Suski C D, Kieffer J D, Killen S S, Tufts B L
Department of Biology, Kingston, Queen's University, Canada ON K7L 3N6.
Comp Biochem Physiol A Mol Integr Physiol. 2007 Mar;146(3):381-9. doi: 10.1016/j.cbpa.2006.11.005. Epub 2006 Nov 24.
Guidelines for ammonia toxicity in fish are often determined using static exposure tests with immature fish over a 96-h period. These results may not be relevant to aquaculture, hauling or angling tournament scenarios where mature fish can be exposed to ammonia for shorter durations, often following additional stressors such as handling. The current study sought to quantify (1) the impact of ambient ammonia on the ability of largemouth bass to recover from exercise, (2) the behavioural response of largemouth bass to elevated ambient ammonia and (3) the concentration of ammonia that can accumulate in a live-release vessel at an angling tournament. After approximately 3 h, total ammonia (T(amm)) concentrations in a live-release vessel at an angling tournament were almost 200 muM. Exposure of fish to 1000 microM T(amm) (a value approximately 80% below the criteria maximum concentration for largemouth bass) caused significant reductions in ventilation rates, and increases in erratic swimming and irregular ventilation. Exposure to 100 microM T(amm) impaired the ability of largemouth bass to recover from exercise relative to fish recovering in fresh water. Therefore, sub-lethal ambient ammonia concentrations cause physiological disturbances that can impair the recovery of largemouth bass from exercise.
鱼类氨毒性指南通常是通过对幼鱼进行96小时的静态暴露试验来确定的。这些结果可能与水产养殖、运输或钓鱼比赛场景无关，在这些场景中，成熟鱼类可能在较短时间内接触到氨，通常是在经过诸如处理等额外应激源之后。本研究旨在量化：（1）环境氨对大口黑鲈运动后恢复能力的影响；（2）大口黑鲈对环境氨升高的行为反应；（3）钓鱼比赛中活鱼放生容器中可能积累的氨浓度。大约3小时后，钓鱼比赛中活鱼放生容器中的总氨（T(amm)）浓度几乎达到200μM。将鱼暴露于1000μM T(amm)（该值比大口黑鲈标准最大浓度低约80%）会导致通气率显著降低，以及不规则游泳和不规律通气增加。相对于在淡水中恢复的鱼，暴露于100μM T(amm)会损害大口黑鲈运动后的恢复能力。因此，亚致死环境氨浓度会引起生理紊乱，从而损害大口黑鲈运动后的恢复。
