Researchers just discovered that the thorny devil lizard has a unique way to draw in moisture. The odd reptile extracts water from sand through special skin folds. The findings are in a paper that was just published in the Journal of Experimental Biology.
The thorny devil (Moloch horridus), also known as the thorny dragon, is a lizard found throughout most of central Australia. Their bodies are covered in thorny scales and spikes to deter predators. They’re also experts at camouflage and move slowly in an attempt to blend in with the desert environment. Thorny devils feed exclusively on ants. They can survive on very little water and can channel moisture into their mouth through grooves in their skin. This capillary action allows them to drink by simply standing in water or rainfall. Researchers believed they could have other methods of drinking, however, since they live in such dry areas. With so little rainfall, there had to be another mechanism for gathering moisture.
A team of researchers from Aachen University in Germany captured a small group of wild thorny devils. The team had the lizards stand in damp sand to see if they could derive enough water to drink. While the capillary channels did begin to fill, the lizards didn’t gather enough moisture to actually drink. The researchers used skin replicas to further their investigation. They found that while standing in moist sand didn’t provide enough water, being covered in the sand completely filled up the channels. It was a slow process but explains the lizards’ habit of kicking sand onto their backs. Previously, this behavior was attributed to camouflage but it appears to also aid in hydration during drought conditions.
The team’s findings provide an explanation for how thorny devils manage to survive in desert regions. While the lizards gain most of their water through their diet of ants, they can also absorb moisture from sand when needed. This unusual adaptation allows thorny devils to thrive in harsh, arid environments.
Comanns et al. Cutaneous water collection by a moisture-harvesting lizard, the thorny devil. The Journal of Experimental Biology (2016).