全封闭循环水养殖系统中养殖密度对钝吻黄盖鲽生长的影响

Effects of stocking density on the growth performance of Pseudopleuronectes yokohamae reared in full-closed recirculating aquaculture system

摘要:

为了评估全封闭循环水养殖系统中养殖密度对钝吻黄盖鲽生长的影响及水质变化情况,将体质量为(250.00±50.83)g的钝吻黄盖鲽分成8个试验组(放养密度分别为18、22、26、30、34、38、42、46 kg/m³),进行了3个月的饲养试验,检测不同养殖密度下鱼的成活率、体质量增长率及饲料系数,同时对试验期间氨氮、亚硝酸盐和溶解氧等各项水质指标的动态变化进行监测。试验结果显示,各试验组鱼的成活率均达到96%以上,但随着养殖密度的增加,钝吻黄盖鲽的成活率总体呈现降低的趋势；低密度组(18 kg/m³)的体质量增长率最高,为36.1%,高密度组(46 kg/m³)的体质量增长率最低,为24.8%,且体质量增长率随着养殖密度的增加而逐渐降低；随着养殖密度的增加,饲料系数呈逐渐升高的趋势；养殖期间各项水质指标均保持在适宜钝吻黄盖鲽生长的范围内。结果表明,在本试验的循环水养殖系统中,综合考量养殖生长指标及单位面积产量,钝吻黄盖鲽规模化生产的最适养殖密度为42～46 kg/m³。

Abstract:

In order to evaluate the effects of stocking density on growth performance and physiological response of Pseudopleuronectes yokohamae reared in a full-closed recirculating aquaculture system(RAS),feeding experiments were conducted with 8 different stocking densities of P. yokohamae[average body weight,(250.00±50.83) g] for 3 months.The eight different stocking densities were 18,22,26,30,34,42,46 kg/m³,respectively.The dynamic changes of various water quality indexes such as ammonia nitrogen,nitrite and dissolved oxygen were monitored during the experiment.The results showed that all water quality indexes were kept within the suitable range for the growth of P. yokohamae and the survival rates were all above 96%.However,the survival rate and body weight growth rate of P. yokohamae decreased with the increase of stocking density.The body weight growth rate of the low density group(18 kg/m³) was the highest(36.1%) and the body weight growth rate of the high density group(46 kg/m³) was the lowest.The feed conversion ratio showed an increased trend with the increase of stocking density.Based on the comprehensive evaluation of growth performance and aquaculture efficiency,the optimal breeding density for large-scale production of P. yokohamae was 42-46 kg/m³ in the recirculating aquaculture system.