Eubranchus capellinii

Eubranchus capellinii (Trinchese, 1879)

Eubranchus capellinii @ Otok Čiovo (Croatia) by Pero Ugarković










































Eubranchus capellinii  (Trinchese, 1879)

 Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 729924).

Taxonomic note: The phylogenetic analyses performed by Cella et al. (2016) revealed that the traditional Tergipedidae family is polyphyletic and belongs to a larger monophyletic clade including members of the traditional families Eubranchidae, Fionidae and Calmidae; this was an unexpected result, since the validity of these taxa and their distinctness from the Tergipedidae was never questioned before. They proposed to join the families Tergipedidae, Eubranchidae, Calmidae and Fionidae under the name of Fionidae. This decision has been reinterpreted and completed in the paper by Korshunova et al. (2017) because it obviated evident morphological and molecular aspects.

Since the middle of the s. XX, E. capellinii has been considered a synonymous species of E. doriae (Edmunds & Kress, 1969, Thompson & Brown, 1984, Thompson, 1988, Picton & Morrow, 1994; Caballer, 2002) or even confused with other species of the genus such as Eubranchus cingulatus (Edmunds & Kress, 1969; Ortea, 1978; Schmekel & Portmann, 1982). However, the original description of E. capellinii (as Tergipes capellinii) and the accompanying color plate (Trinchese, 1879) are clear and illustrative enough to differentiate it from the rest of the Atlantic species of the genus. For this reason Caballer, Ortea & Canteras (2010), using specimens captured in Cantabria, the Algarve coast (Portugal) and the Murcian coast (Spanish Mediterranean), propose to reinstate the species as valid and performed a complete morphological and anatomical study (genitalia, radula and jaws).


  • Capellinia capellinii (Trinchese, 1879)
  • Tergipes capellinii Trinchese, 1879 (original)

The specimens of this species can reach a size of 16 mm (size of the specimens of the original description by Trinchese) but the normal of these animals is 4-5 mm in length. The general color of the body is whitish and semitransparent, with brownish or slightly greenish spots throughout the body, including oral tentacles, rhinophores and cerata. Among the rhinophores and the first group of cerata there is a typical trapezoidal spot of the same color, more or less apparent according to the size of the animals. There are also elongated stains of this color on both sides of the back and between the bases of the cerata. These elongated spots and the trapezoidal dorsal patch are characteristic of E. capellinii and differentiate it from the other species of the genus Eubranchus that have a similar morphology and size. The oral tentacles and the rhinophores are relatively short, with brown spots forming a transverse band and have a white apex. There are up to 7 groups of cerata on each side of the dorsum, with 3-4 cerata in the first group and only one in the final groups. The two frontmost groups are laid symmetrically on each side while the third group and others they are alternated from side to side. The cerata are semitransparent and have 2 to 3 circles of small tubercles. The digestive gland inside may be whitish, yellowish or brown in the largest specimens and fills much of the interior of the cerata. There are usually brown spots on the surface of the cerata and 1-2 brown subapical bands. The anus is located in a prominent white papilla in the right dorsolateral position between the first and second group of cerates behind the cardiac area. The genital pore is located right below the first group of right cerata. The tip of the foot (tail) is rounded.

The specimens of this species usually live in colonies of hydrozoans such as Kirchenpaueria pinnata (Edmunds & Kress, 1969, cited as E. doriae), Plumularia setacea (Thompson & Brown, 1984, cited as E. doriae) or Obelia geniculata (Schmekel & Portmann , 1982, cited as E. cingulatus), of those that possibly feed and with which they maintain a quite cryptic coloration. Schmekel & Portmann (1984, as E. cingulatus) indicated that the spawn is a single-turn ribbon containing white 90 microns eggs.


  • Capellinii. In honor to Prof. Giovanni Capellini, (1833-1922), Italian paleontologyst who was Rector Magnificus of the University of Bologna during 1888, when it celebrated its 800 years of history.

