The result of the regulation of seasonal biorhythms of sturgeon fish in the conditions of recirculating aquaculture systems

Abstract

Background and Aim. This article presents research results on selective breeding of sturgeon for regulating seasonal biorhythms in recirculating aquaculture systems (RAS). The study assessed the use of ultrasound (USG) and biopsy methods to determine gamete maturity, and examined the outcomes of obtaining gametes non-lethally from sturgeon raised under artificial conditions. Changes in physiological processes depending on wintering duration of wintering and temperature regimes were also analyzed.

Materials and Methods. The study included 5 starred sturgeon (Acipenser ruthenus Linnaeus) (16+ years), 14 Siberian sturgeon (Acipenser baerii Brandt) (13+ years), 11 Russian sturgeon (Acipenser gueldenstaedtii Brandt et Ratzeburg) (13+ years), and 7 beluga (Huso huso Linnaeus) ( 9+ years). Fish were selected based on phenotypic parameters and bonification. USG (ultrasound examination) was used as a rapid method for assessing sexual maturity.

Results. The results showed that physiological indices of sturgeon broodstock of different species, and the development of sexual products during wintering under the same hydro chemical and thermal conditions, differed significantly. Optimal values are provided for the average oocyte polarization coefficient, resorption results, interspecific mass ratios, duration of artificial wintering before spawning, and temperature regimes.

Conclusion. These research results may improve technologies for growing sturgeon in artificial conditions. The study found that the optimal average polarization coefficient of oocytes ranges from 0.05 to 0.20 Kp. Effective spawning was observed when the period of artificial wintering before spawning is 50-58 days, and the temperature regime was 5 °C to 22 °C.