延迟投饵对泥鳅仔鱼摄食、生长和存活的影响

试验分延迟0d、1d、2d、3d、4d、5d、6d、7d投饵和完全饥饿9个试验组，研究了延迟投饵对泥鳅仔鱼摄食、生长和存活的影响。结果显示：水温27℃±1℃时，泥鳅仔鱼3日龄开口，混合营养期2d，4日龄卵黄囊消失。开口当日初次摄食率为36%，最高初次摄食率出现在5日龄，达98%，饥饿不可逆点（PNR）在8～9日龄。延迟0d（正常投饵）和1d投饵组仔鱼体长一直呈增长趋势，至11日龄，两组仔鱼体长没有显著差异（P>0.05）；随延迟投饵天数的增加，仔鱼体长生长速度明显降低；完全饥饿组仔鱼3～5日龄呈正增长，随后转为负增长。延迟0d和1d投饵组，11日龄时仔鱼存活率分别为82.67%和89.33%，且两者无显著差异（P>0.05）；随延迟投饵天数的增加，11日龄时仔鱼存活率明显降低；完全饥饿组，11日龄时仔鱼全部死亡。

Effects of Delayed Feeding on Ingestion,Growth and Survival of Misgurnus anguillicaudatus Larvae

Effects of delayed initial feeding on ingestion,growth and survival of oriental weatherfish(Misgurnus anguillicaudatus) larvae were investigated under the condition of water temperature of(27±1)℃,different initial feeding time being 0,1,2,3,4,5,6,7 days delayed,and M.anguillicaudatus being starved.The results showed that the larvae of oriental weatherfish opened mouth 3 days of age,mix of nutrition period was 2 days,and complete yolk sac absorption was 4 days of age.The initial feeding rate was 36%;the highest initial feeding rates reached 98%,oriental weatherfish 5 days of age.The point of no return(PNR) of starvation was in 8th-9th day after hatching.The body length of oriental weatherfish larvae of 0 day and 1 day groups of delayed feeding indicated constant growth,with no significant difference(P>0.05)between two groups till 11 days.With the days of delayed feeding increasing,the growth rate of M.anguillicaudatus larvae obviously decreased.The M.anguillicaudatus larvae under the absolutely starved condition indicated positive growth between 3days old and 5 days old,but subsequently appeared negative growth.At the age of 11 days,the survival rates of the larvae of delayed feeding of 0 day and 1 day were separately 82.67% and 89.33%,and there were no significant difference(P>0.05).With feeding days of delayed feeding rising,on the 11th day,the survival rates of the larvae obviously reduced,while all the larvae died in the starvation group.