Runcina coronata

Ian Smith Pool above HWS, N. coast Anglesey. Hundreds of Runcina coronata September, none found in June. Two spp. Cladophora at surface and on sides, respectively. Corallina deeper. Runcina confined to Corallina. Limapontia senestra (abundant June, a few September) only on Cladophora. David Kipling , this is the pool where I found Asterina phylactica (Sept. & again last Wednesday June 26).

Cynthia D. Trowbridge I have seen loads of Limapontia in such pools; I have even found the species on Codium (confused sacos or any green alga helps metamophose???). Metamorphic cues are much broader than the literature suggests as most people do not try non-host alga species as treatments.

Cynthia D. Trowbridge Does anyone have any idea what flatworms would occur around sea urchin burrows (western Ireland)? I thought perhaps they were commensals or parasites but found no evidence in the urchins I checked. The worms were present in multiple years at the same site. I could not find anything in the literature or from US experts I asked.

Jean Michel Crouzet hello cynthia i am not sure it s flat worms its possible opistobranch limapontia or runcina (sorry for my english i am french divers)

Marco Faasse Interesting ... Any close-up pics?

Brendan Oonk Could there be a connection with the spounge they are on?

Jean Michel Crouzet it's not a sponge it 's calcareous algae and this opistho is eating it

Marco Faasse Apparently Jean Michel Crouzet thinks it may be Runcina, known to occur in coralline rockpools: http://www.marlin.ac.uk/speciesinformation.php?speciesID=4267

Brendan Oonk Does Limapontia eat anything else than green algea (Vaucheria)?

Jean Michel Crouzet i dont no, in Groix where i dive i dont have limapontia and i never saw it but i thinck it is possible; cynthia did you saw on the algae some tracks who loock like little road

Marco Faasse Limapontia species are reported to feed upon green algae, but Runcina is said to graze upon encrusting coralline algae (Lithothamnium): http://www.conchsoc.org/MolluscWorld24/4 ... interesting habit ...

Cynthia D. Trowbridge Thanks for your thoughts. As I am a sacoglossan ecologist and phycologist, I can assure you the species was not Limapontia and there was no Vaucheria or green algae in sight....just coralline algae, urchins, and Codium spp. As I have cultured Elysia viridis through its life cycle, I know these were not juvenile Elysia. I am interested in the suggestion of Runcina. I am familiar with the genus as I rediscovered Runcina macfarlandi on the west coast (and sent specimens to Terry Gosliner to report). But I do think it was too flat to be Runcina. I was with 2 invertebrate students and they both thought it was a flatworm species as well. We were thinking about our Pacific Syndesmis or Synsisyrinx spp. associated with urchins and asked US taxonomists if there was an Atlantic counterpart. I am sorry that I have no close-ups. I collected a bunch and tried to bring them home for microscope work but they did not make it.... If anyone has further thoughts, it would be great. Otherwise I will just have to go back to try to recollect when I am in Ireland this fall :-)

Cynthia D. Trowbridge Perhaps I will say Runcina and/or flatworm until the mystery is solved :-) THANKS!

Ian Smith My first thought was Runcina coronata, but, though it has yellow/tan in close up, it usually appears black-brown in pools. See images at http://www.conchsoc.org/spAccount/runcina-coronata . Cynthia, when was the image taken? Runcina is abundant in coralline pools in April and September, but too small to find easily in June (in my experience - Portland Bill, LlÅ·n peninsula & Anglesey)

Cynthia D. Trowbridge It was tan closeup (field lens) but dark in pools. I visited the same site (Spanish Point near Lahinch, western Ireland) in mid September each year.

Cynthia D. Trowbridge By the way, I have lots of gastropod records from Scotland and Ireland. I sent some sacoglossan records to Julia Nunn a few years ago. If the conchology society collects records still, I would be happy to send ones as I bring under grad and postgrad students over to Ireland every fall.

Ian Smith Cynthia D. Trowbridge your September visits are right for seeing lots of Runcina, so I think it the likely answer. Lucas CerCur posted that he thinks the Runcinas need attention - you never know, the W. of Ireland may have another sp.

Ian Smith Simon Taylor is just getting into harness as our new Conch Soc Marine Recorder. I hope he picks up on your kind offer of records.

Simon Taylor Hi Cynthia - yes I'd be delighted to receive any records you were willing to send and to add them to the Conchological Society's dataset, which is regularly uploaded to NBN.

