11 February 2015

The Secret Lives of Sand Bubbler Crabs

“The path to grandeur starts by assembling tiny forces” – Seb Tzu in The Art of Beach War

Sand bubbler crab, Cambodia

The cannonballs were ready, the trenches perfectly dug out. Thousands of cannonballs had been methodically prepared and lined up around the trenches, awaiting to be hurled at the enemy’s fortresses. The time had finally come for the army of tiny sand crabs to claim their territory back from the race of human beings by attacking their sand castles. And if any of those children dared approaching too close, the crabs would snap right back into their circular trench holes.

Sand bubbler crab, Cambodia

But the battle never took place.

The crabs and the little children suddenly realised that external forces risked overwhelming them. The minuscule crabs hid into their tiny burrows; and the little children ran to their mothers’ arms.

The tide came back up and washed the sand cannonballs and fortresses away.

Interlude. The tide ebbed away.

Sand bubbler crab, Cambodia

“Knock, knock, anyone there? I won’t kick you, I promise!” It did take me some fourteen years to realise that those poor things do have a brain and actually feel pain (read comments on a two-year old post about Thailand’s beautiful hermit crabs: http://goo.gl/7Wwyn). “I’m just here to take pictures of you”.

Sebastian capturing crabs, Cambodia

I completely lied down on the sand – connected to Mother Earth if you will (I will stop with innuendos right away... bad, bad Sebastian). That section of Otres Beach, near Sihanoukville in Cambodia, was a clean stretch of white warm sand. I waited quietly for the adorable one-centimetre-wide crabs to reassuredly come out of their burrows again. Those tiny crabs only exist in parts of southeast Asia but one has to pay attention to actually notice them on the beach. In addition, the light of the sun is often so strong that they appear to be the same colour and pattern as the sand. But upon closer inspection, and some post-processing, it’s possible to discern that these crabs are actually… blue and orange!

Patterns of sand pellets
Sand bubbler crab, Cambodia

The nervous crab I was waiting for cautiously checked multiple times whether it was safe for it to emerge from its circular hole. It then resumed its very peculiar feeding activity, for it had already finished digging its burrow out, having removed all the sand till the tunnel reached the water table. It therefore started sifting through sand particles, pushing them to its mouth with one of its claws, trying to find the even more tiny edible coating at the surface of sand grains. Yummy.

It became even more interesting afterwards. The crab rotated the sand in its mouth and once the accumulated sand became too big, the crab disdainfully kicked the neatly-created round pellet of sand behind it. The crab then moved on to scraping the next teeny-tiny chunk of sand nearby, moving radially away from its burrow. Those so-called “sand bubbler crabs” are actually quite ingenious: by creating little balls of processed sand, they thus make sure not to chew on the same sand from which they had already extracted all the organic matter from – watch the following short video for some live action:


Suddenly, the crab sensed danger: the sea was near, once again. The crab instantly disappeared in its burrow.

The tide came back up and washed the sand pellets, and me, away.

Interlude. The tide ebbed away.

Many crabs emerged from their holes, as if they had synchronised their swift movements. They started creating and discarding little same-sized sand spheres once again, not without reminding me of Sisyphus’s rolling of a boulder all the way up a hill before seeing it roll back down again – except that the crabs at least fed themselves before the sea would disintegrate everything.

The radial motion of the crabs led to the formation of sand ball galaxies on the beach. Crab-drone technology had not been invented yet. The crabs could therefore not grasp the beauty of the ephemeral art they were creating. Individually, a crab’s output didn’t matter. Add another crab’s output and that collaborative harmony started looking meaningful, even pretty. There is something comforting in the aesthetic observation of the parallel movement of the industrious crabs and of the intricate patterns drawn on the sand.

Patterns of sand pellets

Look too closely and you’ll only notice the individual sand pellets. Stand up and they become indistinguishable, leaving the observer’s imagination run free to interpret those gradually-emerging constellations. This improvised art reminded me of Pointillism, that nineteenth-century technique of painting in small, distinct dots of complementary colours, juxtaposed to eventually form an overall image. If you’ve never heard of that style, give a look at the very first work, Baigneurs à Asnières, of the creator of that technique, Frenchman Georges Seurat, although I find Paul Signac’s Palais des Papes more pleasing to the eye.

It’s as if not mixing colours on a palette but instead keeping them separate allowed the artist to paint something more ”pure”, more powerful. There’s both an emotional and rational explanation for why some view Pointillism that way. Emotional because the colour blending is achieved by the eye and the brain as opposed to being achieved by the brush – and quite naturally the brain is considered as superior to mere objects. Rational because it’s the same optical principle used in TVs: mixing independent rays of light is additive since each coloured ray corresponds to a frequency; so simultaneously projecting red, blue and green lights produces a white light. On the other hand, mixing paint is subtractive since the resulting colour is made up of all frequencies not absorbed by each pigment; so simultaneously mixing cyan, magenta and yellow produces black paint.

Sand bubbler crab, Cambodia

Maybe there’s a lesson to be taken here: would it be perhaps worth preserving some independence between things or people, and find ways to complement them, hoping that something beautiful will emerge, instead of seeking to blend or unify them? Aristotle’s saying, "the whole is greater than the sum of the parts”, should perhaps consequentially be extended to express that this is only true when the parts are not merged? How can one also tell that the combination will be complementary, additive and not incoherent, destructive? Is it a risk worth taking? And what’s the real risk anyway: feeling disappointed or hurt? being laughed at?

Being mocked, hmm... for the related anecdote, the name of that painting method – Pointillism – was initially given by art critics to mock it, although even Van Gogh adopted elements from it. I don’t know why that name stuck though, even if the negative connotation has since disappeared: after all, Seurat had given a name to the technique, coining it as “Chromoluminarism”, which does perhaps sound a bit too technical.

I however like Seurat’s scientific approach to his art. According to him, colour could be used to generate emotion, just like music could use variation to obtain harmony. Coincidentally, I discovered there’s something called “Punctualism” in music which then reminded me of this interesting graphical way of representing music:


So neo-impressionist painters, as they were called, codified this art: joy and happiness would be depicted with warm colours and lines going up, while sadness would be painted with dark and cold colours and lines going down.

Connecting the dots, excuse the pun, or rather the sand balls, excuse the double pun, with my little crabs, they were for sure far from worrying about such artistic considerations. There is something a little distressing about the lack of appreciation of art though, let alone when it’s subject to quick disappearance (let’s call this “Snapart” maybe).

If Seurat had counted on leaving a legacy beyond painting, he would have been disappointed. Both of his children died at young age. In fact, Seurat himself died a mere seven years after he invented Pointillism, of the same illness that would then cause the death of his little son two weeks later. Seurat was 31.

The tide came back up and washed the little crabs’ art, and Georges Seurat, away.