Stolonica socialis

Wilfried Bay-Nouailhat hi, to start this discussion group, here is a picture for fans of Pycnoclavella species : Pycnoclavella producta along with Stolonica socialis, Camaret, Brittany, 10 meters, may 2011.

David Kipling This really shows how small the Pycnoclavella are! How characteristic is the square shape to the siphons of S. socialis?

Wilfried Bay-Nouailhat Yes, the siphons have a square opening exept when they are really very very open.

Liz Morris David Kipling, and Wilfried Bay-Nouailhat, I seem to remember from the Ulster museum squirt course a few years back thatt lots of the 4 oral lobed species appear square at times? Including Dendrodoa and Polycarpa? Maybe this would be a useful characteristic in a key, but not the defining feature? What are your thoughts on this?

David Kipling I guess the mechanics of a 4-lobed siphon would mean that relaxation would make it square (as opposed to a star pattern for a 6 or 8-lobed).

Michelle Simpson Me & Spencer Cook are after help with identifying this sea squirt, Paula Lightfoot thinks it might be Dendrodoa grossularia with a bryozoan growing on it, but any ideas (particularly from David Kipling ;) ) would be greatly appreciated!

Nicola Faulks As soon as I saw it I wondered if it was a faded gooseberry sea squirt complete with little compartmentalised friends! Not seen one on a stipe before tho. Is is a current or surge bashed site? :-)

David Kipling The bryozoan looks like Electra pilosa (more circular cells). I wouldn't argue with Dendrodoa, given the homogenous colour. Your other option would be Stolonica socialis but that's more of a teapot as opposed to coffee pot shape (ie taller) and not really the right habitat - whereas Dendrodoa will come happily into the intertidal. How deep was this Michelle?

Michelle Simpson It was approximately 6m depth in a sheltered bay but there would have been current from the tides I assume, but not really surge.

David Kipling I think Paula's right. The one you would usually see on kelp stipes is Distoma variolous, which is a compound squirt with the animals fused together via their basal tests. It sort-of looks like a pomegranate. This isn't that but does show kelp can be fertile ascidian territory provided they can grow fast enough! I think they like to be raised up slightly so they don't choke to death if covered by sediment ... we get a lot of Didemnids wrapped around holdfasts in Pembs for example.

Michelle Simpson Many thanks for your help David, Paula & Nic I'm glad I spotted it :)

David Kipling Dendrodoa factoid: Unusually for a unitary squirt these are brooders ... the eggs get fertilised inside the animal (with sperm from another animal) and a swimming fully-fledged tadpole larva is released. This swims briefly, finds a nice location and settles down. That's why Dendrodoa is often found as dense aggregations (the apple doesn't fall far from the tree). In contrast, unitaries such as Ciona release eggs and sperm into the water column to take pot luck and be fertilised there ... a very different life history when it comes to how much you invest in the egg/larva. Why is this interesting? Because brooding is a common feature of invasive ascidians (eg Corella eumyota) ....

David Kipling I'll shut up now ;)

David Kipling Sorry dear :)

Spencer Cook Well that went a little over my head, but interesting to read.

Michelle Simpson I'm glad you said that hunni, I was thinking the same thing ;)

Richie West not sure about this ascidian, taken at crow rock on 8 july. I thought it might be stolonica socialis but it's very pale and I can't see stolons.

David Kipling It has the right elongated/stretched feel for Stolonica socialis, yes. Colour is a bit pale I grant you. I don't think I've ever actually seen the underlying stolons, too hidden by animals and silt usually.

Tony Gilbert Perhaps this is a more southern species, as I know its found from UK to Canaries, so prob. differs in colouration throughout its range. http://www.flickr.com/photos/tonyjgilbert-images/6983012120/ In Lanzarote, where this image was taken, Stolonica only appears to start below 30m and is usually found on rocks near cliff edges, or isolated rocks below 35m. Interesting to find a UK species though.

Richie West not sure about this ascidian, taken at crow rock on 8 july. I thought it might be stolonica socialis but it's very pale and I can't see stolons.

David Kipling It has the right elongated/stretched feel for Stolonica socialis, yes. Colour is a bit pale I grant you. I don't think I've ever actually seen the underlying stolons, too hidden by animals and silt usually.

Tony Gilbert Perhaps this is a more southern species, as I know its found from UK to Canaries, so prob. differs in colouration throughout its range. http://www.flickr.com/photos/tonyjgilbert-images/6983012120/ In Lanzarote, where this image was taken, Stolonica only appears to start below 30m and is usually found on rocks near cliff edges, or isolated rocks below 35m. Interesting to find a UK species though.

João Pedro Silva Any idea on what the orange "pimples" may be on these squirts? It's not the first time I've seen them with these pimples. This is a crop. The full image is here: http://www.flickr.com/photos/jpsilva1971/9462826046/

Wilfried Bay-Nouailhat these orange dots are not parasitic organisms but are part of Stolonica socialis itself. They are located on the transparent tunic.

João Pedro Silva Another ascidian from the Ria de Ferrol, Galicia, Spain. These were about 6m deep in a dense kelp forest.

Wilfried Bay-Nouailhat Stolonica socialis ;o)

João Pedro Silva Thanks, Wilfried!