Sea Hare eggs

September 21, 2000
From: Nerissa Bontia

Dear Bill,

I am researching on the different web sites and I was so happy when I came across into the Sea Slug Forum. I have read the different messages about sea hares but i've got only a little information regarding the sea hare's egg mass. I am a State College Professor, interested to study on the egg mass of the sea hares specifically Dolabella auricularia which is very common in our country [The Philippines].

Many people are eating these eggs rather than the sea hares itself. What nutrients could we get from the egg? If sea hares are toxic what particular part of the body is affected? Is there a possibility that the egg mass will also contain toxin?

I would appreciate much if you could give me some information on this regard.

Very truly yours,
Nerissa Bontia

poner@irepublic.com.ph

Bontia, N., 2000 (Sep 21) Sea Hare eggs. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/3047

Dear Nerissa,
I am afraid all I know about Dolabella eggs and the possible toxicity of the whole animal is what you will find by reading the other messages on this page. You will find them if you look below your message. I am not sure how familiar you are with web pages but if you click on any underlined topic you will go to a relevant page with more information. In fact the most relevant research has been done in the Philippines.

I can add a little more general information on Sea Hare egg masses.

There are not many records of predators eating the eggs. As far as I can find, only some starfish and the nudibranch Favorinus japonicus. It has been suggested that the reason animals avoid the eggs as food is because they contain distasteful chemicals, in particular secondary metabolites that they obtain from their algal food. However there have been few staudies on the topic. Pennings (1994) offered pieces of egg mass of Aplysia juliana and Dolabella auricularia to crabs and fish but they were rejected. Organic extracts from the eggs of Stylocheilus striatus [as Stylocheilus longicauda] deterred feeding in reef fish at normal concentrations, but the eggs surprisingly did not contain the expected secondary metaobolites.

In another study, Pennings & Paul (1993) could find no secondary metabolites in the egg masses of Stylocheilus, Dolabella or Aplysia californica after adults were fed on either natural diets or diets containing secondary metabolites.

What then makes the eggs distasteful? It has been suggested that it is perhaps related to algal pigments. The egg colour of Sea Hares depends on the colour of the algae they are eating. For example when a Sea Hare changes from green to red algae its egg colour will chnage (Carefoot 1967). The seaweed pigment is transferrd to eggs within 48hrs (Chapman & Fox, 1969,) It is still not clear whether algal pigments are making the eggs distasteful or whether the Sea Hares are producing a new chemical.

Kirstern Benkendorff has just completed a Ph.D thesis [University of Wollongong, NSW, Australia] which included research into the egg masses of Sea Hares. Her findings, when published, will add an interesting new chapter to the story. The papers I have cited can be found on the Sea Hares - Chemical Defence Page.

Best wishes,
Bill Rudman.

Rudman, W.B., 2000 (Sep 21). Comment on Sea Hare eggs by Nerissa Bontia. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/3047

