Diazona violacea

Jeremy Pierce Are these all Diazona violacea? Football sea squirts! The first two pics show the individuals a lot bigger (Taller) than the more obviously looking 'Football' shapes! Taken on the hull of the ELK wreck, Plymouth at about 28m. Cheers JAP <@))))><

Kirstie Harris There are loads of them on the Elk, aren't there! I couldn't believe how many there were, and how big they are.

George Brown It's often difficult to be absolutely certain when looking at juveniles and immature individuals but here they all look like D. violacea. Nice images btw.

David Kipling Very nice! There is a different feel to the juveniles compared to lightbulb squirts but it's quite subtle - slightly fatter and more opaque zooids and the white lines are slightly different. The small patches here still show the fused basal test though, which you never see with light bulbs (they are connected instead by a basal stolen).

Keith Hiscock Up until 2008/9, seeing two or three football seasquirts on a dive out of Plymouth was considered remarkable. They had a significant recruitment that year and have shown recruitment each year since. Four or five zooids in the first year and they are perennial. There are now places out of Plymouth where you could see up to a hundred in a dive. Probably a boom-and-bust species.

Richard Yorke Any ideas about this squirt taken off Weymouth. It looks similar to one I took last year not far from this site. They were both dense masses a good 6" in diameter. This years was at about 20M and last years at about 10M. The picture of last years follows shortly.

David Kipling Very good question. Wilfried Bay-Nouailhat might know. Are you 100% sure it's not a sponge?

Anne Bay-Nouailhat One question : was it encrusting and covering something giving then the impression of a "ball" or was it a real dense mass?

Erling Svensen Is it the Diazona violacea?

Wilfried Bay-Nouailhat Probably Diplosoma spongiforme.

Wilfried Bay-Nouailhat I have already seen this species, I post some pics to convince you ;o)

Richard Yorke I'm as sure as I can be it was not a sponge and it was a real dense mass.

Richard Yorke Having said it was a dense mass, it could have been covering a pebble or similar but if so it was a very thick layer.

Chris Wood This is exactly why we have been thinking about a Seasearch ID Guide for Sponges and Squirts together. I am not convinced that this is Diplosoma spongiforme or indeed a squirt at all.

David Kipling I might refine that thought slightly Chris, since a properly-done sponge guide would be a *massive* undertaking and, to be honest, the majority of sponges don't really look like squirts. Maybe what we need is a squirt guide with a focussed subsection not on sponge species-level ID per se, but rather on how to tell a squirt from other things that look like squirts, which also includes stuff like bivalve siphons***. This is where giving people a good differential understanding of squirt versus sponge internal anatomy may help (once you understand they are made of zooids it really helps) but you probably don't need to go as far as getting people to species-level ID the sponge itself, rather get across the concepts of how (in general) to tell a sponge v. a squirt v. a bivalve. There's been quite a few examples of this on Facebook, including sting winkle egg cases (João Pedro Silva!), sponges, bivalves, and so on. ***Or, in my case, a bit of dead man's finger (intertidal in my defence!) which flinched when I poked it (=not sponge) but then finally extended polyps in the bucket!

João Pedro Silva (those eggs are going to haunt me forever, aren't they?)

David Kipling Sorry ;)

Wilfried Bay-Nouailhat I have just sent a new pic from the same place. Definetly a sea squirt and it could be similar to Richard's one. I still think about an atypical form of D. spongiform. It's been some time since we've been working on underwater identification of sea squirts. Maybe we could work together?

Maria Harwood Does anyone know what this is? Photo was taken on Risga Pinnacle, in Loch Sunart. I think it's some kind of sponge, but can't find it in the guides

Holly Latham I'd go with Dawn... Diazona violacea dying back for the winter.

Maria Harwood Thanks Dawn & Holly. Hadn't realised they did that. There were other football squirts that remained "open"