Department of Zoology, University of Otago, PO Box 56, Dunedin 9054, New Zealand.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2011 Sep;197(9):869-75. doi: 10.1007/s00359-011-0648-3. Epub 2011 May 6.
Temperate-zone ectotherms experience varying or very low ambient temperatures and may have difficulty in attaining preferred body temperatures. Thus, adaptations to reduce the thermal dependence of physiological processes may be present. We measured the optimal temperature range for sprint speed and compared it with the selected body temperatures (T (sel)) of two sympatric, cool-temperate lizards: the diurnal skink Oligosoma maccanni and the primarily nocturnal gecko Woodworthia (previously Hoplodactylus) "Otago/Southland". We also investigated whether time-of-day influenced sprint speed. Contrary to results for other reptiles, we found that time-of-day did not influence speed in either species. For each species, the optimal temperature range for sprinting and T (sel) overlapped, supporting the 'thermal coadaptation' hypothesis. However, the optimal range of temperatures for speed is not always attainable during activity by either species, which have limited opportunities to attain T (sel) in the field. The thermal sensitivity of sprint speed in these two species does not appear to have evolved to fully match their current thermal environment. More data on cold-adapted species are needed to fully understand physiological adaptation in ectotherms.
温带外温动物经历不同或非常低的环境温度，可能难以达到理想的体温。因此，可能存在减少生理过程对温度依赖性的适应。我们测量了短跑速度的最佳温度范围，并将其与两种同域的、冷温带蜥蜴的选定体温（T（sel））进行了比较：昼行蜥蜴 Oligosoma maccanni 和主要夜行壁虎 Woodworthia（以前的 Hoplodactylus）“Otago/Southland”。我们还研究了一天中的时间是否会影响短跑速度。与其他爬行动物的结果相反，我们发现，在这两个物种中，一天中的时间都不会影响速度。对于每个物种，短跑的最佳温度范围和 T（sel）重叠，支持“热协同适应”假说。然而，在活动期间，这两个物种并不总是有机会达到最佳温度范围，因为它们在野外获得 T（sel）的机会有限。这两个物种的短跑速度的热敏感性似乎并没有完全适应它们当前的热环境。需要更多关于耐寒物种的数据来全面了解变温动物的生理适应。
