Thermal limitation of performance and biogeography in a free-ranging ectotherm: insights from accelerometry
Thermal limitation of performance and biogeography in a free-ranging ectotherm: insights from accelerometry
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DOI：
10.1242/jeb.104455
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发表时间：
2014-09-01
影响因子：
2.8
通讯作者：
Payne, Nicholas L.
中科院分区：
文献类型：
--
作者：
Gannon, Ruan;Taylor, Matthew D.;Payne, Nicholas L.
理论和实验室研究普遍表明，变温性能随着温度达到最佳而增加，随后下降。几种生理机制可能形成热性能曲线，但自由放养动物对温度变化的反应将代表这些机制与生态约束之间的妥协。野生动物平衡生理和生态的热性能数据很少，这对预测未来温度变化对种群的影响是一个障碍。我们使用内部植入的加速度计靠近物种地理分布的中间位置，并使用刺网捕获数据靠近物种的纬度极端值来量化野生掠食性鱼类（Platycephalus fuscus）的温度相关活动水平。我们在已建立的热性能模型的背景下检查了我们的数据，以及热性能阈值与生物地理之间的关系。加速度数据近似于热性能曲线，在23摄氏度时达到峰值，但在更高温度下迅速下降。刺网捕捞数据显示了类似的趋势，温带和热带地区的捕捞率分别与温度相关。加速度计外推的零活度（CTmin和CTmax）估计值与该物种分布的南部和北部极限的最低和最高月平均水温相似，符合该物种的性能限制生物地理。这些数据强调了温度对变温动物性能的基本影响，以及热性能限制如何影响生物地理学。生物学方法很少用于检查自由放养动物的热性能曲线，但这可能是理解生理和生态之间权衡的核心，这些权衡限制了物种的生物地理，并决定了变温动物对未来温度升高的敏感性。
Theoretical and laboratory studies generally show that ectotherm performance increases with temperature to an optimum, and subsequently declines. Several physiological mechanisms probably shape thermal performance curves, but responses of free-ranging animals to temperature variation will represent a compromise between these mechanisms and ecological constraints. Thermal performance data from wild animals balancing physiology and ecology are rare, and this represents a hindrance for predicting population impacts of future temperature change. We used internally implanted accelerometers near the middle of a species' geographical distribution and gill-net catch data near the species' latitudinal extremes to quantify temperature-related activity levels of a wild predatory fish (Platycephalus fuscus). We examined our data in the context of established models of thermal performance, and the relationship between thermal performance thresholds and biogeography. Acceleration data approximated a thermal performance curve, with activity peaking at 23 degrees C but declining rapidly at higher temperatures. Gill-net catch data displayed a similar trend, with a temperature-associated increase and decrease in catch rates in temperate and tropical regions, respectively. Extrapolated estimates of zero activity (CTmin and CTmax) from the accelerometers were similar to the minimum and maximum mean monthly water temperatures experienced at the southern and northern (respectively) limits of the species distribution, consistent with performance-limited biogeography in this species. These data highlight the fundamental influence of temperature on ectotherm performance, and how thermal performance limits may shape biogeography. Biologging approaches are rarely used to examine thermal performance curves in free-ranging animals, but these may be central to understanding the tradeoffs between physiology and ecology that constrain species' biogeographies and determine the susceptibility of ectotherms to future increases in temperature.