Doris bicolor

Gary Cobb Opinion needed! I have two Gymnodoris species that were ID'd by Richard Willan a number of years ago as A. Gymnodoris bicolor and B. Gymnodoris aff. citrina. It is my opinion they are A. Gymnodoris citrina and B. Gymnodoris bicolor. Does anyone another opinion? Thank you!

Kristin Anderson I wish I could help! A looks exactly like the G bicolour examples in Coleman's Nudibranchs Encyclopedia, but that's certainly not the last word!

Vishal Bhave Alder and Hancock (1864) described species G. bicolor as "Body elliptic-oblong, nearly linear, tapering to a blunt point behind, white on the head and sides, with an oval dorsal area of a blackish colour, the whole spotted with golden yellow. Tentacles clavate and laminated, white, with the apex and anterior portion yellow; retractile within cavities. Branchial plumes twelve or thirteen, pinnate, forming a circle on the centre of the back ; white, with a yellow midrib externally, and yellow tips. Foot linear, white. Length half an inch."

Gary Cobb Thank you guys! So Vishal what is your opinion as the ID of both?

Vishal Bhave As per website (http://seaslugs.free.fr/nudibranche/a_gymnodoris_citrina.htm) According N. Yonow "These and all other creamy gymnodorids with little yellow spiky papillae, especially around the head and in a V-shape after the gills, a ring of creamy gills in the Indo-Pacific are all Gymnodoris citrina (Bergh, 1875). Often it is cited as 1877 but the illustration was published in 1875 and then the text in 1877. Other authors considered that there are more than one species, so they separated : G. alba, G. bicolor, G. citrina. But if we consider All as one for a moment then why Gymnodoris citrina (Bergh, 1875) is considered over G. bicolor (A&H, 1864);(i did not get) as quite 1864 is old than 1877?

Vishal Bhave I have't seen 'B' in India yet but similar to A we have 2 forms (1- https://lh3.googleusercontent.com/-aqQdP2IFacY/ShholEymvSI/AAAAAAAAIL0/TlVJX5h0wLI/s800/DSCN9482.JPG and 2- https://lh6.googleusercontent.com/-igfs4lEfVjw/ShhqEdf0uKI/AAAAAAAAISg/JvDAacVrHe0/s800/DSCN9743.JPG).

Vishal Bhave Alder & Hancock didn't mentioned oral veil or the Shape of head in general, Plate 29 Fig 11 and 12 shows blunt head with out any oral veil which is clearly present in 'A' so i don't think 'A' is true Gymnodoris bicolor; I have to read more about G. citrina to before I can comment on the 'B'

Gary Cobb Food for thought thank you!

Nathalie Yonow radular dissections, guys!

Nathalie Yonow .. a bit of a mis-quote on the Reunion website!

Nathalie Yonow ... a taxonomic nightmare, which is why they are not included in either of my last two monographs :)

Gary Cobb Thank you Nathalie. I received my book today. Well done. Is it possible you could send me the list of corrections? gary@nudibranch.com.au I am truly blown away by the number of endemics in the Red Sea! I can't wait to start the Nudibranch ID App for this region. On a lighted note what is your opinion of these two animals. Can you place a name to them? Cheers. PS justice will prevail.

Vanessa Knutson Patience, Gary Cobb! You'll have your answer in a few months ;)

Gary Cobb Thank you. I just want the Apps correctly identified. Excitement prevails and is building...

Gary Cobb I think in the interim I will switch the names, that seems more accurate. Thanks to all!

Nathalie Yonow A looks like bicolor/citrina while the orange one looks like inornata. No?!

Nathalie Yonow most definitely - http://www.seaslugforum.net/find/gymninor

Gary Cobb So Nathalie would you, in the interim, call 'A' Gymnodoris citrina and 'B' Gymnodoris inornata?

Nathalie Yonow yes, citrina seems to be more 'in current use' than bicolor, while B is certainly Gymnodoris ornata - I say certainly, nothing is certain without a radular dissection but I am confident!

Gary Cobb Thank you Nathalie.

Gary Cobb Opinion needed! I have two Gymnodoris species that were ID'd by Richard Willan a number of years ago as A. Gymnodoris bicolor and B. Gymnodoris aff. citrina. It is my opinion they are A. Gymnodoris citrina and B. Gymnodoris bicolor. Does anyone another opinion? Thank you!

