April 3, 2009
From: Toh Chay Hoon
Concerning message #22383:
Dear Dr Bill,
Thanks for the information. Here's another two photos of Okenia purpurata that a friend of mine came across during a dive at Pulau Hantu, Singapore, last December.
Locality: Pulau Hantu, 12 m, Singapore, South China Sea, 20 December 2008, Silty substrates. Length: 2, 5 mm. Photographer: Ivan Choong.
I understand from the factsheet that O. purpurata has 4 or 5 long simple gills. However, his photos show both nudibranch with only 3 gills.
Would like to hear your enlightenment.
email@example.comToh, C.H., 2009 (Apr 3) Re: Okenia purpurata from Singapore with 3 gills?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/22397
Dear Chay Hoon,
It's nice to get a second record so quickly. Concerning the number of gills. The small size of these animals is the reason as the number of gills increases as the animal grows to maturity. One thing I meant to mention when I replied to your earlier message was whether you saw any sign of its bryozoan food. In Leanne & David Atkinson's earlier message [#19299] there is a good photo of the very characteristic spiral shape of their bryozoan food, Amathia tortuosa, the name tortuosa in recognition of this shape. In the original of Ivan's lower photo, which I have cropped for the Forum, I thought I could see a sign of these spiral stalks. Could you ask him to check his photos to see if he has got a photo which shows this.
I am not sure how specific this species is to a particular bryozoan but it would be nice if it was eating the same species in Singapore. As an added bonus it would also be the first record of the bryozoan outside Australia.
Re: Okenia purpurata from Singapore with 3 gills?
From: Ivan Choong, April 6, 2009
Okenia purpurata from Singapore
From: Toh Chay Hoon, April 2, 2009
A pair of Okenia purpurata
From: Leanne & David Atkinson, January 23, 2007
Okenia purpurata from New South Wales
From: Leanne & David Atkinson, January 18, 2007
Okenia purpurata - new record
From: L. & D. Atkinson, February 20, 2006