【作者】 吴蒙蒙；

【导师】 李吉方；

【作者基本信息】 中国海洋大学 ， 动物学， 2008， 硕士

【摘要】 本文研究了16±2℃条件下金鳟(Oncorhynchus mykiss)幼鱼(平均初始体重31.52±1.33g)饥饿及恢复投喂不同时间的补偿生长状况。通过研究饥饿和恢复投喂对其形态性状指标、鱼体生化指标、血液生理生化指标、消化酶活性的影响,探讨了金鳟幼鱼在饥饿胁迫下的适应性对策及其补偿机制,结果如下:饥饿后,金鳟幼鱼的体重、体长、比肝重、肥满度和特定生长率均下降,其中体重、比肝重、肥满度和特定生长率对饥饿的反应很敏感。恢复投喂后,各饥饿组体重上升,但仍与对照组存在显著差异,其他形态形状指标均与对照组无显著差异。恢复生长时期金鳟幼鱼饥饿组的生长速度均超过了对照组,摄食率变化不大,食物转化率的变化比较明显。饥饿后,金鳟幼鱼鱼体水分和灰分含量上升,粗脂肪,粗蛋白,肝糖原和肌糖原含量下降;恢复投喂后各饥饿组生化指标除了肌糖原外均恢复到与对照组无显著差异水平。结果表明,肝脏是金鳟幼鱼的主要贮能器官,金鳟幼鱼能较好的利用体内的糖类作为能源物质;在饥饿时首先动用的是糖原,然后是脂肪;从肝糖原和肌糖原变化的情况来看,在饥饿的过程中首先动用肝糖原,然后再大量动用肌糖原;贮存能源物质时是优先积累肝糖原的。饥饿后,金鳟幼鱼红细胞总数、血红蛋白含量和红细胞比容显著下降,白细胞总数上升,红细胞沉降率呈下降趋势;恢复投喂后,血液生理指标均恢复到与对照组无显著差异水平。饥饿后,金鳟幼鱼血糖含量大幅度下降,饥饿初期下降较快,后期则维持在一定水平,胆固醇含量和甘油三脂呈类似锯齿形的阶梯状下降,血液总蛋白含量变化不显著。恢复投喂后,血液各生化指标均恢复到与对照组无显著差异水平。饥饿后,金鳟幼鱼消化道内蛋白酶,类胰蛋白酶和谷丙转氨酶活性均下降,且都在饥饿初期下降较快,后期下降变缓。脂肪酶活性先降低后升高,淀粉酶活性先升高后降低。恢复投喂后,金鳟幼鱼淀粉酶和脂肪酶活力与饥饿前相比都有所上升,但淀粉酶活性总体上仍低于同期对照组,脂肪酶活性总体上高于对照组水平,蛋白酶,类胰蛋白酶和肝胰脏谷丙转氨酶活性恢复到对照组水平,基本上没有变化,而且一直保持平稳的状态。金鳟幼鱼不同消化酶在消化道中的活性分布规律是:蛋白酶和类胰蛋白酶的活性,胃和幽门盲囊中最高,肠中次之,肝胰脏中最低;淀粉酶活性,肠中最高,幽门盲囊中次之,胃比幽门盲囊稍低,肝胰脏中最低;脂肪酶活性,肠中最高,幽门盲囊和胃中次之,肝胰脏中最低。从体重和特定生长率指标的变化可以看出,金鳟幼鱼的补偿生长是部分(有限)补偿生长。从摄食率和食物转化率的变化可以看出,其部分(有限)补偿生长主要是食物转化率提高所致。建议在金鳟人工养殖过程中应尽量避免或减少喂食不足,科学地利用补偿生长生理现象,对金鳟的养殖有着重要的意义。更多还原

【Abstract】 This study is about the compensatory growth of kingtrout juvenile (average initial body weight 31.52±1.33g) under 16±2℃after starvation and refeeding for different days. The changes of character, the body component , the physiological and biochemical index of blood and the digestion enzyme activity have been studied in kingtrout juvenile. Countermeasure and mechanism of compensatory growth have been discussed. The result is as follows:After starvation, the body weight, length , hepatosomalic index , corldition factor and specific growth rate in the experimental group decrease. The body weight, hepatosomalic index , corldition factor and specific growth rate are sensitive to starvation while the body length is not sensitive to starvation. After refeeding, the body character is no significant difference except for body weight compared with control group. In the period of refeeding, the growth speed of starvation group all exceeds the control group. The change of feeding rate is not obvious and that of food conversion efficiency is very obvious.After starvation, the content of moisture and ash of kingtrout juvenile ascends while the content of muscle glycogen and liver glycogen descends. After refeeding, the body component is no significant difference except for muscle glycogen compared with control group. The results indicate that the liver is the main organ stores energy of kingtrout juvenile and the fish can use glycogen as energy sources; What first uses is the glycogen and then it is the fat in hunger; The fish first uses the liver glycogen and then the muscle glycogen in hungry; Kingtrout juvenile first accumulates the liver glycogen when it stores the energy material.After starvation, red blood cell count , hemoglobin , hematocrit and erythrocyte sedimentation rate of kingtrout juvenile levels decline significantly while white blood cell count shows a downward trend; after refeeding, the physiological index of the blood returned to the level with no significant difference compared with control group. After starvation, the glucose level of blood declines significantly and it declines faster in the early period of starvation while later it maintains a certain level. Total cholesterol o and triglyceride levels are similar sawtooth-shaped ladder decline The total protein content of the blood did not change significantly. After refeeding, the biochemical index of the blood returned to the level with no significant difference compared with control group.After starvation, the activities of protease , trypsin and alanine aminotransferase of digestive tract in kingtrout juvenile all decrease. And they all fall faster in the early period then later fall slower. Lipase activity decreased after the first of increased while amylase activity first increased and then decreased. After refeeding, the activities of amylase and lipase are on the rise compared to before, but amylase activity on the whole is still below the same period in the control group while lipase activity is higher compared with control group . The activities of protease , trypsin and alanine aminotransferase return to the level with no significant difference compared with control group. They basically have not changed, and have remained stable condition. The distribution orderliness of different digestive enzymes activities in the digestive tract is: protease and trypsin activities are highest in stomach and pyloric, secondly in intestines ,thirdly in hepatopancreas. Amylase activity is highest in intestines, secondly in pyloric, thirdly in stomach , fourthly in hepatopancreas. Lipase activity is highest in intestines, secondly in stomach and pyloric , thirdly in hepatopancreas.It could be seen from the change of body weight and specific growth rate that kingtrout juvenile shows partially compensatory growth. It could be seen from the change of food conversion efficiency and feeding rate that the partially compensation growth is mainly due to increased food conversion efficiency. Starvation should be avoided or reduced in breeding process of kingtrout . It has important significance to feeding kingtrout by scientific using of this physiological phenomenon.更多还原