The osmorespiratory compromise hypothesis posits that respiratory epithelial characteristics and physiological regulatory mechanisms which promote gas permeability also increase permeability to ions and water. The hypothesis therefore predicts that physiological responses which increase effective gas permeability will result in increased effective ion and water permeabilities. Though analyses of water and gas effective permeabilities using high temperature have generally supported the hypothesis, water permeability responses to hypoxia remain equivocal and the combination of high temperature and hypoxia untested. We measured diffusive water flux (DWF) and oxygen uptake rate (Ṁo₂) in response to acute temperature change, hypoxia, and the combination of high temperature and hypoxia in a hypoxia-tolerant intertidal fish, the tidepool sculpin (Oligocottus maculosus). In support of the osmorespiratory compromise hypothesis, Ṁo₂ and DWF increased with temperature. In contrast, DWF decreased with hypoxia at a constant temperature, a result consistent with previously observed decoupling of water and gas effective permeabilities during hypoxia exposure in some hypoxia tolerant fishes. However, DWF levels during simultaneous high temperature and hypoxia exposure were not different from fish exposed to high temperature in normoxia, possibly suggesting a failure of the mechanism responsible for down-regulating DWF in hypoxia. These results, together with time-course analysis of hypoxia exposure and normoxic recovery, suggest that tidepool sculpins actively downregulate effective water permeability in hypoxia but the mechanism fails with multi-stressor exposure. Future investigations of the mechanistic basis of the regulation of gill permeability will be key to understanding the role of this regulatory ability in the persistence of this species in the dynamic intertidal environment.

渗透呼吸折衷假说认为，促进气体渗透性的呼吸上皮特征和生理调节机制也增加了对离子和水的渗透性。因此，该假设预测增加有效气体渗透率的生理反应将导致有效离子和水渗透率增加。尽管使用高温对水和天然气的有效渗透率进行的分析通常支持该假设，但对低氧的水渗透性响应仍然模棱两可，并且高温和低氧的组合未经测试。我们测量扩散的水通量（DWF）和氧吸收速率（MO ₂）应对耐缺氧的潮间鱼潮潮（Oligocottus maculosus）中的急性温度变化，缺氧以及高温和缺氧的结合。为了支持osmorespiratory妥协的假设，MO ₂DWF随温度升高而增加。相反，在恒定温度下，DWF随缺氧而降低，这与以前观察到的在某些耐缺氧性鱼类暴露于缺氧期间水和气体的有效渗透率解耦一致。但是，同时处于高温和低氧环境中的DWF水平与在常氧环境中暴露于高温的鱼没有什么不同，这可能表明在低氧环境中导致DWF下调的机制失效。这些结果，再加上对低氧暴露和正常氧恢复的时程分析，表明潮汐塘草鱼在低氧条件下会主动下调有效的水渗透性，但这种机制在多应激暴露下会失效。