关键词: 北小麝鼩, 静止代谢率, 体温调节, 热传导, 热中性区

Abstract: 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 whitetoothed 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.

Key words: Lesser white-toothed shrew (Crocidura suaveolens), Resting metabolic rate (RMR), Thermoregulation, Thermal conductance, Thermal neutral zone (TNZ)