Rhopalaea abdominalis

João Pedro Silva Any hint on these? Sesimbra, Portugal, 5m deep, this morning.

João Pedro Silva David Kipling, any ideas?

David Kipling Not a UK species I've seen. Looking at the anatomy you seem to have both oral and atrial siphons opening to the sea, as opposed to atrial siphons discharging into an inner communal cavity that then drains via a common cloaca. [Can you see a cloacal opening? I can't in this pics but if you have other angles, especially side-on, you might get a better idea]. That then makes it somewhat unusual (eg it's therefore not a polyclinid if my understanding is correct). In essence you've got a series of Clavelina-like zooids fused together in a single lobe, but each has its own private set of oral and atrial siphons connected directly to the outside.

Bernard Picton Possibly Pseudodistoma, family Pseudodistomidae?

David Kipling OK I can see where you're going with that Bernard ... http://tunicata.lifedesks.org/node/20

Bernard Picton The Monniot book has keys to all genera, so might be possible to check other possibilities of Aplousobranchs with independent exhalant openings. I'm not sure which of these is known from Portugal or the Mediterranean.

David Kipling Even better, we can let João Pedro do it himself using this - a key to shallow-water Atlantic ascidians, in Portugese! http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032012000100022

João Pedro Silva Let's see if I can find a sponsor for a field guide on portuguese ascidians :) I think that key is for the W Atlantic (authors are from Brazil and I've noticed they mention Rhopalaea abdominalis but not Rhopalaea neapolitana) Unfortunately I didn't take more photos of these.

David Kipling We're certainly finding 'species' in the UK that are readily recognisable, widespread/abundant, but don't appear to be in the literature as far as we can tell - reflecting the paucity of work on these animals since the 1970's in the UK. How much work has been done on ascidians in the Portugal area? It's entirely possible that this is an undescribed species.

David Kipling Are you able to take samples of Portugese ascidians to verify their identification by internal anatomy? I seem to recall you made a comment once about difficulties with permissions etc, or was that Madeira?

Wilfried Bay-Nouailhat Mmmm, it reminds me of some Polycitoridae I saw at the Medes Islands, Polycitor crystallinus. It may be a way to follow. http://www.mer-littoral.org/32/photo-polycitor-crystallinus-wb01.php

João Pedro Silva Getting a license for collection while scuba diving is very difficult here in Portugal (including Madeira and the Azores). But... there may be ways to go around these difficulties.

João Pedro Silva I'll try to find who's been working on Portuguese ascidians.