Caloria elegans

Caloria elegans (Alder & Hancock, 1845)

Caloria elegans by Enric Madrenas

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: Caloria  Trinchese, 1888 
Species: Caloria elegans (Alder & Hancock, 1845) [Eolis


  • Caloria maculata Trinchese, 1888
  • Eolis elegans Alder & Hancock, 1845 (original)

The animals of this species have a very stylized translucent whitish body. The propodial tentacles are thin, translucent and iridescent-white on the leading edge. Oral tentacles are relatively long and of the same color of the propodials. The rhinophores are smooth, finely spotted in cream color and also iridescent-white coloured on the leading edge. In certain cases there are small papillae in certain specimens’ rhinophores. The eyes are clearly visible at the base of the rhinophores. The cerata 7-8 groups are tightly layed on the dorsum almost without gaps, so the back seems to have an homogeneous cover. The digestive gland extends inside the cerata, coloring them usually in yellow or cream tones, but some specimens have colorless cerata. However, all cerata have a very dark brown or black spot near the tip. The apex of the cerata is semitransparent, so with the aid of a binocular microscope it is possible to observe the hepatic duct and the apical cnidosac. Longer cerata are the most internal of each group, are curved and intersect with the cerata from the opposite side. It is not uncommon to observe malformations in some animals, such as bifurcated or trifurcated propodials tentacles and forked cerata near the apex. The foot is semitransparent and the tail is narrow with a middle-dorsal whitish line.

The animals of this species are very active, and extend their cerata resembling to an anemone when disturbed. C.elegans is usually located in rocky walls with algae and hydrarians abundance (Eudendrium, Obelia, Aglaophenia, Tubularia, Campanularia, Halecium, Plumularia) than it can feed on. Schmekel cites this species feeding on Perigonimus (now the genus Bougainvillia, athecate hydrozoan). Very little is known of the biology of this species.


  • Caloria, in honor to the professor Luigi Calori (1807-1896), President of the Royal Academy of Sciences at Bologna (Italy).
  • Elegans = “elegant” in Latin.

It is a widespread species in both European Atlantic and Mediterranean waters. It has also been recorded in the Canary Islands, Madeira and the Açores. In the Iberian Peninsula it has been observed in the Portuguese coast and all the Mediterranean coasts, also in Balearic islands. In Catalonia it appears sporadically in many different localities of the Costa Brava.

Known georeferenced records of the species: Caloria elegans
: GROC 2010-2011
: Enric Madrenas
: João Pedro Silva
: Bernard Picton
: Manuel Ballesteros.
: M@re Nostrum
: Altres fonts
: Marine Regions

References for the species: Caloria elegans

    Portugal: Calado and Urgorri (1999), Calado et al. (1999, 2003). Gibraltar: García-Gómez (1983, 2002), García-Gómez et al. (1989). Andalucía (Med.): Sánchez Tocino, Ocaña and García (2000a), Ocaña et al. (2000). Levante: Fez (1974, as C. maculata), Templado (1982b, 1983, as C. maculata), Templado (1984), Ballesteros et al. (1986), Marín and Ros (1987), Templado et al. (2002). Catalunya: Ros (1975, 1978b), Ros & Altimira (1977), Ballesteros (1980, 1985), Altimira et al. (1981), Pereira & Ballesteros (1982), Huelin & Ros (1984), M@re Nostrum [Illa Mateua (L´Escala) 6/1999 y 4/2006, Aiguafreda 4/2000, Cala Llevadó 5/1997]. Todas las citas como C. maculata excepto Ballesteros (1985) y M@re Nostrum. Baleares: Ballesteros (1981a, as C. maculata), Ballesteros, Álvarez and Mateo (1986), Dekker (1986). Canarias: Moro et al. (1995, 2003), Ortea et al. (2001), Wirtz and Debelius (2003). Madeira: Moro et al. (1995), Wirtz (1998, 1999). Azores: Moro et al. (1995), Wirtz (1998), Ávila et al. (1998), Ávila (2000), Malaquias (2001), Wirtz and Debelius (2003).

    General: Ballesteros, 1985:33; Brown, 1981:335; Brown & Picton, 1979:21; Cattaneo-Vietti, Chemello, & Giannuzzi-Savelli, 1990:207[P]; Picton, 1979:125; Picton & Morrow, 1994:126[P]; Riedl, 1983:327; Schmekel & Portmann, 1982:214[P]; Thompson, 1988:322; Thompson & Brown, 1984:153[P]

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


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

More pictures


Further reading

Cite this article as:

Ballesteros, Manuel, Enric Madrenas, Miquel Pontes (2012-2018) "Caloria elegans" in OPK-Opistobranquis, Published: 17/05/2012, Accessed: 24/01/2018 at (

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