Flabellina browni

Jørn Ari Flabellina browni - http://www.nudibranchia.dk/

Jørn Ari It´s the same browni at all 3 photo´s

Jørn Ari Flabellina browni. Photo taken at Kongebrogaarden - Lillebelt - Denmark 12 Nov. 2011

Ken Thongpila Fantastic shot Jorn Ari :-)

Jørn Ari Flabellina browni from Denmark. 105mm macro with a Subsee +10 dioptre

Ashley Missen Nice Pic

Terry Griffiths I do belive Coryhella gracilis never seen many off these around the S West if i'm correct.

Erling Svensen We have hundreds, and I live South West (Norway)

Terry Griffiths Thanks Erling SW England.

Bernard Picton I think this is Flabellina browni. Note how the white pigment on the cerata forms a broad cylinder rather than a thin, broken ring. Several of these Flabellina are very hard to distinguish....

Erling Svensen I will look through all my Flabellina pictures. I have a bad feeling that many not are what I thought they are. May be Bernard could give us a key for the different species?

Shôn Roberts I took this photo in the Menia Strait's in North Wales.

Sylvie Omnès could be Flabellina browni (Picton 1980) ...

Christopher Thorn The Menai Straits is a wonderful place:-) Thanks for sharing Shôn Roberts, never had the pleasure of diving there myself, but always fancied the low water drift below Menai bridge;-)

Shôn Roberts Excellent dive site. Thanks for the comments and info.

Erling Svensen Could this be Flabellina browni? Quite strange one, I think.....

Terry Griffiths that's one of the variations we have here Erling

Tony Gilbert Yes, it looks vry C. browni Erling, although its digestive gland is quite prominent.

Erling Svensen Thanks both of you :-)

Rob Maller Thought it was Flabellina gracilis .....

Marco Faasse I think Rob Maller is right

Erling Svensen I thought it was too big for gracilis, 3 cm long aprox?

Marco Faasse That's very long for F. gacilis indeed. Other characters match with this species best.

Brendan Oonk Could it be F verrucosa?

Marco Faasse In F. verrucosa I've seen the rhinofores were slightly wrinkled and not pure white. The body was white, not so translucent. The cerata were plumper, with the white closer to the top, and they were held more closely together.

Brendan Oonk I gues this means "no" :)

Tony Gilbert F. verrucosa has thinner white tips on the cerata. Gracilis - I think the cerata are less "smooth" than the browni. Also, F. gracilis max length is half the size of this specimen. Additionally, I don't know which food you found it on/near, but the food sources are different. I still think c. browni at present, but Bernard Picton is your man.

Bernard Picton Yes, I think this is certainly Coryphella browni (Flabellina browni). Now you need to find C. borealis - it should be there somewhere. Radula is different but there are no photos of borealis as far as I know.

Marco Faasse Tony Gilbert mentioned smooth cerata contents for F. browni, the white cerata rings seem to go closer to the tips and the anterior margin of the foot seems to have more white. Are there any other features to distinguish this kind of specimens from F. gracilis, apart from size? They are likely to be identified as F. gracilis, when they arrive where F. browni did not occur (e.g. Netherlands).

Marco Faasse The main difference with this specimen of presumed F. gracilis seems to be broader white rings:

Marco Faasse http://www.facebook.com/photo.php?fbid=356546331089883&set=a.255646997846484.59735.100002035584345&type=3&theater

Rob Maller But still hard to notice the difference to be honost....

Allison Gleadhill Scilly isles 3 weeks ago, 12'C. Coryphella or Fabellina? or something else!

Bernard Picton I'd call it Coryphella browni, but taxonomists who like large genera would call it Flabellina browni...

Paula Lightfoot Hi does anyone know what might have laid these eggs, there were loads of them on a wall at the Farnes yesterday between 9m-12m. The most common nudibranch there was Limacia clavigera but according to other websites their eggs don't look like this. I wondered about Tritonia homergi?

João Pedro Silva These seem too regular and thin for T. hombergii. Tony Gilbert has a photo of it laying eggs.

