficients of genetic relationship. According to the results of molecular genetic studies, 12–22 mitochondrial haplotypes in Russian sturgeon females, and 3–5 mitochondrial haplotypes in beluga females were identified. Species-specific dominant alleles were identified in microsatellite loci of sturgeons Russian sturgeon spawners were characterized by a high level of genetic diversity for nuclear and mitochondrial markers. The most difficult situation is with the genetic diversity of beluga due to the small number of mature spawners in the broodstock. Genetic monitoring of the artificial reproduction of Russian sturgeon and beluga is necessary to obtain genetically diverse offspring in the terms of a reduction in sturgeon fishes in the Volga-Caspian fishery basin.