Cynthia D. Trowbridge Will do :-) We do not due such things in the US...a huge mistake!

Anne Bunker These tiny pink animals were found in Pembrokeshire on 21 September (Natural Resources Wales intertidal survey). The largest is approximately 3mm long. Mid shore rock pools on crustose coralline algae. Exposed shore (Pen y holt). We found them in the same rockpools 3 years ago. Can you help with identification please?

João Pedro Silva Limapontia sp. perhaps?

Christian Skauge Tiny Elysia viridis?

Peter H van Bragt Can you post a cropped, enlarged specimen. I think I see folded parapodia. Could be juv. Seahares??????

Christian Skauge Here's one, Peter H van Bragt. This is what made me think E. viridis - same basic bodyshape and spots on the back ;-)

Peter H van Bragt No rhinophores, so Elysia and seahare don't seem to be an option.

Jan Light Would the rhinophores be developed on such a young specimen?

Ian Smith Rhinophores appear at 3mm on Elysia. I guess Anne 's slugs are bigger, perhaps she could say? See http://www.conchsoc.org/node/5610 (Later edit; I see Anne said largest 3mm.)

Ian Smith Coralline pools on exposed shores have some real surprises. Runcina coronata can be abundant, and has some golden brown in good light, but the shape of these isn't right for it. The slugs shown have a rotundity with some whitish colour; I think this could be an internal shell showing through the mantle. All have a truncate end which, on those turned at the right angle, suggests the cylindrical posterior of the mantle covering the shell, as on Philine punctata http://www.conchsoc.org/spAccount/philine-punctata Christian's crop seems to show parapodia and a thin anterior without any features. The nearest fit to all this; structure, colour and occurrence in tidal pools, in Thompson Opisth Biol vol1 is Philine catena, max length 6-7mm, an uncommon and little-known species. Just a suggestion, but an exciting find whatever it proves to be.

Keith Hiscock Look like Runcina coronata to me. Rarely see them. Last time was at Pendennis Point, Falmouth in May.

Ian Smith Runcina coronata images at http://www.conchsoc.org/spAccount/runcina-coronata Frequent in coralline pools on exposed coast, and the obvious candidate. A good chance that Keith is right, but as I said above, Anne's look different structurally as far as can tell from image. Well worth further investigation.

Jan Light I know Runcina coronate, these animals are not that.

Ian Smith The more I look at the images, the more I'm inclined to reconsider Jan's idea of Elysia viridis before rhinophore development. The general shape is very like the juvenile Elysia image above. I think I MAY be able to make out stumpy early rhinophores on some of them - if only the images were clearer. Pink body Elysia would be expected on pink weed BUT it feeds by piercing individual cells of large celled weeds; do the juveniles have a feeding mechanism that can utilise encrusting Corallina ?? Intriguing.

Anne Bunker They were only on the encrusting coralline algae although there were a lot of other algae in the pools. I brought one back to examine under the microscope but I'm sorry to say that it died and became an amorphous mass about 2 seconds after I turned the microscope light on.

Keith Hiscock This is my pic. of Runcina coronata at Pendennis Point - any comments on confirmation/correction welcome.

Lucas CerCur Or...Runcina ornata

Lucas CerCur Runcina.....another European opisthobranch mess that should be solved.

Ian Smith I agree Keith; typical R. coronata, or whatever it turns out to be when the "mess" is sorted. I've found it in thousands in a single HW pool on exposed coast Anglesey, hundreds in pools at HW on fairly exposed shore Lleyn Peninsula, several in virtually every pool near HW on tip of Portland Bill. Several other records on NBN are from exposed coast. However I've also found it at LWS on sheltered sites such as inner Bay of Firth near Finstown in Orkney and a sheltered LWS pool in Lleyn. It's seasonal; the pool in Anglesey had none findable on a September visit. Could be that the exposed / sheltered ones are different segregates, but they all looked the same. If all one sp. I think it is catholic, but overlooked because of small size except when on contrasting substrate, such as encrusting coralline.

Lucas CerCur I consider (in this moment) that in UK there are 3 species of this genus, i.e. R. coronata, R. ornata and R. ferruginea. But, I think that a deep study should be carried around all Europe.

Ian Smith Lucas, can you tell us how to separate the three spp. morphologically and/or direct us to images on the web?

Lucas CerCur Even if in 2001 and 2002 two relevant contributions were published by Schmekel and Cappellato and several Mediterranean new species were described, all photos were in black snd white and many of non living material and both papers are based on anatomy and morphology.

