Harmful effects of waterborne nonylphenol on reproductive performance in rainbow trout Oncorhynchus mykiss

In this study, the effects of different concentrations (۰, ۵, ۱۰, ۲۵, and ۴۰ μg L−۱) of nonylphenol (NP) for ۹۰ days on the physiological and reproductive parameters in juveniles of rainbow trout were investigated. In the group exposed to ۴۰ μg L−۱ of NP, plasma concentrations of ۱۷β-estradiol (E۲) and ۱۱- ketotestosterone (۱۱-KT) were significantly lower on days ۴۵ and ۹۰ of the experiment in comparison to the control group. With the increase of NP concentration in the environment, plasma concentrations of cortisol were increased on days ۴۵ and ۹۰ of the experiment. At the end of the experiment, in the groups which were exposed to ۲۵ or ۴۰ μg L−۱ of NP, gonadosomatic index (GSI) and hepatosomatic index (HSI) were decreased and increased respectively, compared to the control group. The results of the recent study confirm the disruption of the endocrine and metabolic organs in rainbow trout exposed to NP in the early stages of growth.