Tritonia? from Izu, Japan

August 29, 2000
From: Haruo Kinoshita

Dear Mr Rudman,

Hello, I'm Haruo Kinoshita from Japan. Today, I'd like you to verify a marine creature that my friend, Miyosi found.

I attached the pictures of a marine creature which I consider as another variation of Tritonia.
We found this on right above of a soft coral at a depth of about 160ft. The water temperature was 15c. Its length was about

Can you help to identify for me please ?

Picture was taken by Hisako Yamada.
Izu Ocean Park, Izu penninsula, Japan in Aug, 9th 2000.

Haruo Kinoshita

Kinoshita, H., 2000 (Aug 29) Tritonia? from Izu, Japan. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Haruo,
Welcome to the Forum and thanks for the photos of your interesting nudibranch. It is most probably a species of Tritonia but I don't think it has a name.

The white lines on one of the animals suggests that it lives on a soft coral, such as Dendronepthya, in which the white skeletal spicules form part of the colour pattern. If so the Tritonia must be difficult to see on the soft coral. Have a look at a species of soft coral with pink skeletal spicules.

Best wishes,
Bill Rudman.

Rudman, W.B., 2000 (Aug 29). Comment on Tritonia? from Izu, Japan by Haruo Kinoshita. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from


Tritoniid sp. 4.