不同性别养殖金钱鱼生长性能及消化酶活性的比较

Growth performance and digestive enzyme activity between male and female Scatophagus argus

以金钱鱼为对象,测定1龄雌、雄个体日摄食量(IDF)、特定生长率(SGR)、食物转化率(FC)、性腺成熟指数(GSI),及不同年龄阶段(1龄以下、1～2龄和2龄以上)金钱鱼胃、肝胰脏和肠等组织中胃蛋白酶、胰蛋白酶、淀粉酶和脂肪酶的比活力。结果显示:雌性金钱鱼日摄食量、特定生长率和食物转化率均显著高于雄鱼(P<0.05);3-5月期间雌、雄金钱鱼GSI均上升,且实验结束时(5月底)雌鱼GSI显著大于雄鱼(P<0.05)。对不同年龄阶段雌、雄金钱鱼消化酶比活力的研究发现,1龄以下和1-2龄组金钱鱼,雌鱼胃蛋白酶、胰蛋白酶(后肠除外)、肝胰脏和前肠淀粉酶比活力均显著高于雄鱼(P<0.05),而2龄以上金钱鱼雌鱼上述消化酶及各年龄阶段脂肪酶比活力与雄鱼相比均无显著差异(P>0.05)。雌、雄金钱鱼胃蛋白酶、胰蛋白酶、淀粉酶在不同年龄阶段的比活力均表现为1龄以下组>1-2龄组>2龄以上组,而脂肪酶表现为2龄以上组>1-2龄组>1龄以下组,且1龄以下与2龄以上组(除个别组织外)有显著差异。结果表明2龄以下雌性金钱鱼生长快于雄鱼与其具有较高的摄食量、食物转化率及较高的蛋白酶和淀粉酶活性有关,而2龄以上金钱鱼雌、雄间生长速度出现差异与消化酶活性无关。

In the present study, we investigated the individual day food consumption （IDF）, specific growth rate （SGR） , food conversion （FC） , and gonadosomatic index （GSI） between males and females Scatophagus argus 1 year old, as well as activities of trypsin, amylase and lipase in stomach, hepatopancreas and intestinae in S. argus below 1 year old, 1 -2 years old, and above 2 years old. Result showed that individual day food consumption, specific growth rate and food conversion in female S. argus was significantly higher than males （ P 〈 0.05 ）. GSI increased from March to May, and a significantly higher GSI could be found in females at the end of experiment. Pepsin in stomach, amylase and trypsin （except hindgut ） in hepatopancreas and intestinae exhibited higher activities in females than males in below 1 year old and 1 -2 years old fish , but no difference was found in lipase, pepsin, amylase and trypsin between males and females S. argus above 2 years old. Activities of pepsin, trypsin and amylase were highest in fish below 1 year old, then in 1 -2 years old, and the lowest in that above the 2 years old. However, a reverse trend was found in lipase, and a significant difference was found in the above enzymes （ except some tissues） between 1 year old and 2 years old fish. Results suggested that faster growth rate in females S. argus below 2 years old than males was related to the higher IDF, FC and activities of protease and amylase, but that in fish above 2 years old had nothing to do with digestive enzyme.