杂交鳜仔鱼饥饿试验及不可逆点的确定

在水温（24±1）℃条件下,对翘嘴鳜（♀）×斑鳜（♂）杂交所得的杂交鳜仔鱼进行饥饿试验,确定其初次摄食饥饿不可逆点（PNR）。研究结果表明：杂交鳜仔鱼4日龄开口,此刻仔鱼卵黄囊已吸收完毕,但油球仍在,仔鱼发育进入混合营养期。7日龄仔鱼油球吸收完毕,进入外源营养期,仔鱼混合营养期仅为3d。杂交鳜仔鱼初次摄食率开始时为15%,高峰期出现在油球即将耗尽时的6日龄仔鱼,可达70%。仔鱼不可逆点出现在7～8日龄,杂交鳜仔鱼具有初次摄食能力的时间为4～5d。

Experimental starvation on the hybrid by Siniperca chuatsi (♀) × Siniperca scherzeri(♂)larvae and definition of the point of no return

The starvation trial and the definition of the point of no return（PNR） for the larvae of hybrid species were conducted under the water temperature of（24±1）℃.The results showed that the larvae of hybrid species began to feed on the 4 days old.At this time the yolk-sac was exhausted but the oil globes continued to be absorbed.The developmental stage was a period of mixed nutrition.The larvae came into the stage of nutrition outside completely on the 7 days old.A period of mixed nutrition lasted only 3 days.The initial larval feeding rate of hybrid species larvae reached 15%,but the tiptop initial feeding rate of the larvae occurred on the 6 days old when the oil globes were sufficiently absorbed.The initial larval feeding rate reached 70%.The initial larval feeding rate fell to 50%of the tiptop initial feeding rate,the larvae entered the PNR,which appeared on the 7～8 days old.The initial feeding time of the larvae lasted 4～5 days.