Where do nudibranchs sleep?

January 25, 2002
From: Jeanette McInnes

Dear Dr Rudman,
On a recent trip to Osprey Reef, Coral Sea, it occurred to me that I've only seen nudibranchs out after dark approx. 3 times (Ardeadoris egretta, Glossodoris electra) and asked myself, "Where do 'branchs go to sleep?"

In a bid to save you the pain of answering the same question dozens of times, I searched the sea slug forum for this info... in vain. If I missed it somewhere, then I apologise! Is it possible that some nudibranchs are noctural? Do they keep to a strict timetable like many tropical marine animals? Is it just a coincidence that 2 insomniacs that I've seen are both white? Since they're smelly & poisonous, why don't they camp out in the open like the inedible pufferfish? I'd be interested in any other sleep-related info on our friends.
Love the Slug Forum!
Regards,
Jeanette.

jlmc01@ozemail.com.au

McInnes, J., 2002 (Jan 25) Where do nudibranchs sleep?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/6054

Dear Jeanette,
We still have a lot to learn about activity cycles in sea slugs. There is some information scattered throughout the Forum but I haven't as yet prepared a specific page on the topic. The general feeling about tropical nudibranchs is the reverse of your suggestion. During the day it is thought that only phyllidiids are distasteful enough to blatantly expose themselves while other nudibranchs are hiding under rocks, in crevices, or asleep. The very nasty chemicals that phyllidiids have in their skin are considered so distasteful to fish that they are avoided.

Another group of colourful nudibranchs, the chromodorids, also have nasty chemicals in their skin to deter predators. In both tropical and temperate waters, some species of this family are often out during the day, often in groups. These species usually have a colour pattern which is very similar to that of a group of other species. Have a look at the page on Red Spotted species to see why we think groups of species share similar colour patterns.

Many other nudibranchs are so well camouflaged, or so small, that they are usually overlooked by all but the most fanatical or experienced nudibranch hunter. Also many sponge-feeding dorids eat species of sponges which prefer shaded places and crevices so the nudibranch, even if active during the day, is not very visible. In general we can say that some species have developed protective strategies to allow them to out and about during the day, others have not. There doesn't seem to be any simple rule. Have a look at the page on Defence for some more information.
Best wishes,
Bill Rudman

Rudman, W.B., 2002 (Jan 25). Comment on Where do nudibranchs sleep? by Jeanette McInnes. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/6054

Factsheet

Sea slug questions

Related messages

  1. Sea slug eats own brain??
    From: Charles Stenholm, March 18, 2010
  2. Sea slug eyes
    From: Erwin Kodiat, January 18, 2007
  3. How many noses does a slug have?
    From: Emma, October 3, 2003
  4. The fastest Sea slug?
    From: J.Van Doorslaer, February 24, 2003
  5. Sea Slugs in general
    From: Rachel Wierenga, September 11, 2002
  6. Need some information
    From: Maria Bernamudez, May 14, 2002
  7. Do nudibranchs taste?
    From: Jeanette McInnes, February 12, 2002
  8. Re: Where do nudibranchs sleep?
    From: Brian Penney, January 31, 2002
  9. What does cf mean?
    From: Elianny Dominguez, September 21, 2001
  10. Where do sea slugs live?
    From: Patty, July 17, 2001
  11. What is the family name for the sea slug?
    From: Patrick O'Connor, June 11, 2001
  12. RE: What do var, cf. etc mean?
    From: Nishina Chikako, June 8, 2001
  13. What do var, cf. etc mean?
    From: Nishina Chikako, May 21, 2001
  14. What does 'nudibranch' mean?
    From: David James, April 25, 2001
  15. URGENT QUESTION?
    From: Maggie, April 22, 2001
  16. Are sea slugs harmful to people
    From: Heidi Colonnese, March 10, 2001
  17. What are sea slugs importance to man?
    From: Sarah, January 8, 2001
  18. General information on sea slugs
    From: Nick, December 30, 2000
  19. Nudibranch that eats algae?
    From: Eric Sterns, October 23, 2000
  20. Bubble shell
    From: Jennifer, October 19, 2000
  21. Information about slugs
    From: Kathleen, October 2, 2000
  22. More information on sea slugs
    From: Jennifer & Kate, October 2, 2000
  23. Protection from Dryness
    From: Jacob Benveniste, September 30, 2000
  24. Do nudibranchs have eyes?
    From: Anonymous, May 10, 2000
  25. Re: Nudibranch Information
    From: Anne Dupont, March 15, 2000
  26. Information on adaptations
    From: Ross Sinclair, March 13, 2000
  27. Information on Sea Slugs
    From: M.C.M, March 13, 2000
  28. Information for a School Project
    From: Emilee Bucholz, March 5, 2000
  29. Information for Sigrid, Caroline & Ashlee
    From: Bill Rudman, February 19, 2000
  30. What do they eat?
    From: Samantha , February 16, 2000
  31. How do nudibranchs breathe?
    From: Lillie Hetze, January 21, 2000
  32. How are species recognised?
    From: Nishina Masayoshi, July 4, 1999
  33. Interesting facts about Sea slugs
    From: Hartzell, June 9, 1999
  34. General Habitat
    From: K. Rabinoiwtz, May 24, 1999
  35. Re: Nudibranch questions
    From: Christian Desprez, May 19, 1999
  36. Nudibranch questions
    From: Christian Desprez, May 3, 1999
  37. on rhinophores, cerata, and how many species?
    From: Carlo Magenta, March 15, 1999
  38. Nudibranch info needed
    From: Steve, February 20, 1999
  39. Re: Nudibranch Questions
    From: Beth Kyd, February 16, 1999
  40. Sea Slug questions
    From: Dale Kyd, February 12, 1999
  41. Information on nudibranchs
    From: Ross Tetreault, February 11, 1999
  42. Why study nudibranchs?
    From: Brehan Miller, February 9, 1999
  43. Sea Slug metabolism
    From: Sean Wise, February 5, 1999
  44. Information on Nudibranch biology
    From: Christian Desprez, January 28, 1999
  45. Thanks
    From: Kathie Bryant, December 4, 1998

Show factsheet and all related messages