Known only from the Mediterranean.
Platja de Sant Antoni, Badia de Portlligat, Cadaqués, Girona, 4 metres, Spain, Mediterranean Sea, 31 May 2008, Posidonia oceanica meadows. Length: 15 mm. Photographer: Miquel Pontes.
This species has a slender body with spindle shaped cerata arranged in 5 clusters on each side. The first cluster consists of 3 transverse rows, the 2nd an arch, and the rest are single rows. The oral tentacles are longer than the rhinophores which have scattered rounded tubercles. The anterior foot corners are tentacular.
It is greyish black in colour, the cerata being dark brown going to black near the tip. The rhinophores, oral tentacles, and tips of cerata have scattered whitish spots. There is a median reddish line, outlined in white, running from the head to the tail. It is sometimes broken. A similar line runs along each side of body below the cerata. The spiral egg coil orange.
It grows to at least 16mm and is known from the intertidal to 25 m depth. It feeds on the hydroid Eudendrium sp.
Schmekel, L (1966) Zwei neue Facelinidae aus dem Golf von Neapel: Facelina (A.) fusca n. sp. und Antonietta luteorufa n. sp., n. gen. (Gastr. Opisthobranchia). Pubblicazioni Stazione Zoologisches Napoli, 35, 29-46.
Schmekel, L. & Portmann, A (1982) Opisthobranchia des Mittelmeeres, Nudibranchia und Saccoglossa. Fauna e Flora del Golfo Napoli, 40: 1-410. Springer-Verlag: Berlin
Rudman, W.B., 2005 (April 21) Facelina fusca Schmekel 1966. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/facefusc