延迟投饵对卵形鲳鲹早期仔鱼阶段摄食、成活及生长的影响

利用人工繁殖产生的卵形鲳鲹（Trachinotus ovatus）初孵仔鱼，在水温(26.81.4) ℃、盐度28.20.8条件下，对延迟投饵0~6 d的卵形鲳鲹仔鱼的摄食、生长及其成活情况进行了研究。结果显示，仔鱼于3日龄开口，于开口的当天投饵及延迟投饵1、2、3、4和5 d，投饵后2 h内仔鱼的摄食率分别为15%、30%、50%、25%、15%和5%，每尾鱼的平均摄食量分别为0.4、0.6、1.3、0.6、0.3和0.1个轮虫。延迟投饵6 d一组仔鱼的摄食率均为0。延迟投饵0、1和2 d各组仔鱼的成活率相差不大，但延迟3 d以上仔鱼的存活率急剧下降。卵形鲳鲹仔鱼的初次摄食饥饿不可逆点（PNR）出现在仔鱼开口后4 d，开始投喂饵料的最佳时期应在仔鱼开口后的3 d之内。

Effect of delayed feeding on foraging,survival and growth of ovate pompano (Trachinotus ovatus) larvae during early development stage

Effects of delayed initial feeding on the foraging, growth and survival of artificial bred larvae of ovate pompano (Trachinotus ovatus) were studied under the water temperature of (26.81.4) ℃ and salinity of 28.20.8. The results showed that the larval mouth opened 3 days after hatching, and with the delayed initial feeding of 0, 1, 2, 3, 4 and 5 days, the feeding rate was 15%, 30%, 50% , 25%, 15% and 5%, respectively; the average consumption per larva within two hours was 0.4, 0.6, 1.3, 0.6, 0.3 and 0.1 prey, respectively. At day 6 of the delayed initial feeding, the feeding rate of all larvae was 0; there was no significant difference in the survival rate at the delayed initial feeding of day 0, day 1 and day 2 but the survivorship decreased abruptly while the delayed feeding lasted more than 3 days. The point of no return (PNR) occurred at 4 days after the larval mouth opened, which indicated that the optimum initial feeding time for the larvae was within 3 days after their mouths opened.