Volvatella vigourouxi
(Montrouzier in Souverbie, 1861)

Order: SACOGLOSSA
Superfamily: OXYNOOIDEA
Family: Volvatellidae

DISTRIBUTION

Known from New Caledonia. Until the species of this genus are better understood it is not possible to be sure of their geographic distributions. This possibly has a wide Indo-West Pacific distribution.

PHOTO

Baie de Koumac, Koumac Region, New Caledonia, 20°34.5'S, 164°15.5'E, 3 m, sandy mud, Caulerpa beds. UPPER: 10 October 1993, 8 specimens (3.5, 5, 6, 13, 20, 20, 21 & 22mm long alive), AM C200412. LOWER: 26 October 1993, 2 specimens, AM C200637. PHOTOS: Bill Rudman.
[INSET in upper photo: Shell of Lophocercus vigourouxi from Montrouzier in Souverbie, 1861: Pl.11, fig.1.]

The species of Volvatella have a large, weakly calcified, bulloid-shaped shell. At its posterior end, the shell narrows into a funnel or spout. The foot is relatively short and the head bears a pair of rounded oral lobes and a pair of somewhat flattened, rounded rhinophores. Species are found in association with their food, the green siphonaceous algae, Caulerpa, on which they are well camouflaged. When disturbed a sticky white secretion is released from a gland in the mantle cavity. The identity of species from the Indo-West Pacific is difficult to resolve as many of the early descriptions are very brief. Volvatella vigourouxi was originally described from New Caledonia only from its shell. However the large, corneous inflated shell is quite recognisable and fits a species commonly found in New Caledonia. It has a distinctively yellow-orange animal, and a relatively long posterior 'siphonal canal' on the shell. Baba (1966) described in detail the anatomy of a species from japan which he identified as V. vigourouxi, but as he had no information on the external features of the living animal, we can't be sure of his identification. See separate discussion on some earlier names.

Reference:
• Baba, K. (1966) Gross anatomy of the specimens of the shelled sacoglossan Volvatella (= Arthessa) collected from Okino-Erabu Island, southern Kyushu, Japan (Nudibranchia). Publications of the Seto Marine Biological Laboratory, 14(3): 197-205, Pls 7-10.
• Souverbie, M (1861) Descriptions d'especes nouvelles de l'archipel Caledonien, (6th article). Journal de Conchyliologie, 9: 271-284. (Pl.11)

Authorship details
Rudman, W.B., 2002 (July 3) Volvatella vigourouxi (Montrouzier in Souverbie, 1861). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/volvvigo

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