Sublethal exposure to copper supresses the ability to acclimate to hypoxia in a model fish species.
Sublethal exposure to copper supresses the ability to acclimate to hypoxia in a model fish species.
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亚致死接触铜会抑制模型鱼类适应缺氧的能力。
DOI：
10.1016/j.aquatox.2019.105325
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Fitzgerald JA
中科院分区：
文献类型：
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作者：
Fitzgerald JA
缺氧是水生生态系统生物多样性的主要威胁之一。缺氧与营养丰富的污水输入到水生系统的关联导致缺氧沃茨可能被包括金属在内的各种化学品污染的情况。尽管如此，很少有人知道鱼的能力，以应对缺氧时，暴露发生在环境毒物的存在。我们解决这一知识差距，通过调查暴露于不同水平的氧气在铜的存在或不存在下，使用三刺刺鱼（Gasterosteus aculeatus）模型的影响。将鱼暴露于不同的空气饱和度（AS; 100%，75%和50%）与铜（20 μg/L）的组合超过4天。急性低氧耐受性的指标临界氧水平（Pcrit）在对照条件下为54.64 ± 2.51%AS，在慢性低氧（50%AS）条件下暴露4d为36.21 ± 2.14%，显示了鱼类对低氧环境的适应能力。重要的是，额外暴露于铜（20 μg/L）阻止了Pcrit的这种改善，损害了缺氧适应。此外，与单一应激源或对照组相比，观察到铜和缺氧联合暴露的通气率增加。有趣的是，在暴露于铜的组中，在常氧和缺氧条件下，观察到个体之间测量的Pcritwas的变化大幅增加。如果在野生种群中观察到这种变异，可能会导致选择耐受表型和种群基因库的改变，从而影响其可持续性。我们的研究结果提供了强有力的证据表明，铜通过阻止驯化降低了鱼类对缺氧的反应能力，并将为预测全球其他污染物影响的水系统中缺氧全球增加的后果提供信息。
Hypoxia is one of the major threats to biodiversity in aquatic systems. The association of hypoxia with nutrient-rich effluent input into aquatic systems results in scenarios where hypoxic waters could be contaminated with a wide range of chemicals, including metals. Despite this, little is known about the ability of fish to respond to hypoxia when exposures occur in the presence of environmental toxicants. We address this knowledge gap by investigating the effects of exposures to different levels of oxygen in the presence or absence of copper using the three-spined sticklebacks (Gasterosteus aculeatus) model. Fish were exposed to different air saturations (AS; 100%, 75% and 50%) in combination with copper (20 μg/L) over a 4 day period. The critical oxygen level (Pcrit), an indicator of acute hypoxia tolerance, was 54.64 ± 2.51% AS under control conditions, and 36.21 ± 2.14% when fish were chronically exposed to hypoxia (50% AS) for 4 days, revealing the ability of fish to acclimate to low oxygen conditions. Importantly, the additional exposure to copper (20 μg/L) prevented this improvement in Pcrit, impairing hypoxia acclimation. In addition, an increase in ventilation rate was observed for combined copper and hypoxia exposure, compared to the single stressors or the controls. Interestingly, in the groups exposed to copper, a large increase in variation in the measured Pcritwas observed between individuals, both under normoxic and hypoxic conditions. This variation, if observed in wild populations, may lead to selection for a tolerant phenotype and alterations in the gene pool of the populations, with consequences for their sustainability. Our findings provide strong evidence that copper reduces the capacity of fish to respond to hypoxia by preventing acclimation and will inform predictions of the consequences of global increases of hypoxia in water systems affected by other pollutants worldwide.