放养密度对池塘养殖施氏鲟幼鱼生长和肌肉成分的影响

Effects of Stocking Density on Growth and Muscular Composition in Amur Sturgeon Acipenser schrenckii in Pond Culture

在24.4℃~19.2℃下,运用陆基围隔实验生态学方法,研究在静水土池塘养殖条件下放养密度对施氏鲟Acipenser schrenckii幼鱼生长的影响。将初始体质量(54.86±10.19g)的施氏鲟幼鱼饲养在高密度双面涂塑的聚乙烯编织步制成的面积16m2(4m×4m)、水深1.7m^1.9m围隔中46d,放养密度为2000、3000、4000和5000尾/667m2。结果显示:试验鱼终末体质量、特定生长率、增重率、成活率随放养密度的增大显著降低(P<0.05),饲料系数随放养密度的增大显著升高(P<0.05),产量在放养密度为4000尾/667m2时最高,为352.27±22.38kg/667m2。肌肉中粗蛋白质和粗脂肪含量随放养密度的增加而显著降低(P<0.05),水分和灰分含量的变化不显著(P<0.05)。研究表明:静水土池塘养殖施氏鲟幼鱼(50g左右)的适宜放养密度为3000~4000尾/667m2。

The effects of stocking density on growth and muscular composition in Amur sturgeon Acipenser schrenckii in pond-culture were studied at water temperature of 24.4℃-19.2℃ by an enclosure-experimental method. Juvenile Amur sturgeon with initial body weight of （54.86± 10.19）g were reared in a 16 m2 enclosure made of plastic disposed in an earthern pond at an initial stocking density of 2000 ind./667m2, 3000 ind./667m2, 4000 ind./667m2, or 5000 ind./667m2 for 46 days. The results showed that there were significant decrease in weight increment, specific growth rate, weight gain rate, and survival rate and increase in the food conversion ratio in the juveniles with increasing stocking density （P〈0.05）. The maximal yield per unit area [（ 352.27±22.38 ）kg/667m2] was found at a stock density of 4000 ind./667m2. At the end of the experiment, the crude protein content and crude lipid content were found to be significant decreased （P〈0.05） in muscles, without significant difference in moisture and ash content （P〉0.05）. It is suggested that 3000-4000 ind./667m2 be the optimal stocking density for Amur sturgeon weighting about 50g in pond culture.