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Dendrodoa grossularia
(Van Beneden, 1846)
David Kipling Is the red ascidian Polycarpa ?scuba, or else Dendrodoa grossularia? Siphon arrangement would suggest Polycarpa, yes?
(image taken Pembrokeshire, 15m, limestone reef)David Kipling I'd assumed Dendrodoa at first (cf pic of Aegires climbing over one) but the siphon arrangement on these ones got me panicking!
Message posted on NE Atlantic Tunicata on 15 May 2012
Tony Gilbert In the darkness of the cave near to Sugar Loaf Caves (Isle of Man), at its rear, in 5m of water, the walls are plastered in sponges and ascidians, with edges that stick out covered in Tubularia.
http://www.flickr.com/photos/tonyjgilbert-images/7651717500/in/set-72157630764104272
The image shows a piece of wall with Dendrodoa grossularia and Clathrina coriacea, however I am really unsure as to what the white growths are. Firstly, are they Ascidian or Porifera - as I didn't see inhalant syphons, so am currently thinking sponge. Any ideas - could it be sponge in a morphed state owing to perpetual darkness? Thanks.David Kipling Def sponge - looks like spines on the outside as well, making them grubby (like you would see on a purse sponge). Species? No idea ;)
Nick Owen Yep, sponges. Leuconia would be a place to start. Did you poke 'em? Feel, contraction, etc all important. Get a sample? You're right, sponges are plastic, taking varying forms/colours under varying conditions (eg dark, exposure). To be sure of sponge IDs, you need to do spicule analyses. Cheery thought! Lovely pics (as usual).
Tony Gilbert Thanks Nick, it seems to "fit" Leuconia gossei, although inconclusive. Photographic ID is not enough, agreed. I'd be interested - if anyone goes out there and takes a sample to ID it. We spent 30mins in the small cave which was not enough, it was an Aladdin's cave of wonders, before doing the Fairy swimthrough.
Message posted on Seasearch Identifications on 27 Jul 2012
David Kipling Adult Goniodoris nodosa eating a Dendrodoa grossularia in Pembrokeshire. I'm used to seeing juveniles on the finger bryozoan Alcyonidium diaphanum, so it is nice to see one having moved on to "adult food" ;)Kate Lock I am assuming this was also Linney Head??
David Kipling Yes, taken a few minutes before the Aegires. Habitas has them down as eating Dendrodoa.
Message posted on NE Atlantic Nudibranchs on 15 May 2012
Chris Wood Spider crabs - have you seen them aggregating this year?
Spiny spider crabs, Maja squinado, are known to aggregate in shallow waters at certain times of year for moulting and breeding. A request from a TV company about where to see them and a couple of observations prompts the thought that are people seeing these agreggations this year and if so when and where? In this crazy summer whcih has seen us lurch from winter to tropical heatwave in no time at all who knows what is going on.
The first picture shows a spider crab covered in gooseberry sea squirts, Dendrodoa grossularia, and clearly in need of a spring clean. This was a recent picture from Jersey where many of the spider crabs looked as if they had not moulted for a long while. Meanwhile just off Chesil Beach this weekend the pair to the right were clearly not waiting for their friends to arrive before indulging in some crab action!Kirstie Harris We saw huge numbers of spider crabs this weekend at the Hen & Chicks in Pembrokeshire. Some of the crabs were enormous and I was even 'lucky' enough to catch a pair of them making more crabs :)
Hayden Close Seen large number off aberystwyth coast too
Chris Hopkins Lots in St Brides last year but not seen them yet this year.
Steve Frampton We have them under Selsey Lifeboat station as usual.
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 ;)
Message posted on Seasearch North East England on 01 Aug 2013
Ruth Sharratt Hi Liz, thanks for organising such a good weekend's diving. Thanks for all your hard work, it is much appreciated.
I've attached a couple of pics - one was of a friendly? fish (we think butterfish) in pentapora.
