Category Archives: Nudibranches

Roboastra Gracilis


Small, beautiful, elegant  but dangerous. Mostly we (ai Alexander Schepens #divertothecore ) are finding this nudibranch along the islands of Racha Yai and Racha Noi in Phuket Thailand.

This relatively small nembrothid is growing to about 20-25mm in length. Characterised by the orange longitudinal lines which are sometimes quite onscure. These lines consist of a series of glandular pits which secrete a bright orange substance when disturbed.  This species is a member of a genus which hunts down and eats other opisthobranchs. The large oral tentacles (arrowed) are found in all members of Roboastra and are probably important in tracking down their prey, perhaps by following its mucus trail. Some variants have iso of orange rather yellow stripes._jks4382_jks4376_jks4369_jks4348_jks4346_jks4343


@All for a smile




Nembrotha Kubaryana30

We love diving in Mabul – Borneo

The dive sites are all rich in marine live and a paradise for Macro lovers. Natasha and i had the pleasure diving there with both our sons (be it not with both at them at the same time  so far) Alexander and Constantijn…..always under the dive guidance of one of the best dive instructors we ever have been diving with Ramil Densing Reasonable at Sipadan Water Village.

The Nembrotha Kubaryana is easily confused with a similar species, Nembrotha Cristata although the latter has no red orange border on its foot. As you see from the photo above as our friend was climbing the rock you see a bit of orange on his back and front part.


Also on the second picture the close observer will see that hidden behind the marvellous green is a bit of orange.

Both species the Kubaryana and the Cristata are pretty aggressive nudibranches that would not mind “eating one of their own” …out of pure “love”.

Enjoy a fantastic colourful Valentines day

@All for a smile



Colpodaspis Thompsoni


The last 2 days I shared @All for a smile, 2 for us “new” nudi’s. Today I am posting 2 pictures of the Colpodaspis Thompsoni….another “new” nudi for us.

All 3 of them we saw during our last diving trip to Phuket Thailand and on our last diving day on Jan 5th at Racha Noi – Racha Yai. The Colpodaspis Thompsoni  Alexander Schepens found in Bungalow bay at the end of the dive as we were almost swimming out of the bay with the island on the right shoulder at 12 meter depth. With a size of max o,5 cm a very small brightly coloured, snail-like sea slug.

“The fragile bubble-shaped shell is completely enveloped by the mantle. On the right side of the mantle there is an elongate exhalent siphon. The head is produced into a pair of enrolled tentacles or rhinophores which lead to a deep lateral groove on each side. The eyes are embedded beneath the skin and can be seen as two black spots just in front of the shell. There is a large central mucus gland in the sole of the foot which probably produces a sticky mucus enabling the animal to stick on the algae on which it is found. It is black with large yellowish warts on white patches.
We know nothing of the biology or food of any species of Colpodaspis.

The placing of Colpodaspis with Diaphana and Newnesia in the Diaphanoidea, by most experts, is a marriage of convenience rather than a convincing statement of phylogenetic relationships. Further studies are required before we can say anything sensible about their relationship to each other and to other opisthobranchs.”

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@ All for Smile


Hypsolodoris Constantinos …?

_jks2181During the same dive (cfr. my previous post re Chromodoris Hintuanensis) Constantijn pointed out a very interesting species …..4 mm wide and about 2 cm long …slowly crawling on a hairy rock. While I was taking the picture my brain was already getting excited as this was the second new species in one dive. I had never seen this nudi. _jks2182

Back on the boat we all started looking in the Nudibranch books and could not find any hint to this species. That is when we baptised this species as being the “hypsolodoris Constantinos”.



Later that week Jeffrey Davies found a link via Nudipixel identifying this species as PHYLLIDIA MONACHA.

“This small phyllidiid is characterised by 3, mid-dorsal, longitudinal ridges formed by tiny tubercles plus lots of small, simple tubercles on the flanks resembling those of Phyllidia coelestis. Colour wise the central area is orange and the crests of the ridges are white. On the flanks is a black line (either, simple and straight as in Indonesian specimens, or enlarged and wavy as in the animals from the Red Sea) outlined in white. These broad white halos/stripes are composed of large pigment granules resembling those of Phyllidia willani. The rhinophores are dark orange. This species is uncommon and it was previously only known from the Red Sea. There is a photo of a specimen from Flores in Debelius & Kuiter (page 270, middle of bottom row) — Richard Willan”.

So now we also know that the Phyllidia Monacha is not only living in the Red sea but is also home to Racha Noy …at Maritta’s rock.

