北小麝鼩的代谢产热和体温调节特征

The metabolic thermogenesis and thermoregulation of Lesser white-toothed shrew(Crocidura suaveolens)

为探讨食虫目小型哺乳动物的代谢产热和体温调节特征,本文采用封闭式流体压力呼吸仪测定了北小麝鼩在环境温度5～30℃下的静止代谢率(RMR),结果显示:在环境温度(Ta)为17.5～25℃的范围内,北小麝鼩的体温基本维持恒定,平均体温为36.55±0.38℃;热中性区(TNZ)为20～25℃;基础代谢率BMR为5.46±0.23(mLO2/g.h),其中环境温度在25℃时静止代谢率最低,为4.84±0.39(mLO2/g.h)。在5～25℃环境温度范围内,热传导值保持稳定;在此温度范围内,北小麝鼩的热传导率(C)最低,平均为0.42±0.01mLO2/(g.h.℃)。总之,北小麝鼩的产热和体温调节特征为较高的BMR,中等的热传导率,较低的体温和较宽的热中性区。这些特征可能与该物种体型小、夜行性、主要以无脊椎动物为食等生活习性密切相关。

To investigate the characteristics of metabolic thermogenesis and thermoregulation in small mammals,the restingmetabolic rate （RMR） of Lesser white-toothed shrew（Crocidura suaveolens）was measured at 5-30℃ using a closed circuit respirometer.Our results showed that：Lesser white-toothed shrew could keep a stable body temperature of 36.55±0.38℃ at ambient temperatures（Ta） between 17.5-25℃.The thermal neutral zone （TNZ） was 20-25℃.Mean basal metabolic rate BMR was 5.46±0.23（mLO2/g·h）.The lowest BMR was 4.84±0.39（mLO2/g·h）at Ta 25℃.The thermal conductance （C） within a temperature range of 5-25℃ was stable.Within a temperature range of 5-25℃,the shrews had a low heat conduction with an average result of 0.42±0.01 mLO2/（g·h·℃）.In conclusion,Lesser white-toothed shrews had a higher BMR,a moderate thermal conductance,a lower body temperature and a wide range of TNZ as characteristics of thermogensis and thermoregulation.These characteristics closely related to the small size,nocturnal and invertebrate-eating habits.