Purple Octopus - using citizen science to discover marine interactions
This is the entity page showing aggregated messages and images for the named entity.

Acanthodoris pilosa

(Abildgaard in Müller, 1789)

Klas Malmberg Aquatilis A nice picture of black and white! (Acanthodoris pilosa)

João Pedro Silva Very nice document :) They look like dominoes.

Joshua Hallas so cool

Brendan Oonk Yin yang :)

Robert Eriksson Cool! I am a lumper; some would put the darker one to O. inspicua but they are all A. pilosa to me...

Message posted on NE Atlantic Nudibranchs on 11 Jun 2012
Craig Muirhead Acanthodoris pilosa 05 June, 2012. Loch Fyne, Scotland. 30 mm animal at 18 metres in 11°C water. Fuji E900 in Ikelite housing, Inon CU lenses and 2 x Inon S-2000 flashes.

Joshua Hallas great pic

Arne Kuilman Very rare in the Netherlands. I've seen it once.

David Kipling And comes in a range of colours from pure white thru to almost-black, with a couple of brown/fawn versions in the mix as well (often seen as mixed groups on the same bit of finger bryozoan).

Arne Kuilman Is that what they eat? I'll pay more attention to Alcyonidium diaphanous, but it doesn't look familiar to me. I've seen it at Kistersnol, a dive site where hardly any people dive. I've added the photo.

David Kipling Yes, and I don't think I've ever seen them not actually on the food source either. If a dive site has loads of that bryozoan you can pretty much guarantee there will be a population of Acanthodoris in the area, so go off hunting!

David Kipling Does this species do direct development or planktonic larvae? It's a helluva crawl ...

Brendan Oonk In the Netherlands Acanthodoris is mostly found feeding on the bryozoans (Conopeum) that grow on mytilus shells

David Kipling Planktotrophic veliger larvae apparently, so could swim [if that's the right word] from Dawn's to the Netherlands.

Message posted on NE Atlantic Nudibranchs on 05 Jun 2012
Rudolf Svensen Anybody knows this one? Never seen anything like it before. Image captured right in front of my house on the South West coast of Norway a couple of hours ago. It was quite large. Maybe 30-40 mm long and my best guess is a Acanthodoris pilosa which has been arguing with its hairdresser.

Message posted on NE Atlantic Nudibranchs on 14 Apr 2012
Morten Pettersen Photo taken in Vik i Sogn, Norway. Sorry about the quality of the photo. Its taken with a wideangle lense in a domeport on my first dive with my new camera. I just want to know the species. I have never seen a black nudi before...

Ian Smith I guess Acanthodoris pilosa, but not sure without view of rhinophores that remind me of Longhorn cattle.

João Pedro Silva And this one has very unorthodox rhinophores...

Ian Smith I see what you mean Joao; I thought they were retracted, but very unorthodox if the white tipped bits are close set/united rhinophores.

Morten Pettersen Thanks...

Message posted on NE Atlantic Nudibranchs on 30 Mar 2013
Arne Kuilman Dutch Acanthodoris pilosa at Kistersnol. A rare nudibranch in the Netherlands.

Brendan Oonk I'm sorry Arne but this is not A.pilosa but A white Onchidoris bilamellata

Message posted on NE Atlantic Nudibranchs on 07 Jun 2012
Chris Wood Devon Seasearch 5 day survey Last week Devon Seasearch carried out a 5 day survey of sites from Hatt Rock in the west (and the only site dived within Cornwall) to Prawle Point in the east, only missing one dive when the winds picked up from the south on Sunday afternoon. There was a wide variety of habitats, some dominated by jewel anemones (Hatt Rock), others by pink sea fans (Eddystone), antenna hydroids (Bolt Tail), finger bryozoans (various sites - many with Acanthodoris pilosa eggs and adults - see picture) and featherstars (Plymouth Sound). Amongst new sites dived was the old Erme river bed which can be traced for over a mile off the present shoreline and has steep slopes with deep side 'valleys' with a diverse fauna, including the encrusting sponge Hexadella racovitzai and local specialities, such as crumpled duster sponge, Axinella damicormis and sheets of yellow cluster anemones, Parazoanthus axinellae. Most of the sites surveyed were in Special Areas of Conservation (SACs) or proposed Marine Conservation Zones (MCZs).

Message posted on Seasearch on 29 Jul 2013
Jerry Shine An Acanthodoris pilosa with a Palio dubia hitching a ride

Anne Diver What a fantastic shot!

Jerry Shine Thanks, Anne.

Sutherland Maciver very nice!!

Jerry Shine Thanks, Sutherland. I should have mentioned that the shot was taken just north of Boston in the US.

