Baenopsis baetica

Baenopsis baetica (García Gómez, 1984)

Baenopsis baetica @ Tarifa (Spain) by Manuel Martínez Chacón










































Baenopsis baetica  (García-Gómez, 1984)

 Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 1047764).

Taxonomic note: The classification of the Flabellinidae had remained fairly stable until in 2017 a series of works appeared (Furfaro et al., 2017; Korshunova et al., 2017) that intended to clarify the status of the Flabellinidae family. The main objective of the paper by Furfaro et al. was to molecularly characterize the Mediterranean species while the paper by Korshunova et al. wanted to delve into the phylogenetic relationships between various members of the Flabellinidae family and the other families of aeolidaceans.
Both works were based on the combination of molecular and morphological techniques and, in fact, do not offer very different results, but differ on the size and origin of the studied samples and, mainly, on the interpretation of the results. After the appearance of the paper by Furfaro et al., many Mediterranean species of the genera Calmella, Flabellina and Piseinotecus were grouped under the common genusFlabellina, but had certain problems with some species that did not fit well with the proposed classification (e.g,Flabellina babai) , discovered that the Mediterranean and Atlantic populations ofFlabellina ischitana correspond to two different cryptic species, and noted the problems of the cryptic group formed by Calmella cavolini / Flabellina confusa / Piseinotecus gaditanus, indicating the need for further studies to clarify their status.
Curiously, these studies were being carried out practically in parallel by the group of Korshunova et al. but on a much wider sample of species that included specimens from the Arctic, North Atlantic, Pacific and Indian Oceans. This second paper confirms the polyphily of the family Flabellinidae, but the interpretation of these results becomes a real revolution for the taxonomy of the aeolidaceans, especially for the family Flabellinidae.
Both papers show that there are two well differentiated clades (groups) in the Flabellinidae: species like Coryphella pedata and similars, with cerata that come directly from the back, and species like Flabellina affinis and similars, with cerata of each group coming from a stalk or pod. Although Furfaro et al. consider the species of both clades belonging to the genusFlabellina within the family Flabellinidae, Korshunova et al. distinguishes two families: Coryphellidae and Flabellinidae sensu stricto, also creating many different genera in these families to include the species they study. Its taxonomic proposal, curiously, solves the problems found by Furfaro et al.
In a way, both papers complement to each other, although in the paper by Korshunova et al. it is evident the lack of studies on tropical flabellinid species and those from southern America and Africa, so the subject has not been settled. The proposal to create new genera to collect small groups of species, instead of multispecific genera, seems to be the trend in some of the phylogenetic works of recent years. A detailed discussion of this exciting controversy can be found at (

This species was originally described with the name Flabellina baetica. The author (García-Gómez, 1984) already indicates in the description of the species the unusual nature of the rhinophores for the genus, but due to other morphological and anatomical characters prefers to ascribe the species to the Flabellina genus rather than creating a new one for it. In the phylogenetic tree provided by Furfaro et al. (2018, online September 2017) this species is well separated from the two clades in which the species of the genus Flabellina are distributed, an indication that it may not be a species of this genus and neither belongs to the family Flabellinidae. Korshunova et al. (2017), based on molecular data, create a new family Flabellinopsidae to include the genus Flabellinopsis MacFarland, 1966 with the species of the North Pacific F. iodinea, and a new genus Baenopsis in which they include the species Flabellina baetica, which is now known as Baenopsis baetica (García-Gómez, 1984).


  • Flabellina baetica (García Gómez, 1984)

This aeolidacean species can reach 3 cm in length. The body is coloured hyaline white and translucent, so the the pink or cream coloured internal organs can be seen by transparency. Oral palps, propodial palps and rhinophores are also coloured whitish. The rhinophores have short, rounded and irregular protuberances on all its surfacebut for a slightly sinuous groove that runs along the entire dorsal midline. There are about 7 groups of cerata on each side of the body and each of them emerges from a peduncle. The ceras are long and thin, coloured hyaline white and inside the digestive gland a fine, cream coloured cord can be seen at the base that darkens upwards to become more or less dark red near the apex, where a white cnidosac is found. The tip of the ceras is sharp. The foot has triangular propodial palps.

