不同卤虫混养比例对生物絮凝系统凡纳滨对虾标粗效果的影响

Effect of different Artemia mixed feeding ratio on nursing Litopenaeus vannamei in seawater bioflocs system

在生物絮凝凡纳滨对虾养殖系统中,分别以100%、50%、0%的比例投喂活的卤虫幼体(Artemia spp)和饲料(分别记为A组,AF组和F组),研究其对养殖过程中氮素转化途径及转化效率的影响。卤虫以湿质量计算,饲料以干质量计算。试验结果显示,A组亚硝酸盐浓度显著低于另外2组(P<0.05);各组氨氮浓度在养殖第7天时达到峰值,此后迅速降低并维持在1 mg/L以下,3组之间差异不显著(P>0.05);3组硝酸盐浓度均无积累,且略有下降;养殖30 d后,A组对虾存活率(35.67%)显著高于其余两组(均低于30%)(P<0.05);A组对虾终末平均体质量为(1.92±0.96)g,显著低于AF组的(2.99±1.85)g和F组的(3.25±1.23)g(P<0.05),原因可能是卤虫的营养成分相比配合饲料较为单一。

Biofloc technology involves the manipulation of C/N ratio to convert toxic nitrogenous wastes into useful microbial protein and helps in improving water quality in a closed system.The effect of nursery shrimp Litopenaeus vannamei with different ratios of Artemia in seawater bioflocs system was investigated in the experiment.Three groups were designed:shrimp in the first group were fed with 100%Artemia,referred as A group;shrimp in the second group were fed with 50%Artemia and 50%formulated feed,referred as AF group;shrimp in the last group were fed with 100%formulated food,referred as F group.During the 30 days nursery period,the concentration of nitrite nitrogen in the water of A group was significantly lower than that of the other two groups(P<0.05).No significant difference in the ammonium nitrogen concentration among the three groups(P>0.05).No obvious accumulation of nitrate in the three groups was found during the 30 days period.The survival rate of shrimp in A group(35.67%)was significantly higher than that of the other two groups.However,the average body weight of shrimp in the A group was only(1.92±0.96)g,which was significantly lower than that of AF group[(2.99±1.85)g]and F group[(3.25±1.23)g].