Message posted on EPAM Nudibranchs on 01 Nov 2012
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.

Message posted on NE Atlantic Nudibranchs on 27 Oct 2013
Robert Roy Not sure of ID on this one, possibly Adalaria jannae, or Acanthodoris lutea About 2 cm long, 10 m depth, Hussar Bay, near Port Hardy, British Columbia

Robert Roy hmm, don't think it's Doris Odhneri...

Evette Swindale Hi, found something similar in Nuweiba, Egypt at 4.5m the same size but brown/black, also was unable to find it in any reference books. I called mine a teddy bear nudi as it appears to be furry

Marli Wakeling Acanthodoris hudsoni.

Marli Wakeling It is paler in the yellow areas than most.

Gary Cobb I think this is Acanthodoris pilosa

Robert Roy Yes, I think A. pilosa is correct! Does not have yellow margin of A. hudsoni...

Marli Wakeling A.pilosa has no yellow. I will be stubborn on this one.

Gary Cobb I could not see a yellow margin and so thought it could be A. pilosa. As I look at this photo I can not make out yellow on the papillae. I can see some peppering of cream on the papillae. I know A. pilosa can have cream peppering or brown peppering on the papillae. I have attached a photo taken by Jim Anderson of A. pilosa showing some cream colouration to the papillae and no yellow margin. Hummmm...

João Pedro Silva Again, molecular studies will determine how important is the lack or presence of the yellow margin. A similar case occurs with the northern and southern variations of Cadlina laevis. http://www.seaslugforum.net/find/4793

Gary Cobb Very true Joao. Thanks! Marli don't give in!

Robert Roy Lol, it's interesting to watch the experts debate the ID of this one! I am no expert, but this nudi does not have the yellow margin at the base that seems characteristic of A. hudsoni. It does have long rhinophores that taper backwards, which according to some sources is characteristic of A. pilosi. This nudi does have a bit of yellow on its papillae but I am not sure if that would exclude it as being A. pilosi because A. pilosi is known to have significant colour variation.

Marli Wakeling Let's just call it A. hudlosa and be done with it. LOL. I may be stubborn, but I can also be wrong. I have just dug up this old photo of A. pilosa, and lo and behold, there is some faint yellow.

Gary Cobb Thank you guys for nice dialogue. You know without anaylising this animals DNA we can only hazard a guess based on what we observed in our experiences. You can see putting an ID to an a nudibranch can be tricky. Based on what I have seen I am happy with Acanthodoris pilosa. But everyone can have their own opinion - this is science!

Robert Roy I checked with a few experts who are not on Facebook, and I think the final verdict is Acanthodoris pilosa!

Paula Lightfoot Is this Onchidoris bilamellata? It seems a bit darker than usual.

Christian Skauge No idea, but nice picuture :-)

Tony Gilbert It is quite dark for one,usually they are lighter brown than this. They feed on barnacles, and usually in aggregations.

Jim Anderson Looks like Acanthodoris pilosa

Christian Skauge Jim - yes it does! I have seen that one before :-)

Paula Lightfoot I didn't know Acanthodoris pilosa was also available in brown - but this photo of a brown specimen on the BMLSS website looks a bit like mine: http://www.glaucus.org.uk/seaslug1.htm

Becky Hitchin Paula Lightfoot - we only get them in brown down here!!

Paula Lightfoot At the same site this morning we found a more 'typical' (for the northeast anyway) white one, so I will record it as Acanthodoris pilosa. Didn't see any finger bryozoans but there were encrusting bryozoans on the same boulders where we found the nudis.

Peter H van Bragt Hello Paula, Acanthodosris pilosa indeed. On the Dutch coast we find them from white to black with various brown shades in between. Always monochrome. The spiky tubercles are most indicative as well the typical gills and rhinophores. cheers Peter H van Bragt

Godfried van Moorsel moreover, O. bilamellata has much more gills in a horseshoe

Message posted on NE Atlantic Nudibranchs on 19 May 2012
George Brown First: Thank you Bernard for getting this site up and running. I frequently come up against problem species. This is an invaluable opportunity to discuss these issues with experts. Second: Blue/black onchidorid, April 2009, 20 metres of water, Loch Dunvegan, Isle of Skye, 4mm long, 60mm lens, cropped, running out of air.

Bernard Picton Thanks George, Marco Faasse has found the same animal I think. I'd like to hear Jussi Evertsen's opinion on this one.

Christian Skauge Could this be an Acanthodoris pilosa? I think we found some black/brown variants of it at last year's safari. Not 100% that was the name, though - Jussi, do you remember it?

