Морфофизиологические и биохимические исследования каспийской атерины (Atherina boyeri caspia Risso, 1810)

Abstract

The article highlights physiological and biochemical parameters of atherina (Atherina boyeri caspia Risso, 1810) in the Middle Caspian Sea at various stages of the annual cycle. The state of the fish organism was studied in the period from February to October 2022, which characterized the pre-spawning, spawning and feeding periods. The size-weight and age parameters of atherina were determined. The concentration of the main reserve substances of the fish body - total lipids and water-soluble protein – was analyzed in the muscles of the atherina. In the pre-spawning period and at the beginning of spawning of females, the level of morphological changes in the gonads was studied. There were no found significant differences in the content of total lipids and water-soluble protein in the muscles of males and females. Patterns of changes in the amount of muscle water-soluble proteins and total lipids were recorded in the entire sample of the Caspian atherina during the pre-spawning period and at the beginning of spawning. This is typical for portioned spawning fish, in which the energy expenditure of the body is directed to the formation, maturation of gonads, the removal of sexual products and the maturation of the next portions during the spawning period. In September-October, that is, already at the stage of feeding, a multidirectional character in lipid and protein metabolism was noted in the body of atherina. According to the results of histological examination, the beginning of spawning in atherina was noted in April. Mature oocytes with resorption at an average level of 30-31% were recorded in the ovaries of portioned spawning atherina in February-April, which characterized the adaptive mechanisms of the organism in the conditions of this habitat. In September, there was a significantly positive (p < 0.05) statistical correlation between the concentration of total muscle lipids and the mass of fish (r = +0.47), which characterized a positive energy balance in the body, so necessary for the next stages of life.