Berthellina edwardsii

Berthellina edwardsii (Vayssière, 1896)

Berthellina edwardsii by Enric Madrenas







































Berthellina edwardsii  (Vayssière, 1897)

 Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 181221).
Taxonomic note: This species has been traditionally confused with Berthella aurantiaca because its external morphology is very similar, so much so that it is virtually impossible to distinguish them “de visu”. To differentiate these species is mandatory an study of the mandibular structure and the radular teeth. The radula of B. edwardsii has numerous denticulate teeth (more than 150) in each semi-row and an elongated jaws and with smooth mandibular parts while the teeth of the radula of B. aurantiaca are much less numerous (from 50 to 80 per semi-row) ) the mandibles are shorter and with the mandibular parts with denticles on the sides. Adult specimens can also be differentiated by the size of the inner shell, which in B.edwardsii never exceeds 5.5mm (in specimens up to 60mm) since it stops growing when the animals reach circa 15mm in length (Jakov Prkić, com.pers.), whereas in Berthella aurantiaca the shell is proportionally larger (Vayssière reported a 15mm shell in a 30mm specimen), as it protects the entire visceral mass.


  • Berthella edwardsii Vayssière, 1896

This species can reach a size up to 60 mm in length, although specimens usually seen in the upper infralittoral usually measure between 20 and 30 mm in length. The body is characteristically highly domed and their color is very striking: orange or uniform yellowish orange. The mantle covers the entire animal but the rhinophores, the cephalic veil and back of the foot, that protrudes slightly. The mantle, apparently smooth, when viewed under binocular microscope shows tiny round bumps that form and dissolve in the living animal, and also numerous and very tight rounded structures corresponding to the output of the ducts of the acidic glandular formations that characterize the majority of the Pleurobrancomorphs species. The internal shell cannot be seen by transparency through the mantle tissue, as in other species of Berthella. The shell is flat and auriculate and is covered by a thin membranous periostracum. The cephalic veil is frustoconical shaped with a wider anterior area; ventrally, the cephalic veil is crossed laterally. Auriculate rhinophores can be seen over the cephalic veil, they emerge together from the base and are directed somewhat obliquely in the form of “V”. Rhinophores are of the same color as the body and can be retracted below the anterior mantle. When they are fully extended some slight folds transverse along their surface. The eyes can be seen right behind of the external side of the rhinophores base. The gill is located on the right of the body, between the mantle and the foot, it is bipinnate and has about a dozen lamellas to each side of the central axis. Under the binocular microscope shows that each lamella is also finely pinnulated. The anal orifice is located just above the gill. The foot is broad and oval shaped even in the tail, which is rounded. The color is of lighter yellow than the body and in the center you can see a brown spot due to the viscera below. All along the edge of the foot there is a groove that completely surrounds it.

Studying the anatomy of the specimens that have been found in the north of the Costa Brava, under stones, down to 15-20 meters deep, we have concluded that they all belong to B. edwardsii. Because there has been confusion with B. aurantiaca, few biological data can be secured to B. edwardsii. It could feed on encrusting sponges such as Corticium sp., Tethya aurantium, Aaptos aaptos and Hemimycale sp., all being species that live on the underside of stones where the opistobranch could be found. The spawn consists of a flat light colored ribbon wound in spiral and attached to the substrate by one of its sides, forming characteristic undulations.


  • Berthellina. Probably dedicated to Sabin Berthelot (1794-1880), a French naturalyst who enrolled the Navy and participated in the Napoleonic wars. He lived part of his life at the Canary islands, in his post as French consul in Tenerife. The abbreviation “Berth” is used to indicate Sabin Berthelot as an authority in the scientific botanical description and classification. He wrote the “Historia Natural de Canarias” and directed the Botanical Garden of Puerto de la Cruz.
  • Edwardsii. Dedicate to Henry Milne-Edwards (1800-1885), a French zoologyst supporting the study of animals in their natural environment and not from stuffed specimens.

