杂交青虾“太湖1号”苗种在池塘养殖中的适宜放养密度

The optimal stocking density of young hybrid oriental river prawn "Taihu No.1" in pond culture system

以饲料系数、养殖产量、成虾规格、体长与体质量特定生长率作为判据,水质状况作为参考,以杂交青虾"太湖1号"为实验对象,在放养密度为60、105、150、195、240尾/m35个梯度下进行为期100 d的养殖试验,研究杂交青虾"太湖1号"苗种在池塘养殖中的适宜放养密度。结果显示,150尾/m3组的饲料系数显著低于195尾/m3和240尾/m3组(P<0.05),而养殖产量及成虾规格显著高于其它各组(P<0.05)。在高于150尾/m3的高密度组中,虽然产量也显著高于低密度组(P<0.05),但成虾规格较小。养殖期间各养殖水体的水质均能满足养殖虾的生长需求;高温季节除了高密度组的亚硝态氮盐指标稍有升高以外,水体pH、DO、NH4+-N等指标基本保持一致。将放养密度分别与饲料系数、增重率、体长与体质量特定生长率等指标之间进行二次回归曲线方程拟合,计算出杂交青虾"太湖1号"的适宜放养密度为117～150尾/m3。

Young prawns of hybrid oriental river prawn ＂Taihu No. 1＂ were cultured at five stocking densities at 60, 105, 150, 195, 240 individuals er m^3 respectively for 100 days to test the optimal stocking density for hybrid oriental river prawn ＂Taihu No. 1＂ in the present study. The results showed that the group of 150 individuals/m^3 had significantly lower feed coefficient than the group of 195 and 240 （ P 〈 0.05 ）, but it had significantly higher culture yield and bigger size of a-duh prawns than the other groups （P 〈 0.05 ）. In the groups of stocking density higher than 150, although the culture yields were significantly higher than the groups of lower stocking density （ P 〈 0. 05 ） , they had smaller size of adult prawns. Water quality conditions at all stocking densities during the whole culture period could support the normal growth of oriental fiver prawns. At high femperatures, there were no significant differences in pH and the contents of DO and NH4^ ＋ -N among different stocking densities except that the contents of nitrite-nitrogen slightly increased at higher stocking densities. Quadratic regression analyses were conducted between stocking density and feed coefficient, weight gain rate, special length growth rate and special weight growth rate respectively, and the optimal stocking densities for hybrid oriental fiver prawn ＂Taihu No. 1＂ were 117 - 150 individuals per m^3 water.