Mystery slug from Malaysia

March 26, 2003
From: Michael Smith

In the past eight months, I have seen many large slugs (measured from 20 to 30 cm) in waters off the west coast of penisular Malaysia. The slug is only seen at night and often a half dozen can be found during a single dive. No experienced diver recalls seeing these locally more than a year ago. They all appear as a solid dark red color and have the two "knobs" above the head but no other apparent marking (to my novice eye). Sorry that I can't give any more information until my next night dive; I am new at trying to identify things I see in the sea. If no one knows what these may be, maybe you can tell me what to look for next time. Just keep in mind that I can't tell a gill from a gall bladder so please talk to me like you would to your 12 year old child!
Thanks,
Michael Smith

zippsy@yahoo.com

Dear Michael,
Firstly is there any chance of a photo? As you say you're a novice, the biggest hurdle when trying to describe something in words is knowing what is important. Making a slightly educated guess from what you've told me - large and common, dark red, 2 knobs above the head. There are a few possibilities.

One is Pleurobranchus forskalii. If you look at that page in the Forum and the attached messages below you will see it ranges in colour from a light mottled brown to a dark red. Prod one and see if it has a large gill on the right side of the body below the mantle skin flap. Another possibility is Pleurobranchus grandis which has a similar colour range. Pleurobranchs always have a large gill on the right side of the body

Failing that you might have a Sea Hare. There is a lot on the Forum about these animals - which can be large and numerous. Go to the sea hare page for links to lots of information. One clue is that most species squirt out a purple ink if they are disturbed or prodded.

Let me know if any of these guesses are winners - but best of all see if you can send a photo
Best wishes,
Bill

Rudman, W.B., 2003 (Mar 26). Comment on Mystery slug from Malaysia by Michael Smith. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/9456

Factsheet

Pleurobranchus forskalii

Related messages

  1. Pleurobranchus forskalii from Singapore
    From: Ron Yeo, March 28, 2008
  2. Pleurobranchus forskalii from Indonesia
    From: Mirjam Broos, February 15, 2007
  3. Swimming Pleurobranchus
    From: Mark Schaer, June 20, 2006
  4. A pleurobranch from Saipan
    From: Takao Urasawa, August 19, 2005
  5. Re: Mystery slug from Malaysia
    From: Jimmy Goh, May 10, 2005
  6. Large pleurobranch from Malaysia
    From: Alphonsus Jude Joseph, April 28, 2005
  7. Is this a sea slug?
    From: Dominic Rutherford, February 2, 2005
  8. Pleurobranchus forskalii from Lizard Is
    From: Nils Anthes, January 10, 2004
  9. Pleurobranchus forskalii from Sabah
    From: Asther M. Lau, July 23, 2003
  10. Pleurobranchus forskalii from South China Sea
    From: Audrey Koh, May 9, 2003
  11. Re: Mystery slug from Malaysia
    From: Michael Smith , March 27, 2003
  12. Pleurobranchus forskalii from Lord Howe Island
    From: W.B. Rudman, January 28, 2003
  13. Pleurobranchus forskalii from Solomons
    From: Bruce Potter, July 14, 2002
  14. Pleurobranchus forskalii from South Africa
    From: Valda Fraser, January 3, 2001
  15. Pleurobranchus synonyms in South Africa
    From: Ernest C.J. Seamark, June 17, 2000
  16. Spanish Dancer with white eggs?
    From: Jan Reyniers, April 6, 2000
  17. Re: Notaspidean defensive secretions
    From: Bill Rudman, May 14, 1999
  18. Pleurobranch acid secretions
    From: Rhanor Gillette, May 6, 1999
  19. Skin secretions in Pleurobranchus forskalii
    From: Clay Bryce, April 30, 1999
  20. Pleurobranchus forskalii, P. peroni
    From: K. Koyanagi, April 29, 1999
  21. Pleurobranchus forskalii in South Africa
    From: Ernest C.J. Seamark, April 17, 1999
  22. Opisthobranchs from Durban, South Africa
    From: Ernest Seamark, March 13, 1999

Show factsheet and all related messages