Trinchesia morrowae

Trinchesia morrowae  Korshunova, Picton, Furfaro, Mariottini, Pontes, Prkić, Fletcher, Malmberg, Lundin & Martynov, 2019

Trinchesia morrowae by Enric Madrenas










































Trinchesia morrowae  Korshunova, Picton, Furfaro, Mariottini, Pontes, Prkić, Fletcher, Malmberg, Lundin & Martynov, 2019

 Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 1343994).

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.

This species is similar to Trinchesia caerulea, quite frequent in the Western Mediterranean, in fact they were considered synonyms until the work published by Korshunova et al. (2019).


  • Cuthona caerulea auct., e.g. Thompson & Brown (1984)16, Schmeckel & Portmann (1982)34, Picton & Morrow (1994)31 non Doris caerulea Montagu, 1804.

This is a small species, with a narrow body of about 10mm in length, decorated by a white band that goes from the front of the head to the tail, and thinner white lines that decorate the sides of the body. The rhinophores are smooth and have 1.5 times the length of the oral tentacles. Both rhinophores and oral tentacles have bright yellow / orange tips. Cerata are relatively short and, like the body, they are coloured light gray or yellowish, with a broad band of yellow or gold dots, followed by a thin black band, a broad blue band and a yellow/orange band that almost reaches the distal end, where we find a translucent cnidosac. It has 3 (rarely 4) rows of cerates in front of the pericardium. The foot is narrow and it does not have propodial tentacles on the front end, only angular processes.

It feeds on hydroids Sertularella spp. possibly on Sertularella perpusilla Stechow, 1919 and also from Stylactis inermis Allman, 1872. The spawn is small, consisting on a spiral of 2-2.5 turns or a regular cord, with less than 100 eggs.


  • Trinchesia. In honor of Professor Salvatore Trinchese (1836-1897), Italian opisthobranchologist, Professor of Zoology at the University of Bologna and successor of Paolo Panceri as Professor of Comparative Anatomy at the University of Naples.
  • Morrowae. Dedicated to Christine Morrow, co-author of “A Field Guide to the Nudibranchs of the British Isles” (1994), which sequenced a specimen of Trinchesia cuanensis revealing for the first time the presence of two species of this complex in the north-east Atlantic.

It lives in relatively shallow rocky bottoms, generally above 25 m. It is also found in Posidonia oceanica meadows. It is present in the Mediterranean from Greece to the western basin, but has also been found in the South of the British Isles. In the Iberian Peninsula it is found in all its coastal areas, including Portugal. It has also been reported in the Balearic Islands. In the Catalan coast it has been observed in many localities of the Costa Brava, from Port de la Selva to Blanes.

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

Similar species
This species is very similar to Trinchesia caerulea, quite common in the Western Mediterranean, in fact they were considered synonymous until the work published by Korshunova et al. (2019). They differ in that T. caerulea is larger, has no white dorsal longitudinal band, the tips of the oral tentacles and rhinophores are pale yellow, not orange, and the cerata have only a blue and yellow band. Foot with obvious propodial tentacles.


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

This chart displays the monthly observation probability for Trinchesia morrowae based on our own records.

More pictures


    Ballesteros M, Álvarez C, Mateo B. 1986. Aproximación a la fauna de opistobranquios de la isla de Menorca. Publicaciones del Departamento de Zoología (Barcelona) 12: 93-106.
    Ballesteros M, Pontes M, Madrenas E. 2019. Els nudibranquis del mar català. Figueres: Brau Edicions. 192 p.
    Betti F, Bavestrello G, Cattaneo-Vietti R. 2021. Preliminary evidence of fluorescence in Mediterranean heterobranchs. Journal of Molluscan Studies. 87:eyaa040.
    Canessa M, Bavestrello G, Cattaneo-Vietti R, et al. 2021. Rocky substrate affects benthic heterobranch assemblages and prey/predator relationships. Estuarine, Coastal and Shelf Science 38: 539-558. 261:1–13.
    Cella K, Carmona L, Ekimova I, et al. 2016. A Radical Solution: The Phylogeny of the Nudibranch Family Fionidae. PLoS ONE 12/2016; 11(12):e0167800.
    Furfaro G, Vitale F, Licchelli C, et al. 2020. Two Seas for One Great Diversity: Checklist of the Marine Heterobranchia (Mollusca; Gastropoda) from the Salento Peninsula (South-East Italy). Diversity. 12(12):171.
    Korshunova T, Martynov AV, Picton BE. 2017. Ontogeny as an important part of integrative taxonomy in tergipedid aeolidaceans (Gastropoda: Nudibranchai) with a description of a new genus and species from the Barents Sea. Zootaxa 4324 (1): 1-22.
    Korshunova T, Picton B, Furfaro G, et al. 2019. Multilevel fine-scale diversity challenges the ‘cryptic species’ concept. Scientific Reports. 9(1):6732.
    Parera A, Pontes M, Salvador X, et al. 2020. Sea slugs (Mollusca, Gastropoda, Heterobranchia): the other inhabitants of the city of Barcelona (Spain). Butlletí de la Institució Catalana d’Història Natural, 84: 75-100.

    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:

Pontes, Miquel, Manuel Ballesteros, Enric Madrenas (2023) "Trinchesia morrowae" in OPK-Opistobranquis. Published: 02/02/2018. Accessed: 20/04/2024. Available at (

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