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

Abstract

bstract. 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, Borhrops alternatus. Maximum oxygen consumption rates (V02peak) during digestion increased with temperature, while the time to reach these rates (Tp^ai^) and the duration of the digestive process decreased as temperature was elevated. Both, scope (V02peak/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 V02peak accompanied by an increase in digestion duration. Thermal regime did not affect the energetic cost of digestion in B. alternatus.

Environmental temperature alters the overall digestive energetics and differentially affects dietary protein and lipid use in a lizard

“…In the present study, however, metabolic chambers were very small and movement of the lizards was limited. Some reptile species show a circadian rhythm in postprandial metabolic rate even in constant dark at a constant temperature in small metabolic chambers (Hare et al, 2006), whereas others do not (Gavira and Andrade, 2013). Still, the circadian rhythm observed in this study is stronger at the beginning of the trial when animals are digesting than later when the SDA response has (almost) ended.…”

“…Saito et al, 1975;Konturek et al, 2011;Dibner and Schibler, 2015). Postprandial pit vipers showed that snakes exposed to temperatures fluctuating between 30°C during photophase and 20°C during scotophase exhibited large changes in metabolic rates over several days of digestion (Gavira and Andrade, 2013), but we are not aware of any studies that have evaluated possible circadian rhythms in activity of digestive enzyme in reptiles. If the capacity of processing food is reduced at the end of the day, prey items captured early in the day may give the animals a greater profit (faster and better assimilation of the nutrients) than a prey captured in the afternoon.…”

“…Typically, SMR increases exponentially with temperature due to increased energetic costs of body maintenance (Bennett and Dawson, 1976;Niewiarowski and Waldschmidt, 1992;Clarke, 2003). The magnitude of the peak in postprandial metabolic rate increases with temperature while the duration of the SDA response tends to decrease (Andrade et al, 2005;McCue, 2006;Secor, 2009;Gavira and Andrade, 2013), but the total energy of the SDA response is usually not affected by temperature (McCue, 2006;Secor, 2009;Lei and Booth, 2014). Gut passage rates increase at higher temperatures (Jobling, 1981;McConnachie and Alexander, 2004)although they may decrease above the preferred body temperature (Harwood, 1979;Van Damme et al, 1991;Xu and Ji, 2006).…”

Effects of temperature and meal size on the postprandial metabolic response of Leptodactylus latrans (Anura, Leptodactylidae)

“…Physiological costs associated with the SDA response include both catabolic and anabolic processes (Andrade, Cruz‐Neto, Abe, Wang, & Starck, ; McCue, Guzman, & Passement, ; Secor, ), with protein synthesis identified as the most prominent contributor (Enok, Simonsen, & Wang, ; McCue, Bennett, & Hicks, ; Wang, Hung, & Randall, ). In ectothermic vertebrates, SDA is highly influenced by body temperature ( T b ), meal type, and meal size (Gavira & Andrade, ,b; Grayson et al, ; Powell, Mansfield‐Jones, & Gatten, ; Secor & Faulkner, ). The examination of the effects of these variables on the SDA response contributes to the understanding of the physiological and energetic implications associated with particular attributes of feeding biology.…”

“…Consequently, thermoregulation can be constrained by the availability of adequate thermal niches, and therefore most anurans routinely experience considerable variation in T b (Anderson, Bovo, & Andrade, ; Lillywhite, ; Noronha‐de‐Souza, Bovo, Gargaglioni, Andrade, & Bícego, ; Sievert, ). Variation in body temperature has an almost universal effect on the function of physiological systems (Bozinovic, Catalan, Estay, & Sabat, ; Bozinovic, Medina, Alruiz, Cavieres, & Sabat, ; Kern, Cramp, & Franklin, ; Niehaus, Angilletta, Sears, Franklin, & Wilson, ), including the metabolic rates while fasting and during meal digestion (Gavira & Andrade, ; Secor, ). In the latter case, an increase in T b is accompanied by higher postprandial metabolic rates and a shorter SDA duration (Powell et al, ; Secor, ; Secor & Faulkner, ; Secor, Wooten, & Cox, ).…”