Abstract: Body mass and behavior patterns of animals change accordingly when the environment variations (such as fluctuations in food resources). There may be geographic differences in body mass regulation of one species inhabiting different regions. In the present study, the differences of physiological indices in Eothenomys miletus under fasting and re-feeding in a short time between Xianggelila (XGLL) and Jianchuan (JC) were measured. The results showed that significant effects of short-term fasting on body mass, food intake, serum leptin content, hypothalamic neuropeptide expressions and activity behavior were found in E. miletus. Body mass and serum leptin levels of E. miletus in XGLL were significantly lower than those in JC, and food intake and activity behavior were significantly higher than those in JC. Excluding the serum leptin levels, the physiological indexes of the E. miletus in two areas could restore to the control level after 7 days of re-feeding, showing greater phenotypic plasticity. All of the results suggested that there were significant differences in body mass, food intake, serum leptin levels, hypothalamic neuropeptide expression and activity behavior between different habitats, which might be related to the differences of environmental climate and food resource factors.

Key words: Eothenomys miletus, short-term fasting, refeeding, hypothalamic neuropeptide expression, activity behavior