华北丽斑麻蜥食物同化和疾跑速的热依赖性

作者研究山西阳泉丽斑麻蜥(Eremias argus)成体的选择体温、热耐受性及食物同化和疾跑速的热依赖性。选择体温、临界低温和临界高温无显著的两性差异,分别为36·0℃、1·0℃和44·9℃。在实验温度范围内,体温显著影响食物通过时间、日摄食量、日粪尿排量、表观消化系数和同化效率。食物通过时间在26 -34℃范围内随体温升高而缩短,在更高的体温下则延长。蜥蜴在30、32、34和36℃体温下明显摄入较多的食物、排出明显较多的粪尿。34℃和36℃下的表观消化系数和同化效率大于其它更低或更高温度下的对应数值,但这两个变量未因体温变化而呈现清晰的规律性变化。疾跑速在18 -36℃范围内随体温升高而加快,在38℃体温下则减缓。36℃或附近体温最适合疾跑速。疾跑速最适体温接近蜥蜴的选择体温,表明蜥蜴疾跑速的最适温度可能与其选择体温密切相关动物学报52 (2) : 256 -262 , 2006]。

Thermal dependence of food assimilation and sprint speed in a lacertid lizard Eremias argus from northern China

We collected adult Eremias argus (Lacertidae) from a population in Yangquan (Shanxi, northern China) to study thermal dependence of food assimilation and sprint speed. Selected body temperature (Tsel) measured on a laboratory thermal gradient was 36. 0℃; critical thermal minimum (CTMin) and critical thermal maximum (CTMax) averaged 1. 0℃ and 44.9℃ , respectively. Differences in Tsel, CTMin and CTMax were not found between-sex. Within the range of body temperatures considered, food passage time, daily food intake, daily production of feces and urates, apparent digestive coefficient (ADC) and assimilation efficiency (AE) were all affected by body temperature. Food passage time decreased with increase in body temperature within the range from 26℃ to 34℃ , and then increased at higher body temperatures. Lizards at 30, 32, 34 and 36℃ ate more food and produced more feces and urates than did those at 28℃ and 38℃ . Although ADC and AE were both higher at 34℃ and 36℃ than at other lower or higher temperatures, no clear patterns associated with temperature could be discerned for these two variables. Sprint speed increased with increase in body temperature within the range from 18℃ to 36℃ , and then decreased at 38℃. The body temperatures maximizing sprint speed was around 36℃, which was much close to the mean value of body temperatures selected by lizards on the thermal gradient. This result adds evidence that the range of optimal body temperatures for sprint speed is tightly coupled with Tsel in lizards Acta Zoologica Sinica 52 (2): 256 - 262, 2006].