Re: Are these all Ceratosoma amoena?

August 12, 2000
From: Des Paroz

Hi Bill

Concerning my recent photos. All 3 were taken in New South Wales, Australia.

The top-most photo (long pink bodied nudi) was taken at Nelson Bay, Port Stephens, New South Wales in January.

The bottom-left shot (rounder pinkish body) was taken at Bare Island, Sydney, New South Wales.

The bottom-right picture (shorter, whiter body) was taken on one of the Islands off Wollongong, New South Wales.

The body colour variations I kind of expect, but 2 things picqued my interest
- The shape of the bottom left nudi being quite different to the other two (even though its colourations were closer to the top one).
- The colour of the rhinopores on the top-most photo not having that white streak.

So, that's why my first instinct was that they were all examples of C. amoena, but I am intrigued about the variations if they are.

Best regards


Paroz, D., 2000 (Aug 12) Re: Are these all Ceratosoma amoena?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear des,
Thanks for the information about the slides, and I am glad you are looking for variations and differences.

The shape is the easiest to answer. All nudibranchs can change shape, within limits. C. amoena when crawling, usually stands quite tall, with a lot of the foot visible. However, when at rest on a sponge or softer substrate, its 'posture' often collapses and it becomes a jelly-like shape, fitting in to the substrate. When it nestles into a crevice or hole its shape becomes even more irregular.

The range of colour variation within a species differs from species to species. While many species have very consistent parts to their colour pattern, such as thinophore and gill colouration, others such as C amoena show some variation. There is no easy rule of thumb. We can only be sure how variable a colour pattern can be when we study the anatomy of many animals. C. amoena shows quite a bit of colour variation but I can find no anatomical variation from New Zealand to Western Australia.

Rudman, W.B., 2000 (Aug 12). Comment on Re: Are these all Ceratosoma amoena? by Des Paroz. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from


Ceratosoma amoenum

Related messages

  1. Ceratosoma amoenum from South Australia
    From: Agnieszka Malkowska, April 12, 2010
  2. Ceratosoma amoena 'doing things'
    From: Samuel Kemp, April 27, 2007
  3. Ceratosoma amoena - more photos
    From: Floor Anthoni, April 27, 2007
  4. Ceratosoma amoena - mating aggregation
    From: Floor Anthoni, April 26, 2007
  5. Ceratosoma amoena - feeding aggregation
    From: Dr J Floor Anthoni, April 26, 2007
  6. Ceratosoma amoena - feeding aggregation?
    From: Ross Armstrong, April 25, 2007
  7. Re: Hypselodoris bennetti & Ceratosoma amoena
    From: Lynda Clarke, April 11, 2007
  8. Re: Ceratosoma amoena from sthn Queensland
    From: Rachel Murphy, March 6, 2007
  9. Ceratosoma amoena from Bateman's Bay, New South Wales
    From: Eileen Baker, January 9, 2007
  10. Ceratosoma amoena from sthn Queensland
    From: Bruce Wilkie, July 15, 2006
  11. Ceratosoma amoena from Tasmania
    From: John Silberberg, July 6, 2005
  12. Ceratosoma amoena (?) laying eggs
    From: Martina Fuchsberger, April 11, 2005
  13. Ceratosoma amoena from South Australia
    From: Carl Mooney, January 26, 2005
  14. Ceratosoma amoena from New Zealand
    From: Pam McAssey, February 6, 2004
  15. Ceratosoma amoena
    From: Mathew McGuire, February 1, 2004
  16. Colour variation in Ceratosoma amoena
    From: Sean McMahon, January 21, 2004
  17. Ceratosoma amoena feeding
    From: David & Leanne Atkinson, December 24, 2003
  18. Ceratosoma amoena - feeding
    From: Sue Newson, July 12, 2003
  19. Ceratosoma amoena laying eggs
    From: Leanne & David Atkinson, June 13, 2003
  20. Ceratosoma amoena laying eggs
    From: Leanne & David Atkinson, March 11, 2003
  21. Ceratosoma amoena on food sponge
    From: Mark Burnett, February 23, 2003
  22. Ceratosoma amoena from New Zealand
    From: Mark Burnett, February 21, 2003
  23. Ceratosoma amoena from Lord Howe Island
    From: W.B. Rudman, January 8, 2003
  24. Ceratosoma amoena from Maroubra, Sydney
    From: Chris Partridge, December 8, 2002
  25. Ceratosoma amoena from Sydney, NSW
    From: Allan Saben , November 18, 2002
  26. Ceratosoma amoena from sthn New South Wales
    From: Tim McKenzie, July 10, 2002
  27. The food of Ceratosoma amoena
    From: Craig Worthington, January 3, 2002
  28. Ceratosoma amoena from NSW, Australia
    From: Stuart Hutchison, November 22, 2001
  29. Chromodoris splendida? from New Zealand
    From: Colin Gans, October 5, 2001
  30. Ceratosoma amoena - information needed
    From: Edward Terry, September 27, 2001
  31. Ceratosoma amoena - unusual shape & behaviour
    From: Des Paroz, January 10, 2001
  32. Are these all Ceratosoma amoena?
    From: Des Paroz, August 10, 2000
  33. Ceratosoma amoena mating
    From: Grey McNeil, July 12, 1999
  34. Ceratosoma amoena from New Zealand
    From: Ross Armstrong, December 14, 1998

Show factsheet and all related messages