Berthellina edwardsii

Berthellina edwardsii (Vayssière, 1896)

Berthellina edwardsii by Enric Madrenas
Taxonomy
Class: Gastropoda  Cuvier, 1797
Subclass: Heterobranchia  J.E. Gray, 1840
Clade: Euthyneura  Spengel, 1881
Clade: Nudipleura  Wägele & Willan, 2000
Subclade: Pleurobranchomorpha  Schmekel, 1985  (formerly NOTASPIDEA)
Superfamily:  Pleurobranchoidea  J.E. Gray, 1827
Family:  Pleurobranchidae  J.E. Gray, 1827
Genus:  Berthellina  Gardiner, 1936
Species: Berthellina edwardsii (Vayssière, 1896) [Berthella]

Synonyms

  • Berthella edwardsii Vayssière, 1896

Description
This species can reach a size of more than 50 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.

Biology
Berthellina edwarsii has been repeatedly confused with Berthella aurantiaca, as both species share a similar coloration and morphology. Only by studying and analyzing the internal anatomy and jaw structure of radular teeth, among other details, on can tell one or another species. The radula of B. edwardsii has numerous denticulate teeth (over 150) in each half-row and elongated jaws with smooth jaw parts, while radula teeth of B. aurantiaca are much less numerous (50 to 80 per half-row) with shorter jaws and jaw parts with denticles at the sides. 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. edwarsii. Because there has been confusion with B. aurantiaca, few biological data can be secured to B. edwarsii. 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.

Etymology

  • 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.

Distribution
Because of confusion with B. aurantiaca, quotations from B. edwarsii 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. edwarsii is a common species along the northern coast of the Costa Brava.

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

References for the species: Berthellina edwardsii

    Cantabria: Gofas (unpubl. data). Portugal: Marqués et al. (1982, as B. citrina), García-Gómez et al. (1991), Calado et al. (1999), Muzavor and Morenito (1999). Andalucía (Atl.): Cervera and García (1986, as Berthellina sp.), Templado et al. (1993b, as Berthellina sp.), Cervera, García-Gómez and Megina (2000). Gibraltar: Cervera (unpubl. data). Andalucía (Med.): Ballesteros et al. (1986, as Berthella aurantiaca), Ocaña et al. (2000), Peñas et al. (in press). Levante: Ballesteros et al. (1986, as Berthella aurantica), Templado et al. (2002). Catalunya: Ballesteros (datos no publicados) [Costa Brava]. Baleares: Lacaze-Duthiers (1859, as Pleurobranchus aurantiacus). Canarias: Pérez-Sánchez and Moreno (1990, as Berthellina quadridens), Malaquias (2000), Ortea et al. (2001), Moro et al. (2003), Wirtz and Debelius (2003). Madeira: Wirtz (1999), Malaquias et al. (2001), Wirtz and Debelius (2003). Azores: Vayssière (1896, 1898, 1902), Azevedo and Gofas (1990, as Berthellina sp.), Wirtz (1998), Ávila et al. (1998), Ávila (2000), Malaquias (2001), Wirtz and Debelius (2003).

    Sources: Cervera et al., 2004, Ballesteros, 2007, McDonald, 2006 and other sources.

Abundance

        Western Mediterranean:3 Stars
        Eastern Mediterranean:0 Stars
        Atlantic Ocean:0 Stars
This chart displays the observation probability for Berthellina edwardsii
based on our own records.

More pictures

Bibliography

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) "Berthellina edwardsii" in OPK-Opistobranquis, Published: 15/05/2012, Accessed: 28/03/2017 at (http://opistobranquis.info/en/GXUXd)

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