Ian Smith Can you give us the references? Did they include British material? I'm aware that the Med. has more spp. from viewing Bill Rudman's Seaslug forum.

Lucas CerCur R. ferruginea is very easy, since it is reddish. The remaing two could be more complicate. In general, the typical R. coronata has two more or less evident white arches (half-collar), one below the head and the other before the end of the notum. Moreover, there are a lot of withish and very Little White punctuadion over the notum. R. ornata is like the Keith's photo.

Ian Smith Above, in this string of messages, I hazarded the possibility of Philine catena. By coincidence a friend has sent me a series of images of it from Croatia. None of them hold themselves in a tapered position; all have the wide truncated end shown in this image. So I think my suggestion should be dismissed. It looks as if young Elysia are the best bet.

George Brown Not a nudibranch but is this Lamellaria perspicua? Feeding on ascidians growing on sea grass Zostera marina. 2012-12-01, Ord, Isle of Skye, depth 2.0 metres.

Erling Svensen I think you have the right name, George Brown.

Egidio Trainito Right

Ian Smith Hi George Brown the white ground colour with fine black stipple, low profile and not very prominent tubercles make me think it is L. latens. If it was over 10mm long, I'm wrong. See http://www.conchsoc.org/spaccount/Lamellaria-latens and the perspicua account on same site. Cheers Ian

George Brown Hi Ian. It was your comments that pointed me to L. perspicua particularly the way the head tentacles lie. I should say that it was approximately 15mm long. I knew there was something I forgot to add! Great site btw, and excellent photography. My photo was taken with an Aquatica +5 dioptre. What did you use for your Lamellaria photos if you don't mind me asking?

Ian Smith Hi George If you are sure it was 15mm, perspicua is indicated. Looking carefully at your image I think I can see other latens features apart from those I mentioned. In the posterior half, the mantle, where it is clear of the underlying shell, has faint greyish discs delineated by surrounding whitish pigment, and round the periphery of the mantle I think I can make out a few yellowish white marks, especially near the posterior. I think this is a case where measurement, and examination of the shell would have been helpful. On latens, and some pale perspicua, you can often see the outline of the shell if you examine it with back lighting. In perspicua the spire protrudes from the general oval outline, on latens it doesn’t protrude. In the Conch Soc latens account, the features described are mentioned in various other written sources, except the angle of the tentacles which is from my observations. It needs to be seen from above as the angle alters when viewed obliquely, and is not diagnostic as the tentacles can be moved; the tentacles of latens are more often held at a wide angle, but not always. Apart from the shell spire, the most reliable feature, mentioned in NF McMillan’s account, is probably the fine black/sepia stipple which I think I can see on your photo. Thanks for your kind words about the Conch Soc site. I’ll answer about photography in a separate message. Cheers Ian.

Ian Smith Hi again George Thanks for your comments about my photography, but I think it is less skilled than what you and others do underwater. Mine is table top photography where I can control the substrate’s level and colour, the posing of the subject, the clarity of the water and the positioning of the lighting. I followed Bernard’s good advice and, allowing for model changes before I bought, use Nikon D300s camera, AF Micro-Nikkor 60mm f2.8D lens, two wireless “speedlights”, and a tripod with rack and pinion column which I use to focus (manually) keeping the lens at maximum extension (1:1 ratio). I think the lens has been discontinued, but can still be obtained. It has a short working distance, ok for table top, but perhaps not so easy for divers. The lighting often shows up detail not seen in the field; which I suppose may be considered a disadvantage for helping field recognition. Have a look at the Conch soc Runcina coronata images. The images taken in rock pools show dull blackish creatures, while the table top ones show bright yellowish markings. Cheers Ian http://www.conchsoc.org/spaccount/Runcina-coronata

Lucas CerCur Ahhhh!!!! Runcina. This should be one of the projects that should be carried in all around Europe.

Ian Smith Hi George Brown , I have recalled that I found a white Lamellaria like yours at Weymouth last April. It was ambiguous as it had markings usual for L. latens and, at 11mm long, it was just over the 10mm approximate maximum for L. latens. The shell showed clearly that it was L. perspicua. The account at http://www.conchsoc.org/spaccount/lamellaria-perspicua has been amended in the light of our finds. I have embedded links to relevant images at [14], [15] & [16], and altered the text near the embeds. The quickest way to find the images is to click GALLERY link below the thumbnails; they are the last three images on the gallery (click the images for captions). Cheers Ian