Influence of milt cryoconservation on survival and genetic polymorphism of larvae of Russian sturgeon

The influence of milt cryopreservation on genetic indices of progeny of Russian sturgeon was investigated. Two experiments on fecundation of eggs with the use of native and frozen-thawed milt from the same breeders were held, and the enzymes of malate dehydrogenase and esterase in tissues of larvae at the stage of beginning of active feeding by methods of polyacrilamyde gel electrophoresis are studied. The use of сryopreserved milt led to a decreased number of larvae at the end of the experiment, mainly because of elevated mortality at early embryonal stages. Selective embryonal mortality induced increasing of heterozygosity of brood, changing the rates of genotypes and segregation of rare allele е at esterase locus. This selectivity had the same direction as negative selective impact of artificial breeding on genetic parameters of Volga sturgeon populations.