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This species has been observed on Reunion and Mauritius Island

Order : Sacoglossa Superfamily :  Oxynooidea Family : Volvatellidae Distribution : Indo West pacific Maximal size (shell) : 22 mm Abundance : Species characteristics : It has a distinctly yellow-orange animal, and a relatively long posterior 'siphonal canal' The foot is relatively short and the head bears a pair of rounded oral lobes and a pair of somewhat flattened, rounded rhinophores. It has a large, weakly calcified, bulloid-shaped shell. The shell has a medial constriction and at its posterior end, the shell narrows into a funnel or spout.
	Showing species characteristics...	Photo Pierre Périès Mauricius, Rivière Noire, 2015

See more about : Sightening and mating periods

Remarks :

Identification confirmed by Raymond Huet
    The identity of species from the Indo-West Pacific is difficult to resolve as many of the early descriptions are very brief.
    Synonymous (according worms):
              - Lophocercus vigourouxi Montrouzier, 1861              

Bibliographic data :

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 egg mass is a flattened disk laid on seaweed.

In South West Indian Ocean, we found two different kind of shell, so probably two different species : Volvatella cf. cincta and Volvatella cf. vigourouxi

Volvatella cf. cincta	Volvatella cf. vigourouxi
At its posterior end, the shell narrows into a short (a) funnel or spout.    Important overlapping (b) on the ventral face of the shell	At its posterior end, the shell narrows into a long (a) funnel or spout.     No overlapping (b) on the ventral face of the shell

 

References :

Sea Slug Forum Volvatella vigourouxi
    Sea Slug of Hawai'i Volvatella vigourouxi
    Wild Singapour Volvatella vigourouxi
    Catalogue diversity in the Sacoglossar Volvatella vigourouxi

Publications :

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)

Other photos of Volvatella cf. vigourouxi :

Alexandre Laporte Reunion, Etang Salé on the rocky coast, less 1 m, 13 April 2017, size : 10 mm The foot is relatively short and the head bears a pair of rounded oral lobes and a pair of somewhat flattened, rounded rhinophores (a).

Sébastien Vasquez Reunion, Etang Salé on the rocky coast, less 1 m, 13 December 2015 The shell has a medial constriction (a) and at its posterior end, the shell narrows into a funnel or spout (b).

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