罗氏沼虾与三角帆蚌、鲢和鳙混养模式优化

研究了罗氏沼虾、三角帆蚌、鲢和鳙不同混养系统的养殖产量、饲料系数、增长率、总氮(TN)/总磷(TP)利用率和综合养殖效果,以期获得最优养殖模式。采用基于陆基围隔的比较实验方法,设6个实验组,分别为罗氏沼虾单养(G),罗氏沼虾与三角帆蚌二元混养(GH2)、罗氏沼虾、鲢和鳙三元混养(GSB),罗氏沼虾、鲢、鳙和三角帆蚌按照不同密度放养的四元混养(GSBH1、GSBH2和GSBH3),各实验组设置4个重复。结果表明:GSBH2组罗氏沼虾产量最高(14.71±0.33)kg/32 m2],显著高于G组(12.44±0.60)kg/32 m2,P0.01];GSBH1组饲料系数最低(1.43±0.04);GSBH1组增重率最高(4.66%±0.12%),G组最低(3.80%±0.23%);TN平均相对利用率在(0.92±0.09)~(1.60±0.23)之间,GSB组最高,G组最低;TP平均相对利用率为(0.23±0.03)~(1.46±0.32),GSBH3组最高,G组最低;综合养殖效果指数在(0.91±0.02)~(1.25±0.05)之间,GSB组最高,GSBH1组次之,G组最低,且三元、四元混养组显著大于G组和GH2组(P0.05)。研究表明,混养组能显著提高罗氏沼虾养殖的经济效益和生态效益。

Experimental study on structure optimization for polyculture of giant freshwater prawn with triangle sail mussel, silver carp and bighead carp

This investigation was designed to find out the best polyculture mode of giant freshwater prawn (Macrobrachium rosenbergii, GFP) pond. The culture output, feed coefficienct (FC), growth rate, use efficiency of nitrogen and phosphorus, and integrated farming effect in land-based enclosures, with different culturing combination of Macrobrachium rosenbergii, triangle sail mussel (Hyriopsis cumingii), silver carp (Hypophthalmichthys molitrix) and bighead carp (Hypophthalmichthys nobilis) were studied. There were six treatments, i.e., GFP monoculture enclosure (G), GFP polyculture enclosure with silver carp and bighead carp (GSB); GFP polyculutre enclosure with triangle sail mussel (GH2); and three other GFP polyculture treatments with different proportion of stock density of giantfreshwaterprawn, silver carp, bighead treatment and triangle sail mussel (GSBH1, GSBH2 and GSBH3). Four replicates of enclosure were applied for each treatment. The results indicated that the culture output of giant freshwater prawn ranged from 14.71±0.33kg/32m2 to 12.44±0.60kg/32m2 with the highest yield for treatment GSBH1, which was significantly higher than that for treatment G (P<0.01). Growth rate ranged from 3.80±0.23% to 4.66±0.12%, with the highest growth rate for treatment GSBH1 and the lowest growth rate for treatment G. The mean use efficiency of nitrogen ranged from 0.92±0.09 to 0.09±1.60, with the highest for treatment GSB and the lowest for treatment G. The synthetic efficiency index used for assessing integrated farming effect ranged from 0.91±0.02 to 1.25±0.05, with the lowest for treatment G and the highest for treatment GSB, and with significant difference between treatment G and treatment GH2. In summary, the polyculture treatments obviously improve economic profits and ecological benefits of culutre of the giant freshwater prawn compared with monoculture treament.