Favorinus cf. mirabilis
NE Sulawesi, Indonesia, 13 July 2002. approx 15mm long. Photo: Jim Anderson.
Superficially this animal looks very like Favorinus tsuruganus, which is reported to feed on Hexabranchus eggs. However it differs in a number of features. Although they both have yellow digestive gland ducts in the cerata, in F. tsuruganus the body and the oral tentacles are opaque white and there is a black tip to the cerata, which is unlikely to be food related. Also the rhinophores seem to have four or more leaflets, rather than the three 'cup-shaped swellings' found in F. tsuruganus. In your animal the oral tentacles and the body are translucent orange and the tips of the cerata are white, not black. I suspect that this is a colour form of F. mirabilis. [See my comments in Jim Anderson's message. I have moved messages concerning Favorinus sp. 2 and Favorinus sp. 6 to this page as Favorinus cf. mirabilis.
• Baba, K. (1955) Opisthobranchia of Sagami Bay. Supplement. Iwanami Shoten, Tokyo.
Rudman, W.B., 2002 (July 25) Favorinus cf. mirabilis Baba, 1955. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/favocfmira
Favorinus cf. mirabilis from Reunion Is.
From: Sully Bachel, February 3, 2009
Favorinus cf. mirabilis eating Hexabranchus eggs
From: Ugo Gaggeri, December 6, 2006
Favorinus cf. mirabilis from Mayotte
From: Marina Poddubetskaia, December 15, 2003
Favorinus cf. mirabilis from Mauritius
From: Marina Poddubetskaia, November 13, 2002
Re: Favorinus cf. mirabilis
From: Jim Anderson, July 31, 2002
Favorinus eating Hexabranchus eggs
From: Jim Anderson, July 28, 2002
Favorinus sp. 2? from Madagascar
From: Lindsay Warren, April 8, 2002
Favorinus from Okinawa
From: Bob Bolland, September 4, 1998