Re: Marionia levis

May 20, 2005
From: Binyamin Koretz

Dear Bill,
Concerning the message on Marionia levis from Mombasa [#13785]:

Tritoniid nudibranchs similar to this description are quite common in our area. If they are all Marionia levis, that will clear up a big question for a lot of us.

One complication I think worth mentioning is the degree of variation in color and pattern, which has led me to wonder whether we're seeing 1, 2 or 3 species, although the gills are similarly patterned among most of them, and there may be examples that can't be easily sorted out.

The most common variation is whitish with purple lines and a clear demarcation of the dorsum. Another fairly common type is quite greenish top and bottom, often with a cross-hatch pattern. The third type is quite reddish with white speckling, and with a bright white underside. I've attached one example from each type for illustration.

Locality: Eilat, Israel, Red Sea. all depths. Length: up to 3 cm. various dates. all types of locality. Photographer: Binyamin and Shulamit Koretz

Best regards

Koretz, B., 2005 (May 20) Re: Marionia levis. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Binyamin,
Thanks for this set of photos. We don't know very much about this species. I had begun to wonder whether the elongate body in most photos was different from the original painting in Eliot's description, but your photo alongside of an animal not fully extended looks very like the painting. I agree that your middle photo doesn't show the mantle edge very clearly but I can see a white line on the right side of the animal linking the rhinophores and gills which marks the mantle edge. Certainly the transverse brown, and in some cases whitish lines, across the mantle and sides of the body, and the dark brown spots on the gill stalks and rhinophores sheaths are consistent features of the colour pattern. And the gills arranged in alternating pairs the first held out horizontally then the next vertically, is also a consistent feature.

As I discuss in a separate message [#13842], this species was described from Eilat, as a new species, quite recently. It wouold be interesting to try and get some photos of it on its host soft coral.

Best wishes,
Bill Rudman

Rudman, W.B., 2005 (May 20). Comment on Re: Marionia levis by Binyamin Koretz. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from


Marionia levis

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