Kristin Anderson I wish I could help! A looks exactly like the G bicolour examples in Coleman's Nudibranchs Encyclopedia, but that's certainly not the last word!

Vishal Bhave Alder and Hancock (1864) described species G. bicolor as "Body elliptic-oblong, nearly linear, tapering to a blunt point behind, white on the head and sides, with an oval dorsal area of a blackish colour, the whole spotted with golden yellow. Tentacles clavate and laminated, white, with the apex and anterior portion yellow; retractile within cavities. Branchial plumes twelve or thirteen, pinnate, forming a circle on the centre of the back ; white, with a yellow midrib externally, and yellow tips. Foot linear, white. Length half an inch."

Gary Cobb Thank you guys! So Vishal what is your opinion as the ID of both?

Vishal Bhave As per website (http://seaslugs.free.fr/nudibranche/a_gymnodoris_citrina.htm) According N. Yonow "These and all other creamy gymnodorids with little yellow spiky papillae, especially around the head and in a V-shape after the gills, a ring of creamy gills in the Indo-Pacific are all Gymnodoris citrina (Bergh, 1875). Often it is cited as 1877 but the illustration was published in 1875 and then the text in 1877. Other authors considered that there are more than one species, so they separated : G. alba, G. bicolor, G. citrina. But if we consider All as one for a moment then why Gymnodoris citrina (Bergh, 1875) is considered over G. bicolor (A&H, 1864);(i did not get) as quite 1864 is old than 1877?

Vishal Bhave I have't seen 'B' in India yet but similar to A we have 2 forms (1- https://lh3.googleusercontent.com/-aqQdP2IFacY/ShholEymvSI/AAAAAAAAIL0/TlVJX5h0wLI/s800/DSCN9482.JPG and 2- https://lh6.googleusercontent.com/-igfs4lEfVjw/ShhqEdf0uKI/AAAAAAAAISg/JvDAacVrHe0/s800/DSCN9743.JPG).

Vishal Bhave Alder & Hancock didn't mentioned oral veil or the Shape of head in general, Plate 29 Fig 11 and 12 shows blunt head with out any oral veil which is clearly present in 'A' so i don't think 'A' is true Gymnodoris bicolor; I have to read more about G. citrina to before I can comment on the 'B'

Gary Cobb Food for thought thank you!

Nathalie Yonow radular dissections, guys!

Nathalie Yonow .. a bit of a mis-quote on the Reunion website!

Nathalie Yonow ... a taxonomic nightmare, which is why they are not included in either of my last two monographs :)

Gary Cobb Thank you Nathalie. I received my book today. Well done. Is it possible you could send me the list of corrections? gary@nudibranch.com.au I am truly blown away by the number of endemics in the Red Sea! I can't wait to start the Nudibranch ID App for this region. On a lighted note what is your opinion of these two animals. Can you place a name to them? Cheers. PS justice will prevail.

Vanessa Knutson Patience, Gary Cobb! You'll have your answer in a few months ;)

Gary Cobb Thank you. I just want the Apps correctly identified. Excitement prevails and is building...

Gary Cobb I think in the interim I will switch the names, that seems more accurate. Thanks to all!

Nathalie Yonow A looks like bicolor/citrina while the orange one looks like inornata. No?!

Nathalie Yonow most definitely - http://www.seaslugforum.net/find/gymninor

Gary Cobb So Nathalie would you, in the interim, call 'A' Gymnodoris citrina and 'B' Gymnodoris inornata?

Nathalie Yonow yes, citrina seems to be more 'in current use' than bicolor, while B is certainly Gymnodoris ornata - I say certainly, nothing is certain without a radular dissection but I am confident!

Gary Cobb Thank you Nathalie.

Patrik Good Probably No. 111 for my Gold Coast Seaway (Australia) collection. Gymnodoris sp. 1; 19/4/2013; size 5mm; depth 4 metres; 24 degrees water temperature; 3 metres visibility. This individual reminds of Gymnodoris sp. 4 in Gary's Australia/NZ app. Striking detail are the eyes behind the rhinophores as found in Gymnodoris bicolor and Gymnodoris sp. 3 NOW Debelius/Kuiter. Gills, mantle and sole are present. Head is pointed and lined with a red dotted rim. It looks like the branch has just eaten a shell because the body shape looks just untypical, sort of similar to the tiny white shells that were found everywhere. The Seaway produced great results yesterday and very surprising finds, leading me to question a few hypothesis. Although Gymnodoris eat other fellow branchs and cannibalism was (unintentionally) witnessed they must have a different food source other than branchs. They were the second most abundant genus with probably three different G. species found that evening. All in all 5 different species were found at the Seaway in the afternoon and at least 7 more species were found during a night dive. Beautiful and rarely seen nudi spawn around too. The Seaway is worth branching again!

