Risbecia tryoni
(Garrett, 1873)

Order: NUDIBRANCHIA
Suborder: DORIDINA
Family: Chromodorididae

DISTRIBUTION

Tropical Western Pacific.

PHOTO

UPPER: Coffs Harbour region, northern New South Wales, Australia, December 1990. PHOTO: Bill Rudman.
MIDDLE: Gorgonia Hole, Heron Is., Qld. 15m, 20 Dec. 1980, 61mm long alive. PHOTO: G.Avern.
LOWER: juvenile, Solitary Is., northern New South Wales, October 1990. PHOTO: Bill Rudman.

This is one of a group of similarly coloured species which I have called the "Risbecia tryoni colour group". Other species include Chromodoris geminus, Chromodoris kuniei and Chromodoris leopardus. They all have large purple or purple-brown spots or marks, usually ringed with white, an often reticulate brownish background, and a purple border. Chromodoris geminus differs in having four colour bands around the mantle edge, an outermost white, then translucent greyish purple, then white, then yellow. The other three have a distinct purple line at the border, narrow in C. leopardus and R. tryoni, but broad in C. kuniei. The shape of the body of R. tryoni, high with a reduced mantle overlap, is typical of the genus Risbecia. The three species of Chromodoris have a wide mantle overlap. Of the three with the purple mantle edge, C. leopardus and C. kuniei can be distinguished from R. tryoni by the broad purple border, consisting of three slightly different coloured bands in C. kuniei, and by the leopard-like multiple spots, or marks, forming a hollow square, found in C. leopardus.

References:
• Rudman, W.B. (1984) The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: a review of the genera. Zoological Journal of the Linnean Society 81: 115-273.
• Rudman, W.B. (1987) The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: Chromodoris epicuria, C. aureopurpurea, C. annulata, C. coi and Risbecia tryoni colour groups. Zoological Journal of the Linnean Society 90: 305-407.

Authorship details
Rudman, W.B., 1999 (January 22) Risbecia tryoni (Garrett, 1873). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet.cfm?base=risbtryo

Related messages

  1. Risbecia tryoni from the Philippines
    From: Carrie Lo, June 30, 2008
  2. Risbecia tryoni trailing
    From: Mirjam Broos, December 11, 2007
  3. Risbecia tryoni - what's in its mouth?
    From: Elien Nijland, August 18, 2007
  4. Chromodoris leopardus - just a nice photo
    From: Ken Tucker, August 17, 2007
  5. Risbecia tryoni - Trailing behaviour
    From: Kerem Turker, July 26, 2007
  6. Injured Risbecia tryoni
    From: Clinton Bauder, July 23, 2007
  7. Feeding Risbecia tryoni from Borneo
    From: Richard Swann, May 16, 2007
  8. Risbecia tryoni from the Philippines
    From: Dr. Christine Meier, April 3, 2007
  9. Strange Risbecia tryoni from Indonesia
    From: Fred Vogt, March 8, 2007
  10. Re: Risbecia tryoni - trailing observations:
    From: Jack Connick, August 29, 2006
  11. Trailing Risbecia tryoni from Malaysia
    From: Sven-Urban Fjellner, August 26, 2006
  12. Re: Risbecia tryoni - trailing observations:
    From: Roberto Sozzani, August 26, 2006
  13. Risbecia tryoni - trailing observations:
    From: Hugues Flodrops, August 24, 2006
  14. Risbecia tryoni from Cook Island, Tweed Heads, NSW
    From: Ian Banks, June 12, 2006
  15. Re: More on spots in Risbecia tryoni
    From: Bruce Wilkie, May 11, 2006
  16. Re: More on spots in Risbecia tryoni
    From: Julie Marshall, May 8, 2006
  17. Re: More on spots in Risbecia tryoni
    From: Wayne Atkinson, May 5, 2006
  18. Risbecia tryoni feeding
    From: Bruce Wilkie, February 25, 2006
  19. Re: Another pair of Risbecia tryoni?
    From: Erwin Kodiat, February 8, 2006
  20. Risbecia tryoni found on Sunshine Coast
    From: Gary Cobb, November 13, 2003
  21. Another pair of Risbecia tryoni?
    From: Asther M. Lau, September 9, 2003
  22. More on spots in Risbecia tryoni
    From: Asther M. Lau, September 9, 2003
  23. Risbecia tryoni from East Malaysia
    From: Asther M. Lau, September 6, 2003
  24. Risbecia tryoni trailing
    From: Bruce Potter, July 7, 2003
  25. Juvenile Risbecia tryoni from Indonesia?
    From: Roberto Sozzani, May 26, 2003
  26. Juvenile Risbecia tryoni from Malaysia
    From: Asther M. Lau, May 9, 2003
  27. Juvenile Risbecia tryoni from Vanuatu
    From: Vinka Stenhouse, February 22, 2003
  28. Risbecia tryoni from Indonesia
    From: Kelvin Tan, February 12, 2003
  29. Juvenile Risbecia tryoni from Lembeh Strait
    From: Danny Van Belle, December 14, 2002
  30. Risbecia tryoni with copepod
    From: Marli Wakeling, October 4, 2002
  31. Risbecia tryoni from Sulawesi
    From: Helmut Schirmböck, July 12, 2002
  32. Risbecia tryoni from Julian Rocks, nthn NSW
    From: David Wachenfeld, July 1, 2002
  33. Risbecia tryoni and food
    From: Nishina Masayoshi, June 10, 2002
  34. Risbecia tryoni from Perhentian, Malaysia
    From: Alice Lee, May 26, 2002
  35. Risbecia tryoni from Malaysia
    From: Barbara Phua, May 9, 2002
  36. Risbecia tryoni mating
    From: Mary Jane Adams, May 9, 2002
  37. Risbecia tryoni from Christmas Island
    From: Bill Rudman, April 28, 2002
  38. Risbecia tryoni from Bali
    From: Stuart Hutchison, April 4, 2002
  39. Risbecia tryoni (2)
    From: Stuart Hutchison, April 4, 2002
  40. Juvenile Risbecia tryoni? from Japan
    From: Rie Nakano, January 11, 2002
  41. Risbecia tryoni from Papua New Guinea
    From: Marli Wakeling, October 30, 2001
  42. Risbecia tryoni from Exmouth, W.A.
    From: Kirk Gibson, April 8, 2001
  43. Risbecia tryoni 'tailgating'
    From: Drew Taylor , March 29, 2001
  44. Risbecia tryoni? from Byron Bay
    From: David Harasti, February 26, 2001
  45. Risbecia tryoni from Bora Bora
    From: Daniel L. Geiger, December 24, 2000
  46. A very small Risbecia tryoni
    From: Atsushi Ono, September 13, 2000
  47. Trailing Risbecia with commensal shrimp
    From: M. J. Adams, September 11, 2000
  48. Trailing in Risbecia tryoni
    From: Scott Johnson, August 16, 1999
  49. 'Trailing' behaviour in Risbecia tryoni
    From: Erwin Koehler, April 8, 1999
  50. Risbecia tryoni from the Philippines
    From: Erwin Koehler, January 22, 1999

Show factsheet and all related messages

Australian Museum Online sections

australian museum onlineabout the museumresearch and collectionsfeaturesexplore