We used Takydromus septentrionalis as a model animal to examine whether lizards shift thermal preferences when fasted. The experiment was conducted in March 2007. Thirty-six adults collected from Shengsi, Zhoushan Isl...We used Takydromus septentrionalis as a model animal to examine whether lizards shift thermal preferences when fasted. The experiment was conducted in March 2007. Thirty-six adults collected from Shengsi, Zhoushan Islands, were equally assigned to experimental (fasted) and control (fed) groups, with nine housed together in a 0.6 m×0.2 m×0.5 m glass cage with moist soil (10 cm in depth), debris and grasses. A 100-W light bulb suspended above one end of each cage created a thermal gradient ranging from room temperatures (15℃-24℃) to 60℃ for 12 h daily, so that lizards could thermoregulate during the photophase. Prior to the experiment, lizards were allowed to feed on mealworms (larvae of Tenebrio molitor) for 10 days. Thereafter experimental lizards were fasted for 20 days, and were measured for thermal preferences on Day 1-10, Day 15 and Day 20 since fasting. We found in fasted lizards that selected body temperature (Tsel, a measure of thermal preference) gradually decreased from 32.4℃ to 30.9℃ in the first four days, and then increased to a level similar to that (32.9℃) recorded in the controls. Lizards fasted for 9 days or longer did not differ from controls in Tsel. Our study is the first to demonstrate that lizards fasted for a prolonged time may shift thermal preferences in a pattern well fitting to a Gaussian peak curve.展开更多
动物在野外生境中的活动能力通常会受到许多方面(例如,运动基质表面粗糙程度、遭遇障碍物的大小与形状)的影响。在特定体温(30℃)条件下,测量主要分布区重叠的两蜥蜴种类(北草蜥和中国石龙子)在四种不同基质表面(塑料草坪;表面粗糙不透...动物在野外生境中的活动能力通常会受到许多方面(例如,运动基质表面粗糙程度、遭遇障碍物的大小与形状)的影响。在特定体温(30℃)条件下,测量主要分布区重叠的两蜥蜴种类(北草蜥和中国石龙子)在四种不同基质表面(塑料草坪;表面粗糙不透底的塑料地毯;光滑具透底网格的塑料地毯和表面光滑的塑料地毯)的运动表现,以及两者的攀附能力和最大游泳耐力。基质类型显著影响两种蜥蜴的运动表现。两种蜥蜴在粗糙表面运动时的疾跑速明显大于光滑表面(例如,塑料草坪上北草蜥为15.7 SVL/s,中国石龙子为8.1 SVL/s;光滑塑料地毯上则分别为11.4 SVL/s和3.5 SVL/s)。中国石龙子在光滑塑料地毯上具有最大的持续运动距离(10.6 SVL)和最少的停顿次数(1.9次)。北草蜥在光滑塑料地毯上具有最多的停顿次数(4.6次)。两种蜥蜴运动能力的种间差异显著。北草蜥具有较大的相对疾跑速度(北草蜥和中国石龙子:13.5 SVL/s vs 5.8 SVL/s)和攀附能力(143.8°vs 101.2°),但较小的游泳耐力(83.5 s vs 238.5 s)。运动速度与耐力之间存在种间权衡关系而与攀爬能力无进化冲突的结论。展开更多
文摘We used Takydromus septentrionalis as a model animal to examine whether lizards shift thermal preferences when fasted. The experiment was conducted in March 2007. Thirty-six adults collected from Shengsi, Zhoushan Islands, were equally assigned to experimental (fasted) and control (fed) groups, with nine housed together in a 0.6 m×0.2 m×0.5 m glass cage with moist soil (10 cm in depth), debris and grasses. A 100-W light bulb suspended above one end of each cage created a thermal gradient ranging from room temperatures (15℃-24℃) to 60℃ for 12 h daily, so that lizards could thermoregulate during the photophase. Prior to the experiment, lizards were allowed to feed on mealworms (larvae of Tenebrio molitor) for 10 days. Thereafter experimental lizards were fasted for 20 days, and were measured for thermal preferences on Day 1-10, Day 15 and Day 20 since fasting. We found in fasted lizards that selected body temperature (Tsel, a measure of thermal preference) gradually decreased from 32.4℃ to 30.9℃ in the first four days, and then increased to a level similar to that (32.9℃) recorded in the controls. Lizards fasted for 9 days or longer did not differ from controls in Tsel. Our study is the first to demonstrate that lizards fasted for a prolonged time may shift thermal preferences in a pattern well fitting to a Gaussian peak curve.
文摘动物在野外生境中的活动能力通常会受到许多方面(例如,运动基质表面粗糙程度、遭遇障碍物的大小与形状)的影响。在特定体温(30℃)条件下,测量主要分布区重叠的两蜥蜴种类(北草蜥和中国石龙子)在四种不同基质表面(塑料草坪;表面粗糙不透底的塑料地毯;光滑具透底网格的塑料地毯和表面光滑的塑料地毯)的运动表现,以及两者的攀附能力和最大游泳耐力。基质类型显著影响两种蜥蜴的运动表现。两种蜥蜴在粗糙表面运动时的疾跑速明显大于光滑表面(例如,塑料草坪上北草蜥为15.7 SVL/s,中国石龙子为8.1 SVL/s;光滑塑料地毯上则分别为11.4 SVL/s和3.5 SVL/s)。中国石龙子在光滑塑料地毯上具有最大的持续运动距离(10.6 SVL)和最少的停顿次数(1.9次)。北草蜥在光滑塑料地毯上具有最多的停顿次数(4.6次)。两种蜥蜴运动能力的种间差异显著。北草蜥具有较大的相对疾跑速度(北草蜥和中国石龙子:13.5 SVL/s vs 5.8 SVL/s)和攀附能力(143.8°vs 101.2°),但较小的游泳耐力(83.5 s vs 238.5 s)。运动速度与耐力之间存在种间权衡关系而与攀爬能力无进化冲突的结论。
