ENDOCRINE-RELATED HISTOPATHOLOGICAL ASSESSMENT OF OVARIAN TISSUE OF Clarias gariepinus FROM IKPOBA RIVER, BENIN CITY, EDO STATE, NIGERIA

ABSTRACT

In the past few years, there has been serious environmental health concern about the release of endocrine disrupting chemicals (EDCs) with potential to cause adverse physiological effects in wildlife, especially fish, into the environment. Regrettably however, not much is known about adverse effects of EDCs on fish in developing countries, including Nigeria. This study was therefore carried out to evaluate the reproductive effects of EDCs on C. gariepinus in Ikpoba River, Nigeria. A total of 14 adult female fish was collected for four months (June – September 2019) from two stations in Ikpoba River for histopathological analysis of ovarian tissues. Results revealed endocrine-related histopathological conditions, including intersex (21.4%), nucleoplasmic retraction (21.4%) and oocyte atresia (28.6%). On the basis of histhopathogical scoring, oocyte atresia were both moderate and severe (Station 1), while intersex was severe (Station 2). Overall, the study suggest that C. gariepinus from Ikpoba River is exposed to EDCs with androgenic mode of action, and has altered gonadal development of the fish. It was concluded that further studies should be carried out to better understand reproductive endocrine disrupting effects of EDCs on fish populations in Ikpoba River, and to also identify the responsible endocrine disruptors.