饥饿对斜带石斑鱼卵黄囊期仔鱼摄食、存活及生长的影响

 在培育水温(25±0.5 ）℃、盐度31～32 条件下，斜带石斑鱼仔鱼孵化后第3天开口并进入摄食期，孵化后5.5 d，不能建立外源性营养的仔鱼分别进入不可逆点（PNR期），几乎与此同时，卵黄囊和油球耗尽，仔鱼混合营养期为2~3 d，从初次摄食到进入PNR期的时间为2.5 d；仔鱼在不同饥饿阶段初次摄食发生率的变化式型是：开始较低，此后逐步上升，高峰期出现在卵黄囊接近耗尽时，此后迅速下降，记录到的最高初次摄食发生率为76.7%；饥饿仔鱼的死亡高峰出现在孵化后4~6 d，至第8天，饥饿仔鱼全部死亡；卵黄囊期仔鱼的生长可以分为3个期相：初孵时的快速生长期，卵黄囊消失前后的慢速生长期，以及在不能建立外源性摄食后的负生长期。

Effects of Starvation on Feeding,Surviving and Growth ofYolk-sac Larval Epinepheius coioides

At (25±0.5 )℃, salinity 31~32, the larval grouper started feeding at the 3th day after hatching. At the 5.5 days after hatching, some larvae failed to digest exogenous nutrition and developed into PNR stage, in which the yolk sac and oil were absorbed completely. The nutrition mixture stage was 2~3 days and the interval between the first feeding and the beginning of PNR was 2.5 days. After being starved, the larvae were fed in the different time points and the initial feeding rates were calculated. The initial feeding rate was low at the early stage, and then increased gradually. The initial feeding rate reached the peak while the yolk sac disappeared, and thereafter, the initial feeding rate decreased rapidly. The highest initial feeding rate was 76.7%. During starvation treatment, the mortality of the larvae reached the peak between 4th and 6th day after hatching, and all the larvae died at the 8th day after hatching. The growth of the yolk sac larvae could be divided into three stages: the rapid growth stage after newly hatching, the slow growth stage before or after the yolk sac disappeared, and the minus growth stage when the larva failed to absorb the exogenous nutrition.