饲养密度对银鲳幼鱼增重率及消化酶活性的影响

Effects of rearing density on growth rate and digestive enzyme activity of juvenile Pampus argenteus

研究了饲养密度对银鲳(Pampus argenteus)幼鱼(5.33±0.07 g)增重率及消化酶活性的影响。实验共设4组饲养密度,分别为5、10、15、25 ind.m-3,依次编为D1、D2、D3、D4组,实验周期为60 d。研究结果显示,饲养密度对银鲳幼鱼的增重率具有显著性影响,4组密度组中以D3组银鲳的增重率最高,且均显著高于其它3组密度组(P<0.05)。最高密度组(D4组)的增重率与D2组无显著性差异(P>0.05),但两组的增重率均显著高于D1组(P<0.05)。4组密度组间银鲳胃蛋白酶活性并无显著性差异,但胰蛋白酶、脂肪酶和淀粉酶活性则在不同密度组间呈现出显著性差异。胰蛋白酶与脂肪酶活性均在D3组达到最高值,且均显著高于其它各密度组(P<0.05)。D3和D4组的淀粉酶活性显著高于D1和D2组(P<0.05)。综合分析可知,饲养密度可显著影响银鲳幼鱼的增重率与消化酶活性,本实验条件下的适宜饲养密度范围内(15 ind.m-3左右),银鲳幼鱼具有较好的生长速度及较高的消化酶活性。

The aim of this work was to evaluate the effects of rearing density on growth rate and digestive enzyme activity of juvenile Pampus argenteus （5.33 ±0.07 g）. The fish were kept at the densities of 5, 10, 15 and 25 ind . m-3 （named D1, D2, D3 and Dd, respectively） for 60 days. The results showed that the growth rate of Pampus argenteus was affected significantly by rearing density. Among the four groups, the growth rate of D3 group was the highest, and was significantly higher than those of other three groups （P 〈 0.05 ）. No significant difference was found in growth rate between D4 and D2 groups （ P 〉 0.05 ）, while the growth rates of D4 and D2 groups were both significantly higher than that of D1 group （ P 〈 0.05 ）. Theresults of digestive enzyme activity showed that, there was no significant difference in pepsin activity among 4 groups. However, significant differences were found in trypsin, lipase and amylase activity among different groups. The trypsin and lipase activity of D3 were the highest among the 4 groups, and were significantly higher than those of other groups, respectively （P 〈 0.05）. And also, the amylase activity of D3 and Dg groups were significantly higher than those of D1 and D2 groups （P 〈 0.05）. In general, the growth rate and digestive enzyme activity of silver pomfret could be significantly affected by the rearing density, and at the optimum density （ 15 ind m -3 ）, silver pomfret could have higher ~rowth rate and dizestive enzvma activity