Berthella aurantiaca

Berthella aurantiaca (Risso, 1818)

Berthella aurantiaca by Enric Madrenas







































Berthella aurantiaca  (Risso, 1818)

 Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 140807).
Taxonomic note: This species has been traditionally confused with Berthellina edwardsii 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.


  • Pleurobranchus aurantiacus Risso, 1818 (original)
  • Pleurobranchus elongatus Cantraine, 1835

The specimens of this species usually measure around 20mm with a maximum reported length of 30mm. The body color is orange or red. The body is convex and the dorsal mantle is relatively small and does not completely cover the foot. In the living animal the dorsal integument is hyaline and inside there are stellate spicules, with 3-5 extensions, which have a tissue support mission. The oral veil is highly developed when the animal is moving and has a trapezoidal shape. The rhinophores are tubular and open at the distal end, in the interior zone there are transverse folds corresponding to the rhinophore olfactive areas. The gill is located under the right edge of the mantle, it is bipinnate and has between 15 and 18 lamellae on both sides of the rachis. Gill color is slightly lighter than the rest of the body. The inner shell is ear-shaped and it is fairly developed, taking approximately half of the total length of the animal; the dorsal surface of the shell has more or less marked growth grooves. The foot is very wide, protruding from all the edges of the notum: front, sides and back. Lacaze-Duthiers (1859) describes the anatomy and physiology of this species.

Berthella aurantiaca has been cited living under rocks at shallow depth (Vayssière, 1898), in Posidonia oceanica meadows (Cattaneo-Vietti, 1986) or on sandy or muddy bottoms where commercial fishing trawlers work (Ros, 1975). Until recently, it has been repeatedly cited and confused as Berthellina edwardsii because of the similar coloration and morphology of both species. A summary of the discussion on identifying aurantiaca / edwardsii can be found in Sea Slug Forum. Only by studying the internal anatomy and analyzing the mandibular teeth and radular structure, among other details, it can be told one species or another. VIMAR group has studied the anatomy of the specimens of  aurantiaca / edwardsii morphology that can be observed in the northern Costa Brava (N.E. of Spain), under stones, from low tide zone down to 15-20 m deep and, so far, all specimens belong to B. edwardsii .


  • Berthella. 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. He wrote the “Historia Natural de Canarias” and directed the Botanical Garden of Puerto de la Cruz.
  • Aurantiaca. From Latin “aurantiacus” which means “gold coloured”.

Due to the morphological and coloring similarity between Berthella aurantiaca and B. edwardsii , reports of both species should be confirmed by anatomical studies. Many European reports of B. aurantiaca are, in fact, B. edwardsii (Cervera et al. 2004). These authors indicate, however, that B. aurantiaca is found along most of the Iberian coast (Bay of Biscay, Strait of Gibraltar area and the entire Mediterranean coast), the Balearic Islands and the Azores. B. aurantiaca does not occur in the Adriatic, while B. edwardsii is very common (Jakov Prkić, 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 . However, in the Catalan coast, B. aurantiaca has been properly cited at Es Caials (Cadaqués), the coastline of the Medes Islands and Blanes.

Known georeferenced records of the species: Berthella aurantiaca
: 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 Berthella aurantiaca based on our own records.



