Cratena peregrina

Cratena peregrina (Gmelin, 1791)

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: Aeolidioidea  J.E. Gray, 1827
Family: Facelinidae  Bergh, 1889
Genus: Cratena  Bergh, 1864
Species: Cratena peregrina (Gmelin, 1791) [Doris]

Synonyms

  • Cuthona peregrina (Gmelin, 1791)
  • Doris peregrina Gmelin, 1791 (original)
  • Hervia costai Haefelfinger, 1961 

Description
The largest specimens of this species can reach up to 50 mm in length. The general color of the animal’s body is uniform white with two orange spots on the head just in front of the rhinophores. Oral palps are long, reaching almost one third of the total length of the animal, they are thin and are colored iridescent white. The rhinophores are smooth and are pigmented orange except the basal portion, which is white. There can be up to 9 separate groups of cerata on each side of the body, the cerata of the first group are inserted in the arc-shaped body while the other groups are inserted along single simple rows. The cerata are thin, long and semi-transparent, and the digestive gland is very visible inside, the color of the digestive gland can vary from orange to different shades of brown. There is usually a bluish iridescence near the apex and along the anterior side of each cerati while the apex is intense white due to the presence of a perfectly visible cnidosac. The foot is large and white and has a pair of well-developed triangular propodial tentacles.

Biology
For years, especially in the second half of the twentieth century, this species was cited as Hervia costai (Haefelfinger, 1960) subsequently considered synonymous with the species cited by Gmelin. C. peregrina is, together with Flabellina affinis, possibly one of the most abundant nudibranchs of all the Mediterranean coast. It is very active and it can be located throughout most of the year at shallow depth, feeding on athecate hydrarians colonies of the genus Eudendrium on dimly illuminated walls between 0 and 5 m deep, often sharing substrate with Flabellina affinis. In deeper water it is possible to observe it wandering on dimly illuminated walls among sponges, hydrarians and scyaphilic (=shade-loving) algae like Peyssonnelia sp., Flabellia petiolata and Halimeda tuna but also in photophilic (=light-loving) algae covered walls, in the coralligenous and occasionally under stones. The hydrozoans (Eudendrium ramosum and E.racemosum) over which it is commonly found are their food and are also the substrate where to lay the eggs. The spawn is a gelatinous cord 1.25 mm wide with an irregular outline, filled with white eggs about 90 microns in diameter.

Etymology

  • Cratena, probably from Latin “cratis”, basket; it could be also dedicated to Cratenas, a first century B.C. illustrator of plants.
  • Peregrina=wanderer in Latin.

Distribution
This is an eminently Mediterranean species, having been collected both in the western basin (French, Spanish and Italian shores) and the eastern basin (Greek and Turkish shores). Outside the Mediterranean it has only been observed in the Portuguese coast, in the Andalusian Atlantic coast, in the Strait of Gibraltar and the Canary islands. In the Iberian Mediterranean it is present in all coastal areas and also in the Balearic islands. It has been cited along the shores of Catalonia, like Cadaqués (Es Caials), L’Escala, L’Estartit (Medes islands), Begur (Cala Aiguafreda), Tamariu, Palamos (Cala Margarida ), Tossa de Mar (Cala Llevadó), Lloret de Mar (Cala Santa Cristina), Blanes (Cala Sant Francesc and Punta de Santa Anna), Mataró, Badalona, Cubelles, Salou (La Pineda) and the port of Tarragona.

Known georeferenced records of the species: Cratena peregrina
Sources:
: OBIS
: GROC 2010-2011
: Enric Madrenas
: João Pedro Silva
: Bernard Picton
: GBIF.ORG
: OPK
: VIMAR
: Manuel Ballesteros.
: M@re Nostrum
: Altres fonts
: Marine Regions

References for the species: Cratena peregrina

    Portugal: Calado et al. (1999, 2003). Andalucía (Atl.): García-Gómez (1984a, 2002), Cervera and García (1986). Gibraltar: García-Gómez et al. (1989). Andalucía (Med.): Ballesteros et al. (1986), Schick (1998), Sánchez Tocino, Ocaña and García (2000a), Ocaña et al. (2000). Levante: Templado (1982b), Ballesteros (1985), Ballesteros et al. (1986), Marín and Ros (1987), Aguado Giménez (2000), Templado et al. (2002). Catalunya: Vicente (1964), Ros (1975, 1978b, 1985), Ros & Altimira (1977), Ballesteros (1978, 1980, 1985), Pereira (1980, 1981), Altimira et al. (1981), Pereira & Ballesteros (1982), Huelin & Ros (1984), M@re Nostrum [La Foradada (Portbou) 10/1999, Cap Ras (Llançà) 11/1998, Cap Gros (El Port de la Selva) 9/1999, Cap Norfeu (Roses) 10/1999, Cova del Tamariu (Roses) 10/1999, Illa Mateua 5/1999 y 6/1999, Cadaqués 8/2003, Illa Meda (El Port de la Selva) 9/1998, Mar Menuda (Tossa de Mar) 10/1999 y 11/2000]. La mayoría de las citas como Hervia costai. Baleares: Ballesteros (1981a), Ballesteros, Álvarez and Mateo (1986), Wirtz and Debelius (2003). Canarias: Moro et al. (1995, 2003), Ortea et al. (2001).

    General: Barletta, 1981:112; Riedl, 1970:433; Thompson, 1976a:[P]; Vicente, 1963a:178; 1967:158; 1981:79; 1991:[P] as Hervia costai; Cattaneo-Vietti, Chemello, & Giannuzzi-Savelli, 1990:209[P]; Riedl, 1983:326; Schmekel, 1970:145; Schmekel & Portmann, 1982:212[P]; Wagele & Schminke, 1987:[P] as Cratena peregrina

    Sources: Cervera et al., 2004, Ballesteros, 2007 & 2016, McDonald, 2006 and other sources.

The aeolid Cratena peregrina was recent and informally recorded from Senegal, South Africa, India and in the western Atlantic. In a recent work (Padula et al. 2014), the authors investigate the potential presence of C. peregrina on the coast of Brazil. Brazilian and Mediterranean specimens are compared through multiple approaches, including a molecular phylogenetic analysis. As a result they conclude that the morphological and body colour differences observed between Mediterranean and Brazilian specimens are not due to intraspecific variation but instead, Brazilian specimens belong to a new species, Cratena minor n. sp., which is described.

Abundance

    Western Mediterranean:
    Eastern Mediterranean:
    Atlantic Ocean:
This chart displays the observation probability for Cratena peregrina based on our own records.

More pictures

Bibliography

Further reading

Cite this article as:

Ballesteros, Manuel, Enric Madrenas, Miquel Pontes et al. (2012-2017) "Cratena peregrina" in OPK-Opistobranquis, Published: 17/05/2012, Accessed: 18/12/2017 at (https://opistobranquis.info/en/iNl4a)

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