Eubranchus cingulatus

Eubranchus cingulatus (Alder & Hancock, 1847)

Eubranchus cingulatus by José Carlos García Gómez

Class: Gastropoda  Cuvier, 1797
Subclass: Heterobranchia  J.E. Gray, 1840
Clade: Euthyneura  Spengel, 1881
Clade: Nudipleura  Wägele & Willan, 2000
Order: Nudibranchia  Cuvier, 1817
Suborder: Dexiarchia  Schrödl, Wägele & Willan, 2001
Infraorder: Cladobranchia Willan & Morton, 1984
Parvorder: Aeolidida Odhner, 1934
Superfamily: Fionoidea  J.E. Gray, 1857
Family: Eubranchidae Odhner, 1934
Genus: Eubranchus  Forbes, 1838
Species: Eubranchus cingulatus (Alder & Hancock, 1847)

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.

Many authors (Picton, B. in Sea Slug Forum, 2005; Evertsen, J. in Sea Slug Forum, 2005) think that this species is a junior synonym of Eubranchus vittatus, as both species are very similar and conform to the description by Alder and Hancock (1847). However, it is still considered a valid species, at least until its identity is confirmed by molecular methods.


  • Eolis cingulata Alder & Hancock, 1842 (original)
  • Eolis hystrix Alder & Hancock, 1842
  • Eolis hyxtrix Alder & Hancock, 1842
  • Galvina cingulata (Alder & Hancock, 1842)

Specimens of this species may reach a size of 30 mm (Ortea, 1978). They have a whitish stylized body with numerous green or brown spots that darken the body coloration. On the sides of the dorsum and between the bases of the cerata there is a green or dark brown band. The oral tentacles and the rhinophores have the same tone as the body and they are thin and smooth, the rhinophores are about twice as long as the oral tentacles; both usually have a transversal orange or light brown band in the middle. There are up to 10 groups of cerata on each side of the back, well separated from each other, with 3 to 5 cerata in each group. Cerata have a very variable shape since they are elongated and cylindrical when fully extended and can be globose with 2 or 3 rounds of tubers when contracted. The digestive gland within the cerata is brownish-yellow and the surface of the cerata has 2 to 3 circular olive green bands. The foot is whitish and semitransparent, rounded and somewhat widened in the front area, while in the rear it forms a long, sharp tail.

This species is usually found under stones or between algae. It has been proven that the specimens of this species raise the cerata like the spikes of a porcupine when they are disturbed (Alder & Hancock, 1847), which possibly is a defense mechanism. The same authors indicate that the spawn is a thick cord wound in a spiral of one and a half turns or two, while Schmekel & Portmann (1982) describes it as a spiral of a spin with white eggs of 90 microns in diameter. E. cingulatus has been reported to feed on the hydrozoan Kirchenpaueria pinnata (Thompson & Brown, 1984) in Atlantic waters and Obelia geniculata (Schmekel & Portmann, 1982) in the Mediterranean. This species, because of its small size, general coloration and shape of the cerata is similar to other species of the same genus that can be found in the same habitat, formed by masses of algae with hydrarians or under stones, so their identification may not be easy. Species such as E. cingulatus, E. vittatus, E. exiguus, E. doriae, E. capellinii and others form a complex of cryptic species of difficult separation without a careful morphological examination of the specimens. Molecular analysis should, in a near future, clarify definitively the status of each of these species.


  • Eubranchus, from Greek, meaning “true gills”.
  • Cingulatus, from Latin “cingula”, meaning band, belt, collar (dog).

This species is distributed throughout the European Atlantic coasts, from the British Isles to the Iberian Peninsula, where in addition to the Gibraltar Strait and the Levantine coast it has been reported in the Cantabrian coast, Galicia and Portugal (Cervera, 2004). However, given its similarity to other species of the same genus, some of these reports must be taken cautiously.

Known georeferenced records of the species: Eubranchus cingulatus
: 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 observation probability for Eubranchus cingulatus based on our own records.

More pictures

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Further reading

Cite this article as:

Ballesteros, Manuel, Enric Madrenas, Miquel Pontes et al. (2012-2017) "Eubranchus cingulatus" in OPK-Opistobranquis, Published: 29/12/2015, Accessed: 18/12/2017 at (

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