| 摘要: |
| 在封闭循环水高密度养殖条件下(平均密度14.1 kg/m2±0.51 kg/m2), 设置4 个流速梯度(200, 400,600, 800 L/h,分别以A～D 组表示), 挑选相近体质量(200.3g±7.6 g)的大菱鲆进行42 d 养殖试验, 每个梯度设置3 个重复, 每个重复55 尾鱼, 研究流速对封闭循环水养殖大菱鲆生长、摄食以及水质氮素的影响。试验结果表明: (1) 大菱鲆(Scophthatmus maximus L)特定生长率、增质量率、摄食量随流速增大先快速上升后缓升趋稳, 饲料系数则相反。B、C、D 3 组特定生长率、摄食量分别显著高于A 组30.77%～52.31%、17.30%～22.05%; 饲料系数则显著低于A 组13.83%～22.34%; (2) 养殖水体中总氨氮、非离子氨及亚硝酸氮浓度随流速的增大先快速下降后缓降趋稳。B、C、D 3 组水质总氨氮氨浓度均显著低于A 组53.70%～79.07%; (3) 根据流速对特定生长率、水体总氨氮二者的影响, 得出养殖的生态适宜流速为625 L/h。再结合流速对水循环动力的影响, 得出养殖的生态经济适宜流速为480 L/h。 |
| 关键词: 封闭循环水 流速 摄食 生长 水质 大菱鲆(Scophthatmus maximus L) |
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| 基金项目:国家高技术研究发展计划(863 计划) 重点项目(2006AA100305); 国家农业科技成果转化资金资助项目(2008GB2C100109) |
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| Effects of flow rate on the growth, feed intake and water nitrogen in a closed recirculation aquaculture system of turbots (Scophthatmus maximus L.) |
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| Abstract: |
| Effects of flow rate on the feed intake, growth and water quality of turbot culture were investigated in a closed recirculation aquaculture system. Fish with a mean initial weight of 200.3 g±7.6 g were reared at four different flow rates (200, 400, 600, 800L/h) in 400 L tanks for 42 days. Six hundred and sixty fish were randomly allotted in four treatment groups with three replicates for each treatment at a stocking density of 14.1 ± 0.51 kg/m2. Feed intake, specific growth rate and weight gain rate were increasing rapidly first and then slowly with the increase of flow rate, while food conversion rate showed a reverse pattern. The specific growth rate of group B, C, and D were significantly higher than group A by 30.77%～52.31%, while feed conversion rate ws lower than group A by 13.83%～22.34%. Concentrations of total ammonia nitrogen (TAN), unionized ammonia nitrogen (UIA-N), and nitrite (NO2--N) were decreased rapidly first and then slowly with the increase of flow rate. The ammonia nitrogen of group B, C, and D were significantly higher than group A by 53.70%～79.07%. The optimal ecological flow rate was calculated to be 625 L/h, based on the specific growth rate with total ammonia nitrogen in water. Another optimal ecological economical flow rate was calculated to be 480 L/h, based on the specific growth rate with power consumption and TAN in water. |
| Key words: closed recirculation aquaculture system flow rate feed intake growth water quality turbot (Scophthatmus maximus L) |
