Luisella babai (Schmekel, 1972)
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: Flabellinoidea Bergh, 1889
Family: Samlidae Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, Saito, Lundin, Schrödl & Picton, 2017
Genus: Luisella Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, Saito, Lundin, Schrödl & Picton, 2017
Species: Luisella babai (Schmekel, 1972)
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/).
- Flabellina babai Schmekel, 1972
Specimens of this conspicuous species can reach 40 mm in length. The body color is translucent white, with some blue iridescence on the back, in the cerata and oral palps. In some animals a longitudinal opaque white line can be seen on both sides of the dorsum, just below the base of cerata, that continues forward to the cephalic region and the outer side of oral palps. These oral palps are long and colored white, while the propodial palps are short and are ridged ventrally. Both rhinophores start close together at the base, are colored white and have numerous tightly packed orange lamellae on the tip. The eyes are located at the base of each rhinophore. The cerata are grouped in 7-10 groups on both sides or the back. As with F. affinis, the cerata grow from a common basal pod, in groups of 4-5 cerata, being the outermost the smaller, and the innermost the biggest. The cerata are also colored white, and the digestive gland inside can be seen by transparency as a very soft fine orange cord; subapical area of the cerata is bright orange color that fades towards the base. The tips of cerata are sharp and a white cnidosac can be easily observed inside. The foot is translucent white with an opaque white margin .
This is a very active species that it is often observed wandering on the rocks and that despite its relatively big size and conspicuous colors it was not described to science until 1972 in the Gulf of Naples, one of the most studied areas in the opisthobranchs field. It has been associated with different species of hydroids (Campanularia, Eudendrium, Perigonimus = bougainvilla), but it is unclear whether it feeds on them. The spawn is a string of about 0.7 mm wide with white eggs.
- Luisella, in honor to the nudibranch expert Luise Schmekel, who described this species, and author of the famous monography “Opisthobranchia des Mittelmeeres”.
- babai in honor to the eminent Japanese investigator Kikutaro Baba, deceased in 2001 at the age of 94.
Despite its recent description, it has been cited throughout the Mediterranean, from the Turkish coast to Croatia, the Italian Peninsula, the Portuguese coast, the Andalusian coast and Strait of Gibraltar. Also on the coast of Dakar (Senegal). In Catalonia has been cited in Llançà, Cadaqués, L’Escala and Roses, among other locations.
| : OBIS|
: GROC 2010-2011
: Enric Madrenas
: João Pedro Silva
: Bernard Picton
| : OPK|
: Manuel Ballesteros.
: M@re Nostrum
: Altres fonts
: Marine Regions
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