导　　师： 林学群

学科专业： 083001

授予学位： 硕士

作　　者： ;

机构地区： 汕头大学

摘　　要： 2001年12月到2002年3月在19～24℃条件下对鲮魚/(初始体重：88.86±5.92g/)和鲻鱼/(初始体重：204.42±23.14g/)进行了不同时间的限食处理后再充分投喂的恢复生长实验。结果表明： 限食状态下，鲮鱼和鲻鱼的体长，全长，体重均下降，但与饱食组无显著差异，表明体长、全长、体重指标虽然能不同程度反映鱼体的营养状况，但并不是营养好坏的准确指标。而鲮鱼和鲻鱼的比肝重饥饿组在限食的第一周即已下降到与饱食组有显著差异。再充分投喂两周后，比肝重即迅速恢复到与饱食组无显著差异。这也说明比肝重在鲮魚的形态学指标中是非常敏感的。至于丰满度，在限食过程中，饥饿组鲻鱼与饱食组差异显著，而鲮鱼一直没有出现显著差异。推测出现这种现象可能与鱼体大小有关。鲮鱼在限食过程中，其SGR为负，出现负增长，当恢复投喂四周后，饥饿组SGR升高到1.1±0.2，半饱组SGR达到1.06±0.26，比对照组0.65±0.53高得多。而恢复投喂八周后，饥饿组和半饱组均降至正常水平。 在限食中，不同鱼种各营养成份被动用的先后次序及比例不同，甚至饥饿的不同时期能源动用的成份也不一样。 在限食和再充分投喂过程中，鲮魚和鲻鱼血液生化指标变化明显，鲮鱼血糖、血脂在限食第一周，血蛋白在限食第二周，限食组即显著低于饱食组，鲻鱼血糖、血蛋白在第一周，血脂在第二周，饥饿组降至与饱食组有显著差异，而在再充分投喂两周后，三项指标均恢复到与饱食组没有显著差异。这表明鲮魚和鲻鱼在动用体内能源物质时，血液生化指标能很好的反映鱼体营养状况的好坏。 鲮魚在饥饿的第一周，肝糖原和肌糖原迅速下降，与饱食组有显著差异，而肝脂肪直到饥饿的第四周才有显著差异，肌脂肪、肝蛋白和肌蛋白则都与饱食组无显著差异，在鲻鱼中，也有类似的现象，重喂后，肝糖原、肌肉糖原和肝脂肪均很快恢复到饱食组水平。这表明鲮魚和鲻鱼能很好的利用糖原作为能源物质，其次为脂肪，而蛋白含量变化不明显。从结果中也可以看出鲮魚和鲻鱼动用肌肉生化成分和动用肝脏生化成分相比有一定的滞后性。 饥饿一个月后鲮鱼和鲻鱼肝细胞所含的细胞器总数目减少，核周粗面内质网含量降低，线粒体出现多种形状，其间电子密度较低，嵴更加稀疏，溶解，无全嵴。 鲮鱼在饥饿后一个月，其肝细胞最大的变化肝细胞内的糖原几乎消失，出现大量的溶酶体。 鲻鱼在饥饿一个月后，其肝细胞内的大脂滴基本消失。 重喂后，鲮鱼的糖原大量出现，占据细胞大量空间，而鲻鱼脂滴亦大量出现，比一直投喂组脂滴更大，更多。表明鱼类在一段时间的饥饿胁迫之后，能过量的贮存一些能源物质。 在限食后再充分投喂，鲮魚的摄食率有一定的提高，但并不显著，其饲料效率则显著提高，几乎为饱食组的两倍，因此，鲮魚的补偿生长主要是饲料效率提高的缘故，这对鲮魚的水产养殖或许有十分重要的意义。 Compensatory growth of mud carp/(Cirrhinus chinensis Giinther/) and mullet /(Mugil cephalus Linnaeus/), following 4 weeks of feed deprivation or ration restriction, were studied at Nan'ao Marine Biology Station, Shantou, China ,between December,2001 and March,2002. In the study, the control group was fed to satiation once a day during the 12-week experimental period. The other two groups were deprived or restricted from feed for 4 weeks and then were fed to satiation for 8 weeks. The blood, liver, and white muscle were sampled from six fish each time at weeks 0,1,2,4 in the period of feed deprivation or ration restriction, and at weeks 2,4,8 in the re-feeding period, respectively. The body length, entire length and body weight in mud carp and mullet were decreased but no significant compared with those in full ration during feed deprivation or ration restriction. These results showed that body length, entire length and body length were not good indices for nutritious condition of fishes. On the contrary, hepatosomatic index of the two fishes decreased significantly after one-week feed deprivation and ration restriction, which recover to the level of the feds only in two-week refeeding. The result showed that hepatosomatic index was very sensitive among body parameters in fishes. As for condition factor, there were significant difference in mullet but not in mud carp, which is probably due to the difference of body weight in the two fishes. During feed deprivation or ration restriction period, the SGR in mud carp is negative, indicating negative growth in mud carp, however after four-week refeeding, the SGR of starved and ration restriction group reach 1.1 0.2 and 1.06 0.26, respective ly, much higher than 0.65 0.53 in the control group. It had been found that energy materials were used up in different levels after starvation or ration restriction, and different starvation or ration restriction time could lead to different consumption. The content of plasma glucose, lipid at week 1, plasma protein at week 2 in mud carp, and that of plasma glucose, protein at week 1, plasama lipid at week 2 in mullet decreased rapidly in the period of feed deprivation or ration restriction. After refeeding for 4 weeks, all biochemical composition in blood plasama were recovered to the levels of the fed controls. These results indicated biochemical parameters in blood were sensitive for feed deprivation or ration restriction. After starvation for one or two weeks, the content of the glycogen in liver and white muscle, and that of liver lipid decreased rapidly, however, the lipid content in white muscle and protein content in liver and white muscle had no significant difference from the controls. After re-feeding, all the above parameters in liver and white muscle were recovered to the levels of the controls. The phenomena had been found in mullet also. The results suggested that mud carp and mullet can take good advantage of glycogen, subsequent lipid as energy material. The hepatic ultrastructure in mud carp and mullet had some changes after starvation: the total number of cell organelles, the number of Rough Endoplasmic Reticulum and mitochondria decreased and the latter appeared atrophy and had all kinds of forms. In mud carp, the most significant difference compared with the controls was that the number of lysosome increased dramatically and almost all glycogen disappeared. In mullet, that was the number of lipid drops decreased significantly. After refeeding for 4 weeks, the quantity of cell organelle, Rough Endoplasmic Reticulum, glycogen and lipid rose again, however, the number of lysosome fell significantly. These phenomena demonstrated that the types, the quantities and the forms of cell organelles are closely related to the metabolism of hepatocyte. After feed deprivation or ration restriction for 1 week, the food conversion efficiency in mud carp was almost double of the control groups but the change of ration level was not significant. The results suggested that the mechanism of compensatory growth

关 键 词： 鲮鱼 鲻鱼 限食 重喂 形态形状 生化组成 超微结构 补偿生长

分 类 号： [S917]

领　　域： [农业科学]