unidentified blue thingie

[tom]

Just wondering if anyone can ID some thingies I saw on a dive yesterday (sussex coast UK, about 10m water, boulder reef). I can't find anything in Naylor's "Great british marine animals" that looks right, though I expect it is some kind of sponge (there were a variety of other sponges in the area).

It reminded me very much of Raspberry coral (pocillopora?) from the Red Sea, but a light blue colour. The 'spikes' were about the size of a small finger and on the upper (ie in the light) surfaces of boulders. I think they were in small colonies rather than single. They didn't have the 'fuzz' of dead men's fingers (though there were some of those about too), and the surface seemed porous - very much like some hard corals.

Does this sound familiar to anyone?

[Fiona]

Originally Posted by tom

Just wondering if anyone can ID some thingies I saw on a dive yesterday (sussex coast UK, about 10m water, boulder reef). I can't find anything in Naylor's "Great british marine animals" that looks right, though I expect it is some kind of sponge (there were a variety of other sponges in the area).

It reminded me very much of Raspberry coral (pocillopora?) from the Red Sea, but a light blue colour. The 'spikes' were about the size of a small finger and on the upper (ie in the light) surfaces of boulders. I think they were in small colonies rather than single. They didn't have the 'fuzz' of dead men's fingers (though there were some of those about too), and the surface seemed porous - very much like some hard corals.

Does this sound familiar to anyone?

The "Fuzz" you are referring to on the DMF are the animal when it is feeding when they aren't feeding they look as you have described, "surface seemed porous"

Sorry can't help with your sponge identification though, the only thing I can think off is something like an Elephant eared sponge but they would be in the book and the surfaces sounds flatter than yours.

I am sure Steve will have an explanation

[Dr Stevil]

Anything like this ? If so these are Hymedesmia paupertas

[tom]

not really - more fingerlike. The blue was a little paler than in the pic, and there weren't any of the 'craters' these have. other than that...

[Dr Stevil]

THis could involve a lot of posted pics...
OK starting with their shape only, anything like these (ignore the colour)
Haliclona oculata

[Dr Stevil]

hang on, pale blue might easily be confused with grey, what about this?

[tom]

More like the first one than the second, but no real branching that I remember. Slightly rougher surface I think. I'll take another look in the book tonight and find the closest match and post what it is - there was one that was reasonably similar in form, though the colour was wrong.

I'm certain it was blue, which is what aroused my curiosity - not noticed one that colour before.

[tom]

Had another look in the book last night, again at the sponges.

Closest in form is Raspailia ramosa (those these were not in large 'bushes'). They were blue rather than red though.

I suppose Breadcrumb sponge (Halichondria panicea) might be a possibility, though the physical form is not so close - its colour variability (i.e. algae making it green) might make it a possible candidate though?

[Dr Stevil]

Unfortunately I don't have a copy of this book at the moment, but I expect your beastie will be in it (available from http://www.mcsuk.org/acatalog/)
If you dive this area frequently it might be a good investment

[Fiona]

How about this, boom says Clearly defined masive colony with finger like projections which can contract. Typically about 2cm tall but may reach 12cm.

Colour - Orange, yellow ochre, green or dark grey