横断山区中华姬鼠的体温调节和蒸发失水

为探讨中华姬鼠的生理生态适应特征,对该鼠的代谢率、热传导、体温和蒸发失水等生理生态指标随环境温度从-5℃ ～ 35℃ 的变化进行了测定。结果表明:中华姬鼠的热中性区(TNZ)为20℃ ～ 30℃ ,平均体温为37. 2 ±0.3℃ ,体温在20℃ ～30℃ 范围内维持恒定;基础代谢率为3.17 ±0.08 ml O₂ / g· h,最大非颤抖性产热为5.99 ±0.58 ml O₂ / g· h,非颤抖性产热范围(最大非颤抖性产热与基础代谢率的比率)为1. 90,平均最小热传导(Cm )为0.16 ± 0.02 ml O₂ / g· h℃ ,热中性区内,中华姬鼠的F 值(RMR /Kleiber 期望RMR)/ (C /Bradley 期望C)为1.58 ±0.10,中华姬鼠的蒸发失水随着温度增高而增加,蒸发失水在35℃ 达到峰值,为0.10 ±0.02 mgH₂ O/ g· h。这些结果表明中华姬鼠对林地的适应特征是:基础代谢率较高,体温相对较低,最小热传导率与期望值相当,热中性区较宽,下临界温度较低;较高的最大非颤抖性产热和非颤抖性产热范围;蒸发失水在体温调节中占一定地位;这些特征与该物种的生活习性和栖息生境等因素密切相关,也可能是该物种对横断山区的适应对策。

Thermoregulation and evaporative water loss in Apodemus draco from the Hengduan Mountains region

In order to understand the physiological and ecological adaptations of Apodemus draco to the Hengduan Mountains region,the characteristics of their metabolic rates,thermal conductance,body temperatures (Tb ) and evaporative water loss were measured at a temperature range of -5℃ - 35℃. The thermal neutral zone (TNZ) of Apodemus draco was 20℃ -30℃, and the mean body temperature was 37.22 ± 0.32℃. Apodemus draco was capable of maintaining a stable body temperature at 20℃ -30℃ of ambient temperatures. Basal metabolic rate (BMR),the maximal nonshivering thermogenesis (NST),the range of nonshivering thermogenesis (Percentage of NST and BMR),and average minimum thermal conductance (Cm ) was 3.17 ±0.08 ml O₂ / g· h,5.99 ±0.58 ml O₂ / g· h,2.52,0.16 ± 0.02 ml O₂/ g· h ℃ respectively. F-values (RMR/ Kleiber predicted RMR)/ (C/ Bradley predicted C) of Apodemus draco was 1.58 ±0.10 in their respective TNZs. Evaporative water loss in Apodemus draco increased when the temperature increased,the maximal evaporative water loss was 0.10 ±0.02 mg H₂ O/ g· h in 35℃. These results may reflect the characteristics which have relatively higher BMR,lower body temperature,minimum thermal conductance corresponding expected values,wider TNZ,lower low critical temperature,high maximal and high fluctuations of NST. Evaporative water loss plays a role in temperature regulation. These characteristics are closely related to the species’life history,and habitats,and represents its adaptive strategy to the Hengduan Mountains region.