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Balanus crenatus

BruguiƩre, 1789

George Brown I need help with the ID of this barnacle please. Found in a porthole on the V83, Scapa Flow, Orkney. Shell about 12mm high, water depth 12m.

Ian Smith Hi George I can rule out Balanus balanus and Verruca, but can't be sure what it is. Could you email me off-list a higher res version so I can zoom in?

George Brown Great news Ian, many thanks. I'll crop a RAW file. :)

Keith Hiscock Eve Southward can often give a view or suggest a contact - I will ask.

Ian Smith Hi George Thanks for high res. image. Balanus crenatus seems the best fit of the intertidal Brit. barnacles, ; deeply crenate aperture and shape of the overlapping insertion plates. The useful tergoscutal flap is not visible in your image. However, the postures of the opercular valves and extended cirri don't seem right for B. crenatus. A.J. Southward's Linn. synopsis shows a northern sublittoral sp., Chirona hameri, which is a reasonable match for the plates. Google images has several live pics of hameri by Erling S., and the posture resembles yours. I tend towards it, but can't give a definite id. I hope Erling or Eve (mentioned by Keith - a relative?? of A.J. Southward, deceased) will be able to help.

Ian Smith Have just noticed the red encrusted barnacle top right in your uncropped image above. What I can make out of the general shape is very like Southward's images of hameri; "half open tulip".

Keith Hiscock Eve Southward (widow of Alan) has looked at the pic (from all angles) and, although a barnacle 'expert' once removed, i.e. not a barnacle expert, can only suggest that it is a Balanus sp. I suggest not B. hameri (I have memories of them in the tanks at Menai Bridge). Check the spikey plates, ignore the opercular plates which are pushed-out. Could be B. crenatus, possibly B. balanus.

Andrew Want this photograph leads me to suspect B. crenatus... Just as a related point of interest: I recently came upon a massive specimen of Chirona hameri retrieved off West Mainland Orkney from a buoy at 45 metres depth - it was 63 mm from carina to rostrum (Southward's book has them max. at about 50)!

Message posted on Seasearch Identifications on 18 Nov 2013
Erling Svensen Could this be some kind of barnacles? Norway yesterday evening.

Marco Faasse Sure! Verruca stroemia. Here we call it (translated): zipper barnacle. You see why :-)

Erling Svensen Thanks a lot Marco. A new species on the list. Need to buy a botle of red wine......

Ian Smith http://www.flickr.com/photos/56388191@N08/sets/72157629143972722/

Jane Pottas I recognise them as V. stroemia but I like the name zipper barnacle!

Marco Faasse Congrats, Erling! Keep searching. Always good to find a reason to open a bottle. If I can help to find new species ...

Erling Svensen You are welcome to Norway to help searching.....

David Kipling Ian ... that flickr set is excellent, the way you use the embedded dynamic annotation of the pictures is great, not seen that before!

Ian Smith Thanks David. There have been big changes to Flickr recently: Free storage for about half a million images per person. All users can now arrange images in "collections" of "sets" for free. Sadly the "collections" button is hard to find; users need to click on the 3 dots at top right to get a drop down menu with it on. My collections (barnacles - set each for the 9 littoral UK spp. and gastropods - set each for 4 small spp. ;more to come) are at http://www.flickr.com/photos/56388191@N08/collections/

David Kipling Erling's zipper photo for Inga Williamson, plus do have a look at Ian's flickr album, it has some cool feature. Oh, and welcome to Seasearch ID ;)

Inga Williamson Thanks David - great picture indeed

David Kipling Ian, Erling ... I've never seen these in the UK but there are loads of records. What sort of depth/habitat do you find them?

Ian Smith Low water, Fucus serratus zone downwards. Often on F. serratus and often UNDER stones - look crushed. On Menai Strait often common but invisible under sponge, except for red gape when open. I found a Lamellaria perspicua with a good imitation of the gape and sponge (pic on Conch Soc site). Verruca stroemia is such a distinctive sp. with its chevron pattern of grooves/ridges that I think records will be ok, but a similar Verruca sp. in Mediterranean needs inspection of underside of opercular valves to differ.

David Kipling I shall have to have a hunt!

Ian Smith Southward says to 500 metres. Moment of self doubt -I THINK it occurs on F. serratus, but my memory might be confusing it with Balanus crenatus. Will check on my next visit. Certainly likes under stones, but not exclusively.

David Kipling 500m deep?!?