Bernard Picton No, I'm sure it's an Onchidoris. The gills are small and transparent and the rhinophores are like Onchidoris pusilla.

João Pedro Silva Shall I place this in the "Unidentified" album?

Bernard Picton Hang on a minute - this one has black gills, but in O. pusilla they are transparent. Yes, it's definitely unidentified, if not to say un-named. I've been puzzling over it since George found it. Lin Baldock has also photographed one, so we need to gather them together.

João Pedro Silva I'm trying to figure out a way to move this to the unidentified album... not sure how so far.

Bernard Picton Ok João, now you've lost me, I don't know how you got the other one in there.

João Pedro Silva I've opened the album and then uploaded the photos into it.

Christian Skauge My best guess would have to be O. sparsa, otherwise it's something I've never seen before. A strange one for sure!

Bernard Picton O. sparsa has extra large tubercles at the base of the rhinophores.. http://www.habitas.org.uk/marinelife/species.asp?item=W13380

Bernard Picton O. pusilla has transparent gills... http://www.habitas.org.uk/marinelife/species.asp?item=W13370

Christian Skauge Right you are... enough guesswork - I give up. This one is definitely beyond me ;-)

João Pedro Silva I think it's easier for George Brown to upload the image again into the Unidentified set: https://www.facebook.com/media/set/?set=oa.167103413400947&type=1

Christian Skauge Don't we lose the comments then?

João Pedro Silva well, the discussion will stay here, aswell as the photo.

João Pedro Silva I've only put the other photos there after there was some discussion on as previous post (not a photo though but a link)... as it was inconclusive, I've uploaded the photos.

Christian Skauge Ahh, okay - get it :-)

Kate Lock looks like a nudi that has been feeding on caviar!

Marco Faasse This species has several unusual characters. One of them is that along the mantle edge, at regular intervals, triangular parts of the mantle seem to be missing. When the slug contracts these gaps close.

Christian Skauge I don't think there's anything missing - seems to be close to transparent in "colour" to me.

Marco Faasse Maybe transparant, seems more likely. I don't understand why these parts disappear during contraction.

Christian Skauge They do? How do you know - have you seen this one before?

Bernard Picton Are they not pale patches Marco?

Marco Faasse I watched it through a stereomicroscope. After contraction a tiny whitish stripe remains. Maybe they are transparent parts which contract more strongly?

Joshua Hallas if anyone finds any of these please inform me and PLEASE collect them. I have the one from Marco Faasse and am in need of more....

Message posted on NE Atlantic Nudibranchs on 03 Feb 2012
Paul Freeman https://www.facebook.com/photo.php?fbid=10153131763700352&set=a.10153131695020352.1073741848.712350351&type=1&theater Acanthodoris pilosa - Low lee ledges, Newlyn, Cornwall. 17m

David Kipling Do I see a red blenny in that album Paul?

Paul Freeman yes, seen quite a few recently - see album named Fraggle rock and Hera - a friend pointed out that they were red, rather than just Tompots. Is this unusual, then? Saw a tadpole fish on the Hera too - a rare sighting I am told.

Paul Freeman Tag away if you know the names.

João Pedro Silva Parablennius ruber. Not sure why it's called "Portuguese blenny" on Fishbase: I dive mostly in Portugal and I don't get to see this species very often.

David Kipling It's the colour of the Brits when they come to Portugal ...

João Pedro Silva "Lagostas" in portuguese slang (lobsters) :)

David Kipling Hey, I see Angela Gall's dad!

David Kipling (OK I appreciate that's not actually a species ID....)

Paul Freeman he is a rare sighting this far south these days, though. good spot

David Kipling Red blennys are a very southerly fish - I've only seen them in IoS.

Paul Freeman I never knew they were different - just assumed there was variation in colour. Seen them in Falmouth, now Porthcurnow.

David Kipling Nope, distinct species, P. ruber as JP says.

Paul Freeman now I know I'll keep an eye out.

George Brown I've photographed Parablennius ruber on the west coast of Lewis and St Kilda. Was published in the Daily Mail as incontrovertible proof of global warming. I was just happy with the £80.

Message posted on NE Atlantic Nudibranchs on 15 Aug 2013
Tony Gilbert Interesting colouration of Acanthodoris pilosa, usually white, this is the first brown/mixed one I've seen, and has white gills. Found this on Bryozoan: Alcyonidium diaphanum (thanks Jo). https://www.facebook.com/media/set/?set=a.173485702785521.38902.100003722780643&type=1#!/photo.php?fbid=190530867747671&set=a.173485702785521.38902.100003722780643&type=3&theater

Ian Smith That's a beauty!

Arne Kuilman Nice rhino's!

