Holloway J C, Geiser F
Department of Zoology, University of New England, Armidale NSW, Australia.
Comp Biochem Physiol A Physiol. 1995 Sep;112(1):59-66. doi: 10.1016/0300-9629(95)00089-p.
Daily torpor is an energy-conserving mechanism, used by many small marsupials to reduce energy expenditure during adverse environmental conditions. Since little is known about how much energy is actually saved by torpor in marsupials and how this is related to the duration of torpor bouts, we investigated the effect of ambient temperature (Ta) on different metabolic states and the effect of torpor bout duration in Sminthopsis crassicaudata (16 g) on average daily metabolic rate (ADMR). Ta had a significant effect on the active and resting metabolic rates (MR), both being higher at Ta 12 degrees C than Ta 18 degrees C (P < 0.001, t-test). In contrast, the ADMR at Ta 12 degrees C and Ta 18 degrees C did not differ significantly, and it appears that the increased cost for thermoregulation in normothermic active and resting animals at Ta 12 degrees C was compensated by a decrease in MR during torpor. Torpor bout duration was negatively correlated with ADMR. Torpor bouts of 5 hr reduced ADMR by 12-16%. Torpor bouts of more than 10 hr reduced ADMRs by 30-50%. Our study shows that torpor can significantly reduce daily energy expenditure in S. crassicaudata, and this may be important for the survival of this species in the wild.
每日蛰伏是一种节能机制，许多小型有袋动物利用它在不利的环境条件下减少能量消耗。由于对于有袋动物通过蛰伏实际节省了多少能量以及这与蛰伏时长如何相关知之甚少，我们研究了环境温度（Ta）对不同代谢状态的影响以及粗尾袋鼬（体重16克）的蛰伏时长对平均每日代谢率（ADMR）的影响。Ta对活跃代谢率和静息代谢率有显著影响，在12摄氏度时的这两种代谢率均高于18摄氏度时（P < 0.001，t检验）。相比之下，12摄氏度和18摄氏度时的ADMR没有显著差异，而且似乎在12摄氏度时正常体温的活跃和静息动物用于体温调节的额外成本被蛰伏期间代谢率的降低所补偿。蛰伏时长与ADMR呈负相关。5小时的蛰伏使ADMR降低了12% - 16%。超过10小时的蛰伏使ADMR降低了30% - 50%。我们的研究表明，蛰伏能显著降低粗尾袋鼬的每日能量消耗，这可能对该物种在野外的生存至关重要。
