Tenellia foliata

Tenellia foliata (Forbes & Goodsir, 1839)

Tenellia foliata Murles Point, Co. Donegal, Ireland by Bernard Picton
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 Gray, 1857
Family: Fionidae  Alder & Hancock, 1855
Genus: Tenellia A. Costa, 1866
Species: Tenellia foliata (Forbes & Goodsir, 1839)

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 previously undetected species diversity.


  • Eolidia foliata Forbes & Goodsir, 1839
  • Eolis conspersa Dalyell, 1853 
  • Eolis olivacea Alder & Hancock, 1842
  • Cuthona foliata (Forbes & Goodsir, 1839)
  • Trinchesia foliata (Forbes & Goodsir, 1839)

These is a small-sized aeolidacean that usually does not exceed 5-6 mm in length, although a maximum size of 10 mm has been reported (Bouchet, 1977). The body is usually translucent whitish, with opaque white scores on the head, oral palps, dorsum, flanks and tail. There are characteristic orange lines from the base of the oral palps to the anterior base of the rhinophores and from the posterior base of these, somewhat divergently, to the first group of cerata. The oral palps are short, semitransparent and have white granulations that are usually aligned on the anterior side. The rhinophores are somewhat longer than the oral palps, they have a blunt tip and the upper third is whitish. There are 5 to 7 cerata groups on each side of the back, with up to 5 cerata per group. Between 2 and 3 cerata groups are located in front of the cardiac area. The cerata are relatively short and globose and their apex is rounded and translucent, the cnidosac can be seen by transparency. The color of the digestive gland inside is usually chestnut brown with olive tones. White granulations are scattered on the surface of cerata, more abundant in the upper two thirds. The foot is semitransparent, as the body, and is rounded and slightly widened in the front area, not forming propodial palps.

Like other species of small aeolidaceans, T. foliata is usually found between intertidal or infralittoral algae with epizootic hydrozoans and on the underside of stones. The spawn is shaped like a small semicircular ribbon (Alder & Hancock, 1845).


  • Foliata. From Latin “foliātus”, bearing foliage, bearing leaves, from “folium”, leaf.

T. foliata is a species of the European Atlantic that has been reported from Norway and the British Isles down to Portugal (Bouchet, 1977). This author also indicates the differences between this species and T. genovae, as they are very similar and probably have been confused in the literature, noting that the distribution of T. foliata is eminently Atlantic whereas T. genovae is Mediterranean. Calado (2002) cites T. foliata for the Azores. In the Iberian Peninsula it has been reported from the Bay of Biscay to the Strait of Gibraltar (Cervera et al., 2004). There are some reports of T. foliata in the Mediterranean that would need to be confirmed.

Known georeferenced records of the species: Tenellia foliata (z-200).
: GROC 2010-2011 : VIMAR
: Enric Madrenas : Manuel Ballesteros.
: João Pedro Silva : M@re Nostrum
: Bernard Picton : Other sources
: GBIF.ORG : Marine Regions


        Western Mediterranean:1 Stars
        Eastern Mediterranean:0 Stars
        Atlantic Ocean:2 Stars
This chart displays the observation probability for Tenellia foliata
based on our own records.

More pictures


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:

Ballesteros, Manuel, Enric Madrenas, Miquel Pontes et al. (2012-2017) "Tenellia foliata" in OPK-Opistobranquis, Published: 13/10/2013, Accessed: 20/09/2017 at (http://opistobranquis.info/en/yIcEj)

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