Laboratorio de Ecología Evolutiva y Conservación de Anfibios y Reptiles, Facultad de Estudios Superiores Iztacala, UNAM, Tlalnepantla, Estado de México, Mexico.
Posgrado en Ciencias Biológicas, Unidad de Posgrado, Universidad Nacional Autónoma de México, Ciudad de México, Mexico.
PeerJ. 2024 Jul 19;12:e17705. doi: 10.7717/peerj.17705. eCollection 2024.
The impact of temperature on reptile physiology has been examined through two main parameters: locomotor performance and metabolic rates. Among reptiles, different species may respond to environmental temperatures in distinct ways, depending on their thermal sensitivity. Such variation can be linked to the ecological lifestyle of the species and needs to be taken into consideration when assessing the thermal influence on physiology. This is particularly relevant for snakes, which are a very functionally diverse group. In this study, our aim was to analyze the thermal sensitivity of locomotor performance and resting metabolic rate (RMR) in three snake species from central Mexico (, , and ), highlighting how it is influenced by their distinctive behavioral and ecological traits. We tested both physiological parameters in five thermal treatments: 15 °C, 25 °C, 30 °C, 33 °C, and 36 °C. Using the performance data, we developed thermal performance curves (TPCs) for each species and analyzed the RMR data using generalized linear mixed models. The optimal temperature for locomotion of falls near its critical thermal maximum, suggesting that it can maintain performance at high temperatures but with a narrow thermal safety margin. exhibited the fastest swimming speeds and the highest mass-adjusted RMR. This aligns with our expectations since it is an active forager, a high energy demand mode. The three species have a wide performance breadth, which suggests that they are thermal generalists that can maintain performance over a wide interval of temperatures. This can be beneficial to in its cold habitat, since such a characteristic has been found to allow some species to maintain adequate performance levels in suboptimal temperatures. RMR increased along with temperature, but the proportional surge was not uniform since thermal sensitivity measured through Q increased at the low and high thermal treatments. High Q at low temperatures could be an adaptation to maintain favorable performance in suboptimal temperatures, whereas high Q at high temperatures could facilitate physiological responses to heat stress. Overall, our results show different physiological adaptations of the three species to the environments they inhabit. Their different activity patterns and foraging habits are closely linked to these adaptations. Further studies of other populations with different climatic conditions would provide valuable information to complement our current understanding of the effect of environmental properties on snake physiology.
运动表现和代谢率。在爬行动物中，不同物种可能会以不同的方式对环境温度做出反应，这取决于它们的热敏感性。这种变化可能与物种的生态生活方式有关，在评估温度对生理学的影响时需要考虑到这一点。这对于蛇类来说尤为重要，因为它们是一个非常具有功能性多样性的群体。在这项研究中，我们的目的是分析来自墨西哥中部的三种蛇类（，，和）的运动表现和静息代谢率（RMR）的热敏感性，强调它们独特的行为和生态特征如何影响其热敏感性。我们在五个温度处理条件下测试了这两个生理参数：15°C、25°C、30°C、33°C 和 36°C。利用性能数据，我们为每个物种绘制了热性能曲线（TPC），并使用广义线性混合模型分析了 RMR 数据。的最佳运动温度接近其临界热最大值，这表明它可以在高温下保持性能，但热安全裕度较窄。表现出最快的游泳速度和最高的质量调整 RMR。这与我们的预期相符，因为它是一种活跃的捕食者，需要高能量。这三个物种的表现范围很广，这表明它们是热适应的，能够在广泛的温度范围内保持性能。这对生活在寒冷环境中的可能是有益的，因为这种特征被发现可以使一些物种在非最佳温度下保持足够的性能水平。RMR 随温度升高而升高，但比例增加并不均匀，因为通过 Q 测量的热敏感性在低温和高温处理时增加。低温下的高 Q 可能是一种适应，以在非最佳温度下保持有利的性能，而高温下的高 Q 可能有助于对热应激的生理反应。总的来说，我们的研究结果表明，这三个物种对其栖息环境有不同的生理适应。它们不同的活动模式和觅食习惯与这些适应密切相关。对具有不同气候条件的其他种群进行进一步研究将提供有价值的信息，以补充我们目前对环境特性对蛇类生理学影响的理解。
