Determination of acute toxicity of ammonium in juvenile Patagonian blenny (Eleginops maclovinus)

Abstract Deionized ammonium (NH3) acute toxicity (LC50-96h) in Patagonian blenny juveniles (Eleginops maclovinus) was assessed. Concentrations of deionized ammonium in salt water were prepared by using 24.09 ± 2.1 g ammonium chloride (NH4Cl). Fish were exposed in triplicates to different ammonium concentrations: 0.05; 0.094; 0.175; 0.325 and 0.605 mg NH3 L-1. Additionally, a control group was included. Experimental fish were kept at a photoperiod of 16:8h. Average temperatures were 16.24 ± 1.40 °C. Oxygen concentration was 7.16 ± 0.40 mg L -1. Water pH was 7.89 ± 0.2. LC50-96 h, was estimated by using Probit statistical method (95% intervals) using EPA software (1993). Juveniles of E. maclovinus showed a LC50-96h of 0.413mg NH3 L-1 value, different from most marine species. This study presents the first record of ammonium toxicity in marine species of Chile.

摘要：本研究对巴塔哥尼亚鳚（Eleginops maclovinus）幼鱼的游离氨（NH3）急性毒性开展评估，即96小时半数致死浓度（LC50-96h）。本研究以24.09±2.1 g氯化铵（NH4Cl）配制盐水中的氨浓度梯度。实验鱼以三重重复实验组的方式，暴露于5组不同浓度的氨环境中，浓度分别为0.05、0.094、0.175、0.325及0.605 mg NH3·L⁻¹，同时设置空白对照组。实验期间，鱼群维持16:8小时的光周期，平均水温为16.24±1.40℃，溶氧浓度为7.16±0.40 mg·L⁻¹，水体pH值为7.89±0.2。本研究采用概率单位统计法（95%置信区间），结合美国环境保护署（EPA，1993）开发的软件估算LC50-96h。结果显示，巴塔哥尼亚鳚幼鱼的LC50-96h为0.413 mg NH3·L⁻¹，该结果与多数海洋鱼类的毒性阈值存在显著差异。本研究为智利海域海洋鱼类氨毒性相关研究的首次报道。