Facelina fusca

Facelina fusca Schmekel, 1966

Facelina fusca @ Portlligat (Cadaqués) 20080531 by Miquel Pontes

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: Aeolidioidea  J.E. Gray, 1827
Family: Facelinidae  Bergh, 1889
Genus: Facelina  Alder & Hancock, 1855
Species: Facelina fusca  Schmekel, 1966

The maximum size registered for this species is 16 mm in length. The body is very slim, coloured semitransparent gray with several bands and blackish brown spots covering the oral tentacles, rhinophores, sides of the head, some areas of the back and the cerata, giving the animal a dark appearance referred to in the specific name. There are also small white spots of different sizes in oral tentacles, rhinophores, head, back and cerata. In the middle dorsal line of the body and crossing down to the tail there is usually a very apparent white band. There may also be violet bands, a dorsal one flanking the white line and two lateral lines below the base of the rhinophores. The oral tentacles are long and thin, almost twice the length of the rhinophores; they are almost entirely smooth dark brown, but in the base. The cerata are gathered into 5 well separated groups on each side of the body, they are somewhat fusiform and pointed; within them it is visible the brown digestive gland, slightly darker at the apex of each cerata. The foot develops, in its front side, two short triangular propodial palps.

So far there is very few biological data regarding this rare species. It has been cited as Sphaerococcus coronopifolius living among algae, and on the leaves of the phanerogam plant Posidonia oceanica that have hydrozoans epibionts. Schmekel (1966) mentions, however, that this species feeds on the hydrozoans of the genus Eudendrium, which generally live in shallow dimly lit rocky walls, and not on leaves of Posidonia (?). The spawn is laid in an spiral with orange eggs 180 microns in diameter. This species could be parasitized by copepods that lay their spawn on the back of the aeolidacean.


  • fusca = refers to the dark coloured body, because of the brown and violet dark bands and spots that decorate it.

So far this is a strictly Mediterranean species. It has been only cited in Naples and in the Catalan coast: Cadaqués, Aiguafreda (Begur) and Blanes.

Known georeferenced records of the species: Facelina fusca
: 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 Facelina fusca based on our own records.

More pictures


Further reading

Cite this article as:

Ballesteros, Manuel, Enric Madrenas, Miquel Pontes et al. (2012-2017) "Facelina fusca" in OPK-Opistobranquis, Published: 17/05/2012, Accessed: 18/12/2017 at (https://opistobranquis.info/en/n23ZU)

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