Temperature and Meal Size Effects on the Postprandial Metabolism and Energetics in a Boid Snake

Abstract

We investigated the combined effect of meal size and temperature on the aerobic metabolism and energetics of digestion in Boa constrictor amarali. Oxygen uptake rates (Vd2;o2) and the duration of the digestion were determined in snakes fed with meals equaling to 5%, 10%, 20%, and 40% of the snake's body mass at 25 degrees and 30 degrees C. The maximum Vd2;o2 values attained during digestion were greater at 30 degrees C than at 25 degrees C. Both maximal Vd2;o2 values and the duration of the specific dynamic action (SDA) were attained sooner at 30 degrees C than at 25 degrees C. Therefore, the temperature effect on digestion in Boa is characterized by the shortening of the SDA duration at the expense of increased Vd2;o2. Energy allocated to SDA was not affected by meal size but was greater at 25 degrees C compared to 30 degrees C. This indicates that a postprandial thermophilic response can be advantageous not only by decreasing the duration of digestion but also by improving digestive efficiency. Maximal Vd2;o2 and SDA duration increased with meal size at both temperatures.

Meal size effects on the postprandial metabolic response of Bothrops alternatus (Serpentes: Viperidae)

“…metabolic rates measured during digestion (HAILEY & DAVIES 1987, WANG et al 2003, ZAIDAN & BEAUPRE 2003, the reaching of this meal-size metabolic ceiling during digestion is probably modulated by temperature (TOLEDO et al 2003).…”

“…relative cost of meal digestion (i.e.,% of meal energy allocated for digestion) seems to be unaffected by its size (ANDRADE et al 1997, TOLEDO et al 2003 or, in some cases, to be greater for larger meals (SECOR & DIAMOND 1997a, b, MCCUE & LILLYWHITE 2002. Whether this pattern is affected by differences in feeding habits still deserves further examination, since the effects of prey size on SDA have been quantified only in a limited number of snake species.…”

Adaptive regulation of digestive performance in the genusPython

“…For pythons, as well as for other reptiles and amphibians, the magnitude of peak V O 2, the duration of the metabolic response, and overall SDA are affected by meal type, meal size, body temperature and body size (Secor and Diamond, 1997;Hailey, 1998;Toledo et al, 2003;Wang et al, 2003;McCue et al, 2005;Pan et al, 2005;Secor and Boehm, 2006). Therefore, interspecific comparisons of the SDA response are best made when meal type, relative meal size, body temperature and body size are standardized.…”

The thermogenesis of digestion in rattlesnakes

“…Huey, 1982), behaviorally increase their preferred body temperature, the so-called post-prandial thermophilic response. The primary consequence of such an increase in body temperature, in almost all cases examined, is a shortening of digestion time at the expense of increased rates of metabolism during the period of SDA (Wang et al, 2003;Toledo et al, 2003). Toledo et al (2003), however, found that the SDA of boas fed different meal sizes was energetically less costly at 30°C than at 25°C.…”

“…The primary consequence of such an increase in body temperature, in almost all cases examined, is a shortening of digestion time at the expense of increased rates of metabolism during the period of SDA (Wang et al, 2003;Toledo et al, 2003). Toledo et al (2003), however, found that the SDA of boas fed different meal sizes was energetically less costly at 30°C than at 25°C. Thus, at least in this one particular case, it seems that the post-prandial thermophilic response was advantageous not only by decreasing the duration of digestion but also by improving the energetic return on the meal.…”