Muñoz Nicolas J, Farrell Anthony P, Heath John W, Neff Bryan D
Physiol Biochem Zool. 2018 Jan/Feb;91(1):757-762. doi: 10.1086/695556.
To evaluate whether oxygen-carrying capacity influences thermal tolerance in fishes, we reared four Chinook salmon families in present-day (+0°C) and possible future (+4°C) temperatures and assessed the response of hematocrit (Hct) to acute temperature stress. In the +4°C treatment, Hct increased above control levels when juvenile fish were exposed to their critical thermal maximum (CT). Conversely, no effect of temperature stress on Hct was found in the +0°C treatment. Hct was positively associated with CT ([Formula: see text]; [Formula: see text]), contributing to the CT of the +4°C treatment being significantly higher than that of the +0°C treatment (mean ± SD, [Formula: see text] and [Formula: see text], respectively). The association between CT and Hct found here supports the hypothesis that thermal tolerance is affected by oxygen supply to tissue. Moreover, the developmental plasticity of CT and Hct could represent an adaptive mechanism for salmon faced with climate change.
为了评估携氧能力是否会影响鱼类的热耐受性，我们在当前温度（+0°C）和可能的未来温度（+4°C）下饲养了四个奇努克鲑鱼家族，并评估了血细胞比容（Hct）对急性温度应激的反应。在+4°C处理中，当幼鱼暴露于其临界热最大值（CT）时，Hct升高至对照水平以上。相反，在+0°C处理中未发现温度应激对Hct有影响。Hct与CT呈正相关（[公式：见正文]；[公式：见正文]），这使得+4°C处理的CT显著高于+0°C处理的CT（平均值±标准差，分别为[公式：见正文]和[公式：见正文]）。此处发现的CT与Hct之间的关联支持了热耐受性受组织氧气供应影响的假设。此外，CT和Hct的发育可塑性可能代表了鲑鱼应对气候变化的一种适应性机制。
