Melibe coleman. Romblon, Philippines, March 2017)
Melibe coleman. Romblon, Philippines, March 2017)

Melibe colemani, the Grail of nudibranchs

#Philippines #Romblon

  Philippines: Anilao + Romblon - March 2017

Dear English-speaking readers, this page is an automatic translation of an article originally written in French. I apologise for any strange sentences and funny mistakes that may have resulted. If you read French, click on the French flag below to access the original, correct text: 


His name: Melibe colemani. This little sea animal is the star of Romblon, Philippines. Divers are ready to travel thousands of miles to admire this strange sea slug!

A transparent nudibranch

March 2017. I am on the island of Romblon, in the Philippines. "Here we have the Holy Grail of nudibranchs"Philipp, from the diving center, proudly announces The Three P.

The Grail of nudibranchs? Really? What's so special about it? "This is a newly discovered nudibranch, very hard to find and really amazing. But you have to see for yourself. You know, we have divers from all over the world coming here just to photograph it. Its name is Melibe colemani. Tell the guide that you want to see it, he will show you some..."  

And it's true, you have to see it to believe it... This sea slug is translucent! You can see its organs through! 😮

The Melibe colemani shows me its left profile. You can see its organs through its translucent body. (Romblon, Philippines, March 2017)
The Melibe colemani shows me its left profile. You can see its organs through its translucent body. (Romblon, Philippines, March 2017)
The right profile is good too! (Romblon, Philippines, March 2017)
The right profile is good too! (Romblon, Philippines, March 2017)
This specimen of Melibe colemani is quite large, it is well sized in the 4-5 cm range. (Romblon, Philippines, March 2017)
This specimen of Melibe colemani is quite large, it is well sized in the 4-5 cm range. (Romblon, Philippines, March 2017)

This is not the only oddity. Its body is formed of a network of tubes, of a whitish beige color, which are in fact digestive glands. On its back, they extend in imposing excrescences, called cerata.

I admit, I didn't know any of this until I saw my first Melibe colemani... 😍 Besides, even when I have it in front of me, the first time, I can't see anything!

Very difficult to spot

Joseph alias "Erap", my Filipino guide, however, points at something with insistence, pointing two fingers towards his eyes and then the index finger towards a clump of soft coral. Seeing that I don't see anything, he makes a circle with the tip of his pointer above the polyps, at the place where I am supposed to look, and then delicately moves away the "stems" that are waving in the current. But I still see nothing. Nothing at all. For that matter, I don't even know what the thing I'm supposed to see looks like.

And then, at last, that's it!!! I SEE it!

Now, I'm not too sure what I'm seeing. I take a picture a bit at random.... (Romblon, Philippines, March 2017)
Now, I'm not too sure what I'm seeing. I take a picture a bit at random.... (Romblon, Philippines, March 2017)
That's it, I have the click! I finally discern, in this mass of filaments, an animal... There, the Melibe colemani faces me and "looks" at me (so to speak)... (Romblon, Philippines, March 2017)
That's it, I have the click! I finally discern, in this mass of filaments, an animal... There, the Melibe colemani faces me and "looks" at me (Romblon, Philippines, March 2017)

It takes me a little time to locate the front and the back of the beast, which must be about 4-5 centimeters. Moreover, this nudibranch is on the run. With each movement of the swell, it also undulates, moves forward, straightens up, raises its head... Is that its head, there? Wahoooou... I am hallucinating.

Its mouth is like a reticule, a mini net that I guess is capable of capturing tiny and invisible prey that it only has to digest. It is a gelatinous monster. A multiform slug. A phantom nudibranch.

Here he is standing up and seems to take off, raising his funny face. (Romblon, Philippines, March 2017)
Here he is standing up and seems to take off, raising his funny face. (Romblon, Philippines, March 2017)
It looks like he's opening his mouth wide here... (Romblon, Philippines, March 2017)
It looks like he's opening his mouth wide here... (Romblon, Philippines, March 2017)

Moreover, there is not only one... Joseph draws my attention to his little translucent friends. Underwater, there are nudibranchs corners, as there are mushrooms corners in the forest! 😂

Without the eye of my guide and his knowledge of the site (I spoke about it in a previous article on muck-dive), I would never have succeeded in observing and photographing this wonder of nature... The Melibe colemani is so light, so vaporous, that it must be approached with infinite precautions. Because a simple movement of the hand above the small animal is enough to create a current capable of lifting it from the substrate and to make it float in the water. It does not look like anything anymore. One would easily confuse it with a vague spongy debris carried 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 filter-feeder nudibranch named after its discoverer, the Australian naturalist and photographer Neville Coleman (1938-2012). A find made at Mabulthe neighboring island of Sipadanin Malaysia, near Borneo: Coleman published the very first image of it in 2008, in its Nudibranchs Encyclopedia.

I really like the story he tells about the dive during which he saw and photographed for the first time this curious creature, unknown to scientists until then. It took him some time to really see what he had in front of him... The story is reported here on this American website of enthusiasts:

→ The Slug Site: Melibe colemani

Here too we can see the bodies, red in the middle of the transparent body. (Romblon, Philippines, March 2017)
Here too we can see the bodies, red in the middle of the transparent body. (Romblon, Philippines, March 2017)
The swell folds its growths to one side (Romblon, Philippines, March 2017)
The swell folds its growths to one side (Romblon, Philippines, March 2017)
The Melibe colemani crawls, its progression is fascinating to observe. (Romblon, Philippines, March 2017)
The Melibe colemani crawls, its progression is fascinating to observe. (Romblon, Philippines, March 2017)

The nomenclature and scientific description of the species was 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 to their study:

→ An excerpt from the study here
→ A PDF download here

(Coincidence: I discovered while consulting the Facebook page of The Three P diving center, 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, RomblonThe Three P divers first spotted it in 2013.

The species is probably widespread in the waters of the Coral Triangle. But this nudibranch is so difficult to see, that it is not surprising that it was discovered only recently. Particularly coveted by macro photographers, it is considered a rarity. The advantage in Romblon is that the guides know where to find them.

In any case, for me, underwater is ecstasy. The Melibe colemani does not resemble any nudibranch that I could meet until now. This is something new, something strange. What an extraordinary creature! The Grail. I had been told...

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  Philippines: Anilao + Romblon - March 2017

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