Grooves on spikes of thorny devil lizard provide drinking water by drawing condensed dew to mouth by capillary action.

The Thorny Devil (Moloch horridus) can gather all the water it needs directly from rain, standing water, or from soil moisture, against gravity without using energy or a pumping device. Water is conveyed to this desert lizard’s mouth by capillary action through a circulatory system on the surface of its skin, comprised of semi-enclosed channels 5-150 µm wide running between cutaneous scales. Channel surfaces are heavily convoluted, greatly increasing the effective surface area to which water can hydrogen-bond and hence capillary action force. Passive collection and distribution systems of naturally distilled water could help provide clean water supplies to the 1 billion people estimated to lack this vital resource, reduce the energy consumption required in collecting and transporting water by pump action (e.g., to the tops of buildings), and provide a variety of other inexpensive technological solutions such as managing heat through evaporative cooling systems, protecting structures from fire through on-demand water barriers, etc.

References

“The thorny devil, a tiny highly specialised lizard from the central Australian desert which lives entirely on ants has each scale enlarged and drawn out to a point in the centre. Few birds could relish such a thorny mouthful and to that extent, they must be a very effective defence, but the shape of the scales also serves another and most unusual function. Each is scored with very thin grooves radiating from the central peak. During cold nights, dew condenses on them and is drawn by capillary action along the grooves and eventually down to the tiny creature’s mouth.” (Attenborough 1979:164)

Book
Life on Earth: A Natural HistoryMarch 1, 1970
David Attenborough

Journal article
A synthetic biology challenge: making cells computeMol. BioSyst.December 5, 2016
Cheemeng Tan, Hao Song, Jarad Niemi, Lingchong You

Journal article
Cutaneous Water Acquisition by the Thorny Devil (Moloch horridus: Agamidae)Journal of HerpetologyMay 5, 2006
Philip Withers

Journal article
Rain-Drinking Behaviors of the Australian Thorny Devil (Sauria: Agamidae)Journal of HerpetologyMay 5, 2006
Wade C. Sherbrooke

Journal article
Uptake of Water by the Lizard, Moloch horridusNatureMay 7, 2006
P. J. BENTLEY, W. F. C. BLUMER

Journal article
Functional morphology of scale hinges used to transport water: convergent drinking adaptations in desert lizards (Moloch horridus and Phrynosoma cornutum)ZoomorphologyDecember 5, 2016
Wade C. Sherbrooke, Andrew J. Scardino, Rocky de Nys, Lin Schwarzkopf

Organism
Thorny DevilMoloch horridusSpecies