October 8, 2008
From: Miquel Pontes
We found these two specimens in our last dive. We think it is a Jorunna tomentosa but we would be pleased if you can confirm the identification.
We found them hidden under a stone, sitting on a wide bryozoan colony, and because they were absolutely motionless, we doubted for a while whether it was a sponge or a nudibranch, until we exposed them to sunlight, which they didn't like at all.
The bigger specimen measured about 2 cm. while the smaller one was about 1 cm.
Locality: Platja de Caials, Cadaqués, Costa Brava, 6 metres, Spain, Mediterranean Sea, 27 october 2007, Rocks over muddy bottom. Length: 2 cm. and 1 cm. aprox.. Photographer: Miquel Pontes.
Pontes, M., 2008 (Oct 8) Jorunna onubensis ? from Spain. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/21043
I think this is Jorunna onubensis Cervera, García & García-Gómez, 1986 which is a new species for the Forum. The known species of Jorunna have recently been revised by Yolanda Camacho-García and Terry Gosliner but the range of external appearance for each species is poorly known. The smaller of these two shows the circular darker marks which are supposed to be characteristic of Jorunna onubensis and are different to those of Jorunna tomentosa of this size.
I suspect that Jorunna tomentosa may be a complex of similar-looking species in the Mediterranean and NE Atlantic. We have recently found what we think are two new species in Northern Ireland but it may not be possible to resolve this question without DNA evidence.
I'd be interested in Juan Lucas Cervera's opinion on these ones.
Cervera J. L., Garcia J. C. & Garcia F. J., 1986. Il genere Jorunna Bergh, 1876 (Mollusca: Gastropoda: Nudibranchia) nel litorale Iberico. Lavori, Società Italiana di Malacologia 22: 111-134
Yolanda E. Camacho-García and Terrence M. Gosliner, 2008. Systematic revision of Jorunna Bergh, 1876 (Nudibranchia: Discodorididae) with a morphological phylogenetic analysis. Journal of Molluscan Studies 74(2):143-181