Because of confusion with B. aurantiaca, reports of B. edwardsii should be confirmed. Cervera et al. (2004) conclude, however, that this species is found throughout the Iberian coast, the Balearic Islands, Madeira, Azores and Cape Verde. It is cited as Berthella plumula, B. engeli and B. citrina also on the coasts of France, Italy and other Mediterranean areas. In the Catalan coast B. edwardsii is a common species along the northern coast of the Costa Brava, in places like Cala Sant Antoni, Es Caials and the Medes Islands. VIMAR group has studied the anatomy and morphology of specimens aurantiaca / edwardsii found in the Costa Brava (N.E. Spain), under stones, from the lower tide area down to 15-20 m deep and, so far, they are all B. edwardsii .

Known georeferenced records of the species: Berthellina edwardsii
: 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 monthly observation probability for Berthellina edwardsii based on our own records.



More pictures


    Bacallado JJ, Ortea J, Moro L, et al. 2008. Inventario de los moluscos de la marina de Arrecife, Lanzarote. Canarias Conservación.:1–32. Available from
    Ballesteros M. 2007. Lista actualizada de los opistobranquios (Mollusca: Gastropoda: Opisthobranchia) de las costas catalanas. Spira. 2(3):163–188.
    Ballesteros M, Barrajón A, Luque A, et al. 1986. Contribución al conocimiento de los Moluscos Gasterópodos marinos de Almería. Iberus, 6: 39-57.
    Ballesteros M, Madrenas E, Pontes M. 2016. Actualización del catálogo de los moluscos opistobranquios (Gastropoda: Heterobranchia) de las costas catalanas. Spira. 6:1–28.
    Ballesteros M, Madrenas E, Pontes M. 2024. OPK - Opistobranquis. Available from
    Betti F, Bavestrello G, Cattaneo-Vietti R. 2021. Preliminary evidence of fluorescence in Mediterranean heterobranchs. Journal of Molluscan Studies. 87:eyaa040.
    Bielecki S, Cavignaux G, Crouzet JM, et al. 2011. Des limaces de rêve.
    Cervera JL, García-Gómez JC. 1986. Moluscos opistobranquios del litoral occidental andaluz: nuevas aportaciones faunísticas. Iberus 6 (2): 201-207.
    Cervera JL, Gosliner TM, García-Gómez JC, et al. 2000. A new species of Berthella Blainville, 1824 (Opisthobranchia: Notaspidea) from the Canary Islands (Eastern Atlantic Ocean), with a re-examination of the phylogenetic relationships of the Notaspidea. Journal of Molluscan Studies 66: 301-311.
    Cervera JL, Calado G, Gavaia C, et al. 2004. An annotated and updated checklist of the opisthobranchs (Mollusca: Gastropoda) from Spain and Portugal (including islands and archipelagos). Boletín Instituto Español de Oceanografía, 20 (1-4): 1-111. L.
    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.
    Göbbeler K, Klussmann Kolb A. 2010. Out of Antarctica?-New insights into the phylogeny and biogeography of the Pleurobranchomorpha (Mollusca, Gastropoda). Molecular  Phylogenetics & Evolution. 55(3):996–1007.
    Long SJ. 2006. Bibliography of Opisthobranchia 1554-2000. Bayside Books & Press, Tustin, CA, U.S.A. 672p.
    Malaquias M, Calado G, Padula V, et al. 2009. Molluscan diversity in the North Atlantic Ocean: new records of opisthobranch gastropods from the Archipelago of the Azores. Marine Biodiversity. 2:e38.
    Martínez-Chacón M. 2018. Nudibranquios de la isla de Tarifa, pequeñas joyas del estrecho de Gibraltar. Junta de Andalucía. Consejería de Medio Ambiente y Ordenación del Territorio. Available from
