Issues:
Sections:
Issue 93
GENERAL BIOLOGY
UDK: 597.451-11 (282.247.41)
PHYSIOLOGICAL STATE OF THE FEMALE BLACK-BACKED HERRING DURING SPAWNING MIGRATION IN THE VOLGA RIVER IN THE YEARS 2019-2023
KOZLOVA Natalya V.,
MAKEEVA Olga V.,
NIKITIN Filip I.,
VOINOVA Tatyana V.
In connection with the reduction of spawning stock of the black-backed shad ( Alosa kessleri kessleri ) in the Lower Volga River and the decrease in their natural reproduction, the problem of studying the physiological state of the species is topical. The purpose of this work was to study the physiological state of the black-backed herring during spawning migration in the Volga River. The methods of ichthyology, classical histology and biochemistry were used. The size and weight parameters of females, age of each fish had to be determined. Histological methods were used to study the stage of maturity of the female gonads, disorders in the oocytes. The content of the total lipids and water-soluble protein in the gonads and muscles of individuals has been studied. According to the results of the studies, the black-backed shad is characterized by the age structure of 3,7-4,2 years old. Transitional stages of the gonad maturity (III, III-IV, IV and V) and scattered resorption of the mature oocytes at an average level of 11-26% are observed in the female herring. A high correlation dependency was recorded between the mass of individuals and the mean proportion of oocytes with resorption as well as the length and the mean proportion of oocytes with resorption (r = +0,89 and r = +0,84, respectively). In the muscles and the gonads of the anadromous black-backed shad, a decrease in total lipids was revealed in the period of 2019-2023. The dynamics of water-soluble protein content in tissues tended to increase during the study period, which is explained by the prevalence of younger ages in the population, and, accordingly, by the processes of protein growth over fat accumulation. When comparing with earlier studies, the modern period of 2019-2023 has a decrease in energy biochemical substrates in muscles in the form of total lipids and an increase in the proportion of fish with resorption.
Pages: 6 - 11
Date: 28.06.2024