Balogová Monika, Gvoždík Lumír
Institute of Biology and Ecology, Faculty of Science, P.J. Šafárik University, Košice, Slovakia.
Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Brno, Czech Republic.
PLoS One. 2015 May 20;10(5):e0128155. doi: 10.1371/journal.pone.0128155. eCollection 2015.
Many ectotherms effectively reduce their exposure to low or high environmental temperatures using behavioral thermoregulation. In terrestrial ectotherms, thermoregulatory strategies range from accurate thermoregulation to thermoconformity according to the costs and limits of thermoregulation, while in aquatic taxa the quantification of behavioral thermoregulation have received limited attention. We examined thermoregulation in two sympatric newt species, Ichthyosaura alpestris and Lissotriton vulgaris, exposed to elevated water temperatures under semi-natural conditions. According to a recent theory, we predicted that species for which elevated water temperatures pose a lower thermal quality habitat, would thermoregulate more effectively than species in thermally benign conditions. In the laboratory thermal gradient, L. vulgaris maintained higher body temperatures than I. alpestris. Semi-natural thermal conditions provided better thermal quality of habitat for L. vulgaris than for I. alpestris. Thermoregulatory indices indicated that I. alpestris actively thermoregulated its body temperature, whereas L. vulgaris remained passive to the thermal heterogeneity of aquatic environment. In the face of elevated water temperatures, sympatric newt species employed disparate thermoregulatory strategies according to the species-specific quality of the thermal habitat. Both strategies reduced newt exposure to suboptimal water temperatures with the same accuracy but with or without the costs of thermoregulation. The quantification of behavioral thermoregulation proves to be an important conceptual and methodological tool for thermal ecology studies not only in terrestrial but also in aquatic ectotherms.
许多变温动物通过行为体温调节有效地减少了它们暴露于低温或高温环境温度的情况。在陆生变温动物中，根据体温调节的成本和限制，体温调节策略从精确的体温调节到体温顺应性不等，而在水生类群中，行为体温调节的量化受到的关注有限。我们研究了两种同域蝾螈物种，高山小鲵（Ichthyosaura alpestris）和普通滑螈（Lissotriton vulgaris）在半自然条件下暴露于升高水温时的体温调节情况。根据最近的理论，我们预测，水温升高对其构成较低热质量栖息地的物种，将比处于热良性条件下的物种更有效地进行体温调节。在实验室热梯度中，普通滑螈保持的体温高于高山小鲵。半自然热条件为普通滑螈提供了比高山小鲵更好的栖息地热质量。体温调节指数表明，高山小鲵积极调节其体温，而普通滑螈对水生环境的热异质性保持被动。面对水温升高，同域蝾螈物种根据热栖息地的物种特异性质量采用了不同的体温调节策略。两种策略都以相同的精度减少了蝾螈暴露于次优水温的情况，但有或没有体温调节的成本。行为体温调节的量化被证明是热生态学研究中一个重要的概念和方法工具，不仅适用于陆生变温动物，也适用于水生变温动物。
