Pretty Nudibranch from Lembeh Strait

In 2008 I photographed this nudibranch in Lembeh Strait, while diving from Kungkungan Bay Resort with Nuswanto Lobbu and Captain Jim Black. In those days I was using an Olympus SPS-500 US camera  with one Inon and one Sea&Sea strobe, I forget the models, giving mixed lighting.  This Nudibranch I would like to speciate but am stuck between a Glossodoris, a Chromodoris or a Goniobranchus. Given the ongoing reassignment of Nudibranch species by Dr. Terry Gosliner,  your wise suggestions are welcome.

Hi Elias

I've got a very similar Lembeh pic which, at the time, I thought was Glossodoris cincta,

I've also got a pic of Glossodoris pallida which is also similar. Maybe one of those?

I believe this one is officially an un-described species, that at one time would have been called Glossodoris cincta.  See this link:

https://www.facebook.com/groups/206426176075326/search/?q=cincta

scroll down to the post by Wahrmut Sobainsky, which as a very similar slug also from Lembeh and see the comments.   I do believe you need to be a group member to see the post - it is worthwhile being a member as there are some very experienced people posting there who can assist with ID.

Hi Chris:  Your points are well taken, the taxonomy of nudibranchs is difficult, made even more so by international differences between the US school led by Dr Terence Gosliner of the California Academy of Sciences,  and the Australian tradition of  the late Neville Coleman, carried on, I believe, by Dr Bill Rudman and by the Sea Slug Forum.  For example, if one looks up this nudi, Glossodoris cincta, in the web, the photos that pop up are of fairly different nudis, many quite different, such as with black mantle edges, from the photos I find in the nudi books by Neville Coleman, or by Helmut Debelius, or by Gosliner.  

I looked up the name of the posted G. cincta in the updated Nudibranchs Encyclopedia by Neville Coleman.

To settle the matter on a firm, reproducible basis, Dr. Terry Gosliner has embarked on a many years effort to classify all nudibranchs using DNA taxonomy.  I do not know when the new taxonomy will be published, but so far, Dr Terry has reclassified a lot of nudibranchs, often making it difficult for us plebeians to identify the nudis we meet underwater.  I will ask around, maybe write Dr Terry, to find out where matters stand.  It will be nice to unify the Aussie, US and other nudi classifications into a single DNA based classification.   

10 hours ago, Kraken de Mabini said:

Hi Chris:  Your points are well taken, the taxonomy of nudibranchs is difficult, made even more so by international differences between the US school led by Dr Terence Gosliner of the California Academy of Sciences,  and the Australian tradition of  the late Neville Coleman, carried on, I believe, by Dr Bill Rudman and by the Sea Slug Forum.  For example, if one looks up this nudi, Glossodoris cincta, in the web, the photos that pop up are of fairly different nudis, many quite different, such as with black mantle edges, from the photos I find in the nudi books by Neville Coleman, or by Helmut Debelius, or by Gosliner.  

I looked up the name of the posted G. cincta in the updated Nudibranchs Encyclopedia by Neville Coleman.

To settle the matter on a firm, reproducible basis, Dr. Terry Gosliner has embarked on a many years effort to classify all nudibranchs using DNA taxonomy.  I do not know when the new taxonomy will be published, but so far, Dr Terry has reclassified a lot of nudibranchs, often making it difficult for us plebeians to identify the nudis we meet underwater.  I will ask around, maybe write Dr Terry, to find out where matters stand.  It will be nice to unify the Aussie, US and other nudi classifications into a single DNA based classification.   

To be fair, I believe Bill Rudman and Neville Colman's work was quite some time ago and their books are very much out of date and I'm not sure anyone is still following that taxonomy unless it is people looking up these old references.  Certainly most people I know over here seem to follow Gosliner's work and the NSSI book he is a co-author of is certainly a primary reference for tropical nudis.   Temperate nudis are a little more difficult.

The Seaslug forum and the Kuiter and Debelius book are certainly still good references but you need to take the name and transfer it to the new taxonomy.  If it's tropical you can try looking it up in NSSI or searching for the name on Nudibase Facebook group.  There used to be a couple of good websites that assisted with ID but they seem to have gone by the wayside.  I tend to use Nudibase for ID questions as it seems quite authoritative and people seem familiar with the latest research.

I have just been in contact with David Behrens, a coauthor with Terry Gosliner of their book on nudibranchs, and he tells me the nudibranch reclassification work is still going on and will take several more years, as it involves many hundreds of nudis and a great deal of work for each.
Until further notice, we can continue to rely on the nudibranch books by Gosliner et al, Coleman, Debelius and similar. 

Regarding Glossodoris cincta, its classification and name remain the same and there is no plan to change it, per Dave Behrens, Mike Miller and Capt Jim Black. Until further work is published, the G. cincta photo and its description in the books by Neville Coleman and Helmut Debelius are timely and correct.   

21 hours ago, Kraken de Mabini said:

I have just been in contact with David Behrens, a coauthor with Terry Gosliner of their book on nudibranchs, and he tells me the nudibranch reclassification work is still going on and will take several more years, as it involves many hundreds of nudis and a great deal of work for each.
Until further notice, we can continue to rely on the nudibranch books by Gosliner et al, Coleman, Debelius and similar. 

Regarding Glossodoris cincta, its classification and name remain the same and there is no plan to change it, per Dave Behrens, Mike Miller and Capt Jim Black. Until further work is published, the G. cincta photo and its description in the books by Neville Coleman and Helmut Debelius are timely and correct.   

Interesting,  I would add, particularly for older publications to cross check once you have found your slug, many have already been re-classified, particularly chromodorids.  You could look it up in WORMS for example.

The Sea Slug Forum from Australia posts up to date id's on nudibranchs.  

http://www.seaslugforum.net/general.htm

23 hours ago, Kraken de Mabini said:

The Sea Slug Forum from Australia posts up to date id's on nudibranchs.  

http://www.seaslugforum.net/general.htm

The Sea Slug forum has not been updated since around 2010, it was a great resource in its day.  It can still be quite useful if you take your ID from it and google to check for name changes.  For Chromodoris splendida is now Goniobranchus splendidus and googling the old name will bring up an article with new names.  Many of of the former Chomodoris nudis are now listed as Goniobranchus in the Gosliner/Valdes/Behrens NSSI Book.

Other examples where it is out of date include Pteraeolidia ianthina - the forum only lists one species for all locations, it has since been clarified that Pteraeolidia ianthina is only found in temperate waters off the east coast of Australia and Pteraeolidia semperi is found elsewhere and possibly other species exist.