Ian Smith Well NBN does have a saltmarsh sp recorded on the Brecon Beacons :-)

Message posted on Seasearch Identifications on 11 Jul 2013
Andy Horton Isopod to look out for, or not to overlook

David Fenwick Snr The D. magnitorata was found on the side of a small Corallina covered rock, approx. 25cm dia; in a middleshore rockpool at Chimney Rocks, Penzance, Cornwall. The site is just west of Jubillee Pool. I was informed about this species by David Holdich about 12 months ago, so it has been one I've been looking for. From Hayward and Ryland, adults live in Balanus crenatus, and juveniles can be found on Chrondus crispus and Corallina. So lots of suitable habitat for it in Mounts Bay. Apparently we're right on the edge of it's range; it's known from the Channel Islands, France, and all the way down the Atlantic coast to Africa.

Andy Horton http://www.aphotomarine.com/isopoda_dynamene_magnitorata.html At the time of writing, I am not sure of its size. Is it very small?

David Fenwick Snr Sorry Andy forgot to add that, it was about 6-7mm, books say 6mm; females are smaller.

David Fenwick Snr Having mentioned the site here, I would add that this is one of the best pooling sites in the area, with almost perfect access, it also has quite a diverse range of fauna ''and'' flora. It's therefore incredibly important that any rocks that are turned over are carefully put back the right way after. That said, it remains popular with local children, there are problems there but we continue to try and educate when we're down there. Cracking site for algae.

Andy Horton Perhaps (if you have time) it is worth a special web page? I have not visited it. On my list now, with Looe. I have been to Marazion but that is on the list to go there again. http://www.glaucus.org.uk/Rockpool.htm#Rockpooling%20Venues

Andy Horton There is a close species, the dull white Dynamene bidentata found amongst barnacles on the lower shore, mostly on the western coasts of the British Isles. Hayward (red book) page 68, this one mentioned only (2004).

David Fenwick Snr Yes we regularly find Dynamene bidentata on the middle and lowershore amongst wracks and in crevices close-by, adults are usually an olive-green colour but they can be marked white, juvenile females are usually white or a dull white as you say.

Jade Berman I think I have seen these before maybe even up here in Northern Ireland... thats not a confirmed sighting its more that I have seen similar and next time I will have a proper look!

Andy Horton Jade Berman: what beaches in Northern Ireland? Just curious on what beaches you visit?

Andy Horton The small olive green isopd seems familiar. I have just forgotten now.

Jade Berman I go allthe way around the coast but in particular I was surveying up around Rathilin Island at the time looking for invasives. We didn't record the isopods but I will check iwth some of the others over here if they have seen it

Andy Horton Jade Berman; what are your favourite spots? Have you been to Kinnagoe Bay (over the border in Donegal). We feature coasts on out Coastal Topography section of Torpedo. See also: http://www.facebook.com/groups/BritishCoast/ for general views of the coast although some views are slipping from the original idea to map the coast in pictures.

Andy Horton Rathlin Island: I have heard this is a good spot. I would like to more sometime.

Andy Horton Geography reminder to myself (and others): http://en.wikipedia.org/wiki/Rathlin_Island

Jade Berman It is a lovely spot with great diving, there is some stunning coastline generally up here in Northern Ireland

David Fenwick Snr Sadly I have to report the species in question here is Dyname bidentata as David Holdich has just revised his original opinion. The identity was made certain after I sent some of the Penzance examples to David for microscopic examination as I pointed out that there were a number of red / reddish Dynamene of similar markings in the area. David Holdich is sure that Malcolm Storey's find from Dorset is D. magnitorata so it is certainly here. David went on to say that the best place to look for the species is on the extreme lowershore on mainland Britain and amongst Corallina officinalis, Chrondus crispus or in channels of sponges; of course it's also possible to find D. bidentata in these habitats. At least I'll be able to use the images to be able to display how diverse D. bidentata is in colour and how it may at times be confused with D. magnitorata. Also sent to David was a stage 7 female D. bidentata that was extremely dark with fluorescent blue spots on its sides and top. The animal in the image above is of what is called a stage 8 male.

Animalia (Kingdom)
  Arthropoda (Phylum)
    Crustacea (Subphylum)
      Maxillopoda (Class)
        Thecostraca (Subclass)
          Cirripedia (Infraclass)
            Thoracica (Superorder)
              Sessilia (Order)
                Balanomorpha (Suborder)
                  Balanoidea (Superfamily)
                    Balanidae (Family)
                      Balaninae (Subfamily)
                        Balanus (Genus)
                          Balanus crenatus (Species)
Associated Species