Snakes being warmer while digesting...

[Jeff Hathaway]

Further to the recent debates about thermoregulation, I thought this was pretty interesting. Apparently at least some snakes can create their own gradients

Jeff Hathaway
Sciensational Sssnakes!!

(Thanks to Allen Salzberg's HerpDigest- )
The Thermogenesis Of Digestion In Rattlesnakes.
Tattersall GJ, Milsom WK, Abe AS, Brito SP, Andrade DV.
J Exp Biol. 2004 Feb 1;207(Pt 4):579-585.
Department of Biological Sciences, Brock University, St Catharines, ON, L2S 3A1, Canada Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, British Columbia, Canada, V6T 1Z4 Departamento de Zoologia, c. p. 199, Universidade Estadual Paulista, 13506-900, Rio Claro, SP, Brasil.

Some snakes have a feeding regime characterized by the infrequent ingestion of relatively large meals, causing impressive increments in post-prandial metabolism. Metabolism remains elevated for many days, while digestion proceeds, resulting in considerable investment of time and energy. Snakes actively adjust thermoregulatory behavior to raise their body temperature during digestion, exhibiting a post-prandial thermophilic response that accelerates digestion at the expense of higher metabolic rates. In the present study, we investigated the possibility that endogenously derived heat, originating as a byproduct of the post-prandial increase in metabolism, could itself contribute to the elevated body temperature during digestion in the South American rattlesnake Crotalus durissus. We assessed heat production, at a constant environmental temperature, by taking infrared (IR) images of snakes during fasting and after being fed meals varying from 10% to 50% of their own body masse!
s. Our results show clearly that digesting rattlesnakes have significantly increased body temperatures, even when precluded from adjusting their thermoregulatory behavior. The feeding-derived thermogenesis caused the surface body temperature of rattlesnakes to increase by 0.9-1.2 degrees C, a temperature change that will significantly affect digestive performance. The alterations in body temperature following feeding correlated closely with the temporal profile of changes in post-prandial metabolism. Moreover, the magnitude of the thermogenesis was greater for snakes fed large meals, as was the corresponding metabolic response. Since IR imaging only assesses surface temperatures, the magnitude of the thermogenesis and the changes in deep core temperature could be even more pronounced than is reported here.

[Scales Zoo]

This is interesting stuff.

I've had discussions about this with people recently, as I had read that monitors "create more heat" by the metabolism increases associated with feeding.

The protein changes that occur when an egg is developing (outside of the snake) also create heat, and I've always wondered about the eggs inside the snake also creating heat, since there are also protein changes happening.

Saying reptiles are cold blooded, makes many people think they don't create any heat. Certain life processes do create heat, reptiles can create heat, they are just not able to thermoregulate in the same way as mammals (or to produce enough heat to do so).

Energy in, should equal energy out. What isn't put into growth goes somewhere.

If you come accross more information like this, feel free to pass it along, I love to read this stuff.

Ryan

[Jeff Hathaway]

True enough, Ryan, though most of what doesn't go into growth goes into locomotion, reproduction, or fat storage. The amount of energy being converted to heat would have to be pretty minor, I would think. Pretty cool, though.

Jeff Hathaway
Sciensational Sssnakes!!

[Scales Zoo]

I was thinking about locomotion, I neglected to mention it however.

I'm not an expert, but I wonder if when the energy is released into motion, would heat not also be created - you know, like a lightbulb that creates heat and light...... Something about ATP molecules being used up or released during movement and creating heat is in the back of my head.

Or maybe snakes do create light also! I should get a grant to study this, don't you think.

Ryan

[Stockwell]

I'm not sure I understand how "metabolism" is creating heat in reptiles.
Aren't we talking about the microbial digestive processes in the gut simply spreading out and heating the entire animal, or is something else going on?
I would think that even dead snakes produce heat, for a time, while breaking down, just like dead mammals, or a pile of old leaves

[Jeff Hathaway]

Hey Roy,

I haven't read the actual paper, just what I posted, so I can't say with any certainty. However, I believe that they are referring to the actual metabolic processes of the animal creating heat- the burning of glucose, etc. These reactions do produce heat; that is how our bodies do it! We just have regulatory mechanisms in place to maintain a set point:-) I can't imagine decomposition of prey, or a whole snake, maintain a temperature discernible above ambient, as the small amount of heat would be lost to the atmosphere very quickly without a layer of fur or leaves to act as insulation- the outside of the leaf pile isn't warm, only the inside!

Ryan- yes, locomotion would create small amounts of heat as well, in the same manner as muscle twitches for incubating pythons. I'm not aware of any snakes that produce light instead, but who knows what lurking in a cave somewhere with a phosphorescent glow??? I'd love to see that grant application:-)

Jeff Hathaway
Sciensational Sssnakes!!