Runcina adriatica
Thompson, 1980

Order: CEPHALASPIDEA
Superfamily: RUNCINOIDEA
Family: Runcinidae

DISTRIBUTION

Known from Adriatic Sea, Malta, Mediterranean France, and the Azores.

PHOTO

Upper: 2-3mm long. Found in tide pools (0.25m) on algae, Malta, August 1999. Photo: Constantine Mifsud. Lower: 'La digue', Port-Leucate, France
Mediterranean coast. Depth: 2 m. Length: 3 mm.12 September 2005. Photo: Marina Poddubetskaia Ossokine

The body is a translucent pale with distinct dark brown blotches scattered all over the dorsum and the visible parts of the foot. There a transverse white band across the dorsum, just behind the eyes, which is sometimes reduced to a white patch on either side in some specimens.  There is a second white transverse band which borders the posterior edge of the dorsum. There are a pair of transparent patches on the head through which the eyes can be seen.

There are 1-3 small gills attached to the body wall in the posterior midline, below the dorsum. The shell is reduced to a small internal plate, embedde in the skin of the dorsum in the posterior midline.  It grows to approximately 4 mm in length. Little is known of the biology of this species, but we can assume, that like other runcinids it is a herbivore feeding on filamentous green algae.

  • Gosliner, T. M. (1990). Opisthobranch Mollusks from the Azores Islands. 1. Runcinidae and Chromodorididae. Açoreana, supplement: 135-166
  • Thompson, T. E. (1980) New species of the bullomorph genus Runcina from the northern Adriatic Sea. Journal of Molluscan Studies, 46: 154-157.
  • Thompson, T. E. & Brodie, G. (1988) Eastern Mediterranean Opisthobranchia: Runcinidae (Runcinacea), with a review of runcinid classification and a description of a new species from Fiji. Journal of Molluscan Studies, 54:  339-346.
  • Cervera, J.L., Garcia-Gomez, J.C. & Garcia, F.J. (1981) The genus Runcina Forbes & Hanley, 1851 (Opisthobranchia: Cephalaspidea) in the Strait of Gibraltar, with the description of a new species from the Bay of Algeciras. Journal of Molluscan Studies, 57: 199-208 (T.E. Thompson Memorial Issue).

See Constantine Mifsud's message and Lucas Cervera's reply.

Authorship details
Rudman, W.B., 2005 (September 14) Runcina adriatica Thompson, 1980. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/runcadri

Related messages


Runcina adriatica from the Azores

December 16, 2008
From: Terry Gosliner

Hi Bill,
Here is the photo of Runcina adriatica Thompson, 1980 I reported earlier from the Azores in July 1988

The living animals were 2-4 mm in length. The general body colour is a charcoal grey and the dorsum is covered with large black spots and minute opaque white spots. The white spots form a broken transverse band near the anterior and posterior borders. The foot is translucent brown. Posteriorly, it is covered by dense black pigment. The animals are elongate, truncate anteriorly and simply rounded posteriorly. There are two or three distinct gills, which comprise the ctenidium. Each gill consists of 3-4 simple plicae.

  • Gosliner, T.M. (1990). Opisthobranch Mollusks from the Azores Islands. 1. Runcinidae and Chromodorididae. Açoreana, supplement: 135-166
  • Thompson, T. (1980). New species of the bullomorph genus Runcina from the northern Adriatic. J. Moll. Studies, 46: 154-157

Best wishes,
Terry Gosliner

tgosliner@calacademy.org

Gosliner, T., 2008 (Dec 16) Runcina adriatica from the Azores. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/9930

Dear Terry,
While preparing Gary Cobb's message [#22079] I found this old message of yours which has been languishing unpublished for some years, I think it dates from the time I was forced to close the Forum for some months. All I can say is better late than never.

Sorry,
Bill Rudman

Rudman, W.B., 2008 (Dec 16). Comment on Runcina adriatica from the Azores by Terry Gosliner. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/9930

Runcina adriatica from France

September 16, 2005
From: Marina Poddubetskaia Ossokine

Dear Bill,

Here are some more photos of Runcina adriatica for the Forum. I found this tiny cephalaspidean in French Mediterranean and Lucas Cervera identified it for me.

Locality: 'La digue', Port-Leucate , France. Mediterranean. Depth: 2 m. Length: 3 mm. 12 September 2005. Photographer: Marina Poddubetskaia Ossokine

To be perfectly frank, I know nothing about this species. So, if you could provide me and other participants with some additional information about it, it would be great.

All the best,
Marina.
Nembro website

nembro@nembro.info

Poddubetskaia Ossokine, M., 2005 (Sep 16) Runcina adriatica from France. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/14776

Dear Marina,
We don't know much about the biology of most of the runcinids or their relatives. They are all herbivores, feeding on filamentous green algae. They look quite like aglajids, but they don't have a separate head shield. Internally they have a large grinding gizzard, as do the haminoeids, but they differ in having 4 plates not three. They are all very small, seldom reaching more than 5 mm, and are often quite abundant. Some species have a small internal shell which is reduced to a thin calcified plate. Apart from the few papers I have listed on the Fact Sheet, I don't think much has been published on Runcina adriatica.

  • Rudman,WB (1971): Structure and functioning of the gut in the Bullomorpha (Opisthobranchia) Part 1. Herbivores. Journal of Natural History 5(6): 647-675, 18 figs.

Best wishes,
Bill Rudman

Rudman, W.B., 2005 (Sep 16). Comment on Runcina adriatica from France by Marina Poddubetskaia Ossokine. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/14776