Effects of Photoperiod and Temperature on Energy Budgets and Endocrine Hormones Concentrations in Tupaia belangeri

Abstract

Environmental cues play important roles in the regulation of an animal’s physiology and behavior. In the present study, we performed a factorial experiment (temperature/photoperiod) in which Tupaia belangeri was acclimated to different photoperiods (long photoperiod, 16L:8D; short photoperiod, 8L:16D) and temperatures (warm, 30oC; cold, 5oC) to test the hypothesis that photoperiod, temperature, or both together can trigger changes in energy budgets and endocrine hormones concentrations. The results showed that temperature, photoperiod had a significant effect on energy intake, and digestible energy intake. Both short photoperiod and cold caused animal's gross energy intake to increase by 25.6% and 89.1 %, and caused digestible energy intake to increase by 24.1% and 83.5% respectively compared with that of the initial, but there was no significant interaction between photoperiod and temperature on energy intake and digestible energy intake. Temperature had significant effect on serum thyrotropin (TSH) concentrations, serum leptin level, photoperiod had a significant effect on TSH and melatonin. The present results suggested that T. belangeri adapt cold stress or short photoperiod by increasing energy intake, and may be regulated by endocrine hormones. Furthermore, leptin and melatonin seem to be involved in the regulation of body mass and energy balance in T. belangeri.

Keywords

• Tupaia belangeri
• Energy budgets
• Endocrine hormones concentrations
• Temperature
• Photoperiod