    McDonald G. 2009. Bibliographia Nudibranchia. 2nd Online Edition, Annotated. 1072 pp  Institute of Marine Sciences, University of California, Santa Cruz. Available from
    Menéndez JL, Oliveros J. 2004 2015. Berthellina edwardsi accessed through: AsturNatura on 2015-02-05. Available from
    Moro L, Martín Esquivel JL, Garrido Sanahuja MJ, et al. 2003. Lista de especies marinas de Canarias (algas, hongos, plantas y animales). Consejería de Política Territorial y Medio Ambiente del Gobierno de Canarias. 248 p.
    Naya Garmendia LM. 2016. Nudibranquios de la Costa Vasca: el pequeño Cantábrico multicolor. Aquarium de Donostia-San Sebastián.
    Ortea J, Moro L, Caballer M. 2014. Contribución al estudio de la familia Pleurobranchidae Gray, 1827 (Mollusca: Opisthobranchia) en la Macaronesia y las islas Galápagos. Vieraea. 42:117–148.
    Ortea J, L. Moro MC, Bacallado JJ. 2003. Resultados Científicos del proyecto “Macaronesia 2000” Chinijo-2002: Moluscos Opistobranquios. Revista de la Academia Canaria de Ciencias 14 (3-4): 165-180.
    Ozturk B, Dogan A, Bitlis-Bakir B, et al. 2014. Marine Molluscs of the Turkish Coasts: An Updated Checklist. Tübitak, Turkish Journal of Zoology 38.
    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.
    Peñas A, Rolán E, Luque A, et al. 2006. Moluscos marinos de la zona de la isla de Alborán. Iberus, supplement 6.
    Pontes M, Salvador X, Parera A, et al. 2021. Biodiversity in anthropized marinas. The case of the Barcelona Forum bathing area (Spain). Barcelona: Institució Catalana d’Història Natural (Monografies de la Societat Catalana d’Història Natural). 68 p.
    Prkić J, Petani A, Iglić Ð, et al. 2018. Stražnjoškržnjaci Jadranskoga Mora: Slikovni Atlas i Popis Hrvatskih Vrsta / Opisthobranchs of the Adriatic Sea: Photographic Atlas and List of Croatian Species. Bibinje: Ronilaćki Klub Sveti Roko. 464 p. Available from
    Rudman W.B. et al. 1998 2010. Berthellina edwardsi accessed through: Sea Slug Forum on 2014-12-14. Available from
    Sánchez Tocino L. 2001. Berthellina edwardsi accessed through: Opistobranquios de la Costa de Granada on 2014-12-14. Available from
    Sánchez-Tocino L. 2018. El Litoral de Granada - Opistobranquios. El Litoral de Granada. Available from
    Templado J, Villanueva R. 2010. Checklist of Phylum Mollusca. pp. 148-198 In Coll, M., et al., 2010. The biodiversity of the Mediterranean Sea: estimates, patterns, and threats. PLoS ONE 5(8):36pp.
    Templado J, Guerra A, Bedoya J, et al. 1993. Fauna marina circalitoral del sur de la Península Ibérica; Resultados de la campaña oceanográfica “Fauna I”. Madrid, Spain: Museo Nacional de Ciencias Naturales (CSIC). 166 p.
    Toll L, Ballesteros M. 2017. “Opistobranquios” (Mollusca: Gastropoda) de la colección malacológica Lluís Dantart. Spira 6 (2017): 171–184.
    Trainito E, Doneddu M. 2014. Nudibranchi del Mediterraneo. 2nd. Il Castello. 192 p.
    Vayssière A. 1896. Description des coquilles de quelques espèces nouvelles ou peu connues de Pleurobranchidés. Journal de Conchyliologie 44: 113-137, pl. 4-5.
    Wirtz P. 1999. Opisthobranch Molluscs from the archipelago of Madeira. Vita Marina. 46(1–2):1–18.
    WoRMS Editorial Board. 2023. World Register of Marine Species. WoRMS. Available from

    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, M., Madrenas, E. & Pontes, M. (2023) "Berthellina edwardsii" in OPK-Opistobranquis. Published: 15/05/2012. Accessed: 14/04/2024. Available at (

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