Eubranchus farrani

Eubranchus farrani (Alder & Hancock, 1844)

Eubranchus farrani (forma A) by Enric Madrenas
Taxonomy
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  J.E. Gray, 1857
Family: Fionidae  Gray, 1857
Genus: Eubranchus  Forbes, 1838
Species: Eubranchus farrani (Alder & Hancock, 1844) [Eolis]

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.

Despite the four known forms of Eubranchus farrani are actually accepted, there’s an increasingly accepted opinion among professionals regarding the possibility that they are four distinct species. There are molecular studies on the way.

The Mediterranean specimens identified as Eubranchus tricolor are clearly not conspecific to the Atlantic specimens, but they are quite similar to Eubranchus farrani form “D”, although they could be a new unidentified species.

Synonyms

  • Aeolis adelaidae Thompson, 1860
  • Amphorina alberti Quatrefages, 1844
  • Cavolina farrani (Alder & Hancock, 1844)
  • Eolidia flavescens Risso, 1826
  • Eolis adelaidae Thompson W., 1859
  • Eolis andreapolis MacIntosh, 1865
  • Eolis farrani Alder & Hancock, 1844 (original)
  • Eolis robertianae MacIntosh, 1865
  • Galvina farrani (Alder & Hancock, 1844)
  • Galvina flava Trinchese, 1879

Description
The specimens of this species can achieve more than 20 mm in length but in most cases the specimens are smaller, of 10 to 15 mm. Coloration for this species is highly variable, so several chromatic forms A, B, C and D (Edmunds & Kress, 1969) have been described:

Form A is the most common coloration observed in the Mediterranean specimens: whitish body with yellow or orange spots on the dorsum, head, oral palps, rhinophores, cerata and sides. Form B are those individuals which have the entire body and cerata covered with large brown spots. Specimens of the form C are orange or yellow except the tips of cerata which are white. Form D is composed by those individuals with whitish gray cerata with a white ring at the apex. Oral palps are relatively short and the rhinophores are smooth. The cerata are gathered in groups 7-8 to each side of the back, and the ones in the front may have up to 5 cerata; the cerata may be globular in their middle zone, specially in the Form A specimens, or be less globose and curved inwards. The digestive gland can be observed within the cerata as a somewhat thickened cream colored central cord. The heart region is located between the second cerata group and the anal opening is located in a small papilla placed right behind and slightly to the right of the cardiac area. The genital opening is located below and slightly behind the first right group of cerata. The foot is relatively wide and has no propodial palps in its front zone.

Biology
This species is usually found in shallow littoral bottoms where hydrozoans grow on algae as epibionts. E. farrani feeds on small hydrarians like Obelia geniculata growing on kelp, in Codium fragile and other algae or mussel shells. It can also be located under stones where hydrarians grow. In European Atlantic coasts, specimens of different color forms are often found mating together indiscriminately (Edmunds & Kress, 1969). The spawn is a small ribbon coiled in one turn, or one turn and half, with white or slightly pink eggs of about 90 microns (Schmekel & Portmann, 1982).

Etymology

  • Eubranchus, from Greek, meaning “true gills”
  • Farrani = in honor of Dr. G.P. Farran of Dublín, naturalyst and shell collector who helped in the Alder & Hancock sampling campaign in the Irish shores in 1843, where the type specimen used to describe the species was collected.

Distribution
This species has been cited in Norway, the British Isles, Atlantic coasts of France and the English Channel, the Iberian Peninsula, the Canary islands, Açores and the western Mediterranean. In the Iberian Peninsula shores it has been cited in all areas except in the Bay of Biscay. In the Catalan coast it has been observed in different localities as Cala Sant Antoni, Es Caials, Cadaques, L’Escala, Tossa de Mar, Cala Santa Cristina, Blanes and Cubelles.

Known georeferenced records of the species: Eubranchus farrani (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: Eubranchus farrani

    Galicia: Urgorri and Besteiro (1983, 1984), Rolán (1983). Portugal: García-Gómez et al. (1991), Calado et al. (1999, 2003). Andalucía (Atl.): Cervera and García-Gómez (1986). Gibraltar: García-Gómez et al. (1989). Andalucía (Med.): Templado, Talavera and Murillo (1987), Templado, Luque and Moreno (1988), Sánchez Tocino, Ocaña and García (2000a), Ocaña et al. (2000). Levante: Templado (1982b, 1983, 1984). Catalunya: Ros (1975, 1978b, citada como E. cf. farrani), Ballesteros (1980, 1984b, 1985), Pereira & Ballesteros (1982), Domènech et al. (2002). Canarias: Ortea et al. (2001), Moro et al. (2003), Wirtz and Debelius (2003). Azores: Fontes, Tempera and Wirtz (2001).

    General: Barletta, 1981:105; Brown & Picton, 1979:24; Cattaneo-Vietti, Chemello, & Giannuzzi-Savelli, 1990:175[P]; Edmunds, 1969:[P]; Edmunds & Kress, 1969:889; Hayward, Wigham, & Yonow, 1990:721; Heppell, 1964a:413; Hunnam & Brown, 1975:156; Just & Edmunds, 1985:106, 108[P]; O'Donoghue, 1929:749; Picton & Morrow, 1994:116[P]; Riedl, 1983:330; Schmekel, 1970:159; Schmekel & Portmann, 1982:241[P]; Thompson, 1988:294; Thompson & Brown, 1976:166; 1984:134[P]

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

Abundance

        Western Mediterranean:2 Stars
        Eastern Mediterranean:1 Stars
        Atlantic Ocean:2 Stars
This chart displays the observation probability for Eubranchus farrani
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) "Eubranchus farrani" in OPK-Opistobranquis, Published: 16/05/2012, Accessed: 23/08/2017 at (http://opistobranquis.info/en/zq0hl)

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