Trapania graeffei

Trapania graeffei  (Bergh, 1881)

• Drepania graeffei Bergh, 1881

Description
The body is elongated, with a maximum reported size of 15mm, generally half this size. It is coloured transparent white with pinkish hue on the tail and appendages, with more or less dense brown spots, sometimes confluent forming big patches both on top and sides of the body. Rhinophores are transparent pinkish-white with yellow tips, with about 7 lamellae on the middle part and with a cylindrical apex. Eyes are located on the rear side of the rhinophores’ base. Oral tentacles have the tips coloured yellow. Gills are also transparent pinkish-white, sometimes with yellow tips. Foot is narrow and the tail is tappered with a yellow coloured tip.

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.
• Graeffei. In honor to Austrian naturalist Eduard Heinrich Graeffe, (1833-1916), educated at the University of Zürich, who wrote about the marine fauna of the Trieste area.

Distribution
Traditionally confused with the Atlantic species Trapania fusca, a recent paper by Doneddu et al. (2020) has revealed they are indeed different species. All reports in literature of Trapania fusca from the Mediterranean Sea correspond to Trapania graeffei. It has been reported so far in Italy (Trieste, Naples, Livorno), Malta and France (Villefranche-sur-Mer and Banyuls-sur-mer).

Known georeferenced records of the species: Trapania graeffei

Sources:
OBIS GROC 2010-2011 Enric Madrenas João Pedro Silva Bernard Picton GBIF	OPK VIMAR Manuel Ballesteros M@re Nostrum Altres fonts Marine Regions

More pictures

Trapania graeffei 5mm @ Delimara, Malta 5-10m depth 15-09-1996 by Carmel Sammut

Trapania graeffei 5mm lateral @ Delimara, Malta 5-10m depth 15-09-1996 by Carmel Sammut

Trapania graeffei 5mm @ Delimara, Malta 5-10m depth 15-09-1996 by Carmel Sammut

Bibliography

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Bibliography based on the works by Steve Long, 2006. Bibliography of Opisthobranchia 1554-2000 and Gary McDonald, 2009. Bibliographia Nudibranchia, with later updates from other resources.

Further reading

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