Marionia? laying eggs

February 16, 2005
From: Yuki Shigematsu

We encountered this unique nudibranch at Mentjeng wall, Sangeang island in Indonesia. Well, it was very unique nudi laying beautiful curly purple tape-like eggs. We tried to identify this species in nudi books, but cannot find exactly the same kind of nudi in any books. My friend says it is a kind of Marionia, but all the Marionia in the books have much less fluffy things around their bodies. Is this really Marionia?

Locality: Mentjeng wall, Sangeang island, Indonesia, Flores sea. Depth: approx 3 meters. Length: approx 4-5 cm. 02 January 2005. Reef top with black sand. Photographer: Yuki Shigematsu

Yuki Shigematsu

Shigematsu, Y., 2005 (Feb 16) Marionia? laying eggs. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Yuki,
Yes this is a species of Marionia. This species usually has some green colouration on it as well. It looks very 'fluffy' because its body is contracted. When it is stretched out crawling the gills down each side will be more spread. I won't put a name on your animal at present because there is quite a lot of confusion over the names of these species in the Indo-West Pacific and I don't want to add more confusion at present. I will call it Marionia sp. 5.

As you have discovered, these animals sometimes lay a long tangled egg ribbon and then walk away still trailing a thin thread of egg ribbon material behind. In the photo alongside, it is possible that the whitish soft-coral in the top left corner is its food.
Best wishes,
Bill Rudman

Rudman, W.B., 2005 (Feb 16). Comment on Marionia? laying eggs by Yuki Shigematsu. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from


Marionia sp. 5