More pictures


    Altimira C, Huelin MF, Ros J. 1981. Mol·luscs bentònics de les illes Medes (Girona). I. Sistemàtica. Butll. Inst. Cat. Hist. Nat. (Sec. Zool.), 47: 69-75.
    Avila C. 1993. Sustancias naturales de moluscos opistobranquios: Estudio de su estructura, origen y función en ecosistemas bentónicos. Tesis Doctoral. Universitat de Barcelona. Universitat de Barcelona.
    Ballesteros M. 2007. Lista actualizada de los opistobranquios (Mollusca: Gastropoda: Opisthobranchia) de las costas catalanas. Spira. 2(3):163–188.
    Ballesteros M, Pontes M, Madrenas E. 2015. Opisthobranch from Medes Islands (Marine Protected Area, Costa Brava, Catalonia, NE Spain): 40 years of study. Available from
    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
    Bergh LSR. 1892. Opistobranches provenant des campagnes du yacht Hirondelle. Résultats des campagnes scientifiques accomplies sur son yacht par Albert 1er, Prince souverain de Monaco 4: 1-35.
    Bielecki S, Cavignaux G, Crouzet JM, et al. 2011. Des limaces de rêve.
    Calvín Calvo JC. 1995. El ecosistema marino mediterráneo, guía de su fauna y su flora.
    Cattaneo-Vietti R, Chemello R, Giannuzzi-Savelli R. 1990. Atlas of Mediterranean Nudibranchs. Rome, Italy: La Conchiglia. 264 p.
    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.
    Crocetta F, Zibrowius H, Bitar G, et al. 2013. Biogeographical homogeneity in the eastern Mediterranean Sea - I: the opisthobranchs (Mollusca: Gastropoda) from Lebanon. Mediterranean Marine Science, Vol 14, no.2.
    Domènech A, Ávila C, Ballesteros M. 2006. Opisthobranch molluscs from the subtidal trawling grounds off Blanes (Girona, north-east Spain). Journal of the Marine Biological Association of U.K. 86:383–389.
    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.
    García-Gómez JC. 1987. Adiciones a la fauna de Opistobranquios del Estrecho de Gibraltar (sur de España), I. Iberus 7 (2): 197-209.
    Gili JM, Ros J. 1984. L’estatge circalitoral de les Illes Medes: el coralligen; pp 678-700, In: Els sistemes natural de les Illes Medes. Institut d’Estudis Catalans, 828 pp.
    Hidalgo JC. 1917. Fauna malacológica de España, Portugal y las Baleares. Trabajos del Museo Nacional de Ciencias Naturales. Serie Zoología (Madrid) 30: 752 pp.
    Huelin MF, Ros J. 1984. Els mol·lucs marins de les illes Medes In: Els sistemes naturals de les Illes Medes. Arxius de la Secció de Ciéncies, J Ros et al (eds) 73: 457-500. IEC. Barcelona, Spain.
    Lacaze-Duthiers H. 1859. Histoire anatomique et physiologique du pleurobranche orangé. Annales des Sciences Naturelles (Zoologie) 11: 201-202; pls. 6-12.
    Long SJ. 2006. Bibliography of Opisthobranchia 1554-2000. Bayside Books & Press, Tustin, CA, U.S.A. 672p.
    Malaquias MAE. 2001. Updated and annotated checklist of the opisthobranch molluscs (excluding Thecosomata and Gymnosomata), from the Azores archipelago (North Atlantic Ocean, Portugal). Iberus 19 (1): 37-48.
    Maluquer M. 1912. Contribució a la fauna malacologica de Catalunya. Boletín del Instituto Catalán de Historia Natural, 2.a época 12: p. 50.
    Maluquer M. 1906 1909. Mol·luscs marins de Catalunya. Trabajos del Museo de Ciencias Naturales de Barcelona 1906-1907: 14, 27, 42 and 103.
    Maluquer M. 1916. Treballs oceanografics de la costa de l’Empordá. Anuari - Junta de Ciències Naturals (Barcelona): 221-261.
    Maluquer J. 1907. Mol·luscs marins de Catalunya. Butlletí de la Institució Catalana d’Història Natural. 7:19–21.
    Marín A, Ros J. 1987. Catálogo preliminar de los gasterópodos marinos del sudeste español. Iberus 7 (1): 137-145.
    McDonald G. 2009. Bibliographia Nudibranchia. 2nd Online Edition, Annotated. 1072 pp  Institute of Marine Sciences, University of California, Santa Cruz. Available from
    Ocaña Martín A, Sánchez Tocino L, López González S, et al. 2000. Guía submarina de invertebrados no artrópodos. Granada: Comares.
    Ortea J. 1977a. Moluscos marinos gasterópodos y bivalvos del litoral asturiano entre Ribadesella y Ribadeo, con especial atención a la subclase de los opistobranquios. Tesis Doctoral. Oviedo: Universidad de Oviedo.
    Pontes M, Dacosta JM, Ollé i Callau A, et al. 2023. M@re Nostrum. Available from
    Riedl R. 1983. Fauna und Flora der Mittelmeeres, ein systematischer Meeresfuhrer fur Biologen und Naturfreunde, 836 pp. Paul Parey, Hamburg & Berlin.
    Risso A. 1818. Mémoire sur quelques Gastropodes nouveaux, Nudibranches et Tectibranches observés dans la mer de Nice. Journal de Physique 87: 368-377.
    Ros J. 1981b. Noves citations de Gasteropòdes opistobranquis de les Gimnésies. Boletín del Instituto Catalán de Historia Natural 47 (Secció Zoología 4): 175-177.
    Ros J. 1975. Opistobranquios (Gastropoda: euthyneura) del litoral ibérico. Investigacion Pesquera. 39(2):269–372. Available from
    Ros JD. 1985b. Els poblaments d’Opistobranquis de coves submarines mediterránies: noves dades i comentaris sobre llur afinitat faunistica. Boletín del Instituto Catalán de Historia Natural 52 (Secció Zoología 6): 87-94.
    Ros J. 1978. Distribució en l’espai i en el temps dels opistobranquis iberics, amb especial referencia als del litoral catalá. Butll. Inst. Cat. Hist. Nat., 42 (Sec. Zool., 2): 23-32.
    Ros J. 1973. Opistobranquios (Gastropoda: Euthyneura) del litoral ibérico : Estudio faunístico y ecológico [Tesis Doctoral]. Barcelona: Universitat de Barcelona. 285 p.
    Ros J, Gili JM. 1985. Opistobranches des grottes sousmarines de I’lle de Majorque (Baleares). Rapport de la Commision Internationale de la Mer Mediterranée 29 (5): 141-145.
    Sánchez Tocino L. 2001. Berthella aurantiaca 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.
    Trainito E, Doneddu M. 2014. Nudibranchi del Mediterraneo. 2nd. Il Castello. 192 p.
    Trainito E, Trainito S. 2003. Mediterranean harlequins : a field guide to Mediterranean sea slugs. Olbia (SS), Italia: Taphros.
    Vayssière A. 1898. Monographie de la famille des pleurobranchidés. I. Annales des Sciences Naturelles (Zoologie) 8 (8): 209-402.
    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) "Berthella aurantiaca" in OPK-Opistobranquis. Published: 15/05/2012. Accessed: 17/04/2024. Available at (

To copy this cite click on the right button.