棉酚对尼罗罗非鱼（Oreochromis niloticus）生殖机能影响的研究

EFFECT OF GOSSYPOL ON REPRODUCTIVE FUNCTIONS OF NILE TILAPIA(OREOCHROMIS NILICUS)

用含０．１％乙酸棉酚的饲料饲养二月龄尼罗罗非鱼稚鱼四个月，其增重和血浆睾酮水平与对照鱼无显著差异，并且同时开始发情、交配和产卵，生殖腺发育正常，仅血浆皮质醇水平略高于对照组。实验结果表明，棉籽饼（粉）内含的棉酚浓度（０．０３－０．０５％）不会影响尼罗罗非鱼的性腺正常发育和生殖机能。肌肉中棉酚残留量为１０．３ｐｐｍ，远低于食用油的允许量（２００ｐｐｍ）。

Fingerlings of Nile tilapia were fed on a formulated diet containing0.1% gossypol acetate for four months.Gossypol treated fish sexually matured and started mat-ing and breeding at the same time as the control fish. Anatomical and histological exami-nations of gonads in both control and GP-treated fish showed normal structure. Plasma testosterone level in GP-treated tilapia was not significantly different from that in con-trol fish,while plasma cortisol level in Gp-treated fish showed a slight higher than that in the control.The above results demonstrated that gossypol level in cottonseed cake in-hibited neither gonad development not reproductive functions of Nile tilapia. Weight gain and feed conversion of GP-treated fish were not lower than that of control.The res-idue of gossypol in muscle of GP-treated fish was 10.3ppm,much lower than the maxi-mum allowable gossypol concentration for edible oil(200 ppm).