Dear English-speaking readers, this page is an automatic Google translation from a post originally written in French. My apologies for the weird sentences and the funny mistakes that could gave been generated during the process. If you can read French, the original and correct version can be found here:
This small marine animal is the star of Romblon, Philippines. Divers are ready to travel thousands of kilometers to admire this strange sea slug!
A transparent nudibranch
March 2017. I am on the island of Romblon, in the Phillippines. "Here we have the Holy Grail of nudibranchs", announces me proudly Philipp, of the diving center The Three P.
The Nudibranch Grail? Carrément? What's so special about it? "It's a newly discovered nudibranch, very hard to find and really amazing. But you have to see for yourself. You know, we have divers from around the world who come here just to photograph it. His name is Melibe colemani. Tell the guide you want to see, he'll show you ... "
And it's true, you have to see it to believe it ... This sea slug is translucent! We see his organs through! 😮
This is not the only quirk. His body is a network of tubes, a whitish beige color, which are in fact digestive glands. On its back, they extend in imposing outgrowths, called cerata.
I admit, I did not know anything about that before I had my first Melibe colemani... 😍 By the way, even when I have it in front of me, the first time, I do not see anything!
Very difficult to spot
Joseph, aka "Erap," my Filipino guide, still points to something with insistence, pointing two fingers at his eyes and then his index finger at a tuft of soft coral. Seeing that I do not see anything, he makes a circle with the tip of his pointer above the polyps, where I am supposed to look, then gently removes the "rods" that dotted in the current. But I still do not see anything. Nothing at all. Besides, I do not even know what the trick looks like.
And then, finally, that's it! ! ! I see him !
I need a little more time to spot the front and back of the beast, which must be within 4-5 centimeters. In addition, he runs, this nudibranch. With each movement of waves, he waves too, moves forward, stands up, raises his head ... It's his head, there? Wahoooou ... I hallucinate.
His mouth is like a reticle, a mini-net that I guess can capture tiny and invisible prey that he has to digest. It's a gelatinous monster. A multiform slug. A ghost nudibranch.
In addition, there is not only one ... Joseph draws my attention to his translucent little friends. Underwater, there are nudibranch corners, as there are mushroom corners in the forest! 😂
Without the eye of my guide and his knowledge of the site (I mentioned in a previous article on muck-dive), I would never have managed to observe and photograph this wonder of nature ... Melibe colemani is so light, so vaporous, that it must be approached with infinite precautions. Because a simple movement of the hand over the little beast is enough to create a current able to lift it from the substrate and float it in full water. It does not look like anything anymore, then. It would be easily confused with a vague spongy debris washed away by the current.
During this dive - and a few others the following days, where I will ask again to see the Melibe colemani - So I spend a very long time stuck on the spot, to observe and photograph the tiny and fascinating animal. A game of patience ...
Melibe colemani, a recent discovery
The Melibe colemani is a nudibranch filterer who was named after the man who discovered him, the Australian naturalist and photographer Neville Coleman (1938-2012). A find made at Mabul, the neighboring island of Sipadan, in Malaysia, near Borneo: Coleman published the first image in 2008, in its Nudibranchs Encyclopedia.
I really like his account of the dive in which he first saw and photographed this curious little creature, hitherto unknown to scientists. He also took time to really see what he had in front of him ... The story is reported here on this American site of enthusiasts:
The nomenclature and scientific description of the species were only established in 2012 (one month after Coleman's death) by two marine biologists specializing in nudibranchs, the Spanish Marta Pola and the American Terrence Gosliner. For science buffs, here are two links (in English) to their study:
(Coincidentally, I discovered on The Three P dive center's Facebook page that Terrence Gosliner also spent a week in Romblon recently, in April 2017, for his scientific research!)
In addition to Mabul in Malaysia, Melibe colemani has also been observed in Indonesia Komodo and Lembeh. In the Philippines, Romblon, divers at The Three P Center spotted it for the first time in 2013.
The species is probably widespread in the waters of the Coral Triangle. But this nudibranch is so hard to see, that it is not surprising that it was discovered only recently. Especially coveted by the divers photographers macro, it is considered a rarity. The advantage in Romblon is that the guides know where to find them.
In any case, for me, under water, it's ecstasy. The Melibe colemani does not look like any nudibranch I've encountered so far. It's new, strange. What an extraordinary creature! The Graal. I had been told ...