US Geological Survey, Leetown Science Center, S.O. Conte Anadromous Fish Research Laboratory, One Migratory Way, Turners Falls, MA, 01376, USA.
US Geological Survey, Leetown Science Center, S.O. Conte Anadromous Fish Research Laboratory, One Migratory Way, Turners Falls, MA, 01376, USA.
J Therm Biol. 2020 Apr;89:102559. doi: 10.1016/j.jtherbio.2020.102559. Epub 2020 Feb 26.
As stream temperatures increase due to factors such as heated runoff from impervious surfaces, deforestation, and climate change, fish species adapted to cold water streams are forced to move to more suitable habitat, acclimate or adapt to increased thermal regimes, or die. To estimate the potential for adaptation, a (within individual) repeatable metric of thermal tolerance is imperative. Critical thermal maximum (CT) is a dynamic test that is widely used to measure thermal tolerance across many taxa and has been used in fishes for decades, but its repeatability in most species is unknown. CT tests increase water temperature steadily over time until loss of equilibrium (LOE) is achieved. To determine if CT is a consistent metric within individual fish, we measured CT on the same lab-held individually-marked adult brook trout Salvelinus fontinalis at three different times (August & September 2016, September 2017). We found that CT is a repeatable trait (Repeatability ± S.E.: 0.48 ± 0.14). CT of individuals males was consistent over time, but the CT of females increased slightly over time. This result indicates that CT is a robust, repeatable estimate of thermal tolerance in a cold-water adapted fish.
由于不透水表面的热径流、森林砍伐和气候变化等因素，溪流温度上升，适应冷水溪流的鱼类被迫迁移到更适宜的栖息地，适应或适应更高的热区，或死亡。为了估计适应的潜力，需要一种（个体内部）可重复的热耐受性度量标准。临界热最大值 (CT) 是一种广泛用于测量许多分类群热耐受性的动态测试，已经在鱼类中使用了几十年，但在大多数物种中的可重复性尚不清楚。CT 测试会随着时间的推移逐渐升高水温，直到达到平衡丧失 (LOE)。为了确定 CT 是否是个体鱼类内部的一致指标，我们在三个不同时间（2016 年 8 月和 9 月、2017 年 9 月）对相同的实验室饲养的个体标记成年溪红点鲑 Salvelinus fontinalis 进行了 CT 测量。我们发现 CT 是一个可重复的特征（可重复性 ± 标准误差：0.48 ± 0.14）。个体雄性的 CT 随时间保持一致，但雌性的 CT 随时间略有增加。这一结果表明，CT 是一种对适应冷水的鱼类的热耐受性进行稳健、可重复的估计。
