The Thorny Devil Lizard’s Moisture-Extracting Skin
THE Australian thorny devil lizard (Moloch horridus) extracts moisture from fog, humidity, and wet sand. Then it channels the water to its mouth for drinking. How? The answer may lie in the lizard’s amazing skin.
The thorny devil’s skin is overlaid with scales. Some scientists think that moisture or dew collected on the scales runs down to the rough surface of the skin and enters the skin’s network of half-open channels, or grooves, located between the scales. These channels are interconnected and lead to the sides of the thorny devil’s mouth.
But how does this lizard draw up water—up its legs, across its body, and into its mouth— defying gravity in the process? And how does the thorny devil extract moisture from wet surfaces by rubbing its belly against them? —a phenomenon in which water is drawn into narrow spaces even against the force of gravity. The lizard’s skin thus acts as a sponge.