Jorunna onubensis
Cervera, Garcia & Garcia, 1986

Order: NUDIBRANCHIA
Suborder: DORIDINA
Superfamily: EUDORIDOIDEA
Family: Dorididae

DISTRIBUTION

 Originally described from Portil, Huelva, [SW] Spain. Until the taxonomy of this group is better understood, its true distribution is impossible to determine.

PHOTO

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.

Similar in external appearance to Jorunna tomentosa, ranging in colour from greyish to greyish maroon. In a recent revision, Camacho-García & Gosliner (2008) repeat a statement found in the original description of J. tomentosa saying that J. tomentosa differs in colour from J. onubensis in having 5-6 brown spots on the sides of the body which are absent in J. onubensis. I can't find any photo or description reporting these spots in J. tomentosa. Both species seem to have dark spots on the mantle, sometimes, but not always.

The only clear differences seem to be internal with J. onubensis having an unusual section of the male reproductive duct which includes both a swollen prostate gland and then a much thinner, non-glandular, coiled vas deferens, while J. tomentosa lacks the large coiled vas deferens. In the foregut, J. tomentosa lacks jaw plates, while J. onubensis possesses them.

It is possible animals identified here as J. tomentosa may be J. onubensis or indeed other species, but until animals of this genus from the Atlantic and Mediterranean coast are studied in more detail we cannot be sure of identificatios from external features alone.

  • 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
Authorship details
Rudman, W.B., 2008 (October 8) Jorunna onubensis Cervera, Garcia & Garcia, 1986. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/joruonub

Related messages


Jorunna onubensis ? from Spain

October 8, 2008
From: Miquel Pontes

Dear Bill,

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.

Best regards,
Miquel Pontes
http://marenostrum.org

info@marenostrum.org

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

Dear Miquel,

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

Best wishes,
Bernard Picton

Picton, B.E.., 2008 (Oct 8). Comment on Jorunna onubensis ? from Spain by Miquel Pontes. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/21043