Specimens of this species are usually found on rocky bottoms on the hydrozoans from which they feed. Very few biological data of the species are known. García-Gómez (1986) indicates that some specimens have been observed on gymnoblastic hydrozoans of the genus Eudendrium; this author describes the egg-mass as a long cord, somewhat curled and irregularly wrapped, 1 mm high, with ovigerous capsules of 90-100 microns containing a single white egg.


  • Baenopsis, derived from the specific name of Flabellina baetica, the type species of this genus, named after the ancient Roman province “Baetica“.
  • Baetica. Name of an ancient Roman province formed under Augustus, circa 15-12 BC, after the division of the Lusitania from the Hispania Ulterior. The land area of the Roman province corresponded to more than 75% of the current Andalusia (Spain), specifically it included the full provinces of Huelva, Seville, Cadiz, Malaga and Cordoba, the western half of Granada and Jaen and a fifth of that of Almería, and a quarter of the current Extremadura (south of Badajoz).

This species has only been reported from the Straits of Gibraltar (García Gómez, 1984; M.Martínez Chacón, pers.comm.), but there are also unpublished observations by Dr. César Megina of the Sevilla University in Western Andalucia shores.

Known georeferenced records of the species: Baenopsis baetica
: 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 Baenopsis baetica based on our own records.