Accepting the opinion of Caballer, Ortea & Canteras (2010) that the reports of E. doriae and E. cingulatus probably correspond to E. capellinii. This species is distributed from the British Isles, the Atlantic coasts of the Iberian Peninsula, the Iberian Mediterranean and the coast of Naples. Recently this species has also been reported in the Adriatic Sea, where there are two reports, one by Alen Petani in Vrsine (Croatia) and the other by Pero Ugarković in Otok Čiovo (Croatia) that corresponds to the attached pictures. It is possible that some of the reports of Eubranchus doriae from the Catalan coasts (Ballesteros et al., 2016) refer to E. capellinii.

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

Similar species
Eubranchus doriae, without the trapezoidal spot on the back, behind the rhinophores, nor the elongated spots between the base of cerata. Eubranchus cingulatus, with smooth cerata.


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

This chart displays the monthly observation probability for Eubranchus capellinii based on our own records.

More pictures


    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. (
    Ballesteros, M., M. Pontes, and E. Madrenas. 2019. Els nudibranquis del mar català. Brau Edicions, Figueres.
    Caballer, M. 2007. Catálogo de los sacoglosos y opistobranquios (Mollusca: Gastropoda) de sustrato rocoso de la Bahía de Santander. Revisión de los géneros con especies cripticas.
    Caballer, M. 2002. Contribución al estudio del género Eubranchus Forbes, 1838 (Mollusca: Nudibranchia) en el Atlántico Norte. Research seminar, University of  Cantabria, Spain. 56 pp.
    Caballer, M., J. Ortea, and J. C. Canteras. 2010. Re-instatement of the name Eubranchus capellinii (Trinchese, 1879) (Mollusca: Opisthobranchia: Nudibranchia). Journal of Conchology. 40: 169–177.
    Edmunds, M., and A. Kress. 1969. On the european species of Eubranchus (Mollusca: Opisthobranchia). Journal of the Marine Biological Association of the United Kingdom 49: 879-912.
    Ortea, J. 1978. Cinco opistobranquios nuevos para la fauna ibérica (Gastropoda: Opistobranchia) colectados en Asturias. Suplemento de Ciencias del Boletín del Instituto de Estudios Asturianos 23: 107-120.
    Picton, B. E., and C. Morrow. 1994. A Field guide to the Nudibranchs of the British Isles. Immel Publishing Ltd. London: 143 pp., London.
    Prkić, J., A. Petani, Ð. Iglić, and L. Lanča. 2018. Stražnjoškržnjaci Jadranskoga Mora: Slikovni Atlas i Popis Hrvatskih Vrsta / Opisthobranchs of the Adriatic Sea: Photographic Atlas and List of Croatian Species. Ronilaćki Klub Sveti Roko, Bibinje.
    Schmekel, L., and A. Portmann. 1982. Opisthobranchia des Mittelmeeres, Nudibranchia und Saccoglossa. Fauna e Flora del Golfo Napoli. Springer-Verlag, Berlin.
    Thompson, T. E. 1988. Molluscs: benthic opisthobranchs (Mollusca: Gastropoda) keys and notes for the  identification of the species., 2nd ed, Synopses of the British fauna,. Brill, E. J. & Backhuys, W., Avon, Great Britain.
    Thompson, T. E., and G. H. Brown. 1984. Biology of Opisthobranch Molluscs. Vol. 2. Ray Society, London 156, pp. 229:
    Trinchese, S. 1877. Æolididae e famiglie affini del Porto di Genova. Part 1. Anatomia, fisiologia, embriologia delle Phyllobranchiae, Hermaeidae, Aeolididae, Proctonotidae, Dotonidae del Porto de Genova. Atti della R. Università di Genova. Atlas, pp. 1-94, pls. 1-35.
    Trinchese, S. 1879. Generi illustrati nella prima parte della sua opera intitolata Aeolididae [Aeolididae e famiglie affini del Porto di Genova].
    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:

Caballer, M., Ballesteros, M., Madrenas, E. & Pontes, M. (2023) "Eubranchus capellinii" in OPK-Opistobranquis. Published: 28/02/2017. Accessed: 27/02/2024. Available at (

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