The physiological state of sterlet in the conditions of cage and basin farms

Abstract

The growing conditions of sturgeon fish affect the growth and physiological state, their morphological characteristics. The study of changes in physiological processes under the influence of a complex of factors in the conditions of cage complexes and closed water supply systems will allow for timely adjustment of technology and reduce risks when growing commercial products. The repair and breeding herds of fish breeding enterprises contain sterlet individuals of different ages, which annually, upon reaching puberty, enter the fish breeding process as producers. In this regard, we have studied the main morphophysiological indicators of two-year-olds kept in cages and in closed water supply installations (CWSI). The influence of environmental factors was noted not only on growth indicators, but also on the size of the internal organs of fish and their condition. The unstable temperature regime in the cages, dependence on unpredictable changes in the hydrochemical parameters of the aquatic environment contributes to deep physiological transformations of an adaptive nature, which slows down the growth rate and accumulation of reserve substances. Changes in morphometric parameters were also evident. In sturgeon, there is an increase in the relative weight of the heart, spleen and gonads, a decrease in the weight of the kidneys and liver. The influence of optimal temperature and trophic conditions on the index of the gastrointestinal tract was noted, which was slightly lower in fish from the CWSI than in individuals exposed to negative factors in cages. Sterlet blood counts, regardless of the conditions of detention, corresponded to physiologically healthy individuals. The creation of optimal hydrological and trophic conditions in CWSI contribute to the accumulation of phospholipids and linolenic fatty acids in tissues, which play an important role in the adaptation of the body to negative environmental factors.