Adalaria proxima

Sarah Bowen Is this by any chance Adalaria proxima? Taken in Fair Isle; August 2011.

Erling Svensen Yes, I would say so.

Kate Lock great shot Sarah!

Sarah Bowen Thanks Erling, one of those times when you go back to something with fresh eyes - why didn't we think of that before?!

Jørn Ari Adalaria proxima

Jen Firth I want to share this! It's awesome!!

Cat Wilding Can anyone help with an ID for this nudi please? Adalaria proxima or Onchidoris muricata? Neither of these have been recorded near the site before. From ~8m in mid-Fowey estuary, on a pontoon. This is the best photo I have in which the tubercles appear quite rounded, suggesting O. muricata? Cheers!

George Brown Have you considered Onchidoris bilamellata? The remains of many barnacles appear close by.

Ross Bullimore Yup... + 1 ..what George Brown said!

Fiona Crouch Yep that would be my first thought George and Ross.

Peter H van Bragt And indeed it is O. bilamellata.

Cat Wilding Awesome, thank you :)

Erling Svensen Adalaria proxima and A. loveni from todays dive.

Ronni Bless Bekkemellem great !!

Jussi Evertsen So which one is the A proxima?

Erling Svensen The white one I hope.

Ian Smith Are you sure? The tubercles are much more widely spaced than on A. proxima that I have seen. See http://www.conchsoc.org/node/5333

Erling Svensen I am not sure, but if I look at Bernards "Encyclopedia of Marine Life" pages, the tubercles are different on these two. The yellow one has more flat tubercles, and the white one more pointed. But I do not know. Please look at Bernards pages on these two species. This is interesting..... :-)

Erling Svensen What about this one?

Erling Svensen .... and this one?

Ian Smith My white Orkney one is typical of several I sent to T.E.Thompson author of Biol Opisth Moll. He checked the radulae and all were proxima. Your two latest postings: yellowish one O. muricata & white one I don't know; neither proxima nor muricata.

Erling Svensen Could the white one be Acanthodoris pilosa or Aldisa zetlandica?

Ian Smith Tubercles on your last image are such a good match for the encrusting organism it is on that it surely is the pablum.

Erling Svensen Ian - my english is not good enought. What is pablum? There are one white and one reddish brown on the last image.

Ian Smith Apologies Erling , "pablum" is Latin for "nourishment / food" and is used in some scientific papers. I misinterpreted your photo; I thought the reddish-brown one was the food organism. I was right about the match of tubercles :-) Your last white posting does have soft linear tubercles like pilosa but it doesn't look quite right - flatter than I'm used to, but it's a possibility - I'd feel safer if we could see the kinked rhinophores that remind me of the horns of long-horn cattle. I'm not familiar with zetlandica, so can't comment on it.

Erling Svensen Thanks, Ian. Here is for sure the Aldisa zetlandica.

Ian Smith Thanks. I'd say that is a closer match, but you'll know more about it than I.

Paula Lightfoot I think this is either Onchidoris muricata or Adalaria proxima but not sure if it's possible to tell from this photo? From Eyemouth.

Rob Spray Not easy to tell but using Bernard's ID advice from Habitas I would say flat tubercles... so prob O.Muricata? http://www.habitas.org.uk/marinelife/species.asp?item=W13240

Brendan Oonk Based on the discription of Adalaria proxima on sea slug forum "Very similar in shape, colour variation, food and habitat to Onchidoris muricata. It grows to a larger size (17-25mm - compared to 12mm for O. muricata), and the mantle papillae taper to a slender rounded tip while in O. muricata they are flattened with projecting spicules." I would say: O. muricata

Ian Smith I read somewhere that radula examination is necessary to separate them, but in the 70's when I sent material from Orkney to Thompson & Brown, my prediction of species based on tubercle shape was always confirmed when radulae were examined. It would help if the image were cropped in tighter, but I think I can see mainly flattish topped tubercles, so I agree with Rob in saying muricata. Also, in the south muricata is usually (but not always) white and proxima yellowish (colours reversed in Orkney). T&B suggest that proxima doesn't come south of Bristol Channel, and records to the south are misident. of muricata; two more factors that add to the probability of your specimen being muricata. You can see tubercle comparison on the Conch Soc A.proxima page at http://www.conchsoc.org/spaccount/Adalaria-proxima there is a link to the muricata page on it too. Note that the comparison images are from Orkney so proxima white, muricata yellow. Cheers Ian

Paula Lightfoot I think this is either Onchidoris muricata or Adalaria proxima but not sure if it's possible to tell from this photo? From Eyemouth.

