饥饿和补偿生长对史氏鲟幼鱼摄食、生长和体成分的影响

Effect of starvation and compensatory growth on feeding, growth and body biochemical composition in Acipenser schrenckii juveniles

报道了饥饿和再投喂对史氏鲟幼鱼摄食、生长以及生化组成的影响。22±2℃条件下,随着饥饿时间延长,幼鱼白肌的RNA/DNA比值不断减小,体重逐渐下降,后者与同期对照组之间存在极显著性差异(P<0.01)。饥饿7d,鱼的肝糖原和肌糖原含量显著降低(P<0.05),但随着饥饿时间的延长,肝糖原和肌糖原含量则出现不同程度的回升;脂肪含量和蛋白质含量分别在饥饿14d和21d时下降幅度最大,提示史氏鲟幼鱼动用储存物质的顺序依次是糖原、脂肪和蛋白质。而饥饿过程中鱼体水分和灰分含量则有所上升。恢复投食后,饥饿幼鱼的摄食强度增大,生长加快,其中7d、14d饥饿组幼鱼的RNA/DNA比值达到或接近正常投喂组水平,但21d饥饿组的比值仍明显低于正常投喂组(P<0.05)。恢复投食30d后,7d和14d饥饿组幼鱼体重接近对照组(P>0.05),21d饥饿组的终体重未能赶上对照组(P<0.05),这表明史氏鲟幼鱼的补偿生长随饥饿时间不同而异。试验结束时,各处理组鱼体生化组成与正常投喂组没有显著差异(P>0.05)。

The effect of starvation for different time and re-feeding on growth, feeding and body biochemical composition of Amur sturgeon juveniles(Acipenser schrenckii) were investigated indoor under 22±2℃. The body weight and ratio of RNA/DNA of fish decreased with the increasing of starvation period. After being deprived of food for 7 days, 14 days or 21 days, body weight was significantly lP<0.01). At the same time, protein, lipid and glycogen content of fish were lower, while ash and moisture content became higher of the starved group than that of the control. The liver glycogen and muscle glycogen content reduced mainly in the first week, and lipid and protein content reduced obviously in second and third week of food deprivation respectively. The results indicated that sturgeon juveniles mobilize energy from glycogen, lipid and protein in turn. Upon re-feeding, all the starved groups exhibited higher feed intake rates and specific growth rates than that of the control group. The ratio of RNA/DNA of fish deprived of food for 7 and 14 days reached or approximated to that of the control, while the ratio of RNA/DNA of the testing fish starved for 21 days was lower significantly comP<0.05). After re-feeding for 30 days, there were no significant differences in body biochemical composition among four groupP>0.05). The fish deprived of food for 7 and 14 days were able to catch up with the control in body weight, while the fish weight of starving 21 P<0.05). It suggested that both complete and partial compensation is contributed somewhat by improvement feeding rate in Amur sturgeon.