Trapania fusca

Trapania fusca (Lafont, 1874)

• Drepania fusca Lafont, 1874 (original)

Description
Body soft, smooth, convex at the back, coloured dark brown with minute, dense white spots. The head is rounded and the tail is tappered. The oral tentacles are cylindrical, yellow with a brown base. The rhinophores are greenish yellow, clavate, translucent at the base, with 7 lamellae in the middle part and a cylindrical apex, provided with a sickle-shaped lateral appendages at the base. The gills are pale yellow, with 3 branched leaves, and is also provided with sickle-shaped lateral appendages. The foot is narrow, expanded at the top and elongated. The genital orifice is located under the right sickle shaped tentacle on the side of the head.

Biology
Actually unknown. However other species from the genus feed on tiny organisms that grow on sea sponges called Entoprocta.

Etymology

• Trapania. The original generic name of this species was Drepania, proposed by Lafont in 1874. Pruvot-Fol in 1931 proposed changing the generic name to Trapania to disambiguate it from Drepania Hübner, 1816 (a group of lepidoptera). Madame Pruvot-Fol does not indicate the origin of the name, but there are two theories: the first would be dedicated to the city of Trapani, the province capital of western Sicily; the second would be inspired on the original generic name Drepania, derived from the Greek “Drepane” which means “sickle” and presumably refers to the shape of the appendages located on the sides of the rhinophores and gills in this genus. Pruvot Fol would have chosen the new name on the basis that it has the same meaning, but not the same sound and thus avoid confusion.
• Fusca. From Latin “fuscus”, brown, blackened.

Distribution
The specimens reported in the original description by Lafont were found in the Baie d’Arcachon (France) where he considered them as “common” and are the only ones corresponding to this species. Other reports from the Atlantic (Fischer, 1875, 1878; Locard, 1886a, 1886b, 1888; Vayssière, 1901; Cuénot, 1904, 1927; Pruvot-Fol, 1954; Bebbington & Thompson, 1968; Bouchet & Tardy, 1976; Montaudouin & Sauriau, 2000) merely cite Lafont’s findings. All reports of this species from the Mediterranean Sea correspond to a different species, Trapania graeffei, traditionally confused with T. fusca (see Doneddu et al., 2020). The fact that it has not been found again since its description would make this species creditor of the label “species inquirenda” but the confusion with the Mediterranean Trapania graeffei has saved it from this, so far.

Known georeferenced records of the species: Trapania fusca
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

Abundance

Western Mediterranean:
Eastern Mediterranean:
Atlantic Ocean: