Physiological state of female bream (Abramis brama Linnaeus, 1758) in case of reproductive system pathology

The development and functioning of the reproductive system of fish is a key indicator of the health of populations and the state of organisms in various habitats. Anomalies in the development of the reproductive system can serve as an indicator of the level of well-being of certain populations. Bream (Abramis brama Linnaeus, 1758) is one of the numerous fish inhabiting the Volga-Caspian basin and is an important object of trade. Currently, the bream population has significantly decreased. When assessing the physiological state of bream based on blood parameters, it was found that their average values b-typical for carp fish and bream from other water bodies. However, these parameters had a wide range and individual specimens with extremely low levels were detected annually — with anemia, exhaustion, etc. In terms of the amount of stored lipids, bream is currently inferior to that studied here earlier. The number of females with resorption, including mass resorption, and the number of oocytes with resorption changed annually. On average, the number of female breams in 2007–2017 with resorption was 63% in spring, 58% in autumn, with mass resorption of 14 and 6%, oocytes with resorption of 26 and 27%, respectively. Female bream with resorption differed from females with normal gonads in biochemical parameters. That is, deviations in the physiological state of bream producers are a marker of a possible decrease in the reproductive potential of such an individual. At the initial stages of resorption, deviations in the functional state of female bream with low indicators of stored energy substrates are one of the root causes of these resorption processes, in addition to external unfavorable physical factors (temperature, hydrochemical regime), while at the final stages the resorption process depletes the fish body. Negative changes in the physiological state of female bream may be associated with the impact of the current tense toxicological situation in the Volga-Caspian basin.