The Effects of Cold Acclimation on Supercooling \nPoint and Freezing Point of Rana dybowskii

Abstract

To evaluate cold tolerance of Rana dybowskii and its ability to adapt to low temperature,and provide reference data for the breeding,transportation and temporary rearing,we measured the supercooling point and freezing point of farm-reared Rana dybowskii at 25℃,4℃ and 0℃.The results showed that the minimum supercooling point of Rana dybowskii could reach-2.6℃,the highest was-1.4℃,and the freezing point could be as low as-2.3℃,the highest was-1.2℃,while cold acclimation could significantly reduce the freezing point.Based on our experimental results and review of literature we conclude that cold acclimated Rana dybowskii can maintain a metastable state of supercooling at about-2℃ by increasing blood sugar and belongs to the freeze-avoiding species.For artificial breeding of Rana dybowskii in winter,temporary rearing and transport,the temperature should be above-1℃ for freeze avoidance and high-quality food should be prvoded.\n