What is a Scincus scincus?
Also known as the common sandfish or common skink, the Scincus scincus is a species of skink that lives in the Sahara
How does the sandfish swim through sand?
To avoid predators and the relentless sun, the sandfish opts for subterranean travel, plunging head-first into the ground and navigating the safer and cooler subsurface. But, unlike a mole or prairie dog, it does not rely on a network of tunnels – it swims through the sand.
The initial dive is a lot like a swimmer’s front crawl. The lizard alternately extends and pushes back with its left and right limbs, penetrating deeper with each stroke. Once submerged, it pins its legs to its sides and zigzags like a snake, using its whole body to generate enough power. With this method, the sandfish moves itself through a sea of solid particles at about one body length per second – that’s better than an Olympic swimmer can do in the water.
The reptile’s wedge-shaped snout makes a convenient cutting edge and its clear eyelids act as protective windows while the animal moves, but its unique scales are what make its underground journeys possible.
Each is covered with countless microscopic, tooth-like protrusions. Believe it or not, this rough surface actually reduces friction to almost nothing, as the weight of each grain of sand is distributed over some 20,000 contact points – the sandfish is more slippery than Teflon. This surface structure is also hardier than steel, ensuring the lizard a lifetime of relatively easy travel in its hostile habitat.
What do sandfish eat?
Sandfish eat insects. While avoiding the heat of the day, under the surface they listen for the vibrations insects make as they move around, then grab their victims
How big are the sandfish?
Scincus scincus can grow up to 20 cm (8 inches) long, including the tail
Main image: Desert sandfish © Getty Images