Document Type: Original Article
Iranian Fisheries Science Research Institute Agriculture Research, Education and Extension Organization, Tehran, Iran
Present address: Freshwater Fish Group and Fish Health Unit, School of Veterinary and Life Science, Murdoch University, Perth, Australia
Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
Department of Fisheries Science, Science and Research Branch, Islamic Azad University, Tehran, Iran
This study aimed to assess the effect of 4-nonylphenol (4-NP), a ubiquitous aquatic micro-chemical pollutant substance on some on some reproductive parameters and histology in koi carp. Fish were intraperitoneally subjected to ascending doses of 4-NP at 10, 50 and 100 μg/g body weight (BW) on days 7, 14 and 21 after the initiation of the experiment. Also, one group was treated with 17β-estradiol (E2) at 2 μg/g BW, positive control group (C2) received the vehicle (50 μL of coconut oil + 50 μL Ethanol) per fish and a negative control group (C1) was considered without injection. The results showed that 4-NP induced significantly an increase in E2, progesterone, and plasma vitellogenin at 50 μg/g in both male and female, while level of testosterone significantly decreased in the treated fish compared to control fish (P < 0.05). Conversely, the levels of these parameters at the higher concentration of 4-NP (100 μg/g) were significantly reduced compared to control one (P < 0.05). Also, some sever histopathological changes were observed in ovary, testicular and liver of treated fish, reflecting fish sensitivity to 4-NP at higher doses. This study showed that 4-NP has an estrogenic potency in the sexual development, hepatotoxicity and gonado-toxicity of koi carp.