饥饿及再投喂对牙鲆幼鱼氮、磷排泄的影响

采用静水试验法,在水温为（15.0±1.0）℃下,研究了饥饿及再投喂对牙鲆Paralichthys olivaceus幼鱼（体质量为69.56 g±2.35 g）氨氮、活性磷排泄率的影响。结果表明：饥饿初期牙鲆氨氮、活性磷排泄率呈直线下降,随着饥饿时间的延长排泄率处于相对稳定状态;再投喂后,各饥饿处理组牙鲆氨氮、活性磷排泄率快速恢复到对照组水平,摄食对牙鲆氨氮、活性磷排泄率的影响显著（P〈0.05）。在饥饿和饱食状态下,牙鲆氨氮、活性磷排泄率的峰值均出现在10：00,为摄食后4 h,以后逐渐下降;低谷均出现在18：00;再投喂期间平均氨氮排泄率昼夜差异不显著（P〉0.05）,活性磷排泄率白天略高于夜间（P〈0.05）。

Effect of starvation and refeeding on excretion of nitrogen and phosphorus in Japanese flounder Paralichthys olivaceus

The effect of starvation and refeeding on excretion of nitrogen and phosphorus in Japanese flounder Paralichthys olivaceus（body weight of 69.56 g±2.35 g） were investigated by still water experiment method in a laboratory at water temperature of（15.0±1.0）℃.The results showed that the excretion rate of N and P was sharply decreased in the initial starvation and became relatively stable with the starvation preceeded.After the starved fish were refed,the excretion rates of N and P in the starved fish in the treatment groups were returned to those in the control group,indicating that there were significant effect of refeeding on the excretion of N and P（P0.05）.The maximal N and P excretion rates were found at 10：00 of 4 h after refeeding in the fed and starved fish,and decreased gradually with the minimum at 18：00.There was no significance in diurnal N excretion during the refeeding period（P0.05）.However,the average P excretion was found slightly higher（P﹤0.05） in the day time than during the night.