Tony Gilbert Thanks. And the A. pilosa next door was white, on the same bryo.

Message posted on NE Atlantic Nudibranchs on 22 Sep 2012
Jim Anderson Scottish Nudibranchs has been updated. www.nudibranch.org This is an Acanthodoris pilosa.

Patrik Good Nice critter, interesting website. Congratulations.

Jim Anderson Acanthodoris pilosa - juveniles. The 'big' one was approx. 6mm long Loch Fyne, Scotland

Ken Thongpila Wow! Nudi from Scotland :-) nice...

Gary Cobb Burrrrr....

Jim Anderson Scottish Nudibranchs has been updated. www.nudibranch.org This is an Acanthodoris pilosa

Message posted on Underwater Macro Photographers on 06 Mar 2012
Becky Hitchin I've officially given up trying to ID nudibranchs, especially TINY nudibranchs. Is the yellow / white one a small P. faeroensis? But I couldn't see any yellow oral fringey bits.

Marco Faasse It's less common/more special than P. faeroensis in my opinion :-)

Becky Hitchin I think I only know yellow and white nudis that have that yellow oral fringe. Hmm. Goes to look at Scottish Nudibranchs ...

Becky Hitchin Ancula gibbosa?

Marco Faasse I'm sure you'll be able to find what it is ...

Marco Faasse That's quick! I think so ...

Becky Hitchin I'd never even heard of Ancula, but I flicked through Jim's species and it does look right http://www.nudibranch.org/Scottish%20Nudibranchs/html/ancula-gibbosa-06.html

João Pedro Silva Yes, A. gibbosa.

Becky Hitchin A completely new nudibranch for me :D

Peter H van Bragt And Acanthodoris pilosa for the other tint one!

Becky Hitchin it was *so* small. It then occurred to me that I don't know how old that one would have been. Is that from last year? The year before? Has anyone looked at age sequences in nudis / Dorises?

Lucas CerCur Two of them are potos of Ancula gibbosa.

Peter H van Bragt most likely specimen from last years' spawn which developed from larvae to slugs this springbut this spring

Becky Hitchin That's just great :) now I want to look for more, and find it about larval / juvenile acanthodoris

Message posted on Seasearch Identifications on 26 Jun 2013
Becky Hitchin Washed up on a strandline today were loads of these little beasties. Are they juvenile Acanthodoris? That's my only guess :)

João Pedro Silva Try photographing the animal submerged. It can be almost unrecognizable.

Becky Hitchin They were all washed up, and dead, unfortunately :)

Becky Hitchin I mean :( !

João Pedro Silva Even so, it may show better detail submerged.

Becky Hitchin I do have some here ... let me see if I can take a better pic

Andy Horton Adult Acanthodoris pilosa

Andy Horton http://www.glaucus.org.uk/A_pilosa-dark-1_AH.jpg

Becky Hitchin These were teeny compared to our normal adult ones!

Andy Horton I only see the small ones. Dark or white coloured.

Becky Hitchin these are more normal for us: http://www.flickr.com/photos/elegaer/5974609585/in/set-72157625425775330, http://www.flickr.com/photos/elegaer/5975169536/in/set-72157625425775330

Kate Lock How many were there?? I am kinda with Dawn as O.bilamellata are found in shallow waters in large congregations feeding on barnacles.....so are more likely to be found washed up in large numbers like this. A.pilosa is found in deeper waters....and not usually in large congregations...maybe 2-3 together.......on Alcyidium diaphranum. But agree need a submerged picture!

Becky Hitchin Submerged picture has been posted, if FB will let me say that! Well, I reckon there was 1 every 10cm or so in the strandline, and that was just looking at the surface

Jan Light Is there a circlet of gills at the tail end? Otherwise this looks like the pulmonate sea slug, Onchidella celtica, to me.

Andy Horton I think I have got the species muddled up. http://www.seaslugforum.net/acanpilo.htm Young A. pilosa.

João Pedro Silva Jan Light, the photo taken with the submerged subject clearly shows the gills: https://www.facebook.com/photo.php?fbid=10150623623459232&set=o.166655096779112&type=1&ref=nf

Message posted on NE Atlantic Nudibranchs on 08 Mar 2012
Animalia (Kingdom)
  Mollusca (Phylum)
    Gastropoda (Class)
      Heterobranchia (Subclass)
        Opisthobranchia (Infraclass)
          Nudibranchia (Order)
            Euctenidiacea (Suborder)
              Doridacea (Infraorder)
                Onchidoridoidea (Superfamily)
                  Onchidorididae (Family)
                    Acanthodoris (Genus)
                      Acanthodoris pilosa (Species)
Associated Species