不同溶氧水平下氨氮和亚硝酸盐对黄颡鱼的急性毒性研究

在高溶氧(10.77±0.40)mg/L、中溶氧(6.89±0.33)mg/L和低溶氧(3.45±0.54)mg/L水平下,研究了氨氮和亚硝酸盐对黄颡鱼急性毒性效应。结果显示:高溶氧水平下,氨氮和亚硝酸盐对黄颡鱼的96 h-LC50值(95%可信区间)分别为148.1 mg/L(125.03～172.37 mg/L)、206.52 mg/L(164.25～246.23 mg/L);在中等溶氧水平下,氨氮和亚硝酸盐对黄颡鱼的96 h-LC50值(95%可信区间)分别为106.69 mg/L(89.92～123.70 mg/L)、145.77 mg/L(116.77～174.77 mg/L);而低溶氧水平下,氨氮和亚硝酸盐对黄颡鱼的96 h-LC50值(95%可信区间)分别为68.03 mg/L(58.32～77.89 mg/L)、81.33 mg/L(64.76～96.70 mg/L)。结果表明,在3种溶氧条件下,氨氮对黄颡鱼的毒性明显大于亚硝酸盐对黄颡鱼的毒性,因而氨氮对黄颡鱼的毒性成为其养殖过程中的重要影响因子。

Acute toxic effects of ammonia and nitrite on yellow catfish (Pelteobagrus fulvidraco) at different dissolved oxygen levels

The acute toxic effects of ammonia and nitrite on yellow catfish(Pelteobagrus fulvidraco) were studied at high dissloved oxygen(10.77±0.40)mg/L,medium dissloved oxygen(6.89±0.33)mg/L,and low dissloved oxygen(3.45±0.54)mg/L.The results showed that the 96 h-LC50(95% confidence interval) of ammonia and nitrite to the yellow catfish were 106.69 mg/L(89.92~123.70 mg/L) and 145.77 mg/L(116.77~174.77 mg/L) respectively at medium dissolved oxygen level.While they were exposed to high dissolved conditions,the 96 h-LC50(95% confidence interval) of ammonia and nitrite increased to 148.1 mg/L(125.03~172.37 mg/L) and 206.52 mg/L(164.25~246.23 mg/L)respectively.When they were exposed to low dissolved conditions,the 96 h-LC50(95% confidence interval) of ammonia and nitrite decreased to 68.03 mg/L(58.32~77.89 mg/L) and 81.33 mg/L(64.76~96.70 mg/L) respectively.No matter at what dissolved oxygen conditions,ammonia was much stronger than nitrite in toxicity to yellow catfish.So ammonia in toxicity to the yellow catfish is one importent factor in aquaculture.