关键词: 大绒鼠, 高山姬鼠, 体温调节, 产热

Abstract: Eothenomys miletus and Apodemus chevrieri are small mammals inhabiting in Hengduan mountains region. To better understand their physiological and ecological adaptations to this region,we quantified characteristics of their thermoregulation and thermogenesis. Metabolic rates were measured using a closed-circuit respirometer.The thermal neutral zone (TNZ) of Eothenomys miletus was 25-32.5℃ and of Apodemus chevrieri was 25- 30℃. Mean body temperatures were for the 2 species were 35.92±0.37℃ and 36.01±0. 83℃. E. miletus was capable of maintaining a stable body temperature at 20-27. 5℃;the corresponding temperature range for A. chevrieri was 15- 27. 5℃. Basal metabolic rates (BMR) were 3. 76±0.07 ml O₂/g.h and 4.58±0.09 mlO₂ /g. h, respectively. Average minimum thermal conductance (Cm )was 0. 28±0.005 ml O₂ /g.h ℃ and 0.32±0.009 ml O₂ /g.h℃,respectively,and their F-values (RMR/ Kleiber predicted RMR) / (C/ Bradley predicted C) were 0.88±0.05 and 1.10±0.05 in their respective TNZs. We postulate that thermogenic characteristics and thermoregulatory styles of these 2 species reflect features of small rodents which have relatively low body temperatures,relatively high BMR,high Cm and can keep their body temperatures stable within relatively narrow ambient temperatures in the Hengduan mountains region. Body temperature,Cm and BMR of A. chevrieri were all higher than those of E. miletus. A. chevrieri was capable of maintaining a stable body temperature over a wider range of ambient temperatures than E. miletus. These differences in their thermogenic characteristics and thermoregulatory styles are closely related to their taxonomic status,life histories,and habitats.

Key words: Apodemus chevrieri, Eothenomys miletus, Thermore gulation, Thermogenesis