Factsheet

Dolabella auricularia

Related messages

  1. Re: Suitability of Dolabella auricularia in an aquarium
    From: Jorgen Svard, March 8, 2010
  2. Dolabella auricularia diet
    From: Keith Teller, November 16, 2009
  3. Re: Dolabella auricularia from Tonga
    From: Alastair Robertson, October 13, 2009
  4. Re: Marine Spaghetti from the Philippines
    From: Lorraine M. Cueva, September 25, 2009
  5. Unknown from Camden Haven, New South Wales
    From: Samson Kwok, January 9, 2009
  6. Dolabella auricularia from Mozambique
    From: Valda Fraser, April 14, 2008
  7. Sea hare from Port Hacking, Sydney
    From: David Robertson, April 7, 2008
  8. Dolabella from South Africa
    From: Waldo Nell, August 16, 2006
  9. Re: Lukot - Marine Spaghetti from the Philippines
    From: Richard Parker, August 3, 2006
  10. Lukot - Marine Spaghetti from the Philippines
    From: Richard Parker, August 1, 2006
  11. Is Dolabella auricularia hermaphrodite?
    From: Gary Majchrzak, July 10, 2006
  12. Dolabella auricularia from Forster, NSW.
    From: Colin Malakou, March 23, 2006
  13. Re: Is my sea hare sick?
    From: Brian Vastag, July 19, 2005
  14. Dolabella auricularia from Sth Korea
    From: Dong Bum Koh, July 18, 2005
  15. Is my sea hare sick?
    From: Brian Vastag, July 18, 2005
  16. Dolabella auricularia from Natal
    From: Gerda du Raan, June 6, 2005
  17. Dolabella auricularia in aquarium
    From: Tomoko Schum, February 8, 2005
  18. Sea Hare from Hawaii
    From: Lyudmila Zinkova , December 23, 2004
  19. Dolabella auricularia from Sydney Harbour
    From: Greg Braun, August 11, 2004
  20. Re: Sea Hares
    From: Tom and Jack Burrows, February 4, 2004
  21. Sea slugs?
    From: Tom and Jack Burrows, February 3, 2004
  22. Dolabella auricularia from Red Sea
    From: Isabelle Drouet, January 22, 2004
  23. Suitability of Dolabella auricularia in an aquarium
    From: Carolyn Bryce, December 6, 2003
  24. Inking behavior in Dolabella auricularia
    From: Jaron Brown, October 3, 2003
  25. Dolabella auricularia in the South China Sea
    From: Kheong San Chang, April 17, 2003
  26. Re: Dolabella - Captive breeding
    From: Cathryn Clarke, March 31, 2003
  27. Dolabella auricularia captive breeding
    From: Hervé, March 29, 2003
  28. Dolabella auricularia from the Philippines
    From: Anevi Gunday, February 6, 2003
  29. Dolabella auricularia from Lord Howe Island
    From: W.B. Rudman, January 30, 2003
  30. Dolabella auricularia and egg masses
    From: Rachel Przeslawski, January 14, 2003
  31. Re: Growth stages in Dolabella auricularia
    From: Alicia Hermosillo, January 4, 2003
  32. Re: Growth stages in Dolabella auricularia
    From: Alicia Hermosillo, January 2, 2003
  33. Re: Dolabella juveniles
    From: Mary Jane Adams, January 2, 2003
  34. Growth stages in Dolabella auricularia
    From: Mary Jane Adams , January 1, 2003
  35. Dolabella auricularia in the Philippines
    From: Jonathan P. Ubaldo, December 5, 2002
  36. EU survey of Dolabella
    From: Kim Friedman , September 23, 2002
  37. Aplysiid from Bahia de Banderas
    From: Alicia Hermosillo, September 13, 2002
  38. About dolastatines
    From: Denis Berlemont, July 6, 2002
  39. Dolabella auricularia from Sth Korea
    From: Dong Bum, Koh, June 28, 2002
  40. Natural history of Dolabella auricularia
    From: Sheena, March 5, 2002
  41. Dolabella auricularia from Japan
    From: Nishina Masayoshi , November 5, 2001
  42. Where can we find Dolabella
    From: T. Thiru, September 15, 2001
  43. Chemical defense in Dolabella
    From: Julia Brooke, April 8, 2001
  44. Diet of Dolabella auricularia
    From: Arnaud Parenty, March 28, 2001
  45. Re: Dolabella auricularia and burrowing
    From: Don Barclay, March 19, 2001
  46. Dolabella auricularia and burrowing
    From: Don Barclay, March 17, 2001
  47. Dolabella auricularia - source of new drug
    From: Arnaud Parenty, February 24, 2001
  48. Re: Sea Hare eggs
    From: Nerissa Bontia, October 14, 2000
  49. Dolabella auricularia from Solomon Ids
    From: Bruce Potter, October 13, 2000
  50. Aplysiid egg compounds
    From: Kirsten Benkendorff, September 22, 2000
  51. Re: Dolabella as food
    From: Claudia Armann, July 23, 1999
  52. Dolabella auricularia research
    From: Sandeep K. Singh, June 22, 1999
  53. Dolabella egg masses
    From: Erwin Koehler, April 1, 1999
  54. Re:Dolabella in Fiji - as food etc
    From: Veikila Vuki, March 17, 1999
  55. Re:Dolabella research in Fiji
    From: Sandeep K. Singh, March 16, 1999
  56. Re: Dolabella in Fiji
    From: Sandeep K. Singh, March 16, 1999
  57. Dolabella research in Fiji
    From: Dr. Veikila Vuki, March 10, 1999

Show factsheet and all related messages