PDF(Pubmed)
Abstract：
Temperature profoundly impacts all living creatures. In spite of the thermodynamic constraints on biology, some animals have evolved to live and move in extremely cold environments. Here, we investigate behavioral mechanisms of cold tolerance in the snow fly (Chionea spp.), a flightless crane fly that is active throughout the winter in boreal and alpine environments of the northern hemisphere. Using thermal imaging, we show that adult snow flies maintain the ability to walk down to an average body temperature of -7°C. At this supercooling limit, ice crystallization occurs within the snow fly\'s hemolymph and rapidly spreads throughout the body, resulting in death. However, we discovered that snow flies frequently survive freezing by rapidly amputating legs before ice crystallization can spread to their vital organs. Self-amputation of freezing limbs is a last-ditch tactic to prolong survival in frigid conditions that few animals can endure. Understanding the extreme physiology and behavior of snow insects holds particular significance at this moment when their alpine habitats are rapidly changing due to anthropogenic climate change. VIDEO ABSTRACT.
摘要：
温度深刻影响所有生物。尽管生物学受到热力学限制，一些动物已经进化到在极端寒冷的环境中生活和移动。这里,我们研究了雪蝇耐寒的行为机制（Chioneaspp。),一种不会飞的起重机，在整个冬季在北半球的北方和高山环境中活跃。使用热成像，我们表明，成年雪蝇保持行走能力，平均体温为-7°C。在这个过冷极限下，冰结晶发生在雪蝇的血淋巴内，并迅速扩散到全身，导致死亡。然而,我们发现，雪蝇经常通过在冰结晶扩散到其重要器官之前迅速截肢而在冰冻中存活。冻结肢体的自我截肢是在很少有动物可以忍受的寒冷条件下延长生存的最后手段。了解雪虫的极端生理和行为在这一刻具有特殊意义，因为它们的高山栖息地由于人为气候变化而迅速变化。视频摘要.
