Known from Adriatic Sea, Malta, Mediterranean France, and the Azores.
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).
Rudman, W.B., 2005 (September 14) Runcina adriatica Thompson, 1980. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/runcadri