Volvatella viridis
Hamatani, 1976

Superfamily: OXYNOOIDEA
Family: Volvatellidae


Japan, possibly Indo-West Pacific.


Hachijo Island, Japan. Depth: 2m, Size: 20mm. Photo: Shouichi Kato

Described from Japan where it was reported to feed on Caulerpa racemosa. Shell approx 12mm long. When alive the shell appears deep green due to the colour of the mantle. The exposed body is opaque white. Recently, Jensen & Wells, (1990) have described V. ventricosa from southern Western Australia. It has very similar external characters (green mantle, white animal, fragile shell, position and size of shell 'spout') but they suggest it differs from V. viridis in having a small penial spine. This spine is extremely small, and although Hamatani states he could not see it in 2 specimens he examined, I think it should be re-examined before we can be sure these two species are different.

• Hamatani, I. (1976) Preliminary account of a new species of Volvatella Pease, 1860, V. viridis sp.nov., found in the Caulerpan Microfauna in Japan (Opisthobranchia: Sacoglossa). Publications of the Seto Marine Biological Laboratory, 22(6): 371-376, Figs 1,2, Pl.6.
• Jensen, K.R. & Wells, F.E. (1990) Sacoglossa (= Ascoglossa) (Mollusca, Opisthobranchia) from southern Western Australia. In: Wells, F.E., Walker, D.I., Kirkman, H. & Lethbridge, R. Proceedings of the Third International Marine Biological Workshop: The Marine Flora and Fauna of Albany, Western Australia. Western Australian Museum, Perth, Vol. 1: 297-331.

Authorship details
Rudman, W.B., 2002 (July 3) Volvatella viridis Hamatani, 1976. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/volvviri

Related messages

Volvatella viridis? from Hachijo Island Japan

July 7, 2002
From: Shouichi Kato

Dear Bill,
This animal are found only several times on Caulerpa sp. during Spring and the beginning of Summer. It looks Volvatella viridis to me, but I'm not sure.
Please give me your help.

Depth : 2m
Size : 20mm

S. Kato


Kato, S., 2002 (Jul 7) Volvatella viridis? from Hachijo Island Japan. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/6563

Dear Shouichi,
This certainly fits the description of Volvatella viridis. It is good to get photos of these shelled animals alive as we know so little about their habits and distribution.
Best wishes,
Bill Rudman

Rudman, W.B., 2002 (Jul 7). Comment on Volvatella viridis? from Hachijo Island Japan by Shouichi Kato. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/6563

Volvatella viridis from Queensland

July 7, 2002
From: Bill Rudman

To accompany Shouichi Kato's message about Volvatella viridis from Japan, here is a photo of a similar animal from Heron Island, at the southern end of the Greata Barrier Reef Queensland. While other species of Volvatella were found on the common Caulerpa racemosa this was the only one I found on this quite differently shaped species of Caulerpa.

Data: Heron Is, Queensland, Australia, on Caulerpa sp., June 1983. AM C138571. PHOTOS: Bill Rudman.

As I discuss elsewhere, the green mantle, which makes the transparent shell look green, and the white animal are characteristic of both V. viridis and the more recently described V. ventricosa. I have tentatively decided to identify this as Volvatella viridis, but we need a re-examination of the anatomy of that species to determine if it does differ from V. ventricosa. If there are two species, this record represents an increase in the know range of V. viridis from Japan to the south Pacific, or of V. ventricosa from the eastern Indian Ocean to the south west Pacific.
Best wishes,
Bill Rudman

Rudman, W.B., 2002 (Jul 7) Volvatella viridis from Queensland. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/7452