Myxilla fimbriata

Tony Gilbert This was taken at Carrick a Rede, Antrim. What struck was the vibrant orange colouration. I am pretty sure its Myxilla fimbriata, seems to fit the description quite well on colouration, size, oscules slightly raised and transparent rims, and singular colonies, and about 6cm across. I think this site is superb for marine diversity, esp. the side to the east where it drops from around 8m in a long slope type affair to around 30m where there is a Bryoa garden. This in Sept last year was covered in nudibranch species. It then goes around the corner (the end of the small island) at about 25m, and up a vertcial wall (which reminds me of High Point in Pembrokeshire).

Tony Gilbert It can be quite morphic A. fucorum, but this specimen was a single colony, that was less lobose than A. fucorum. On the N. Wales Llyen, we get whole beds of A. fucorum, mostly tassled and it is a more intense red-orange, but that may depend on water clarity and current strengths.

Claire Goodwin This looks like A.fucorum to me Tony Gilbert - mainly because of the colour, the form can be quite variable. I wouldn't want to ID it confidently without a sample though - as you say it is not typical form.0

Bernard Picton I think it is probably Mycale rotalis, something about the surface and the shape.... http://www.habitas.org.uk/marinelife/species.asp?item=C5530

Tony Gilbert Looking at the alternative pictures, it does share a lot of visual characteristices, I'll need to read up a little more...

Claire Goodwin And start collecting samples :).