@ All for a smile




Chromodoris Hintuanensis

img_3069Early January 2017. It is Friday and Racha Noi day in Chalong with Seabees diving. For Natasha and me it is also our last diving day of this holiday as we need to fly back to Almaty Kazakhstan to take on our professional duties (which for the time being are not yet full time diving). The tour leader on the Excalibur II is Alexander Schepens. Also today he had a marvellous team of dive instructors on the boat as always….and not by accident(;,. We are lucky to have also Jeffrey Davies, one of the worlds famous Nudibranch experts on the boat….and while we are not diving in the same “dive group” we decided to be diving closely together. Good specialists together see more then on their own….l’union fait la force_jks2149

The first dive is at Maritta Rock. Natasha and I are diving with Alexander as our dive instructor and with Nick another “loyal” seabees diver. As we decent into the crystal clear water  we enjoy the big boulders and soon we are at +- 23 meter. On the edge of a very big boulder Jeff is photographing the Chromodoris Hintuanensis. For me it is the first time I see this nudibranch in Phuket. I take 3 pictures with my Nikon D800 at F16 and 1/200 at ISO200._jks2149-imp

After the dive also Jeff can not immediately remember the name and when he has seen the Hintuanensis the last time….turns out that in 2008 he posted the last sighting on Nudipixel. Very happy to have found a for us “new species”. We finish a very nice first dive of the day.

After lunch we do the second dive of the day at Racha Noy “Natka Rock”….always quite and “easy”…..but never boring and always ready for some new “news”. We frankly called the dive site like this as the Thai name we always forget ….and as it is next to “Maritta rock”…and Natka is my better second half and super dive lady and dive partner.

This time Natka and I dive with Alexander, Nick and Ladina. What a big surprise when we find after a few minutes already another Chromodoris Hintuanensis, this time a very juvenile one. Also new, at least for us is that in this specimen the rhinophores are disproportionately developed. Be it an aberation of nature or a “normal” evolution where juveniles have when they are very young disproportionate rhinophores we do not know yet… if you have any inside on this just let us know.




On the same dive day we found for us 3 more “new species” of nudibranches that at least Natasha , Alexander, Ladina and I have never seen on Racha Noy…..more on this in some later post.

Enjoy the beauty of the see….

@ All for a smile



Halgerda, a dream in orange to enjoy

Halgerda Bacalusia – Phi Phi Island – Turtle Rock – found by Alexander

Halgerda is a genus of sea slugs, dorid nudibranchs, shell-less marine gastropod mollusks in the family Discodorididae… this is a mouth full when you check out Wikipedia.


The ovate bodies of the members of this nudibranch family are covered with dorsal tubercles and ridges. the rhinophores and the gills are retractable and mostly white with dark brown to black lines. Members of this genus are oval in shape with the mantle overlaying the foot. They feed normally on sponges creating often a nice background for underwater photographers. There are a lot of species already named but if anything there are still quite some of them out there not named at all. Do you want to take on the challenge and eternalise your name with one of these beauties baring your name ?

All my pictures are taken in Phuket and Similan Islands. Friends informed me that they also got some nice shots from Indonesia so more beauty to come …

Halgerda Stricklandi  Phi Phi Island – Turtle rock – found by George
Halgerda Stricklandi – Similan Islands


Juvenile hiding behind Mommie….

Enjoy a fantastic Sunday

© All for a smile





Jan 1th 2016 ….Cuthona Sibogae

_JKS3706 - Version 5During old years day, december 31th of 2015 we had a hec of a diving day in the ” Northern part of the Similans”.  During the day we had likely the strongest “current” dive out of my 450 + dive history. We jumped at the Koh Tachai pinnacle without being at the mooring line. And while we jumped close to the mooring line a mooring line has never been further away. We were swimmng  against the current to finally reach the line. It was like running a 100 meter sprint that turned into a 400 m steeple chase. 60 Bar later we had protection down there behind the rocks. When we came up the wind blow stronger and Nelson , the Marco Polo tourleader, decided to go straight to Surin so that we could try on new years day to get to the famous Richelieu Rock.

Jan 1th 2016…..04.00 am (did we sleep already…?) the captain is leaving the protected bay in Surin to make way to Richelieu. An hour later we are back on the bay. The waves are simply too big and while we could get there diving would be not safe. So we celebrate our first dive of the year in Surin. Guess whom we meet under the water…our good friend Ricardo from the Giamani is wishing us with a perfect side mount trim “happy new-year” under the water…..

Later that day the wind is calming down and we make our way to Richelieu Rock. Our dive  there turned out to be one of the highlights of our trip. 20 min in the dive this nudibranch Cuthona Sibogae is welcoming us in his house together with his/her partner._JKS3708

They are moderately large aeolid nudibranch in which the cerata are arranged in about eight fan-like clusters on each side of the body. The cerata are cylindrical, tapering at the tip to a rounded point. The general body colouration is pale lilac purple. The oral tentacles and the upper half of the slender smooth rhinophores are a reddish purple. The cerata are similar in colour to the body except for a bright golden yellow tip and a band just below the yellow tip which ranges from deep reddish purple to deep purple. Many of the smaller outer cerata in each row are golden yellow with nno purplish basal region. It grows to 35mm in length. It is usually found associated with its food, an orange hydroid, Sertularella quadridens.

Thanks to Alexander and the entire Marco-Polo crew under leadership of Nelson and Anita for showing is this wonderful Nudibranch. Enjoy.


_JKS3706 - Version 5

© All for a smile,