延迟投饵对真鲷、牙鲆仔鱼早期阶段摄食、存活及生长的影响

EFFECT OF DELAYED FEEDING ON FEEDING ABILITY, SURVIVAL AND GROWTH OF RED SEA BREAM AND OLIVE FLOUNDER LARVAE DURING EARLY DEVELOPMENT

试验结果表明：（１）２日龄真鲷、牙鲆仔鱼初次摄食，在６～７日龄和５～６日龄，不能建立外源性营养的仔鱼分别进入ＰＮＲ期，而卵黄囊均在此前１～２天已耗尽。混合营养期分别为３～４天和１～２天。（２）真鲷和牙鲆仔鱼在不同饥饿阶段初次摄食率的变化式型是：开始较低，此后逐步上升，高峰期出现在卵黄囊接近耗尽时，此后开始下降。记录到的最高初次摄食率分别为８６．７％和３５％。（３）牙鲆仔鱼体长的增长率随延迟投饵天数的增加而降低，牙鲆仔鱼的存活率与延迟投饵天数的关系也是如此。延迟２天投饵对真鲷仔鱼的存活率影响不大。

The effect of starvation to the growth, feeding ability and survival of red sea bream (Pagrosomus major) and olive flounder (Paralichthys olivaceus) larvae during early development were examined in the delayed feeding trials. Red sea bream larvae arrived the point of no return (PNR) at 6-7 days of age, its yolk exhausted at 5-6 days of age. The PNR of olive flounder larvae was one day or two to three days ahead of yolk exhaustion. The initial feeding rate was lower, then slowly increased to the peak when the yolk almost exhausted, after that, it decreased. The highest initial feeding rate of red sea bream was 86.7%, and olive flounder was only 35%. The growth and survival rates decreased with increasing of feeding delayed time. The survival rate was not affected when the initial feeding was at the age of 3 days for red sea bream.