Large pleurobranch from Malaysia

April 28, 2005
From: Alphonsus Jude Joseph

Found this big slug moving rather fast over a sandy bottom and it started climbing a jetty pillar. Any idea what slug this is? Around 25cm long.

Locality:  Salang Jetty, Tioman, Malaysia. South China Sea. Depth: 18 metres. Length: 25 cm. 09 September 2004. Under Jetty. Photographer: Alphonsus Jude Joseph.

Alphonsus Jude Joseph

Joseph, A.J., 2005 (Apr 28) Large pleurobranch from Malaysia. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Alphonsus,
I am pretty sure this is Pleurobranchus forskalii which can grow to about 30 cm in length. It ranges in colour from this dark brown form to a very light brown with dark brown markings. There is another species which sometimes looks quite similar, Pleurobranchus mamillatus, [see messages #10962, #2346] but that species has some very large conical papillae and I can't see any sign of them in your photos.
Best wishes,
Bill Rudman

Rudman, W.B., 2005 (Apr 28). Comment on Large pleurobranch from Malaysia by Alphonsus Jude Joseph. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

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