| The objective of this study was to determine whether hornyhead turbot males exhibiting abnormally high concentrations of plasma 17beta-estradiol (E2) might also exhibit potential feminization in their reproductive phenotype. In this research, male plasma E2 concentrations did not differ from female levels, and were significantly higher in individuals from a wastewater treatment plant (WWTP) location as compared with a reference site. Despite such differences in E2 among male groups, there were no associated alterations in gonadal phenotype (gonadal growth, histomorphometric indicators) or in levels of the androgens, testosterone (T) and 11-ketotestosterone (11-KT). When males with high E2 levels were removed from the WWTP environment and placed into clean water, E2 reduced to normal male levels, while 11-KT remained largely unaffected. Therefore, the findings suggest that an environmental factor, potentially an endocrine-disrupting chemical, may underlie elevated E2 in male hornyhead turbot, although potential reproductive impacts of the high E2 are not yet understood. |
