Marionia sp. 2 from Japan

October 1, 2001
From: Mizuho Iwaihara

Dear Bill,
Could you please help me identify this animal, which I found on March, 2001 at Bonotsu, Kagoshima, Southern Japan. I usually see this species on rocky or sandy bottom in this area, shallow water less than 10m.

I think this animal is a tritoniid but I could not find the exact species.

Iwaihara, M., 2001 (Oct 1) Marionia sp. 2 from Japan. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Mizuho,
Your animal is indeed a tritoniid. It is a species of Marionia but I am afraid that our knowledge of the family is not good enough to give them names at present. Is this one of the species which regularly opens and shuts its gills as it is crawling along? In some species the gills expand into large bushy structures which almost completely hide the animal while in others the gills expand and contract regularly. I suspect the ones that expand and contract feed on the xeniid soft corals which rhythmically open and close their tentacles.
Best wishes,
Bill Rudman

Rudman, W.B., 2001 (Oct 1). Comment on Marionia sp. 2 from Japan by Mizuho Iwaihara. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from


Marionia sp. 2

Related messages

  1. Marionia sp. from Japan
    From: Hikaru Nakada, July 5, 2002

Show factsheet and all related messages