David Fenwick Snr Have found similar with Favorinus branchialis

Peter H van Bragt For sure not T. Hombergii or Limacia clavigera. There are a few options... Possibly Flabellina gracilis but other aeolids are also an option. Spawn laid on a flat surface looks very often like this, but when laid in hydroids they are very irrugular shaped.

Jim Anderson This looks like Flabellina browni spawn to me.

Bernard Picton or possibly Facelina bostoniensis...

Jørn Ari Snoghøj - Lillebælt OLYMPUS DIGITAL CAMERA Copyright: Jorn Ari

Jim Anderson I would say it is not - it looks more like Flabellina browni to me

Jørn Ari But what about the red oesophagus, situated just behind the rhinophores, is clearly visible?

Robert Eriksson Look at the length of the oral tentacles,, they are about the same as the rhinohores=flabellina if much longer then Facelina! Rings and colour are not very stable traits for species discrimination!

Robert Eriksson .. blooper.. Rings on the Rhinophores (lamellae) are a stable trait though. Not sure what you mean mean rings Jorn? Coloured rings of e.g. White pigmentstions are not stable for species deduction in any species of the Flabellina or Facelina (personlopinion).

Robert Eriksson ... Mind that the oral tentacle and rhinophores are retractible and you need to Watch the animal for some time to be able to deduce it's "normal" relaxed state. I agree that it is a Flabellina, but never saw brownii as a good species - any gene-studies done on brownii?

Jørn Ari I ment lamellae

Bernard Picton Sorry, but I completely disagree with you Robert Eriksson, details of coloration are very good characters, but you have to weight them by how big and mature each individual animal is. There is considerable evidence that CO1 barcode sequences are identical in closely related species of marine invertebrates, so the DNA evidence is partly dependent on which bit of DNA you sequence. There is a lot of observing and collecting to be done yet before we have all the answers...

Lucas CerCur I agree with you Bernard Picton

Bernard Picton Oh, and I should say I've seen hundreds of Coryphella browni in the field, kept them in containers with Coryphella lineata which they were sharing their Tubularia indivisa with, watched them considering whether to mate with a C. lineata and deciding not to....

Lucas CerCur I have seen photos of Trapania lineata mating with supposed T. fusca!!!!! from southern Spain.

Bernard Picton ;-) so then we have to determine whether the offspring were fertile. Horse + Donkey = Ass.

Bernard Picton So absence of mating is evidence of separate species, if mating is possible by the species normally sharing a habitat.

Bernard Picton But cross-species mating occurs, and sometimes hybrids are even fertile. It is thought from DNA evidence that the "species" Alcyonium hibernicum is a hybrid, yet it occurs in areas where neither parent is present.

Lucas CerCur Of course.

Lucas CerCur As I told to my students, Biology is no Maths

Lucas CerCur Fortunately....

Robert Eriksson Don't be sorry, for disagreeing, Bernard Picton, these discussions are advancing our knowledge! I would like to expain myself briefly about the colouration issue. In Flabellina, the colouration of the rhinophores and the cerata is very variable, at least when looking at Nordic specimens. Some specimens have rings, some have a partial ring, some have only spots of pigment. I am only claiming these traits in adult specimens. Colouration might be stable in other species. Of course variability of genes depends on what part of the DNA you are sequencing, as you stated. Thats why you tend to use noncoding or at least more variable genes (with a "faster evolution") for deducing closely related species. I am truly confident in that we never will have all the answers...

Erling Svensen Could this be Flabellina browni? Quite strange one, I think.....

Terry Griffiths that's one of the variations we have here Erling

Tony Gilbert Yes, it looks vry C. browni Erling, although its digestive gland is quite prominent.

Erling Svensen Thanks both of you :-)

Rob Maller Thought it was Flabellina gracilis .....

Marco Faasse I think Rob Maller is right

Erling Svensen I thought it was too big for gracilis, 3 cm long aprox?

Marco Faasse That's very long for F. gacilis indeed. Other characters match with this species best.

Brendan Oonk Could it be F verrucosa?

