半封闭和全封闭循环水养殖南美洲鳗鲡的效果比较

Comparison of effects of semi-enclosed and enclosed recirculating aquaculture of Anguilla rostrata

为提升循环水养殖南美洲鳗鲡(Anguilla rostrata)的节水、水质与养殖效果,通过增加移动床生物膜反应池等单元,对半封闭循环水养殖系统进行升级,建立全封闭循环水养殖系统,并开展养殖对照试验,试验为期180 d。结果显示:全封闭循环水养殖(处理组)的单产、结束尾重、尾日增重和日水循环利用率分别为62. 8 kg/m^3、621. 7 g、3. 28 g和92%,较半封闭循环水养殖(对照组),分别提高了15. 4%、15. 5%、16. 3%和73. 3%(P <0. 05);处理组的饲料系数1. 55,显著低于对照组12. 5%(P <0. 05);处理组的总氮、硝酸盐氮、亚硝酸盐氮、氨氮、活性磷和总磷质量浓度分别低于对照组14. 8%、37. 0%、42. 6%、79. 1%、17. 9%和15. 6%(P <0. 05)。全封闭循环水养殖南美洲鳗鲡较半封闭循环水养殖具有提高水循环利用率、改良水质、提高单产和生长速度以及降低饲料系数和发病率等优点。

To improve the water saving,water quality and culture effects of recirculating aquaculture of Anguilla rostrata,one semi-enclosed recirculating aquaculture system was upgraded to construct the enclosed recirculating aquaculture system by adding the units such as moving bed biofilm reaction pool,and comparative experiments on aquaculture were carried out with a duration of 180 d.Results showed that the yield per unit,final weight,final weight increment and daily water recirculation rate of enclosed recirculating aquaculture(treatment group)were 62.8 kg/m^3,621.7 g,3.28 g and 92%respectively,which were 15.4%,15.5%,16.3%and 73.3%more than semi-enclosed recirculating aquaculture(control group)respectively(P<0.05);feed coefficient in the treatment group was 1.55,significantly 12.5%less than the control group(P<0.05);the concentrations of total nitrogen,nitrate nitrogen,nitrite nitrogen,ammonia nitrogen,labile phosphorus and total phosphorus in the treatment group were respectively 14.8%,37.0%,42.6%,79.1%,17.9%and 15.6%less than the control group(P<0.05).Compared with semi-enclosed recirculating aquaculture,enclosed recirculating aquaculture of Anguilla rostrata had the advantages of improving water recirculation rate,improving water quality,increasing yield per unit and growth rate,and reducing feed coefficient and morbidity.