The effectiveness of sodium chloride for the treatment of Russian sturgeon (Acipenser gueldenstaedtii) caviar from saprolegniosis

The article presents the results of experimental work on the treatment of fertilized oocytes and developing embryos of the Russian sturgeon ( Acipenser gueldenstaedtii ) with 0,8% sodium chloride solution by various methods in order to suppress the growth and development of the family micromycetes sem. Saprolegniaceae, which cause saprolegniosis of eggs during factory incubation. Due to the intensive development of commercial aquaculture, an increase in the scale of artificial reproduction, as well as taking into account the limitations of the use of previously used veterinary drugs to combat saprolegniosis of incubated caviar, this research area is relevant. The purpose of the research work was to evaluate the effectiveness of using three different methods of treating caviar infected with micromycetes sem. Saprolegniacea with a solution of sodium chloride. Experimental work was carried out in factory conditions in the incubation apparatus «Sturgeon» under optimal hydrochemical conditions for the development of Russian sturgeon embryos. The experimental groups corresponded to the methods used (therapeutic baths and drip method in the apparatus, therapeutic baths outside the incubation system). The experiment was carried out in parallel in 2 repetitions in the presence of a control. In the course of the work, fish-breeding, biological and hydrochemical research methods were used. The effectiveness of the effect of sodium chloride solution by three different methods (drip method, therapeutic baths in an incubation apparatus of the «Sturgeon» type, short-term therapeutic baths outside the incubation system) on the embryonic development of sturgeon and micromycetes was assessed by such indicators as the percentage of fertilization of eggs, normally and abnormally developing embryos, hatched pre-larvae, the proportion of embryos infected with saprolegnium micromycetes at two stages of caviar development (stages 16 and 22). The most effective method that improves the fish-breeding and biological parameters of incubated Russian sturgeon caviar and reduces the extent of its invasion by family micromycetes sem. Saprolegniaceae is a drip method.