The other is of the nudibranch goniodoris nodosa. It's not a brilliant pic but (it's the same species as the one I photographed for you Kathryn) however the book says it feeds on Dendrodoa grossularia. This was photographed on the 2nd dive on Sunday, so may affect what we thought the sea squirt was which was covering the boulders and gullies. Paul B, what do you think. I guess it's possible that D. grossularia was there as well.David Kipling Some of those siphons look quite square in cross section, which is a feature of Polycarpa scuba (which looks quite similar),.
Ruth Sharratt Thanks David, Paul Brazier had said they were Polycarpa scuba. Picton did say that it feeds on ascidians, so it includes polycarpa as well. I'm never sure how fussy these creatures are.
David Kipling I imagine that once you climb inside an ascidian the soft bits probably are all the same to eat!
Paul Brazier Hi Ruth. I notice from habitats.org that there is a picture of the eggs, which are a string, rather than a ribbon, so that may account for the extensive strings of eggs that you saw on the same dive. I also spotted a G nodosa in the adjacent bay.
Liz Morris Hi guys - good tips. I saw loads of Goniodoris nodosa on that second dive Ruth, so think you're right. I'd put these down as Dendrodoa grossularia actually. As I understand from previous squirt courses, any species with 4 oral lobes can appear 'square', including both Dendrodoa and Distomas. These guys look quite stout, more of Dendrodoa than Polycarpa. And I think Distomas would generally be tighter packed and with more stripey siphons. So very tricky. Interesting that David and Paul think Polycarpa - I'll have to look more closely and dig one out nex time. Save your pics and we'll try to go through them on the upcoming ID course and see what the others reckon.
Message posted on Seasearch North Wales on 16 Apr 2012
Paula Lightfoot Aplysilla sulfurea maybe...?Liz Morris Id agree with A.sulfurea, I think I've seen it up to 10cm cushions, and looking at the size of your Dendrodoa this prob wasnt more than that? but I'm no expert!
Tony Gilbert Yes, does certainly look like it, I've not seen this, assume its locally abundant in North Sea? Are those Polycarpa scuba nearby (Dendrodoa grossularia are more rounded)?
Message posted on Seasearch Identifications on 29 Jul 2012
Ruth Sharratt Hi Liz, thanks for organising such a good weekend's diving. Thanks for all your hard work, it is much appreciated.
I've attached a couple of pics - one was of a friendly? fish (we think butterfish) in pentapora.
The other is of the nudibranch goniodoris nodosa. It's not a brilliant pic but (it's the same species as the one I photographed for you Kathryn) however the book says it feeds on Dendrodoa grossularia. This was photographed on the 2nd dive on Sunday, so may affect what we thought the sea squirt was which was covering the boulders and gullies. Paul B, what do you think. I guess it's possible that D. grossularia was there as well.David Kipling Some of those siphons look quite square in cross section, which is a feature of Polycarpa scuba (which looks quite similar),.
Ruth Sharratt Thanks David, Paul Brazier had said they were Polycarpa scuba. Picton did say that it feeds on ascidians, so it includes polycarpa as well. I'm never sure how fussy these creatures are.
David Kipling I imagine that once you climb inside an ascidian the soft bits probably are all the same to eat!
Paul Brazier Hi Ruth. I notice from habitats.org that there is a picture of the eggs, which are a string, rather than a ribbon, so that may account for the extensive strings of eggs that you saw on the same dive. I also spotted a G nodosa in the adjacent bay.
Liz Morris Hi guys - good tips. I saw loads of Goniodoris nodosa on that second dive Ruth, so think you're right. I'd put these down as Dendrodoa grossularia actually. As I understand from previous squirt courses, any species with 4 oral lobes can appear 'square', including both Dendrodoa and Distomas. These guys look quite stout, more of Dendrodoa than Polycarpa. And I think Distomas would generally be tighter packed and with more stripey siphons. So very tricky. Interesting that David and Paul think Polycarpa - I'll have to look more closely and dig one out nex time. Save your pics and we'll try to go through them on the upcoming ID course and see what the others reckon.
Message posted on Seasearch North Wales on 16 Apr 2012