The Specialized Diestive System of Snakes

Eating, or ingesting food, is one of the main characteristics of the animal kingdom. The digestive system, that enables animals to digest and absorb food, is generally one of the most complex of the organ systems. Often, the digestive system is also specially adapted for the particular type of food or feeding behavior of the animal.

Recently, scientists studied the digestive system (specifically the small intestine) of certain snakes, such as vipers, boa constrictors, and pythons. In these snakes the period of time between meals can range from a few weeks to several months. It was found that during the long periods of fasting that the lining, or mucosa, of the small intestine becomes atrophied (i.e., decreases in thickness and activity), conserving the body's energy and resources.

Snakes such as these consume large meals ranging from 50% to as much as 160% of their body weight. To accommodate such a large meal the snake needs a fully functional digestive system. It was found that feeding stimulates rapid growth of the intestinal lining. The weight of the small intestine can actually double in a few hours after a meal due to the rapid growth of the mucosa. One study demonstrated that the activity of the intestinal cells also increases after a meal. It was found, for example, that the uptake of nutrients, such as amino acids, increased by as much as 16 fold over a period of three days.

Thus, the digestive system of these snakes is well adapted to their intermittent feeding behavior. During times of fasting, the small intestine becomes less active and atrophied. Following a meal, however, this organ quickly adjusts to the increased demands, enters into a period of rapid growth and increased activity, all of which is necessary to assimilate the large meal.

Though disliked and feared by many, even snakes can remind us of the greatness of God's creation. Highly specialized and efficient adaptations such as these clearly point to the wisdom of the One who made them.

Reference: A. R. Cossins and N. Roberts, "The Gut in Feast and Famine," Nature 379:23, January 4, 1996.


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