【作者】 王晴晴；

【导师】 李吉方；

【作者基本信息】 中国海洋大学 ， 水生生物学， 2011， 硕士

【摘要】 本文研究了18摄氏度±2摄氏度条件下金鱼(平均初始体重36.78±3.08克)饥饿(分别饥饿7天、14天、21天)及恢复投喂不同时间的补偿生长状况。通过研究饥饿胁迫和恢复投喂对其形态性状指标、体组分和糖原、消化酶活性及组织学的影响,探讨了金鱼在饥饿胁迫下的适应性对策及其补偿机制。结果如下:饥饿后金鱼的体重、体长、肝体指数、肥满度和特定生长率均下降,其中体重和特定生长率对饥饿的反应很敏感,体长、肝体指数和肥满度对饥饿的反应不是很敏感;恢复投喂后各饥饿组的形态性状指标均与对照组无显著差异。恢复生长时期各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。饥饿胁迫使得各饥饿组的肝糖原、肌糖原含量和粗脂肪含量显著下降,水分含量上升,粗蛋白含量和灰分基本无变化。恢复投喂后各饥饿组生化指标除了粗脂肪外均恢复到与对照组无显著差异水平。金鱼在饥饿时,首先动用的是体内贮存的糖原,然后才是脂肪,最后可能会动用蛋白质。饥饿状态下脂类被用作能源物质,缺失部分被水分所取代。在恢复投喂时,各营养成分恢复的顺序是体内贮存的糖原,然后才是脂肪。饥饿胁迫使蛋白质含量,蛋白酶活性,类胰蛋白酶活性,脂肪酶活性有降低趋势,恢复投喂后,均有升高趋势,至实验结束,除肠蛋白酶活性一直高于同期对照组外,饥饿组活性基本等同于同期对照组。饥饿胁迫使淀粉酶活性有升高趋势,恢复投喂后至实验结束淀粉酶活均高于同期对照组。金鱼不同消化酶在消化道中的活性分布规律是:肠蛋白酶和类胰蛋白酶活性高于肝胰脏,肝胰脏淀粉酶活性高于肠;肠脂肪酶活性基本等同于肝胰脏。饥饿7天的金鱼肝胰脏和肠道组织学特征基本与对照组相同;而饥饿14天、21天的实验鱼组织变化较明显:肝细胞体积缩小,排列不规则,出现细胞间隙,细胞界限不清,核由细胞一侧变移至细胞中央。肠绒毛和上皮细胞的高度下降,肠上皮细胞的微绒毛不整齐。恢复投喂后各主要结构均有所恢复,有些恢复到饥饿前水平,但大部分未能达到。金鱼在饥饿和恢复投喂的过程中,体长、肝体指数和肥满度对饥饿的反应不是很敏感,体重和特定生长率对饥饿的反应较为敏感。从体重和特定生长率指标的变化可以看出金鱼的补偿生长方式为完全补偿生长,从摄食率和食物转化率的变化可以看出,其完全补偿生长主要是食物转化率提高所致。建议在金鱼的人工养殖过程中可以适当和适量的减少喂食,科学地利用补偿生长生理现象,对金鱼的养殖有着重要的意义。更多还原

【Abstract】 This study is about the compensatory growth of goldfish(average initial body weight 36.7275±3.08g)under 18±2℃after starvation and refeeding for different days. The changes of phological traits, the body component, the digestive enzyme activity and histology have been studied in goldfish; from which the countermeasure and mechanism of compensatory growth have been discussed. The result is as follows:After starvation, the body weight, length, hepatosomalic index, condition factor and specific growth rate in the experimental group decrease. The body weight and specific growth rate are sensitive to starvation while the body length, hepatosomalic index and condition factor is not. After refeeding, the body character is no significant difference 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 but the food conversion efficiency is high.After starvation, the content of moisture of goldfish ascends and the content of liver glycogen, muscle glycogen and content of fats descends, while the content of protein and ash doesn’t change. After refeeding, the body component is no significant difference except for content of fats compared with control group. The results indicate that glycogen is used first and then it is the fat in hunger, finally may be protein. Goldfish use fat as energy sources, the lost part is replaced by moisture. Goldfish first accumulates the glycogen when it stores the energy material,then is fat.After starvation, the activities of protease, trypsin and lipase of digestive tract in goldfish all decrease, whatmore after refeeding, the activities ascends. At the end of the experiment, the enzyme activities is significant difference compared with control group, except protease in intestines is higher than the control group. After starvation, the activities of amylase ascends. The activities of amylase is always higher than the control group after refeeding until the end of the experiment. The distribution orderliness of different digestive enzymes activities in the digestive tract is:protease and trypsin activities in intestines is higher than the activitie in hepatopancreas; Amylase activity in hepatopancreas is higher than the activitie in intestines; Lipase activity in hepatopancreas is same with the activitie in intestines.Intestines and hepatopancreas of goldfish after starvation for 7d is the same to the control group, while the fish after starvation for 14d and 21d change obviously: hepatocyte is irregular and diminishes, and intercellular space appears, cell boundary dims, the nucleus shift from one side of the cell to the center, the height of intestinal villus and epithelium descends. Microvilli of the intestinal epithelium is irregular. After refeeding,most primary structure resumes, some of the factors reurn to previous levels but most factors not.During starvation and refeeding of goldfish, the body weight and specific growth rate are sensitive to starvation while the body length, hepatosomatic index and condition factor is not sensitive to starvation. It could be seen from the change of body weight and specific growth rate that goldfish shows completely compensatory growth, It could be seen from the change of food conversion efficiency and feeding rate that the completely compensation growth mainly due to the increased food conversion efficiency. Starvation could be used in breeding process of goldfish appropriately and moderately. It is important to feeding goldfish by scientific using of this physiological phenomenon.更多还原