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Molgula citrina

Alder & Hancock, 1848


Erling Svensen Molgula citrina from Egersund, Norway.

Bernard Picton Erling this is really nice. It shows the right hand side, with the kidney at the bottom, then the gonad with central, pink female part and white male parts. I think the pink cluster to the left of that is embryos and then the dark brown lobes are the kidney. The gut and another gonad will be on the opposite side.

Cynthia D. Trowbridge Bernard, is this the genus with the cool, spiral-shaped pharyngeal "slits"? I will have to dig through my photos...

Wilfried Bay-Nouailhat Hi Erling, could you say what size was this molgula, was it more than 1 cm or less than 1cm ?

Erling Svensen More than 1 cm, aprox 1,5+ cm. They are quite common in Norway in exposed places. I will put another one out in 15 minutes....

Message posted on NE Atlantic Tunicata on 07 Apr 2013
David Kipling I keep seeing these sand-encrusted unitary ascidians that I assume are Molgulids from the little "crown" around the siphon. Could these just be M. manhattensis or is it likely they are another of the numerous european Molgulids ?

Becky Hitchin what is the "official" definition of manhattensis?

Marco Faasse Here I ID'd a species like that as Molgula complanata. Sometimes it occurs in mats. I remember I've seen the larvae and looked at the rim of the siphons, but forgot which combination of literature sources I used for ID. Superficially, your species looks similar.

David Kipling I've just had a look on NBN. Very few complanata records in UK *but* there are a couple around Skomer (including a recent one done by EMU, so Ali B should have ID'd it - I'll ask her) as well as one at South Hook just up the river. So that would certainly fit ... I'll get a body next time. Thanks!

Liz Morris Hi David, We took some of these molgulids from Thorn to the squirt workshop a few years back and Kate Northern and I dissected them under the supervision of John Bishop with the Moniot key. I think we came up with two species.. M.complanata (i def have photos of dissection) and M.oculata. I also have dissection images of M.socialis looking scarily similar from Strangford loch. Its got something to do with the curve in the gut and reproductive bits, apparently. So I always stick with 'Molgula sp' since then!

Tom Kerr Looking at R H Millar's book, I would suggest M. occulta is a possibility.

Wilfried Bay-Nouailhat Hi, we dissected some Molgula occulta and they don't look like the sea squirt on your photo. Monniot's document clearly shows the difficulty to identify this species, several specimens anatomically different are described

Bernard Picton Molgula occulta and Molgula oculata are both buried completely in sediment, the first in muddy sand, the second in coarse gravel. Epiphytic on seaweed like this are Molgula citrina (green, no attached sand) and Molgula complanata from what we found back in the 1980's. I think a focus on habitat preferences might be helpful with Molgula.

David Kipling Liz Morris ... was your M. oculata from a buried specimen or stuck growing on weed?

Liz Morris The M.complanata which I've got images of are from weeds like yours. I thought we had M.oculata growing from weed too, but I will have to dig out notes. Take Bernard's advice on that because at the mo its just from memory. I can be sure of the M.complanata on weed in the Haven though. Sorry, not very useful! I;ll see if I can find the fieldbook from back then.

Bernard Picton These are big animals, 3cm across. Quite unmistakeable with that bare patch between the siphons. http://www.habitas.org.uk/marinelife/species.asp?item=ZD2580

David Kipling Well unless it happens to be Eugyra arenosa ....

Liz Morris uffa!

David Kipling We had a buried one on the NRW squirt course that we thought would be M. oculata/occulta ... turned out to be Eugyra arenosa (cue head bashing against wall in frustration). So "lumpy solitary sp." for me.

Bernard Picton You would only confuse Eugyra with Molgula occulta, not M. oculata, David. I suspect that Eugyra has no space between the siphons and that it is the one I have (wrongly) illustrated on the Habitas M. occulta page.

Wilfried Bay-Nouailhat Hi, here is for sure M. occulta : http://www.mer-littoral.org/32/photo-molgula-occulta-wb01.php But I've often seen M. occulta in coarse sand, never in mud.

Wilfried Bay-Nouailhat The external description of M. citrina by Monniot doesn't match with this species but goes perfectly with Erling Svensen's photo. https://www.facebook.com/photo.php?fbid=503931053005129&set=gm.453166558092521&type=1&theater So I think it can't be M. citrina. I saw too, a species similar to David Kipling's one in south-Brittany, area from where M. citrina is supposed to be absent. M. complanata is covered in sand, lives on all kind of substratum and is said to be common, it seems to be a good option to explore. Other proposition : M. bleizi, small size 0,8-1 cm, slightly covered in sand, living on rocks and seaweeds.

Message posted on NE Atlantic Tunicata on 30 Sep 2013
Taxonomy
Animalia (Kingdom)
  Chordata (Phylum)
    Tunicata (Subphylum)
      Ascidiacea (Class)
        Stolidobranchia (Order)
          Molgulidae (Family)
            Molgula (Genus)
              Molgula citrina (Species)
Associated Species