蜕壳对河蟹幼体能量密度及蛋白质和脂肪积累的影响

Effects of Successive Molting on Energy Density,Protein and Lipid Accumulation in Larva of Chinese Mitten Crab(Eriocheir sinensis)

为了研究蜕壳对河蟹幼体成分和能量的影响,从幼体即将孵化开始,采集每次临近蜕壳前和刚刚蜕壳后的幼体作为样品,检测其干物质含量、干样品的粗蛋白、总脂含量和能量密度。结果表明,幼体孵化后的干物质含量显著低于孵化前卵的干物质含量(p<0.05),较孵化前降低42.7%。第1~3次蜕壳后的干物质含量显著低于临近下次蜕壳前(p<0.05)。幼体干样品的能量密度、粗蛋白含量在孵化和每次蜕壳后均显著低于孵化和蜕壳前(p<0.05),孵化到第3次蜕壳阶段每次临近下次蜕壳的能量密度和粗蛋白含量均显著高于刚刚蜕壳时(p<0.05)。幼体干样品总脂含量除孵化前后外,其余各阶段均无显著差异(p>0.05)。总脂和粗蛋白2种供能物质中,粗蛋白和能量密度的相关性更大,说明河蟹幼体蜕壳时能量的变化主要受蛋白质供应的影响。本研究为河蟹幼体的营养管理提供了更多依据,补充了河蟹的基础研究。在育苗的各阶段为了保证能量的供给,应当及时补充优质蛋白质,以促进蟹苗的蜕壳。

In order to study the effects of each molt on the composition and energy of larvae of Chinese mitten crabs,the larva before and just after each molting was collected as a sample to test its dry matter,crude protein,total lipids content and energy density from the time when the larva was about to hatchor molt.The results showed that the dry matter content of the larva after hatching was significantly lower than that of the pre-hatching eggs(p<0.05),which was 42.7%lower than that of before hatching.The dry matter content after 1~3 molting was significantly lower than that of before the next molting(p<0.05).The energy density and crude protein content of the larvae after hatching and each molting were significantly lower than that of before hatching and each molting(p<0.05).The energy density and crude protein content before the next molting was significantly higher than that of just molting during the stage of hatching-the third molting(p<0.05).The total lipids content of the larva increased first and then decreased throughout the larval stage.Except before and after hatching,there was no significant difference in total lipids content at all stages(p>0.05).Among the two energy sources,total lipids and crude protein,the correlation between crude protein and energy density was greater indicating that the change of energy was mainly affected by protein supply.This study provides more basis for nutritional management of river crab seedlings and supplements the basic research of river crab.Therefore,in order to ensure sufficient energy,high-quality protein should be added in time to promote the molt of larva crab.