三个种群有尾和断尾丽斑麻蜥的选择体温、表面活动和摄食量

Selected body temperature, surface activity and food intake in tailed versus tailless Mongolian racerunners Eremias argus from three populations

用2006年4-6月捕自长安(陕西)、共和(青海)、哈尔滨(黑龙江)三个地理隔离种群尾部完整的丽斑麻蜥(Eremias argus)成年雄体检测断尾对选择体温、表面活动(表面调温个体数)和摄食量的影响。各种群个体均分为实验和对照组,在距尾基部10 mm处切除实验组蜥蜴尾部,获得断尾个体。实验和对照组个体饲养在相同的实验室条件下收集相关数据,历时四周。表面活动的种群间差异是不同种群个体对其所处区域热环境长期适应的结果。断尾个体减少表面活动见于所有三个种群,表明尾自切能导致丽斑麻蜥活动水平的改变。同一种群断尾和有尾个体表面活动的时间格局无显著差异,不同种群表面活动的时间格局无显著差异,这些结果表明丽斑麻蜥白天活动节律具有种的特异性,不受断尾影响。丽斑麻蜥选择体温随纬度或海拔升高而降低,这种变化趋势可能是热环境制约的结果。所有三个种群断尾个体的选择体温均低于有尾个体,表明断尾可改变丽斑麻蜥的体温调定点。丽斑麻蜥摄食量存在种群间差异,长安种群蜥蜴的摄食量显著大于共和种群蜥蜴。三个种群断尾个体均未增加摄食以满足尾再生的额外能量需求。

Adult males of Eremias argus initially having intact tails were collected from three geographically separated populations （the Chang＇ an population in Shaanxi, the Gonghe population in Qinghai, and the Harbin population in Heilongjiang） between April and June 2006 to examine the effects of caudal autotomy on selected body temperature, surface activity （ the number of individuals thermoregulating on the surface） and food intake. Lizards from each of the three populations were equally divided into experimental and control groups. We removed the tail 10 mm from the vent from each experimental lizard, thereby producing tailless lizards. Experimental and control lizards were maintained under identical laboratory conditions for four weeks to allow the accumulation of sufficient data. Surface activities differed among lizards from different populations, primarily as the consequence of long-term adaptation to local thermal environments. Reduced surface activities in tailless lizards were found in all the three populations, suggesting that E. argus is among lizard species where tail loss may modify activities. The temporal patterns of surface activity did not differ between experimental and control lizards within each of the three populations and among lizards from different populations, suggesting that there is a species-specific activity pattern in E. argus, and that the pattern is unaffected by tail loss. Selected body temperature increases with increase in latitude in E. argus, and this trend should be attributable to the constraints imposed by the thermal environment. Tailless lizards selected lowcr body temperatures than did tailed lizards in all three populations, suggesting that E. argus is among lizard species where tail loss may modify the set-point of thermoregulation. Food intake differed among lizards from different populations, with lizards from the Chang＇ an population ingesting significantly more food than those from the Gonghe population. In all three populations, increased energy demands associated with tail regeneration did not result in increment of food intake in tailless lizards. This finding suggests that increasing food intake is not a strategy adopted by tailless E. argus to compensate for the energetic costs of tail loss