Favorinus tsuruganus
Baba & Abe, 1964

Order: NUDIBRANCHIA
Suborder: AEOLIDINA
Family: Glaucidae

DISTRIBUTION

Originally described from Japan and found uncommonly in eastern Australia down to about Sydney. I have also found it in New Caledonia so it probably a wide western Pacific distribution.

PHOTO

Angourie, North Coast, New South Wales, March 1982. Inset showing characteristic ornamentation on the rhinophores. PHOTO: Bill Rudman.

Body and oral tentacles opaque white. Ceratal wall translucent, but digestive gland duct is orange with a black tip, giving the species its characteristic colouration. The rhinophores are black and have three 'cup-shaped' or 'collar-like' swellings. When first described, the rhinophores were said to have 2 large swellings but in a subsequent description the authors described specimens with these cup-shaped swellings. To accomodate their earlier account they suggested the shape of the rhinophores was variable in this species, but I know of no subsequent reports of a similarly coloured animal with two swellings on the rhinophores. Species of Favorinus eat other opisthobranch eggs. In most species, the colour of the ceratal digestive gland is dependent on the colour of the eggs they are eating. In Favorinus tsuruganus however, the cerata are consistently yellow-orange with a black tip.

See Favorinus japonicus as an example of a species changing colour as the colour of its food changes.

References:
• Baba, K. & Abe, T. (1964) Record of Favorinus tsuruganus n. sp., from Tsuruga Bay, Japan (Nudibranchia - Eolidoidea). Publications of the Seto Marine Biological Laboratory, 12(2): 163-164.
• Baba, K. & Abe, T. (1975) Comments on further specimens of Favorinus tsuruganus Baba & Abe from Echizen-cho near Tsuruga Bay, Japan (Nudibranchia: Eolidoidea: Favorinidae). Publications of the Seto Marine Biological Laboratory, 22(1-4): 117-120.

Authorship details
Rudman, W.B., 1999 (March 19) Favorinus tsuruganus Baba & Abe, 1964. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/favotsur

Related messages

  1. Re: Colour forms of Favorinus tsuruganus
    From: Colin Ogden, June 27, 2007
  2. Colour forms of Favorinus tsuruganus ?
    From: Richard Swann, May 23, 2007
  3. Favorinus tsuruganus from Sydney Harbour
    From: Nicholas Missenden, May 27, 2005
  4. Favorinus tsuruganus in the Red Sea
    From: Jacob Dafni, April 25, 2005
  5. Favorinus tsuruganus from Reunion Island
    From: Philibert Bidgrain, February 22, 2005
  6. Favorinus tsuruganus on Goniodoris felis eggs
    From: Dong Bum Koh, February 7, 2005
  7. Favorinus tsuruganus from Sth Korea
    From: Dong Bum Koh, December 19, 2003
  8. Favorinus tsuruganus eating Hexabranchus eggs
    From: Yves Coze, December 1, 2003
  9. Favorinus tsuruganus from Korea
    From: Dong Bum Koh, November 15, 2003
  10. Favorinus tsuruganus - egg-laying observations
    From: Jim Black, August 20, 2003
  11. Nembrotha rutilans & Favorinus tsuruganus
    From: Mark Burnett, December 30, 2002
  12. Favorinus tsuruganus - feeding on eggs
    From: Dave Harasti, December 8, 2002
  13. Favorinus tsuruganus from Indonesia
    From: Ginette Allard, November 27, 2002
  14. Favorinus tsuruganus - new record from N.Z.
    From: Gareth Jones, February 14, 2002
  15. Re: Egg eater from Japan
    From: Nishina Masayoshi, August 5, 2001
  16. Egg eater from Japan
    From: Nishina Masayoshi, July 30, 2001
  17. Re: Colour of Favorinus tsuruganus
    From: Stuart Hutchison, June 4, 2001
  18. Favorinus tsuruganus from Indonesia
    From: Stuart Hutchison, June 3, 2001
  19. Photo of Favorinus tsuruganus
    From: Lindsay Warren, March 19, 1999

Show factsheet and all related messages