Ceratosoma sinuata - how long-lived?

October 19, 2000
From: Donata P. & Akos L.

Note added 30 April 2007: Until now on the Forum C. flavicostata has been considered a form of C. sinuata [see message #19854]. It is now recognised as distinct.

Hi Bill,

We saw quite a few large, one about 10-12cm long,Ceratosoma sinuata (magnificent colour form), on a rock at Kurnell last summer/ autumn. Just yesterday, 15 October, 2000, two of our friends have seen a C. sinuata (sinuata form) on the very same rock. We have personally observed the two colour forms previously at Shark Point, Clovelly on the very same two rocks, which are about 50m apart over the last two summers.

Could it be possible that since the adults have obviously found a great feed, they've laid their eggs and these hatched some time later? I mean, we have not seen the adults at either of the two dives for around six months. I think it would be too much of a coincidence that the new specimens pop up in the very same location.

Only on one of the Shark Point rocks did we find eggs, not on the other rock, nor at Kurnell. Well, if there were more eggs, they must have been pretty inconspicous.

Wouldn't the larvae from the hatched eggs still "enjoy" the planktonic stage? If somehow they do, then it may just be a total fluke that they landed on the same rocks two years in a row.

Any comments?
Donata & Akos


Piotrowska, D. & Lumnitzer, A. , 2000 (Oct 19) Ceratosoma sinuata - how long-lived?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/3185

Dear Donata & Akos,
I suspect this animal is an annual, lasting only about a year, but we do not know much about the lifecycles of most nudibranchs.

In species with no free-swimming larval stage, such as Chromodoris tasmaniensis, then the young are often found clustered together on the food sponge of their parent. Similarly there are species with a very abbreviated larval life which also can mean that a species can stay in one locality for a number of generations. But I don't think C. miamira falls into either of those categories. Its eggs are numerous and small, so I suspect it has relatively long-lived veliger larvae. To find adults regularly at one spot means that either they live longer than one year (and hide for part of it) or there is something that attracts the larvae each year to settle at that spot. The possibility is that it is a good place for their food sponge, which may live for many years.

The other possibility is that it is a coincidence. By bet would be that the food sponge likes the spot and has survived there for a number of years.
Best wishes,
Bill Rudman.

Rudman, W.B., 2000 (Oct 19). Comment on Ceratosoma sinuata - how long-lived? by Donata P. & Akos L.. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/3185

Related messages

  1. Re: Ceratosoma flavicostatum feeding
    From: Teresa Zuberbühler, June 10, 2008
  2. Coincidental occurrence of Ceratosoma flavicostatum & S. ornatum
    From: David Mullins, September 6, 2007
  3. Re: Ceratosoma flavicostatum feeding
    From: Leanne & David Atkinson, July 5, 2007
  4. Ceratosoma flavicostata feeding
    From: Danny Van Belle, April 30, 2007
  5. Ceratosoma sinuata from Queensland
    From: Gary Cobb, July 14, 2003
  6. Sprinting Ceratosoma sinuata
    From: Sabine Noack, October 22, 2002
  7. Ceratosoma magnifica trailing
    From: Ákos Lumnitzer, January 10, 2002
  8. Ceratosoma sinuata from Indonesia
    From: Ken Knezick , January 16, 2001
  9. Re: Left-handed Ceratosoma sinuata
    From: Donata P. & Akos L., October 27, 2000
  10. Ceratosoma sinuata - magnifica form
    From: Akos L. & Donata P, October 25, 2000
  11. Miamira from New South Wales
    From: Scott Jamieson, April 13, 1999
  12. Photo of Miamira at Point Cartwright
    From: Wayne Ellis, May 26, 1998

Show factsheet and all related messages