More pictures


    Ballesteros M, Pontes M, Madrenas E. 2019. Els nudibranquis del mar català. Figueres: Brau Edicions. 192 p.
    Ballesteros M, Madrenas E, Pontes M. 2024. OPK - Opistobranquis. Available from
    Bedulli D, Cattaneo-Vietti R, Chemello R, et al. 1995. Gastropoda Opisthobranchia, Divasibranchia, Gymnomorpha, Fascicolo 15, pp. 1-23.  In: A. Minelli, A. Ruffo, & S. La Posta (Eds.). Checklist delle specie fauna italiana. Bologna: Calderini (Checklist delle specie della Fauna Italiana).
    Carmona L, Pola M, Gosliner TM, et al. 2013. A tale that morphology fails to tell: A molecular phylogeny of Aeolidiidae (Aeolidida, Nudibranchia, Gastropoda). PLoS ONE 8(5): e63000. doi:10.1371/journal.pone.0063000.
    Cattaneo-Vietti R, Thompson TE. 1989. Mediterranean opisthobranch molluscs: a zoogeographic approach. Bollettino Malacologico (Pubblicazione Mensile Edita dalla Societa Italiana di Malacologia) 25(5-8):183-204.
    Cattaneo-Vietti R, Chemello R, Giannuzzi-Savelli R. 1990. Atlas of Mediterranean Nudibranchs. Rome, Italy: La Conchiglia. 264 p.
    Cervera JL, Templado J, García-Gómez JC, et al. 1988. Catálogo actualizado y comentado de los Opistobranquios (Mollusca, Gastropoda) de la Península Ibérica, Baleares y Canarias, con algunas referencias a Ceuta y la isla de Alborán. Iberus, supl. 1: 1-84.
    Cervera JL, Calado G, Gavaia C, et al. 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.
    Furfaro G, Salvi D, Mancini E, et al. 2018. A multilocus view on Mediterranean aeolid nudibranchs (Mollusca): Systematics and cryptic diversity of Flabellinidae and Piseinotecidae. Molecular Phylogenetics and Evolution. 118:13–22.
    Garcia FJ, Bertsch H. 2009. Diversity and distribution of the Gastropoda Opisthobranchia from the Atlantic Ocean: A global biogeographic approach. Scientia Marina. 73(1):153–160.
    García-Gómez JC. 1986a. El género Flabellina Voigt, 1879 (Gastropoda: Nudibranchia) en el litoral ibérico. Bollettino Malacologico 22 (1-4): 37-48.
    García-Gómez JC. 1984. A new species of Flabellina (Gastropoda, Nudibranchia) from the Gibraltar Strait (Southern Spain). Vie et Milieu 34 (1): 61-64.
    García-Gómez JC. 2002. Paradigmas de una fauna insólita; Los moluscos opistobranquios del estrecho de Gibraltar (Serie Ciencias) 20: 397 pp. Instituto de Estudios Gibraltareños. Algeciras, Cádiz, Spain.
    García-Gómez JC, Cervera JL. 1989. A new species and genus of aeolid nudibranch (Mollusca, Gastropoda) from the Iberian coasts. Bulletin du Muséum National d’Histoire Naturelle (section A Zoologie) (4) 11 (4): 733-741.
    García-Gómez JC, Cervera JL. 1989. A new species of the aeolid genus Flabellina  (Nudibranchia) from the strait of Gibraltar. Journal of Molluscan Studies 55: 411-417.
    García-Gómez JC, Cervera JL, García FJ, et al. 1989. Resultados de la Campaña Internacional de Biología Marina “Ceuta-86”: Moluscos Opistobranquios. Bollettino Malacologico. 25:223–232.
    Korshunova TA, Martynov AV, Bakken T, et al. 2017. Polyphyly of the traditional family Flabellinidae affects a major group of Nudibranchia: aeolidacean taxonomic reassessment with descriptions of several new families, genera, and species (Mollusca, Gastropoda). ZooKeys 717: 1-139.
    Korshunova TA, Martynov AV, Bakken T, et al. 2017. Corrigenda: Polyphyly of the traditional family Flabellinidae affects a major group of Nudibranchia: aeolidacean taxonomic reassessment with descriptions of several new families, genera, and species (Mollusca, Gastropoda). ZooKeys 725: 139–141. org/10.3897/zookeys.725.23022.
    Long SJ. 2006. Bibliography of Opisthobranchia 1554-2000. Bayside Books & Press, Tustin, CA, U.S.A. 672p.
    Martínez-Chacón M. 2018. Nudibranquios de la isla de Tarifa, pequeñas joyas del estrecho de Gibraltar. Junta de Andalucía. Consejería de Medio Ambiente y Ordenación del Territorio. Available from
    McDonald G. 2009. Bibliographia Nudibranchia. 2nd Online Edition, Annotated. 1072 pp  Institute of Marine Sciences, University of California, Santa Cruz. Available from
    Ortea J. 1989. Descripción de algunos Moluscos Opistobranquios nuevos recolectados en el Archipiélago de Cabo Verde. Publicações Ocasionais da Sociedade Portuguesa de Malacologia 13: 17-34.
    Ortea J, Espinosa J. 1998. Estudio de nueve especies del género Flabellina Voight, 1834 (Mollusca: Nudibranchia) colectadas en Angola, Cabo Verde, Costa Rica, Cuba y Portugal, con la descripción de tres especies nuevas. Avicennia 8-9: 135-148.
    Perrone AS. 1990. Recenti acquisizioni faunistiche relative agli Opistobranchi (Aplysiomorpha, Pleurobrancomorpha, Sacoglossa, Nudibranchia) del Mediterraneo. Lavori (Soc. Ven. Sc. Nat) 15:21- 27.
    Sabelli B, Gianuzzi-Savelli R, Bedulli D. 1990. Catalogo annotato dei Molluschi marini del Mediterraneo. Libreria Naturalistica Bolognese. Bologna, Italy: 348 pp.
    Santini F, Winterbottom R. 2002. Historical biogeography of Indo-western Pacific  coral reef biota: is the Indonesian region a centre of origin? Journal of Biogeography 29(2):189-205.
    Schulze A, Wägele H. 1998. Morphology, anatomy and histology of Flabellina affinis (Gmelin, 1791) (Nudibranchia, Aeolidoidea, Flabellinidae) and its relation to other Mediterranean Flabellina species. Journal of Molluscan Studies 64(2):195-214.
    Templado J, Villanueva R. 2010. Checklist of Phylum Mollusca. pp. 148-198 In Coll, M., et al., 2010. The biodiversity of the Mediterranean Sea: estimates, patterns, and threats. PLoS ONE 5(8):36pp.
    Trainito E, Doneddu M. 2014. Nudibranchi del Mediterraneo. 2nd. Il Castello. 192 p.
    Valdés A, Heros V. 1998. The types of Recent and certain fossil opisthobranch molluscs in the Museum national d’Histoire naturelle, Paris. Zoosystema 20(4):695-742.
    Wägele H, Willan RC. 2000. Phylogeny of the Nudibranchia. Zoological Journal of the Linnean Society. 130(1):83–181.
    WoRMS Editorial Board. 2023. World Register of Marine Species. WoRMS. Available from

    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) "Baenopsis baetica" in OPK-Opistobranquis. Published: 18/01/2015. Accessed: 17/04/2024. Available at (

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