Moon D Y, MacKenzie D S, Owens D W
Dept. of Biology, Texas A&M University, College Station 77843-3258, USA.
J Exp Zool. 1997 Aug 15;278(6):372-80.
Captive immature green (Chelonia mydas) and Kemp's ridley (Lepidochelys kempi) sea turtles were examined to determine if a hibernation-like state could be induced under controlled conditions. Both species demonstrated that they are able to acclimate to cold temperatures behaviorally. However, the two species appeared to respond differently to decreasing temperature. Whereas the green turtles tolerated the onset of cold water temperatures by reducing swimming activity, the ridleys became very agitated and active as they were exposed to temperatures below 20 degrees C. Nevertheless, both species displayed semi-dormant behavior at temperatures below 15 degrees C, coming to the surface to breathe periodically at intervals of up to three hours. At low temperatures, venous blood pO2 and pCO2 decreased, whereas venous blood pH increased. Feeding also decreased as either species was exposed to cold temperature: greens (at 15 degrees C) and ridleys (at 20 degrees C) decreased food consumption to 50% of control levels, and ceased feeding below 15 degrees C. Thus, these species tolerated temperature drops and the associated hypophagia. They did not exhibit cold-stunning behavior, as has been observed in wild sea turtles exposed to rapid temperature drops, or prolonged periods of hibernation-like dormancy, as has been proposed for wild sea turtles during cold winter months.
对圈养的未成熟绿海龟（蠵龟）和肯氏丽龟进行了检查，以确定在可控条件下是否能诱导出类似冬眠的状态。这两个物种都表明它们能够在行为上适应低温。然而，这两个物种对温度下降的反应似乎有所不同。绿海龟通过减少游泳活动来耐受冷水温度的开始，而丽龟在暴露于20摄氏度以下的温度时变得非常烦躁和活跃。尽管如此，两个物种在15摄氏度以下的温度时都表现出半休眠行为，每隔长达三个小时周期性地浮出水面呼吸。在低温下，静脉血的氧分压和二氧化碳分压下降，而静脉血的pH值升高。随着任何一个物种暴露于低温环境，进食也会减少：绿海龟（在15摄氏度时）和丽龟（在20摄氏度时）的食物消耗量降至对照水平的50%，并在15摄氏度以下停止进食。因此，这些物种耐受温度下降和相关的摄食减少。它们没有表现出冷麻痹行为，就像在暴露于快速温度下降的野生海龟中所观察到的那样，也没有表现出如有人提出的野生海龟在寒冷冬季所经历的长时间类似冬眠的休眠状态。
