Plasma 17beta-estradiol and alkali-labile phosphoprotein levels in male and female Tench (Tinca tinca) in the Anzali and Amirkolayeh wetlands

Environmental pollutants are potentiate to disturb biological processes such as metabolism, growth and reproduction of aquatic organisms. These compounds are able to cause gonadal abnormalities, biased sex ratios and alteration in reproductive physiology in fish. The aim of this study was to examine plasma 17β-estradiol (E2) and alkali-labile phosphoprotein (ALP) levels in male and female Tench (Tinca tinca) from a polluted (the Anzali Wetland) and a non-polluted environments (the Amirkolayeh Wetland). Samples were collected over the maturation season of Tench between May and June 2017. The results revealed significant difference in mean ALP and E2 between genders in the polluted environment. However, the mean plasma ALP concentrations in male Tench of the polluted environment (39.46±1.02 µg/ml) was 45% of the average recorded in female (86.18±2.25 µg/ml) and was two times higher than the amount measured in males in the non-polluted environment (18.68±0.35 µg/ml). High concentrations of E2, were detected in the male samples from the Anzali Wetland. Mean plasma E2 concentrations for male in the Anzali Wetland was almost two times higher than male in the Amirkolayeh Wetland. The results indicate that the reproductive physiology of Tench was affected by contaminants found in the Anzali Wetland, a highly polluted area.