Rob Spray Not easy to tell but using Bernard's ID advice from Habitas I would say flat tubercles... so prob O.Muricata? http://www.habitas.org.uk/marinelife/species.asp?item=W13240

Brendan Oonk Based on the discription of Adalaria proxima on sea slug forum "Very similar in shape, colour variation, food and habitat to Onchidoris muricata. It grows to a larger size (17-25mm - compared to 12mm for O. muricata), and the mantle papillae taper to a slender rounded tip while in O. muricata they are flattened with projecting spicules." I would say: O. muricata

Ian Smith I read somewhere that radula examination is necessary to separate them, but in the 70's when I sent material from Orkney to Thompson & Brown, my prediction of species based on tubercle shape was always confirmed when radulae were examined. It would help if the image were cropped in tighter, but I think I can see mainly flattish topped tubercles, so I agree with Rob in saying muricata. Also, in the south muricata is usually (but not always) white and proxima yellowish (colours reversed in Orkney). T&B suggest that proxima doesn't come south of Bristol Channel, and records to the south are misident. of muricata; two more factors that add to the probability of your specimen being muricata. You can see tubercle comparison on the Conch Soc A.proxima page at http://www.conchsoc.org/spaccount/Adalaria-proxima there is a link to the muricata page on it too. Note that the comparison images are from Orkney so proxima white, muricata yellow. Cheers Ian

David Fenwick Snr Another curious yellow slug, thankfully not Berthella this time. Haven't a clue what it is despite doing a lot of looking. Has anyone come across it ?

David Fenwick Snr It's about 12mm and found under a rock in a pool at Lariggan Rocks, Penzance, Cornwall. 06.04.12.

Steve Trewhella Onchidoris muricata ?

David Kipling There have been a few records of Doris ocelligera from the Penzance area. That can come in a yellow form with dark tips to the tubercles (which you seem to have here). Only a handful of UK records to date, it's on the northernmost limits of its range.

David Kipling See here in particular Julia Nunn's picture of the yellow variant. http://www.seaslugforum.net/showall/doriocel

David Fenwick Snr Thanks David that's the beast, flatter than O. muricata, white tubercules, and larger tubercules in the centre getting smaller round the edges and with like you say dark tips to the tubercules. Brilliant. It just didn't fit in with O. muricata or Adalaria proxima, know I know why. Just as your mail came in I grey scaled the images and increased brightness and contrast to see what it would look like being white. It still didn't look like O. muricata, I think what stands out the most is that the slug is flatter than O. muricata and the tubercules are larger down the center, O. muricata seem to be quite uniform and equal sized. Thanks David

David Kipling Do re-post to NEAN, it's a good find!

David Kipling Jim Anderson has a good selection of (Scottish) O muricata here, which show those even-shaped tubercles all the way to the edge. http://www.nudibranch.org/Scottish%20Nudibranchs/onchidoris-muricata.html

David Kipling The other key thing are those dark spots that make the tubercles look like little chimneys. And as you say, the tubercles get smaller near the edge.

David Fenwick Snr Just been to http://www.seaslugforum.net/showall/doriocel and read about all the Cornish records. Glad to see there's a Mounts Bay record for the species. Will sent the info on and make sure your records also go on the ERICA database; the species doesn't currently feature. Thanks David

David Kipling There is another Penzance record; in (?) 2009 Matt Swardlow of Buglife was rummaging around in the rockpools under the Jubilee swimming pool on the seafront and found one. It got a mention in Simon Barnes' column in the Times (Aug 22 2009) under the heading 'Dirty Doris'. Text of the article is copied below. "Dirty Doris Biodiversity is one of the great resources of a nation, or a planet, and it is to be celebrated in its endless forms most beautiful. So I called Matt Shardlow at the invertebrate charity, Buglife, to ask what I had seen on the Cornish cliffs. It looked, I said, like an ichneumon wasp. It was, he told me, an ichneumon wasp, so I was delighted with myself. It was slender, long-bodied, with a rather floaty flight and a ginger band round what we entomologists call the bum. The ichneumons are a large group: this was a species of Netelia, and I am the richer for knowing this. But Matt himself had done rather better on his own Cornish jaunt. He had, he told me, found Doris ocelligera in a rockpool. This is a sea slug 2cm long, and it is only the third time that one has been found in this country. It is rare throughout its range, a dirty white thing with dirty white lumps that have dark tips. And no one has any idea at all what it eats. Isn’t that all strangely and quietly wonderful? There’s beauty everywhere, if you care to look. Good idea not to destroy it, in my view." (reposted from http://www.timesonline.co.uk/tol/comment/columnists/simon_barnes/article6805779.ece)

