Analysis of the fluctuating asymmetry of bilateral traits in the Russian sturgeon grown in fish farms of various types

Abstract

The aim of our work was to determine the influence of the Russian sturgeon breeding conditions on its phenotypic variability in the process of ontogenesis. The phenotypic variability identification work was carried out on the Russian sturgeon fingerlings and juveniles grown in three different fish farms: Sturgeon fish hatchery Bertyulskiy with an intensive pond type of breeding, Fish hatchery of Elektrogorsk SDPS named after R.E. Klasson with an intensive cage type of breeding and Mozhaisk production and experimental fish hatchery with an industrial use of RAS. In the first two farms, the fishes were studied postmortally, and in the third farm, the fishes were examined in vivo, by studying the fluctuating asymmetry of traits recorded on previously taken photographs. In the course of our study, it was found that the smallest impact on the organism development stability, estimated by the value of the average frequency of the asymmetric manifestations for trait (0.6), was found in the fish farms with an intensive method of reproduction in small ponds, as in the BSFH enterprise. The highest impact (0.8) was found in the farms using an industrial reproduction in RAS as organized in MPEFH. In the Elektrogorsk SDPS fish hatchery, an average value between the three compared farms, 0.7, was recorded, which is explained by the minimal temperature fluctuations of water due to the discharge of warm water into the cooling pond where the fishes are bred. Also, during the determination of the developmental stability level, estimated by the magnitude of the variance of the fluctuating asymmetry of bilateral traits, it was found that it depends on the temperature regime stability in the fish farms. It has also been established that the temperature changes in the spring-summer period lead to the formation of the physiological deviations in fishes, expressed by the fluctuating asymmetry of bilateral traits, mainly by the number of lateral and ventral scutes, as well as the number of rays of pectoral and ventral fins. The obtained data has high reliability at the level of Pі0.01 when comparing the above results.