Abstract：
Whether scales reduce cutaneous evaporative water loss in lepidosaur reptiles (Superorder Lepidosauria) such as lizards and snakes has been a contentious issue for nearly half a century. Furthermore, while many studies have looked at whether dehydration affects thermal preference in lepidosaurs, far fewer have examined whether normally hydrated lepidosaurs can assess their instantaneous rate of evaporative water loss and adjust their thermal preference to compensate in an adaptive manner. We tested both of these hypotheses using three captive-bred phenotypes of bearded dragon (Pogona vitticeps) sourced from the pet trade: \'wild-types\' with normal scalation, \'leatherbacks\' exhibiting scales of reduced prominence, and scaleless bearded dragons referred to as \'silkbacks\'. Silkbacks on average lost water evaporatively at about twice the rate that wild-types did. Leatherbacks on average were closer in their rates of evaporative water loss to silkbacks than they were to wild-types. Additionally, very small (at most ∼1°C) differences in thermal preference existed between the three phenotypes that were not statistically significant. This suggests a lack of plasticity in thermal preference in response to an increase in the rate of evaporative water loss, and may be reflective of a thermal \'strategy\' as employed by thermoregulating bearded dragons that prioritises immediate thermal benefits over the threat of future dehydration. The results of this study bolster an often-discounted hypothesis regarding the present adaptive function of scales and have implications for the applied fields of animal welfare and conservation.
摘要：
鳞片是否可以减少蜥蜴和蛇等鳞龙爬行动物（SuperorderLepidosauria）的皮肤蒸发水分流失，这已经是近半个世纪以来的一个有争议的问题。此外，虽然许多研究已经研究了脱水是否会影响鳞龙的热偏好，很少有人研究正常水合的鳞龙是否可以评估其瞬时蒸发失水率并调整其热量偏好以适应性方式进行补偿。我们使用来自宠物贸易的三种圈养的胡须龙（Pogonavitticeps）表型测试了这两个假设：“野生型”\'棱皮\'表现出减少的突出度，和无鳞的胡须龙被称为“丝背”。丝背平均蒸发失水的速度约为野生型的两倍。平均而言，棱皮类的蒸发水损失率比野生型更接近。此外,三种表型之间的热偏好存在非常小的差异(至多~1°C)，差异无统计学意义。这表明，由于蒸发水损失率的增加，热偏好缺乏可塑性。并且可能反映了热调节胡须龙采用的热策略，该策略优先考虑直接的热收益而不是未来脱水的威胁。这项研究的结果支持了关于当前尺度自适应功能的经常被低估的假设，并对动物福利和保护的应用领域产生了影响。
