Study
A vertebrate model of extreme physiological regulation
Secor, Stephen M.; Diamond, Jared
Nature, 1998
Metabolic rate, intestinal structure and organ masses were measured in Burmese pythons through a full fast-and-feed cycle, comparing animals that had been fasting for weeks against the same species in the days after a large meal.
- Studied in
- Python molurus
- Sample size
- Burmese pythons across fasting and feeding states
Metabolic rate rose roughly fortyfold after feeding — comparable to a mammal at maximum exercise, sustained for days. Intestinal surface and nutrient uptake capacity increased several-fold within a day or two, and heart, liver, kidney and intestinal masses increased substantially, then regressed once digestion was complete.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Sit-and-wait predators that feed rarely and enormously downregulate the gut between meals and rebuild it on demand, which is energetically cheaper than maintaining unused capacity.
How NatureHQ reads it
This is the physiological answer to "how can a snake go months without eating", and it is the opposite of the intuitive one. The animal is not running slowly on reserves so much as switching an expensive organ system off and rebuilding it. It also reframes the famous image of a python swallowing something enormous: the swallowing is the easy part and the digestion is the extraordinary one, because a meal of that size requires the animal to grow a bigger intestine to process it.
- One species with an unusually extreme feeding ecology; frequent feeders show far smaller changes.
- Laboratory feeding regimes are more regular and more predictable than wild ones.
- Organ mass changes were measured across animals rather than repeatedly within individuals.
What this study is used for on NatureHQ
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Published by: Nature PortfolioPublished in a Nature Portfolio journal.
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