混养鲫鱼对罗氏沼虾种虾培育效果的影响

在3口面积各为0.3 hm^2、深度2.0 m的长方形池塘(1#、2#、3#)中放入体长0.7～0.8 cm的罗氏沼虾"南太湖2号"无特定病原种虾,密度为3.0×10~5尾/hm^2;养殖30 d时,2#、3#池塘分别混养质量3～4 g/尾的鲫鱼450、900尾,1#池塘不混养作对照组。经过近110 d的培育,1#、2#、3#池塘"南太湖2号"种虾的平均体质量分别达18.36、18.95、22.6 g,收获量分别达931.5、898.4、842.95 kg,饵料系数分别为1.36、1.53和1.71。试验结果表明,罗氏沼虾"南太湖2号"种虾培育池塘混养合理密度的鲫鱼,虽然影响种虾养殖产量,饲料系数增大,但培育出的种虾个体较大,饱满度较高,作为亲本可以为后期育苗工作的顺利开展打下良好基础。

Effects of Polyculture of Crucian Carp on Growth of Malaysian Prawn Macrobrachium rosenbergii in a Pond

Malaysian prawn Macrobrachium rosenbergii "South Taihu No.2" SPF Shrimp with body length of(0.7—0.8) cm were reared in three rectangular ponds(1#, 2# and 3# ponds) of each 0.3 hm^2 with depth of 2 m at stocking density of 3.0×10~5 individuals/hm^2 for 30 days, and then crucian carp Carassius auratus with body weight of(3—4) g were polycultured with Malaysian prawn at a rate of 450 fish in 2# pond, 900 fish in 3# pond, and 0 fish in 1# pond as a control group for nearly 110 days. At the end of the experiment, South Taihu No.2 had final body weight of 18.36 g, with yield of 931.5 kg and food conversion ratio of 1.36 in 1# pond, final body weight of 18.95 g, with yield of 898.4 kg and food conversion ratio of 1.53 in 2# pond, and final body weight of 22.6 g, with yield of 842.95 kg and food conversion ratio of 1.71 in 3# pond. It is concluded that Malaysian prawn South Taihu No.2 has large final body weight, and high condition factor as broodstocks for seedling in the polyculture of South Taihu No.2 with crucian carp, in which there were relatively low yield and high food conversion ratio.