Cratena peregrina (Gmelin, 1791)

WoRMS Taxonomic Information
Current classification
| Superdomain | Biota |
|---|---|
| Kingdom | Animalia |
| Phylum | Mollusca |
| Class | Gastropoda |
| Subclass | Heterobranchia |
| Infraclass | Euthyneura |
| Subterclass | Ringipleura |
| Superorder | Nudipleura |
| Order | Nudibranchia |
| Suborder | Cladobranchia |
| Superfamily | Aeolidioidea |
| Family | Facelinidae |
| Genus | Cratena |
| Species | Cratena peregrina (Gmelin, 1791) |
- Cuthona peregrina (Gmelin, 1791)
- Doris peregrina Gmelin, 1791 (original)
- Hervia costai Haefelfinger, 1961Â
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 Straits 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, L’Escala, L’Estartit, Begur, Tamariu, Palamós, Tossa de Mar, Lloret de Mar, Blanes, Mataró, Badalona, Cubelles, Salou and Tarragona.
The aeolid Cratena peregrina was 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 Brazilian specimens belong to a new species instead, Cratena minor n. sp., which is described in the paper.
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Similar species
Paraflabellina gabinierei, with brown cerata, without orange marks on the face. Calmella cavolini, smaller, with red cerata, with purple marks on the face.
Abundance
| Western Mediterranean: | ★★★★☆ |
| Eastern Mediterranean: | ★★★☆☆ |
| Atlantic Ocean: | ★☆☆☆☆ |
This chart displays the monthly observation probability for Cratena peregrina based on our own records.
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Further reading
Cite this article as:
Ballesteros, M., Madrenas, E. & Pontes, M. (2025) "Cratena peregrina" in OPK-Opistobranquis. Published: 17/05/2012. Accessed: 03/09/2026. Available at (https://opistobranquis.info/en/?p=609)












