Catriona maua

Catriona maua  (Ev. Marcus & Er. Marcus, 1960)

Catriona maua @ Lake Worth Lagoon, Florida 23-09-2016 by Ariane Dimitris










































Catriona maua  Ev. Marcus & Er. Marcus, 1960

 Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 141612).

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.


  • Tenellia maua   Ev. Marcus & Er. Marcus, 1960

This is a small aeolidacean, with a maximum reported size of 12mm.  It has a translucent white or yellowish body with opaque white irregular patches. The head is narrow as in other species of the genus. The head tentacles are short, colored with opaque white and directed to the sides. Rhinophores are finger shaped, smooth and short, with the anterior side colored opaque white and a bright red or orange stripe on the posterior side of their base. The eyes are black. The anterior angles of the foot are rounded; the foot is not as broad as the body, and the tail is pointed. The club shaped cerata (wider above the middle) are numerous, there could be up to 11 rows of cerata on each side of the body, the most populated rows are 2 to 4, and the less populated are the ones closer to the tail. The cerata do not cover the anterior body region nor the tip of the tail. Anus and nephroproct are located close to the innermost cerata of the 5th right row, while the gonopore is between the first and the second right rows. The bright red oesophagus is visible by transparency, as are the brown and smooth diverticula of the digestive gland in the base of cerata.

It is generally found in shallow water (from 1 to 8 meters depth) on sponges or hydrozoan branches. Thompson (1980) collected this species in Jamaica from Pennaria hydrozoans, while Marín & Ros (1987) collected it on Ventromma halecioides in the Mediterranean. This species is more freqüent between November and January, and from April to June. The spawn is a one turn coil (Marcus & Marcus, 1960) or kidney shaped (Marín & Ros, 1987) with about 70 eggs of 100 microns of diameter. Hatching occurs after 16-17 days at 16ºC.


  • Maua, of uncertain origin, seems related to cats.

Catriona maua has an amphi-Atlantic distribution. It has been cited in the Western Atlantic at Miami, USA (Marcus & Marcus, 1960), Curaçao and Bonaire (Marcus & Marcus, 1963), Jamaica (Edmunds, 1964; Thompson, 1980), Barbados (Edmunds & Just, 1983) and Bahamas (Redfern, 2001). In the Eastern Atlantic it has been cited in Gran Canaria, Tenerife and La Gomera (Canary Islands by Ortea et al, 2002), Azores (Malaquias et al., 2009), Cape Verde (Ortea et al., 2002) and the Atlantic Southern coast of Spain (Cervera, unpublished data). In the Mediterranean it has been cited in the Gulf of Naples, Italy (Schmekel, 1968; Schmekel & Portmann, 1982) and in the Mar Menor, Murcia, Spain (Marín & Ros, 1987).

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


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

This chart displays the monthly observation probability for Catriona maua based on our own records.


Catriona maua @ Lake Worth Lagoon, West Palm Beach, Florida, USA by Ariane Dimitris

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Further reading

Cite this article as:

Ballesteros, Manuel, Enric Madrenas, Miquel Pontes (2021) "Catriona maua" in OPK-Opistobranquis. Published: 16/05/2016. Accessed: 08/03/2021. Available at (

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