Calmella cavolini

Calmella cavolini (Verany, 1846)

Calmella cavolini by Enric Madrenas

Taxonomy
 

Superdomain

Biota  

 

Kingdom

Animalia  

 

Phylum

Mollusca  

 

Class

Gastropoda  

 

Subclass

Heterobranchia  

 

Infraclass

Euthyneura  

 

Subterclass

Ringipleura  

 

Superorder

Nudipleura  

 

Order

Nudibranchia  

 

Suborder

Cladobranchia  

 

Superfamily

Flabellinoidea  

 

Family

Flabellinidae  

 

Genus

Calmella  

 

Species

Calmella cavolini  (Vérany, 1846)

 
 Classification according to Bouchet et al. (2017)
Taxonomic source: World Register of Marine Species (AphiaID: 139978).

Taxonomic note: The classification of the Flabellinidae had remained fairly stable until in 2017 a series of works appeared (Furfaro et al., 2017; Korshunova et al., 2017) that intended to clarify the status of the Flabellinidae family. The main objective of the paper by Furfaro et al. was to molecularly characterize the Mediterranean species while the paper by Korshunova et al. wanted to delve into the phylogenetic relationships between various members of the Flabellinidae family and the other families of aeolidaceans.
Both works were based on the combination of molecular and morphological techniques and, in fact, do not offer very different results, but differ on the size and origin of the studied samples and, mainly, on the interpretation of the results. After the appearance of the paper by Furfaro et al., many Mediterranean species of the genera Calmella, Flabellina and Piseinotecus were grouped under the common genusFlabellina, but had certain problems with some species that did not fit well with the proposed classification (e.g,Flabellina babai) , discovered that the Mediterranean and Atlantic populations ofFlabellina ischitana correspond to two different cryptic species, and noted the problems of the cryptic group formed by Calmella cavolini / Flabellina confusa / Piseinotecus gaditanus, indicating the need for further studies to clarify their status.
Curiously, these studies were being carried out practically in parallel by the group of Korshunova et al. but on a much wider sample of species that included specimens from the Arctic, North Atlantic, Pacific and Indian Oceans. This second paper confirms the polyphily of the family Flabellinidae, but the interpretation of these results becomes a real revolution for the taxonomy of the aeolidaceans, especially for the family Flabellinidae.
Both papers show that there are two well differentiated clades (groups) in the Flabellinidae: species like Coryphella pedata and similars, with cerata that come directly from the back, and species like Flabellina affinis and similars, with cerata of each group coming from a stalk or pod. Although Furfaro et al. consider the species of both clades belonging to the genusFlabellina within the family Flabellinidae, Korshunova et al. distinguishes two families: Coryphellidae and Flabellinidae sensu stricto, also creating many different genera in these families to include the species they study. Its taxonomic proposal, curiously, solves the problems found by Furfaro et al.
In a way, both papers complement to each other, although in the paper by Korshunova et al. it is evident the lack of studies on tropical flabellinid species and those from southern America and Africa, so the subject has not been settled. The proposal to create new genera to collect small groups of species, instead of multispecific genera, seems to be the trend in some of the phylogenetic works of recent years. We hope to see new papers expanding the knowledge on the aeolidaceans soon. A detailed discussion of this exciting controversy can be found at (https://opistobranquis.info/en/flabellinidae/).

Synonyms

  • Aeolis digitata Costa A., 1866
  • Eolidia cavolini Vérany, 1846 (original)
  • Jojenia rubrobranchiata Aradas, 1847
  • Flabellina cavolini (Vérany, 1846)

Description
This is a small aeolidacean species that rarely exceeds 10 mm in length. Its small size, the coloration of its cerata and its morphology make it distinctive in the environment. The body is narrow, elongated and colored opaque white, sometimes with a slightly iridescent blue shade. The white oral tentacles and rhinophores are long and slender, of almost the same length; some specimens may have orange pigmented tips. The rhinophores are smooth throughout its length. On the back of the head and front of the rhinophores there can be seen two purplish spots, corresponding to the animal jaws, seen by transparency. There can be up to 7 groups of cerata on each side of the body. The cerata of each group come from the same dorsal stalk, that can be bifurcated or trifurcated, something characteristic of several species in the Flabellinidae family. The cerata are semitransparent and the orange or red colored digestive gland can be observed through the skin, the top being more pigmented than the rest. The apex of the cerata is white, and the cnidosac could be observed inside. The foot is semitransparent and has a pair of short propodial palps in its anterior zone. The tail is long and very narrow.

