Zinc content in organs and tissues of the Caspian fish Vimba vimba persa (Pallas, 1814)

The results of a study of zinc concentrations in organs and tissues (gills, liver, genitals, muscle tissue, gastroin-testinal tract) of the Caspian fish Vimba vimba persa (Pallas) sampled in the middle part of the Caspian Sea in the autumn period of 2020-2023 are presented. The results were obtained using the appropriate atomic absorption methods. The sex and age characteristics of the metal distribution have been determined. A redistribution of zinc was noted when the fish reached puberty (the gonads and liver became indicative in our case). Age-related changes in the accumulation of zinc are noted in the eggs of females upon reaching the age of 3 years and, conversely, a slight decrease in the concentration in the milk of males. The concentration of metal in the gills decreases in females and males with increasing age, in the gastrointestinal tract, on the contrary, the concentration increases with age. Despite the redistribution of metal across organs and tissues, the maximum concentration of zinc was always found in the gills. Minimal concentrations were found in muscle tissue (the exception was 3-year-old males, who showed a sharp decrease in zinc in the gonads). The average concentration of zinc in the body of females and males aged 2 years is approximately at the same level; at the age of 3 years, the concentration in the body of males decreases and reaches a difference of 1.3 times compared with the average concentration of metal in the body of females aged 3 years. Accordingly, the average zinc content in the body of females is higher (45.62 mg/kg of dry matter) compared with males (40.12 mg/kg of dry matter).