School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia.
J Fish Biol. 2022 Dec;101(6):1595-1600. doi: 10.1111/jfb.15213. Epub 2022 Sep 21.
Experimental hyperoxia has been shown to enhance the maximum oxygen uptake capacity of fishes under acute conditions, potentially offering an avenue to test prominent physiological hypotheses attempting to explain impacts of climate warming on fish populations (e.g., gill-oxygen limitation driving declines in fish size). Such benefits of experimental hyperoxia must persist under chronic conditions if it is to provide a valid manipulation to test the relevant hypotheses, yet the long-term benefits of experimental hyperoxia to oxygen uptake capacity have not been examined. Here, the authors measured aerobic metabolic performance of Galaxias maculatus upon acute exposure to hyperoxia (150% air saturation) and after 5 months of acclimation, at both 15°C and 20°C. Acute hyperoxia elevated aerobic scope by 74%-94% relative to normoxic controls, and an elevation of 58%-73% persisted after 5 months of hyperoxia acclimation. When hyperoxia-acclimated fish were acutely transitioned back to normoxia, they maintained superior aerobic performance compared with normoxic controls, suggesting an acclimation of the underlying metabolic structures/processes. In demonstrating the long-term benefits of experimental hyperoxia on the aerobic performance of a fish, the authors encourage the use of such approaches to disentangle the role of oxygen in driving the responses of fish populations to climate warming.
实验性高氧已被证明可增强鱼类在急性条件下的最大摄氧量能力，这可能为测试试图解释气候变暖对鱼类种群影响的突出生理假设提供了一种途径（例如，鳃氧限制导致鱼类体型下降）。如果实验性高氧要为测试相关假设提供有效的操作，那么其在慢性条件下的这些益处必须持续存在，但实验性高氧对摄氧量的长期益处尚未得到检验。在这里，作者在 15°C 和 20°C 下测量了急性暴露于高氧（空气饱和度的 150%）和 5 个月适应期后，大鳞麻斑鱼的有氧代谢性能。急性高氧使有氧范围相对于正常氧对照提高了 74%-94%，而在 5 个月的高氧适应后，仍保持了 58%-73%的提高。当高氧适应的鱼类急性过渡到正常氧时，它们与正常氧对照相比保持了优越的有氧性能，这表明潜在的代谢结构/过程发生了适应。在证明了实验性高氧对鱼类有氧性能的长期益处后，作者鼓励使用这种方法来阐明氧气在驱动鱼类种群对气候变暖的反应中的作用。
