Aglaophenia pluma

Tony Gilbert To me this looks like a Coryphella browni, the cerata tips have white rings just below them (and not covering the whole tip), and no blue tinges, so didn't think it was F. bostoniensis. Animal was 1.5cm long if that. As you can see it appears to munching away quite happily at this hydroid. I think this one is Aglaophenia pluma, which I think Doto koenneckeri is specific to, and was found in the strong tidal streams of the Menai Straits. This food source for C. browni isn't its primary, so I thought it was interesting to see the image.

Torjus Haukvik To me, the rhinophores doesn't look like they're belonging ta a Flabellina. I also have the understanding that Facelina auriculata is supposed to have the blue tinges, not F. bostoniensis. Feel free to correct me if I'm wrong.. I would say Facelina bostoniensis..

Tony Gilbert Thanks Torjus. As I understand it, both F. bostoniensis and F. auriculata have blue tinges/irridescence, but F. bostoniensis has them to a lesser degree. I've images of both Facelinas and we see mostly F. auriculata in Menai Straits but also C. brownii, both are usually on Tubularias. The F. bostoniensis I've mostly seen are quite large anyway, so that doesn't help. I wondered whether F. bostiensis has white below the cerata tips, or whole of the cerata tip? I.e. Are the white just below the cerata tips diagnostic of a C. browni? Also F. bostoniensis is mostly found on Tubularia, so whether the nudi is C. or F. they are not usually on the hydroid I photographed with the nudi.

Torjus Haukvik You had me pull out some litterature now. My key uses the lamellaes as a character to separate between Facelina and Flabellina, and the blue irridescence to distinguish Facelina bostoniensis from F. auriculata. Although the description of F. bostoniensis states that it can display a blue irridescence in rar occations, the description of F. auriculata states that this allway has blue irridescence. But, my book is quite old, so I'm not going to say anything for certain. About the coloration on the cerata tips in the Flabellina genus, I'm not your guy..! ;)

Tony Gilbert You've solved the nudi ID anyway, thanks! I also had another look at both, and checked a second picture I took. This first picture does show some red around the mouth area, and very long oral tentacles. The second picture, which I didn't post, is a head shot and clearly shows white pigment on the head between the rhinophores. So, I think you were right that it is F. bostoniensis, which is great, cos its my first one in the Straits (I think). So, the cerata tip colouration below the tips isn't diagnostic of C. browni. And, this nudi (F. bostoniensis) is not eating Tubularia or Clava.

Brendan Oonk F.bostoniensis indeed. Although it prefers Tubularia as it's food. It is know to eat all kinds of hydroids and even other nudibranchs

Tony Gilbert Thanks all.

David Kipling And the answer is ....

Becky Hitchin Aglaophenia?

Becky Hitchin But I say that for any fluffy hydroids with gonothecae obvious!

Tony Gilbert Yes, Aglaophenia pluma

David Kipling We went with George Brown and recorded this as Aglaophenia tubulifera. Dawn?

Bernard Picton A. pluma is mostly in shallow water, usually on large algae like Halidrys or Sacoglossum. It also grows directly on rock in areas of high water movement. It is quite a dark brown in colour, tubulifera is the only one in our area which is this yellow colour.

George Brown Is there a prize?

David Kipling I've just been pimped by Dawn Watson. My life is complete...

George Brown Changed my mind it's Holothuria forskali!

Tony Gilbert Ok, thanks, noted.