饥饿对南方鲇和草鱼的生长及能量代谢的影响

On Effects of Starvation on Growth Performance and Energetic Metabolism in Silurus Meridionalis and Ctenopharyngodon Idellus

以南方鲇(Silurus meridionalis)和草鱼(Ctenopharyngodon idellus)为对象,在(27.5±0.5)℃条件下,分别饥饿0d,3d,7d,14d,21d和28d,观察各实验处理对鱼体的生长及能量代谢的影响.研究发现:在饥饿28d后,2种鱼的体质量、体长无显著变化,但各自的肥满度和肝器官指数均显著降低(p<0.05),南方鲇脂肪含量的降低幅度大于草鱼,其蛋白含量的降低幅度却小于草鱼.各饥饿处理时间点的草鱼静止代谢率(RMR)均显著高于南方鲇(p<0.05),且随饥饿时间的延长呈直线下降的趋势;而南方鲇的RMR则呈先上升再下降的趋势.2种鱼的特定体质量生长率(SGR)在饥饿进程中均呈负增长,南方鲇和草鱼的各线粒体状态3呼吸率和细胞色素C氧化酶活性随饥饿时间延长均表现出了不同的变化的趋势.以上结果表明,南方鲇和草鱼应对饥饿胁迫的生理生态学机制存在组织特异性和物种特异性.通过讨论提出,由于南方鲇与草鱼为不同的营养类型,尤其是捕食行为模式各异,因此进化出不同的适应饥饿胁迫的能量生态对策.

The growth performance and energy metabolism of the juvenile southern catfish（Silurus meridionalis）and juvenile grass carp（Ctenopharyngodon idellus）in six different groups which were deprived of feed for 0,3,7,14,21,28 days were observed at 27.5±0.5℃,respectively.As expected,starvation resulted in cessation of growth and there was no significant difference in body weight and body length of the starved fish for 28 days compared to their initial condition for both species.However,condition factor and hepatosomatic index（HSI）of two species were found to be significantly lower after a 28-day period of food deprivation（p0.05）.The Protein content of southern catfish decreased much less than that of grass carp in response to starvation.Opposite trend was observed for the change of lipid content.The resting metabolic rates（RMR）of grass carp were significantly higher than that of southern catfish in each starvation period（p0.05）,and its RMR decreased with the increasing starvation time.RMR of southern catfish increased at initial starvation for 7 days,and then decreased until the end of starvation for 28 days.The specific weight growth rates（SGR）of the two species presented negative during deprivation.During each deprivation period the differences between SGRs of the two species were insignificant.State 3 respiration rates and activity of cytochrome C oxidas of mitochondria in southern catfish and grass carp have different changes with increasing starvation period.The results indicated that the ecophysiological mechanisms in response to starvation for southern catfish and grass carp should be tissue-specific and species-specific,it is concluded that southern catfish and grass carp with different feeding habits and different patterns in predatory behavior,so they have evolved the different ecological strategies in energy metabolism to adapt starvation stress.The results of this study support the view that the carnivorous fish is more tolerant to starvation than herbivorous fish.