pH与氨氮对黄颡鱼幼鱼生长与肝脏超氧化物歧化酶的影响

Growth and hepatic SOD activity of darkbarbel catfish Pelteobagrus vachelli under influences of water pH and ammonia nitrogen

为了解不同水体pH和氨氮组合对瓦氏黄颡鱼(Pelteobagrus vachelli)特定生长率(SGR),饲料效率(FE)和肝脏超氧化物歧化酶(SOD)活力的影响。实验采用中心复合设计与响应曲面法分析方法,利用瓦氏黄颡鱼幼鱼开展试验,养殖周期为7周。结果表明,水体氨氮对SGR,FE和肝脏SOD活力有显著影响;pH对SGR有显著影响。pH对SGR,FE和SOD活力存在显著的二次效应。氨氮浓度小于1.7 mg/L时对黄颡鱼生长无抑制作用;高氨氮与高pH环境对幼鱼的生长、饲料利用与肝脏SOD活力有明显的抑制作用。水体pH和氨氮水平分别为7.5和1 mg/L时,SGR、FE和SOD同时最优,分别为1.47%/d、1.71和97.9 U/(mg.prot),优化的可信度为0.836。建议在黄颡鱼养殖中,将pH与水体氨氮维持在7.0~8.0与0.1~1.7 mg/L内,从而保证黄颡鱼的正常生长与较强的抗氧化活性。

The present study was performed to investigate the effects of pH （5-10）,ammonia nitrogen （AN）,and their interaction on the specific growth rate （SGR）,feed efficiency （FE） and activities of superoxide dismutase （SOD） in juvenile darkbarbel catfish Pelteobagrus vachelli by two-factor central composite rotatable design （CCD） with response surface methodology （RSM）.The experiment under laboratory conditions lasted for 7 weeks.The results showed the significant linear effect of ammonia nitrogen （AN） on SGR,FE and hepatic SOD activity.Meanwhile,there had significant linear effect of pH on SGR.The quadratic effects of pH on SGR,FE and SOD were significant.There had no inhibiting effect on growth when AN level was lower than 1.7 mg/L .However,high AN and low pH or high pH significantly reduced SGR,FE and hepatic SOD activity.The optimal combination of pH and AN was 7.5 and 1 mg/L,at which the higher growth,FE and hepatic SOD activity were 1.47%/d,1.71 and 97.9 U/（mg·prot）,respectively.The optimization credibility was 0.836.It is suggested that the pH and AN in water should be kept within the range of 7.0 to 8.0 and 0.1 to 1.7 mg/L in the culture of P.vachelli,respectively,which can ensure the normal growth and strong antioxidant activity.