Swimming in the sand

If you look at the two photos above, you will notice that the sand has
moved – there is something down there…….

I have long been fascinated by the sandfish – the sand swimmer, the sand
skink, or Scincus scincus – and wrote
about this remarkable critter and its contribution to robotics a couple of
times (see the link there for the earlier piece). But I never thought that I
would actually see one and watch its performance.

However, during my recent visit to the Moroccan Sahara for a couple of days
on the hump of a camel (more – perhaps – of that later), I was lucky. My guide
and cameleer, Ibrahim, knew the desert like the back of his hand, every track
and trail in the sand, every burrow, every bush, and, thank heavens, every
route. We paused for a rest at a small oasis:

Ibrahim, grinning, comes up to me and opens his hand, in which, pert and
unperturbed, was a sandfish, the poisson du sable.

After a little research on my return, I see that this is not Scincus
scincus, the robotic inspiration, but probably its western cousin,
Scincus albifasciatus laterimaculatus  - hardly important here, because
both have the same amazing abilities. They doliterally swim into and
under the sand. It’s all beautifully fluid – the movement of the skink
and the behaviour of the sand (click image to enlarge):

We re-excavated the poor little fellow several times and put him (or her –
skink-sexing is not an area of my expertise) through his/her paces until the
little critter became somewhat exhausted. A drink of water proved reviving, and
off he/she disappeared into the sands.

As evidenced by the astonishing network of tracks and trails that greet you
each morning in the sand, the majority of the local inhabitants are nocturnal.
The sandfish is an exception, on the move during the day, and I am immensely
grateful to Ibrahim and this delightful little skink for the pleasure of this
meeting. SIGNATURE

Comments

Richard Bready (2013-04-19):

Charming chap, or chapess. So much prettier than a naked mole rat, a star mole, or other near-surface dwellers. Thanks for the encounter, and the splendid photos. Skink and swim. Hope the camels were as engaging. Glad your journey went well.

dan@sandandgravelsurrey (2013-05-15):

Sand fish are true wild animals that cannot breed in captivity. I recently read a NASA article on the study of the sand fish and how it moves through the different density’s of sand. They intend to apply their findings on burrowing robots…For Mars I assume!

Sandglass (2013-05-15):

A number of different robotics labs are already working on this - see the linked posts.

Originally published at: https://throughthesandglass.typepad.com/through_the_sandglass/2013/04/swimming-in-the-sand.html