Nemertesia antennina

Tony Gilbert Again, from St. Abbs, Scotland. This time in 15m on shell sand, on Nemertesia antennina. This Doto nudibranch I think is D. pinnatifida - and the other could be D. millbayana. Any ideas. Each animal was around 6-7mm and nearby to egg rings.

David Kipling In-your-face Lomanotus ...

Arne Kuilman Cool, first time I hear of this nudibranch.

David Kipling L marmoratus found on Nemertesia antennina in Strangford Lough, NI.

Keith Hiscock Desmacidon fruticosum (a sponge) has always fascinated me since seeing castle-like growths of it in the Isles of Scilly in the late 1960s. Is it long-lived and slow growing or what? I believe this pic. is of D. fruticosum (Pencra Head, Lizard, Cornwall, about 30m depth) and it seems to have overgrown Tubularia indivisa (suggesting fast growth). The collected specimen slimed profusely but I will have a look at the spicules next time in the lab. Meanwhile, what you think about the id.?

Chris Wood Also saw it on the same dive around Nemertesia antennina

Kirstie Harris Found this chap on a site in Pembrokeshire over the weekend. Can anyone tell me what it is? Thanks.

João Pedro Silva Really need some more detail, but I think there are only 3 possibilities * in your area: Doto fragilis, Doto pinnatifida and Lomanotus marmoratus. My guess is D. pinnatifida. * feeding on Nemertesia antennina

Kirstie Harris Thanks! My husband took some photos too, so he might have a better one. If he has, I'll ask him to post it.

Terry Griffiths I would go for D. pinnatifida

Klas Malmberg Aquatilis D. pinnatifida - black tipped tubercles both on cerata and on the sides of the body

João Pedro Silva After downloading and enhancing the image, no doubt on my first guess.

Kirstie Harris Thanks for your help, everyone.

Carol Horne Photos from last weekend...queries...any ideas/suggestions? The hedgehog sponge has some strange red sticklike things top left. Varieties of bugula?... The strange pink and white thing with polyps? And the brown colony of hard tubes, attached to the seabed with a thinnish 'stem'. Another one I thought might be Scrupulocellaria....

Daniel James McLaughlan Your 'pink and white thing' looks like leptasterias. I'll go on the laptop to get a better look at the others!

David Kipling Hard tubes look like colonies of Jassa falcata

David Kipling Red sticks look like stems of Nemertesia antennina flopped over on their side

João Pedro Silva Any idea on what this may be? A flatworm? Maybe nemertea? Swam slowly with lateral movements. Was near Nemertesia antennina.

Tony Gilbert I think it is probably a free-swimming worm Nemertea, perhaps not directly associated with the sea beard though. Not sure when your dive was, but we had aggregations of them/similar free-swimming in the water column at night, in 12m. Quite aggressive, had to dust them away as they liked our lights. These were slightly longer, and only obtained 1 shot: http://www.flickr.com/photos/tonyjgilbert-images/6679780851/in/set-72157628362398207

João Pedro Silva I think yours is a bristle worm (Polychaeta). But you're right, this is probably a nemertea.

Tony Gilbert I looked at Polychaeta at the time, but none fitted, and many are mainly burrowers and bottom living. This seemed to be more aggresive. There were not many bristles on the worm, only what you see, and the remainder was smooth. I saw a few on a night dive in March, but too fast to photograph. We were too busy dodging them - visions of entry into wet suits was in our minds!

João Pedro Silva I once got such an "attack" also during a night dive. Plus minute shrimp aroung the focus light. Nemertea shouldn't have any bristles, although some have a sort of "stiletto".

Marco Faasse Certainly a nemertean. Could be a Tetrastemma, with 4 eyes in a square.

João Pedro Silva The 4 eyes are clearly visible! Thanks, Marco!

Tony Gilbert Thanks Joao, I'll revisit the Polychaeta again...

João Pedro Silva Loads of Nemertesia antennina... and a single solitary and, yes, alone Doto pinnatifida.

João Pedro Silva Doto are really hard to spot and sometimes even harder to identify. It's very important to also document the hydroid they're on. This Doto pinnatifida feeds exclusively on Nemertesia antennina. It cand be mistaken for Doto tuberculata but the later feeds on Sertularella gayi.