Clathrina coriacea

Wilfried Bay-Nouailhat Hi, Can anyone confirm the ID of these two calcareous sponges? Clathrina coriacea ? and Leuconia johnstoni ?

Wilfried Bay-Nouailhat Merci Dawn

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.