David Kipling I hope Jan Light is listening to this, she wrote up the original sightings for Mollusc World.

David Kipling Matt's record is useful as it confirms you can find this critter in rockpools (which is where you found it David?). Ie it's not a just deep-water critter.

David Kipling If confirmed, yours is only the fifth ever sighting in the UK (AFAIK). Bernard Picton will probably want you to pickle it!

David Fenwick Snr Sadly we put them back, we found two under the same rock, they were in a small middleshore pool on the west side of the rocks at Lariggan Rocks. Can look for them again if Bernard wants to see them.

David Kipling It would be interesting to know what else is under that rock. The shape of the nudi makes it look like a sponge, with those little chimneys looking like oscules. The information I can find suggests that it is a sponge-eating Dorid, with suggested foods including Halichondria, Haliclona and Hymeniacidon, based on this review: http://www.theveliger.org/nudibranch_food.html Any encrusting sponges under those rocks?

David Fenwick Snr I think we'd best have a look for some more !!!

David Kipling You took this specimen from Lariggan Rocks in Penzance. This is 1km along the coast from the outdoor swimming pool where Matt Shardlow from Buglife made his 2009 rockpool sighting of this species. Add to that our own sighting (at 25m deep on a wreck about 1km south of this point in the bay) then it sounds like you have got a stable(ish) local population of this species in Mount's Bay.

David Fenwick Snr We regularly go to Chimney Rocks (west of swimming pool) and haven't seen it there yet, but we'll keep a good eye out for it now though, and also at other sites as across the bay.

Bernard Picton David Fenwick, this is a really exciting find. I've never seen one, but it does look as though it is now well-established on the south coast there. Julia Nunn, found more than one (mentioned above). There are no old records at all from this far north, so a good candidate for climate change spread.

Joshua Hallas has anybody been seeing any Adalaria loveni? i need some for my project

David Kipling We saw one the other year in Orkney/Fair Isle if I recall - this is the one with the pointy tubercles, yes?

Julia Nunn that would be Adalaria proxima, David. The jury is out as to whether Adalaria loveni exists in UK/Ireland. Bernard can help there

David Kipling Oh no there's two Adalarias?!? Bother!

Joshua Hallas i was wondering if anyone lives or frequents the Isle of Man

Sarah Bowen No, but I know someone who does now live there. He's a keen Seasearch diver; don't think he does FB though so isn't on here. Any particular reason?

Bernard Picton Christine did the 3rd year of her degree course at the marine station in Port Erin. Unfortunately Liverpool University have closed the station, but I'd have contacts on the island...

Joshua Hallas I'm looking for any and all onchidorids from that area, specifically Onchidoris pusilla. The radula of a potentially new species is extremely similar to O. pusilla. So DNA and anatomy is important for me to verify that what i have is different from O. pusilla. I know that Miller was able to find lots of O. pusilla back in the 50's and right now its towards the end of their spawing time. So if your contacts Sarah Bowen and Bernard Picton are able to help me out that would mean a lot.

Bernard Picton Miller collected most of his specimens by dredging I think, looking on dead bivalve shells and other substrata with encrusting bryozoa. I do have some Bouin's fixed specimens of O. pusilla I think, but have not seen it for years. The best place to look is under stones and rocks, which divers don't usually do.

Joshua Hallas if you end up finding those Bouin's fixed O. pusilla i would love to see them because than the radual and the reproductive system would be able to looked.....

Bernard Picton OK, Josh, I got some Onchidoris muricata and Adalaria proxima into ethanol for you last week, so I'll send a package.

Joshua Hallas thanks a lot, hopefully O. pusilla might shine a light on the black onchidorid from scotland