Marco Faasse In F. verrucosa I've seen the rhinofores were slightly wrinkled and not pure white. The body was white, not so translucent. The cerata were plumper, with the white closer to the top, and they were held more closely together.

Brendan Oonk I gues this means "no" :)

Tony Gilbert F. verrucosa has thinner white tips on the cerata. Gracilis - I think the cerata are less "smooth" than the browni. Also, F. gracilis max length is half the size of this specimen. Additionally, I don't know which food you found it on/near, but the food sources are different. I still think c. browni at present, but Bernard Picton is your man.

Bernard Picton Yes, I think this is certainly Coryphella browni (Flabellina browni). Now you need to find C. borealis - it should be there somewhere. Radula is different but there are no photos of borealis as far as I know.

Marco Faasse Tony Gilbert mentioned smooth cerata contents for F. browni, the white cerata rings seem to go closer to the tips and the anterior margin of the foot seems to have more white. Are there any other features to distinguish this kind of specimens from F. gracilis, apart from size? They are likely to be identified as F. gracilis, when they arrive where F. browni did not occur (e.g. Netherlands).

Marco Faasse The main difference with this specimen of presumed F. gracilis seems to be broader white rings:

Marco Faasse http://www.facebook.com/photo.php?fbid=356546331089883&set=a.255646997846484.59735.100002035584345&type=3&theater

Rob Maller But still hard to notice the difference to be honost....

Erling Svensen And this one, a F. pullucida - or something else? Quite big, 3 cm long. From 15 meters deapt.

Jim Anderson Looks like Flabellina pellucida to me.

Bernard Picton I just added some pictures of Flabellina pellucida. I think this is another species, more swollen cerata, white pigment on cerata showing a clear, pointed tip. It might be F. nobilis, perhaps? Jussi Evertsen, what do you think? http://www.facebook.com/photo.php?fbid=10150589901704682&set=oa.180702332041055&type=1&theater

Christian Skauge I would have guessed F. pellucida too based on the thin, long cerrata, but it might be F. nobilis... these buggers are really hard to tell apart!

Jussi Evertsen No they are not, just look at the rhinophores

Christian Skauge Hmm... I do, and I still think they're difficult ;-) But I need to read up on those Flabellina species...

Jussi Evertsen The rhinophores seems to be covered with minute papillae which indicates Flabellina nobilis

Christian Skauge I think you're right, Jussi. I have read up on this, and the oral tentacles also match up. Erling, do you have another image showing the tip of the tail as well?

Erling Svensen I do not know. Have to take a look when I have finished my work where I suppose to make my money....... ;-)

Christian Skauge What - you have a DAYJOB???

Bernard Picton Thanks Jussi, I agree, though I've only seen a juvenile which I decided was F. nobilis, at Mulroy Bay, Co Donegal on the north coast of Ireland. http://www.seaslugforum.net/showall/flabnobi

Bernard Picton Jim Anderson found a couple of specimens in NW Scotland which we decided were probably this species. It is very difficult to distinguish from Flabellina browni in photographs though. I think there's quite a difference in the shape of the lateral radula teeth, so some specimens from Scotland would help confirm its presence in Britain and Ireland. http://www.nudibranch.org/Scottish%20Nudibranchs/html/flabellina-nobilis-01.html

Bernard Picton Checking the Sea Slug Forum I see Jussi and I collaborated on these already, so I'll post the links here: http://www.seaslugforum.net/find/4733

Bernard Picton And from Jussi, http://www.seaslugforum.net/message/4876

Jørn Ari OLYMPUS E-420 Jorn Ari

Jim Anderson Looks like Flabellina verrucosa to me.

Bernard Picton The broad white bands at the tips of the cerata are more typical of Flabellina browni. The rhinophores and oral tentacles both look robust. We must not forget Flabellina borealis in your region; as far as I know it has not been photographed, but looks a bit like this.

Bernard Picton How big was it, Jorn?

Jørn Ari I guess it´s 15-20 mm Its two years ago and before I started recording my observations.