Biology
This species is fairly common all year long in shallow rocky walls with abundance of sciaphilic algae, sponges and hydroids. It is usually found associated to hydrarians as Halecium pusillum and Eudendrium racemosum, from which it may feed upon. Is also located on the gorgonian Paramuricea clavata. The spawn has the form of a narrow spiral ribbon of pinkish eggs about 100 microns in diameter.

Etymology

  • Calmella. In 1910 Eliot creates the genus Calmella from the genus name Calma, of which this word is diminutive. According to the Celtic historian Peter Berresford Ellis, Calma is one of the sons of Carmán, a Greek warrior goddess who devastated Ireland with her three ferocious sons: Calma (Brave), Dubh (Black) and Olc (Evil). Eventually they were defeated by the Tuatha Dé Danaan, after which Carmán died in an unpleasant way.
  • Cavolini. In honor of Filippo Cavolini (1756-1810), who was a rich merchant and one of the earliest marine zoologists. In 1785 and 1792 he published a few articles about polyps, fishes and crustaceans. He had built a special laboratory in his villa in Posillipo. In 1813 it was posthumously published “Abhandlungen über die Pflanzenthiere des Mittelmeeres”.

Distribution
So far this is a strictly Mediterranean species, found mainly in the western basin. Recent observations have cited it in Turkish waters. In the Iberian Peninsula has been observed in the Mediterranean coast of Andalusia, in the southeastern coast, in Catalonia and the Balearic Islands. The Catalan locations where it has been cited are: the Cap de Creus and Es Caials (Cadaqués), L’Escala, Illes Medes (L’Estartit), Cala Aiguafreda (Begur), Palamos, Tossa de Mar, Cala Canyelles and Cala Santa Cristina (Lloret de Mar), Blanes, Badalona, the Barcelona harbor, Cubelles and in the beach of La Pineda (Salou).

Known georeferenced records of the species: Calmella cavolini
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: Calmella cavolini

    Andalucía (Med.): Ballesteros et al. (1986), Sánchez Tocino, Ocaña and García (2000a), Ocaña et al. (2000), Wirtz and Debelius (2003). Levante: De Fez (1974), Templado (1982b, 1983, 1984), Ballesteros et al. (1986), Marín and Ros (1987). Catalunya: Ros (1975,1978b), Ballesteros (1978, 1980, 1985, 1985), Altimira et al. (1981), Pereira & Ballesteros (1982), Huelin & Ros (1984), M@re Nostrum [Punta del Ferro (L'Escala) 4/2000, Illa Rodona (Llançà) 11/1998]. Baleares: Ballesteros (1981a, 1985), Ballesteros, Álvarez and Mateo (1986), Dekker (1986).

    General: Cattaneo-Vietti, Chemello, & Giannuzzi-Savelli, 1990:165[P]; Fez Sanchez, 1974:105; Nordsieck, 1972:74; Perrone, 1986a:33; Pruvot-Fol, 1948b:273; 1951:62; 1953b:51[P]; 1954b:415; Riedl, 1970:431; 1983:326; Schmekel, 1970:1434; Schmekel & Portmann, 1982:193[P]; Thompson, 1976a:[P]; Vayssiere, 1913a:295; Vicente, 1967:160

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

Abundance

    Western Mediterranean:
    Eastern Mediterranean:
    Atlantic Ocean:

More pictures

Bibliography

Further reading

Cite this article as:

Ballesteros, Manuel, Enric Madrenas, Miquel Pontes (2012-2018) "Calmella cavolini" in OPK-Opistobranquis, Published: 17/05/2012, Accessed: 18/11/2018 at (https://opistobranquis.info/en/cF2bU)

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