高碱度和高氨对达里湖瓦氏雅罗鱼耗氧率和排氨率的影响

Effects of high carbonate alkalinity water and high ammonia water on oxygen consumption and ammonia excretion in Leuciscus waleckii Dybowski

采用静水密闭的方法,比较了体质量为(72.62±3.70)g达里湖瓦氏雅罗鱼(Leuciscus waleckii Dybowski,简称雅罗鱼)在高碱度(Na HCO350 mmol/L)和高氨(NH4CO31.5 mmol/L)胁迫下处理4个时间点(2 h、4 h、6 h和8 h)耗氧率和排氨率的变化。耗氧率实验结果表明:与淡水组相比,高碱度和高氨显著抑制了雅罗鱼的耗氧率(P<0.05);高碱度组与高氨组相比,雅罗鱼耗氧率除了在监测的第1个时间点内存在显著性差异外(P<0.05),其他时间点无明显差异(P>0.05)。排氨率实验结果显示:与淡水组相比,高碱度和高氨均显著抑制了雅罗鱼的排氨率(P<0.05)。其中高氨组排氨率在所监测的4个时间点内全部下降,并与淡水组和高碱度组相比存在极显著差异(P<0.01)。能量代谢研究发现,淡水组和高碱度组氧氮比均无显著差异(P>0.05);与淡水对照组和高碱度组比较,高氨组氧氮比差异极显著(P<0.01)。

Using hydrostatic water in sealed chamber for measurement, this study compared the change of oxygen consumption rate and ammonia excretion rate of Leuciscus waleckii Dybowski （72. 62 ± 3.70） g exposed in high carbonate alkalinity water （ CA 50 mmol/L） and high ammonia water （NH4CO3 1.5 mmol/L） for 4 time points （2 h, 4 h, 6 h and 8 h） measurement. Oxygen consumption rate was significantly inhibited in carbonate alkalinity water and high ammonia water when compared that in fresh water （ P 〈 0. 05 ）. No significant difference of the oxygen consumption rate between carbonate alkalinity and ammonia water treated fish was detected for the last three tested time points, 4, 6, and 8 except for the first testing time point. Results of ammonia excretion rate showed that com- pared with those in fresh water, the ammonia excretion rate of fish exposed in carbonate alkalinity water and ammonia water was signifi-cantly inhibited （ P 〈 0. 05 ）. In ammonia water, the ammonia excretion rate of L. waleckii Dybowski for all 4 time points decreased, which had an extremely significant difference compared with fresh water and carbonate alkalinity water. Energy metabolism （O ： N） study found that there had no significant difference in oxygen-nitrogen ratio in fish between fresh water and carbonate alkalinity water. However, compared with fish in fresh water and carbonate alkalinity water, fish in ammonia water had an extremely significant differ- ence in oxygen-nitrogen ratio.