Rubramoena amoena

Rubramoena amoena (Alder & Hancock, 1845)

Rubramoena amoena 6 mm @ Lephinchapel, Loch Fyne, Scotland 15m 5-10-2008 by Jim Anderson










































Rubramoena amoena  (Alder & Hancock, 1845)

 Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 890616).

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. Within Fionidae, obtained results demonstrated the need of developing a new classification as previous classifications (for instance, separating Catriona, Cuthona and Trinchesia as distinct taxa) were inconsistent with the resulting phylogeny. Analyses also recover a clade (Tenellia) that includes all members of the genera Tenellia, Trinchesia, Phestilla, Catriona and the majority of described and undescribed Cuthona species. New genera Rubramoena, Abronica and Tergiposacca are proposed to group other species. This molecular study also suggests that Fionidae is rich in cryptic species complexes, difficult to separate by traditional taxonomic characters, and a great previously undetected species diversity.
A few months later Korshunova et al. (2017) take up the study of the phylogeny of the Tergipedidae and using not only molecular data but also morphological and ontogenetic data they severely criticise the work by Cella et al. (2016), proposing to reinstate the families Calmidae, Eubranchidae, Fionidae, Tergipedidae, Cuthonidae, Cuthonellidae and Trinchesiidae, the latter being the most abundant in specific taxa. They also reinstate the genera Catriona, Diaphoreolis, Phestilla and Trinchesia that in the paper by Cella et al. (2016) had been included in the genus Tenellia. Korshunova et al. also describe a new genus, Zelentia that includes Z. pustulata (type species Eolis pustulataAlder & Hancock, 1854), Z. fulgens (MacFarland, 1966) and a new species from the Barents Sea, Z. ninel, indicating important p-distances among the three species (between 10.49% and 13.83%). All previous genera, Korshunova et al. (2017) consider them within the family Trinchesiidae. They also question the validity of the Rubramoena genus of Cella et al.
The position of WoRMS is conservative, maintaining the families Cuthonidae, Calmidae, Cuthonellidae, Eubranchidae, Fionidae, Pseudovermidae, Tergipedidae and Trinchesiidae within the superfamily Fionoidea. The European species that, until recently, were considered as Cuthona, WoRMS considers them within the genus Trinchesia, as T.albopunctata, T.caerulea, T.foliata, T.genovae, T.granosa, T.ilonae, T.miniostriata and T.ocellata. Rubramoena is also considered a valid genus in WoRMS. These opinions are those that we accept in OPK while no other more conclusive data are available.

All molecular analyses recovered Cuthona amoena and Cuthona rubescens in a separate clade Rubroamoena. Both species are apparently very similar, but Picton and Brown (1978) stated the main differences between them when they described Cuthona rubescens.


  • Eolis amoena Alder & Hancock, 1845
  • Trinchesia amoena (Alder & Hancock, 1845)
  • Cuthona amoena (Alder & Hancock, 1845)

Typically measuring 10 mm in length, it has a translucent body with patches of brown at the base of the cerata, and characteristic brown rings on the rhinophores and oral tentacles. The upper part of the body and the cerata are sprayed with golden or yellowish irregular dots, being more dense at the tips of the head tentacles and cerata. The jaws are visible by transparency in the head. The foot is narrow, with the anterior margin slightly lobed, and a little rounded and widened at the sides.

It is usually found on the hydroid Halecium halecinum, that seems to be its food. The spawn is a thin white waved thread, usually wound around the branches of its food, or forming an spiral of two or three turns.


  • Rubramoena. Refers to the specific names of the two species it contains, Rubramoena amoena (type species) and Rubramoena rubescens.
  • Amoena. It is the feminine word for Latin word “amoenus”, pleasant, lovely, beautiful.

From Norway and the Orkney down to the Mediterranean. Common around the British Isles and Ireland. In the Iberian Peninsula it has been cited in the Atlantic northern shore of Spain, also in Galicia and Portugal. In the Mediterranean it is reported from Catalunya, from the Italian Salento and the Adriatic Sea. In Catalan waters it has been found at Cap de Creus, also in Begur, Palamós, Sant Feliu de Guíxols and Mataró.

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

References for the species: Rubramoena amoena

    Cantabria: Ortea (1977c, as Cratenopsis). Galicia: Urgorri and Besteiro (1983), Rolán (1983). Portugal: Calado et al. (2003). Gibraltar: García-Gómez (1983, 2002). Catalunya: Ballesteros (1980, 1985).

    General: Nordsieck, 1972:81 as Cratenopsis amoena; Pruvot-Fol, 1953b:52[P]; 1954b:384; Sordi & Majidi, 1956:241; Thompson & Brown, 1976:188 as Trinchesia amoena; Brown, 1980:247; Brown & Picton, 1979:7; Dekker, 1985a:71; 1989:104; Hayward, Wigham, & Yonow, 1990:726; Picton & Morrow, 1994:98[P]; Swennen, 1987:47; Thompson, 1988:264; Thompson & Brown, 1984:117[P]; Vayssiere, 1913a:281 as Cuthona amoena

    Sources: Cervera et al., 2004, Ballesteros, 2007 & 2016, McDonald, 2006 and other sources.


    Western Mediterranean:1 out of 5 stars
    Eastern Mediterranean:0 out of 5 stars
    Atlantic Ocean:2 out of 5 stars

This chart displays the monthly observation probability for Rubramoena amoena based on our own records.

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Further reading

Cite this article as:

Pontes, Miquel, Manuel Ballesteros, Enric Madrenas (2012-2019) "Rubramoena amoena" in OPK-Opistobranquis, Published: 17/05/2012, Accessed: 23/05/2019 at (

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