Runcina bahiensis

Runcina bahiensis (Cervera, García-Gómez & García, 1991)

Runcina bahiensis by Enric Madrenas




































Runcina bahiensis  Cervera, García-Gómez & F. J. García, 1991

 Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 141408).
This species can reach a size of about 3 mm. The shape of the body is characteristic. The head is thin on the front, foot edges clearly protruding at its sides. Behind the head, the body maintains the same width until the end of the notum, where it expands appreciably sideways, ending in a short, wide tail. The body is coloured beige and could have some greenish tones. The body is covered with white scores but for two areas on the sides of the head, where the eyes are located, the margins of the body and where the pattern of white scores forms a sort of ridges or undulations. In the dorsum there are two areas of higher white spot concentration, one in the head region from the front end to the first third of the length of the animal, and the other, narrower, at the end of the notum. Foot white scores are much less abundant than in the notum. Tail white spot density is also less than on the notum, but much greater than on the foot. On a light background and by body translucency, there is a series of dark scores on the margins of the notum. The foot protrudes behind the notum as a short and rounded tail, semitransparent and with white scores. Below the right rear part of the notum, between it and the foot, there are 4 small gill leaves.

From this species it is only known that lives among algae and in Posidonia oceanica rhizomes.


  • Runcina. From Latin “runcina”, carpenter’s plane, a tool used to smooth the wood’s surface.
  • Bahiensis, from “the bay”, meaning the Algeciras bay (Spain), where the two type specimens used to describe the species were found.

Runcina bahiensis is a very rare species which, so far, only two specimens have been collected in the Strait of Gibraltar (Cervera et al., 1991) that were used to describe the species, two other specimens in the Catalan Costa Brava, which are the second worldwide cite for the species (Correa, 2014) and a few more specimens (attached pictures) found by Enric Madrenas (2014, pers. comm) also in the Costa Brava.

Known georeferenced records of the species: Runcina bahiensis
: GROC 2010-2011
: Enric Madrenas
: João Pedro Silva
: Bernard Picton
: Manuel Ballesteros.
: M@re Nostrum
: Altres fonts
: Marine Regions


    Western Mediterranean: ☆☆☆☆☆
    Eastern Mediterranean: ☆☆☆☆☆
    Atlantic Ocean: ☆☆☆☆☆

This chart displays the monthly observation probability for Runcina bahiensis based on our own records.

More pictures


    Ballesteros, M., M. Pontes, and E. Madrenas. 2015. Opisthobranch from Medes Islands (Marine Protected Area, Costa Brava, Catalonia, NE Spain): 40 years of study.
    Ballesteros, M., E. Madrenas, and M. Pontes. 2016. Actualización del catálogo de los moluscos opistobranquios (Gastropoda: Heterobranchia) de las costas catalanas. Spira. 6: 1–28.
    Ballesteros, M., E. Madrenas, and M. Pontes. 2023. OPK - Opistobranquis. (
    Cervera, J. L., J. C. García-Gómez, and F. J. García. 1991. The genus Runcina Forbes & Hanley, 1851 (Opisthobranchia, Cephalaspidea) in the Strait of Gibraltar, with de description of a new species from the Bay of Algeciras. Journal of Molluscan Studies. 57: 199–208.
    Cervera, J. L., G. Calado, C. Gavaia, M. A. E. Malaquías, J. Templado, M. Ballesteros, J. C. García-Gómez, and C. Megina. 2004. An annotated and updated checklist of the opisthobranchs (Mollusca: Gastropoda) from Spain and Portugal (including islands and archipelagos). Boletín Instituto Español de Oceanografía, 20 (1-4): 1-111. L.
    Correa, M., E. Madrenas, A. Riesgo, and M. Ballesteros. 2015. First molecular approach to the study of Mediterranean Runcina Forbes [in Forbes & Hanley], 1851 (Heterobranchia: Runcinacea).
    Long, S. J. 2006. Bibliography of Opisthobranchia 1554-2000. Bayside Books & Press, Tustin, CA, U.S.A. 672p.
    McDonald, G. 2009. Bibliographia Nudibranchia. 2nd Online Edition, Annotated. 1072 pp  Institute of Marine Sciences, University of California, Santa Cruz. (
    WoRMS Editorial Board. 2023. World Register of Marine Species. WoRMS. (

    Bibliography based on the works by Steve Long, 2006. Bibliography of Opisthobranchia 1554-2000 and Gary McDonald, 2009. Bibliographia Nudibranchia, with later updates from other resources.

Further reading

Cite this article as:

Ballesteros, M., Madrenas, E. & Pontes, M. (2023) "Runcina bahiensis" in OPK-Opistobranquis. Published: 14/08/2013. Accessed: 02/12/2023. Available at (

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