• Dr. Nilanjana Bhattacharyya Nath

Natural sexual steroid hormones play a major role in controlling sex differentiation and reproduction in fish. Additionally, physiological concentrations of these hormones are essential for the maintenance of cell proliferation, growth and several other biological activities. Imbalance in hormonal status caused by higher level of endogenous hormones as well as by exposure to exogenous steroid-like compounds is known to produce adverse effects on reproductive processes. In the present investigation, Clarias batrachus treated with three different heavy metals at different doses. Lead, mercury and arsenic exposed fish had significantly decreased gonadosomatic index. In case of control fish, in the month of June, the level of 17β estradiol was 0.75 ngml-1 where as in the treated fish the amounts were 0.70 ngml-1 for Lead, 0.60 ngml-1 for Mercury and 0.63 ngml-1 for Arsenic and the level of testosterone in both control and treated group were 1.61 ngml-1 and 1.47 ngml-1, 1.27 ngml-1and 1.43 ngml-1 respectively. Among the three heavy metals, the level of gonadal hormone of Clarias batrachus treated with any chemical was disturbed and in case of mercury exposed fish the reduction was maximum.

Lead, Mercury, Arsenic, Gonadosomatic Index, Estradiol, Testosterone, Clarias batrachus.

"Effect Of Heavy Metal(loid)s On The Level Of Gonadal Hormone During The Sexual Maturity And Breeding Period Of Catfish, Clarias batrachus (L.).", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 6, page no.124-130, June 2019, Available :http://www.jetir.org/papers/JETIR1906X50.pdf

"Effect Of Heavy Metal(loid)s On The Level Of Gonadal Hormone During The Sexual Maturity And Breeding Period Of Catfish, Clarias batrachus (L.).", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 6, page no. pp124-130, June 2019, Available at : http://www.jetir.org/papers/JETIR1906X50.pdf