广东罗坑自然保护区鳄蜥的体温调节及静止代谢率的热依赖性

Thermoregulatory and thermal dependence of resting metabolic rates in the Chinese crocodile lizard Shinisaurus crocodilurus in the Luokeng Nature Reserve,Guangdong

为探讨鳄蜥(Shinisaurus crocodilurus)的体温调节和静止代谢率及其热依赖性特征,测定了在自然和实验室条件下的环境温度、鳄蜥体温以及静止代谢率(RMR)等热生物学指标。结果显示:在自然条件下,鳄蜥的野外活动体温(Tb)稍高于基质温度(Tc)和空气温度(Td)并与后二者呈正相关关系(Tb=11.65+0.47Tc,r2=0.34,F1,75=39.11,P<0.0001;Tb=11.61+0.46Td,r2=0.56,F1,75=96.56,P<0.0001)。鳄蜥在野外的活动体温存在明显的月份间差异,但无性别及年龄上的差异。环境温度为15℃-30℃的实验条件下,鳄蜥的静止体温(Tb)与环境温度(Ta)呈正相关关系:Tb=12.450+0.5641Ta(F1,110=11.34,r2=0.997,P<0.001);在缺乏温度梯度的环境中,尽管鳄蜥的体温、空气温度和基质温度都有显著的昼夜差异,但体温、空气温度和基质温度的日平均温度之间无显著差异。鳄蜥的RMR不存在雌雄个体间的差异,并与环境温度呈正相关关系。分析显示鳄蜥的体温既有行为调节也有生理调节,其体温调节及RMR符合变温动物的热生物学特征,但是相对于其他活动较多的蜥蜴而言,鳄蜥的生理调节能力较强,这可能与其活动时间分配中静栖占绝大部分的行为特点是相适应的。

To explore the thermoregulatory and thermal dependence of resting metabolic rates （RMR） in the Chinese crocodile lizard Shinisaurus crocodilurus, we measured the active body temperature, the diel variation in body temperature, the average daily body temperatures, the ambient temperature and the resting metabolic rate in the wild and under controlled laboratory conditions. Results showed that in the wild, active body temperature （Tb） was higher than substrate temperature （Tc） and air temperature （Td） and was positively correlated with the latter two （Tb = 11.65 ＋ 0.47Te, r^2 = 0.34, F1.75 = 39.11, P 〈 0.0001; Tb = 11.61 ＋ 0.46Td, r^2 = 0.56, F1.75 = 96.56, P 〈 0.0001）. The active body temperature of the lizard in the wild showed monthly variations, and no effect of age or sex. In the laboratory in a gradient of 15℃ - 30℃ , the resting body temperature （Tb） was positively correlated with ambient temperature （Ta） ： Tb = 12.450 ＋ 0.5641 Ta （F1. 110 = 11.34, r^2 = 0.997, P 〈 0.001）. In the environment without thermal gradients, there was a significant diel variation in body temperature, air temperature and substrate temperature, but there were no significant differences in average daily body temperature, air temperature and substrate temperature. The RMR showed no difference between sexes, and it increased with ambient temperature （Ta）. Further analysis indicated that the thermoregulation of Chinese crocodile lizard was conducted by both behavioral and physiological means, and both thermoregulation and the resting metabolic rates of Chinese crocodile lizard were in accordance with the thermal biology of this ectothermic species. The capability of physiological thermoregulation of Chinese crocodile lizard was relatively higher than that of other more active lizards. The thermoregulation of Chinese crocodile lizard parallels its behavioral characteristics of spending most of their time at rest [Acta Zoologica Sinica 54 （6） ： 964 - 971, 2008] .