Temperature and thermal regime effects on the specific dynamic action of Bothrops alternatus (Serpentes, Viperidae)

摘要

Metabolic studies in ectothermic vertebrates are, almost always, conducted at a constant temperature, a valid and recommended procedure in most instances. However, for long term measurements, for example during snakes digestion, keeping experimental temperature constant subjects the animals to a condition potentially quite diverse from what animals may experience in nature. Thus, we investigated the influence of constant (20°C, 25°C, and 30°C) and fluctuating (circadian thermoperiod cycles of 20:30°C, 12:12 h) temperatures regimes on the post-prandial metabolic response of the Crossed pit viper, Bothrops alternatus. Maximum oxygen consumption rates (VO_(2peak)) during digestion increased with temperature, while the time to reach these rates (T_(peak)) and the duration of the digestive process decreased as temperature was elevated. Both, scope (VO_(2peak)/RMR) and SDA coefficient were not influenced by temperature. When compared to the results obtained at constant 25°C (which is equivalent to the average temperature of the fluctuating regime), the fluctuating temperature regime caused a decrease in RMR and VO_(2peak) accompanied by an increase in digestion duration. Thermal regime did not affect the energetic cost of digestion in B. alternatus.