Gary Cobb This looks like a juvenile Gymnodoris alba Patrik.

Patrik Good juvenile and cf. sound always good. I found a Gymnodoris alba too. I will try to take a better picture and will probably stick with the sp. I have seen juvenile G. alba but this one is different, not just because of the visible eyes. What also puzzles me is that Debelius/Kuiter say that most Gymnodorids have non-retractile rhinophores and an almost complete loss of the mantle skirt both of which does not apply to this guy. What I think is that nobody knows and what I know is that nobody wants DNA or radular analysis done on this one :-)

Gary Cobb Congrats on the find I am sure the critter will love it's new name!

Patrik Good No critter likes the name 'sp.', Gary :-) Well, maybe some additional information on this one: this individual is back in the Sea. I don't think it had swallowed a shell because it was curled into a 1.5mm blob for a long time. The shape (quite unusual for a Gymnodoris) and colour of the critter stayed the same over night in captivity. Even with better lighting during the day I was not able to take a better picture showing the eyes. But I have about 100 poor photos of the critter :-) The find of so many Gymnodoris was a real surprise that changed my perception of this genus and their food source. There are simply not that many (visible) prey out there to support the kind of population of Gymnodoris (size and amount) that I encountered.

Kati Burg ID help, please. Unfortunately I don't have a better photo. Found at 3 meters depth. Around 2,5 cm long. If you zoom in, you can see tiny orange spots. Found in Romblon Island, Philippines.

Marli Wakeling Possibly Gymnodoris citrina. Any views of the "tail"?

Kati Burg No, unfortunately not. Is there a special feature on the "tail"?

Marli Wakeling Silly me. I meant another view of the head. There are two distinctive folds. It looks like your critter may have them, but the overexposure limits the detail.

Gary Cobb This looks like Gymnodoris bicolor.

Marli Wakeling Interesting find if it is.

Vanessa Knutson This is unlikely to be either. I've never seen defensive glands like these in G. citrina or G. bicolor. The taxonomy of these is unclear to begin, but this is most likely an undescribed species.

Gary Cobb What defensive glands do you mean? Even the slightly raised pustules match. I am quite happy with Gymnodoris bicolor. DNA will tell us no doubt.

Kati Burg Thanks everyone for the helpful comments. I uploaded all photos of this nudi to a folder (As I said, unfortunately they are not that good): https://www.facebook.com/media/set/?set=a.613112888712064.1073741832.184660758223948&type=3

Franca Wermuth-Vezzoli Could it be that this is the same species? Also in Romblon, Philippines.

Vanessa Knutson I won't go into too much detail here so I suppose you will have to wait for the paper, Gary! The "subcutaneous glandular tubes" or "defensive glands" were documented in G. aurita by Gosliner (1997), though since G. aurita is not transparent, you can't see them through the skin. In others, they are visible through the skin. If you look at photos of G. okinawae as an example, they are usually quite obvious. You can see them pointed out on the bottom image here: http://seaslugs.free.fr/nudibranche/a_gymnodoris_okinawae.htm DNA can tell us a lot, but unfortunately, it will never be able to tell us what on earth Alder and Handcock were describing when they described G. bicolor. Out of curiosity, what source do you base G. bicolor identifications on? Franca Wermuth-Vezzoli- It is possible that these are the same- the genital opening is in the same place for both and both seem to have that large, feathery gill, spots, and looks like it has the "defensive glands" too, but difficult to tell with just the photos and no specimens.

Gary Cobb Thanks Vanessa for that, I look forward to the new paper! The source is Richard Willan. I have questioned his ID more than once and he sticks with it!

Gary Cobb Here is the animal Richard ID http://www.nudibranch.com.au/pages/9049c.htm

Kati Burg Thanks to everyone for all those very helpful comments!