Effects of Exogenous Melatonin on Serum Steroid Hormones, GSI, Survival Ratio and Sex Reversal in Rice Field Eel, (Monopterus albus)

Abstract:

The aim of this study was to investigate the effects of exogenous melatonin on sex reversal in the rice eel (Monopterus albus). This was carried out by evaluating the estradiol (E2) and testosterone (T) concentrations, gonadosomatic index (GSI) and sex ratio. Fish (9.80 ± 1.20 g average initial weight; n = 3 per group) were fed with one of five practical diets containing 0 (control), 10, 30, 50 or 70 mg kg-1 dietary melatonin contents to apparent satiation for fifteen months. Serum E2 and T concentrations were determined by radio immunoassays. E2 and T concentrations, GSIs and survival rates significantly decreased with increased concentrations of exogenous melatonin. Fish fed 70 mg kg-1 of dietary melatonin showed significantly lower rates of E2, T, GSIs and survival ratio than those fed with lower melatonin concentrations or the control group. The shift of sex ratio towards more male and intersex fish was correlated with increasing dietary melatonin contents. Therefore, a high dosage of melatonin may inhibit gonadal development and promote sex change from female to male in M. albus.

• Periodical: Applied Mechanics and Materials (Volume 142)
• Pages: 238-242
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.142.238
• Online since: November 2011
• Authors: Han Wen Yuan, Fang Chen, Qiao Qing Xu, Shi Yuan Gong, Deng Hang Yu, Dai Qin Yang
• Keywords: Gonadosomatic Index, Melatonin, Monopterus albus, Sex Reversal, Steroid Hormones

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