That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information

Recently I reported on a study that documented declines of 50-90% in 17 populations of 8 snake species (please see article linked below).  These findings brought to mind the global amphibian decline that was first uncovered in 1990.  Since then, an emerging disease caused by the fungus Batrachochytrium dendrobatitis has likely caused the extinctions of over 100 frog species.  Researchers seeking to avoid a similar crisis among the world’s snakes have now identified an emerging illness, Snake Fungal Disease, as cause for serious concern.  Associated with a newly-described fungus, Chrysosporium ophiodiicola, the disease has been found in several species in 9 states (USA), but is likely much more widespread.

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New Victims of a New Fungus

The global snake declines mentioned above first came to light in the late 1990’s, but explanations remain elusive.  In 2008, herpetologists became alarmed when Eastern Massasaugas (or Swamp Rattlesnakes) in Illinois and Timber Rattlesnakes in New Hampshire showed evidence of an unusual fungal infection.  A fungus (Chrysosporium sp.) that had previously been isolated from captive snakes, but never in the wild, was identified from head lesions on the Timber and Swamp Rattlesnakes.  All of the snakes submitted for study expired.

In April of 2013, the USGS National Wildlife Health Center announced the discovery of a fungus new to science, Chrysosporium ophiodiicola.  This fungus has been implicated in an emerging disease that is now afflicting snakes in the Eastern and Midwestern USA.  Increasing numbers of snakes showing evidence of infection have been found by USGS biologists, who fear that the disease may devastate snake populations. Read More »

Like most reptile keepers, I have often marveled at the efficiency of snake digestive systems.  I attributed their abilities to break down bone to “powerful digestive enzymes”, but recent research has shown that, at least for Burmese Pythons (Python molurus), a far more complex and amazing process is at work.

Digesting Large Vertebrates

I’ve observed some quite large snake feasts – a Red Foot Tortoise and a 60 pound deer taken by Green Anacondas (the tortoise was an unfortunate exhibit mate; the deer fell to an anaconda at my study site in Venezuela) and 40 pound pigs regularly fed to Reticulated and Burmese Pythons under my care at the Bronx Zoo, for example.

A few shell scutes, hoofs, some bone fragments and fur where all that passed in the feces of these snakes – the rest being digested.  How do they do it?

Bone-Digesting Cells

Research at the Louis Pasteur and Indiana Universities has revealed that, after feeding, the digestive systems of Burmese Pythons undergo a dramatic transformation.  New cells are produced and worn-out cells die and are eliminated in preparation for the work at hand.

Studies of the small intestine have uncovered a new type of cell, previously unknown to science.  These cells are responsible for degrading bone and releasing its components into the snake’s bloodstream.  This process promotes efficient calcium absorption, and may be the reason that most captive snakes do not require a UVB source if fed a diet comprised of whole rats, mice and other vertebrates.

Warm-Blooded Snakes?  Not Quite, but…

We’ve known for some time now that Burmese Pythons break the “cold-blooded” rule when digesting their meals.  While most snakes must seek out a hot basking spot in order to maximize digestion, Burmese Pythons can actually raise their internal temperatures without an external heat source! 

Further Reading

Please see Big Snake Meals for some examples of how large (and unusual) snake prey can be.

To read about recent research concerning another unusual snake feeding adaptation, please see How Snakes Grow despite Food Deprivation.

An account of the original research showing that pythons can raise their body temperatures may be found in this Journal of Herpetology article.