Histological alternation and vitellogenin induction in adult rare minnow (Gobiocypris rarus) after exposure to ethynylestradiol and nonylphenol

Adult rare minnow (Gobiocypris rarus) were exposed to 0, 1, 5, and 25 ng/l (nominal concentrations) of 17α-ethynylestradiol (EE₂) and 3, 10, and 30 μg/l (nominal concentrations) of 4-nonylphenol (NP) under flow-through conditions for a period of 28 d. Low mortality was observed at 5 and 25 ng/l EE₂ and the growth of fish reduced significantly at 25 ng/l EE₂ compared to controls. However, the gonadosomatic indices (GSI) of male fish were significantly higher in 1 ng/l EE₂ treatments and in 10 and 30 μg/l NP treatments (p