Cuthona anulata

Niels Schrieken This picture was taken on the english part of the Doggerbank at the wreck Inger Nielsen. The nudibranch Cuthona is well known from the English waters, but what caught my attention was the foraging behavior. With at least 40 individuals encircled around a metal tube eating Hydractinia echinata from the left side of the tube and leaving eggstrings behind. I find it awesome to see.

Christian Skauge Fantasic shot! Talk about teamwork :-)

David Kipling Good grief, amazing! How deep was this?

Niels Schrieken It's about 20 meters deep.

George Brown Incredible photograph of fascinating behaviour.

Julia Nunn absilutely wonderful picture

Tony Gilbert Amazing shot, I am still looking for C. nana on Hydractinia, so every hermit crab with "fur" that comes along! Think I just missed a Cuthona nana on this hermit specimen, as it seems that its had a reverse-mohican "haircut" down the centr... http://www.flickr.com/photos/tonyjgilbert-images/7501686530/in/set-72157630420768730

Christian Skauge How about a picture like that, with two C. nana's mating on top of the hermit...?

Niels Schrieken Yes Christian that is where I am always looking for when I see hermitcrab. But I have never thought to see a tube with nana eating hydractina like this.

David Kipling Am I right in thinking we should be calling Cuthona now Trinchesia?

Niels Schrieken In the world register of marine species cuthona nana is the correct scientific name: http://www.marinespecies.org/aphia.php?p=taxdetails&id=141627

David Kipling There's a thread on one of the other nudi forums about changing all the Cuthonas to Trinchesia. I personally think we should stop doing that, and move to colour and shape-based names, be much easier to identify them! "Mr Yellow Clubby" is far easier to remember than Limacia clavigera, for example ...

Christian Skauge Problem is, there are lots of different "common names" depending on where you are - latin is the only thing keeping the whole thing together... As for Cuthona to Trinchesia - I have no idea whats right.

Niels Schrieken The other way around if I may believe WoRMS. Example Trinchesia anulata -> Cuthona anulata: http://www.marinespecies.org/aphia.php?p=taxdetails&id=534077

David Kipling There's a long thread on the NUDIBRANCH LOVERS group entitled "Trinchesia instead of Cuthona". I think C nana is actually the sole species allowed to still be called Cuthona!

Christian Skauge DNA matching will eventually save the day :)

Jim Anderson The abstract from Michael Miller's paper in the Journal of Natural Histopry Vol 38 Issue 9, 2004 says in closing. "Re-examination of the local Cuthona species led to a re-assessment of several other tergipedid genera based on the arrangement of the digestive ducts. As a result the genus Cuthona Alder and Hancock, 1855 is restricted to one species, C. nana (Alder and Hancock, 1842), and the genus Trinchesia von Ihering, 1879 re-introduced for the rest of the species previously included in Cuthona." Histopry Vol 38 Issue 9, 2004.

João Pedro Silva I'd really love to hear/read Bernard Picton's view on this.