Assimilation efficiency and gut passage time in an African elapid snake,Hemachatus haemachatus

Abstract

We measured apparent assimilation efficiency (AAE) and gut passage time in the African elapid snake Hemachatus haemachatus under laboratory conditions. AAE was dependent on food type, being 89.8% when snakes were fed frogs and 82.8% when fed mice. Differences in AAE for different meal types could be ascribed to the indigestible hair in mouse meals because differences were lost once this component of the mouse meals was removed from the calculation. AAE did not depend on snake body mass and there was no significant difference between AAE measures made at 208C and 278C for mouse meals. Gut passage time was 25% faster at 278C than at 208C, but was not affected by food type or snake body mass. Larger meals took longer to digest. Thus, H. haemachatus appears to offset reduced digestive performance at lower temperatures by retaining food in the gut for longer when at lower body temperatures (T b s). These results fit an emerging pattern in snakes whereby digestive efficiency is generally high and insensitive to T b over the selected thermal range, but may become dependent at lower T b s when digestion is eventually arrested. The rate of digestion is highly temperature-sensitive and is fastest in the selected T b range. Diet appears to affect digestive efficiency owing, mainly, to the presence of indigestible components such as hair. Using a comparative framework, venom does not appear to improve digestion for this species, at least over the temperature range tested, relative to other snake species in the literature.

Temperature induces changes in Drosophila energy stores

“…In contrast, the assimilation efficiencies of larvae of various insects 51–53 and terrestrial salamanders 54 are inversely related to ambient temperature. Finally, the assimilation efficiencies in numerous insects 55–57 , snails 58,59 , sea urchin Lytechinus variegatus 12 and reptiles 60,61 are temperature invariant. Whether the assimilation efficiency is affected by temperature in Drosophila is not known and requires further study.…”

Gut and intestinal passage time in the Rainbow Skink (Trachylepis margaritifer): implications for stress measures using faecal analysis

“…Gaboon Adders ( Bitis gabonica ) have gut passage times of up to 183 days, whilst Burmese Pythons ( Python bivittatus ; as Python molurus ), Western Ratsnakes ( Pantherophis obsoletus as Elaphe obsoleta ), Madagascan Speckled Hognose Snakes ( Leioheterodon geayi ) and Emerald Tree Boas ( Corallus caninus ), all under the same standard conditions, have gut passage times of 35.4, 2.6, 11.6 and 25.4 days respectively (Lillywhite et al., 2002). Alexander et al. (2012) report gut passage times of between 3.9 and 5.2 days, depending on temperature, for Rinkhals ( Hemachatus haemachatus ).…”

Consequences of complex environments: Temperature and energy intake interact to influence growth and metabolic rate

“…Although digestive efficiency can be temperature-dependent, some taxonomic groups exhibit high digestive efficiencies that are relatively insensitive to temperature (snakes: reviewed in Alexander et al, 2012). In these taxa, growth is putatively driven by food intake, resource allocation, and energy expenditure (rather than by digestive efficiency).…”