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This species has been observed on Reunion, Maurice, Mayotte, Madagascar and Seychelles Islands

Order : Nudibranchia Suborder : Euctenidiacea Superfamily : Doridoidea Family : Chromodorididae Distribution : Indian Ocean. (Kenya, South Africa, Sri Lanka, Thailand, Reunion, Mayotte). Maximal size : 40 mm Abundance : Frequently on the rocky coast Species characteristics : The gills of this Chromodoris are lined with red or reddish-orange.     The rhinophore are uniformly red or reddish-orange with a with white stalk.     The body is pale violet with rounded areas of creamy yellow pustules, and deeper violet and red markings. These marks follow the contours of bilaterally symmetrical yellow pustules.
	Showing species characteristics...	Photo Philibert Bidgrain Reunion, Etang salé les bains, 14 November 2005.

See more about : Sightening and mating periods
   See more about : Goniobranchus conchyliatus variability in Southwest Indian ocean

Remarks :

Identification confirmed by Bill Rudman and Nathalie Yonow
    Goniobranchus conchyliatus from the Indian Ocean, has been considered a sibling species of Goniobranchus geometricus from the Western Pacific. But Valda Fraser (June 2000) clearly shows that both species co-exist in the western Indian Ocean (south coast of Kwazulu-Natal). Colin Ogden maked also the same observation in South Africa (Sodwana Bay, 2005). And also in Mayotte and Reunion Islands ( see G. geometricus)
    On the posterior end of the foot of Goniobranchus geometricus, we often observed two black lateral lines that join in the midline, which is not the case on our specimens of Goniobranchus conchyliatus. Observation to confirm
    Synonymous : (according Worms)
          - Chromodoris conchyliata, Yonow, 1984

Bibliographic data :

The name "conchyliata" is derived from the Latin conchyliatus meaning "dressed in purple".
    Ventrally, the head, the simple oral tentacles and the foot are white. In lateral view, a longitudinal dark violet line can be seen between the foot and the mantle. Orange and purple coloring to the ventral surface of the anterior mantle.
    The gills, usualy 8 simple pinnate structures, are tricolored : the upper half is red or orange (both rachis and pinnae), and the lower half has a pale violet internal rachis and anus area with white pinnae.
    They have the distinctive habit of waving the anterior portion of the mantle skirt up and down as they craw
    Goniobranchus conchyliatus is similar to Goniobranchus hintuanensis and Goniobranchus geometricus but :

	G. geometricus	G. conchyliatus	G. hintuanensis
Localisation	Tropical Indo-West Pacific	Indian Ocean	Western Pacific
Behavior	They have the distinctive habit of waving the anterior portion of the mantle skirt up and down as they crawl
Gills	The gills are speckled with opaque white basally and apically vivid green (most often), greenish yellow or watery orange	The gills are lined with red or reddish-orange.	The gills are a translucent reddish purple colour edged with a dark line of the same colour.
Rhinophores	The rhinophores have a stalk speckled with opaque white and the clavus is vivid green (most often), greenish yellow or watery orange	The rhinophore are uniformly red or reddish-orange with white stalk.	The rhinophores are a translucent reddish purple colour edged with a dark line of the same colour.
Mantle	The mantle is pale brown, grayish to purplish with a network of black lines surrounded groups of low white pustules	The body is pale violet with rounded areas of creamy yellow pustules, and deeper violet and red markings.	The body has a network of pale plum area    Small circles of deep magenta outline 5-8 of the small opaque white rounded nodules on the medium area of the dorsal surface of the animal.
Undersurface of the mantle	The undersurface of the mantle is flushed with purple anteriorly	The undersurface of the mantle is flushed with orange and purple anteriorly	The undersurface of the mantle is flushed with deep purple anteriorly

References :

Site de Bill Rudman : Sea Slug Forum : Chromodoris conchyliata
   Nudipixel Chromodoris conchyliata

Publications :

Rudman, W.B. (1973) Chromodorid opisthobranch Mollusca from the Indo-West Pacific. Zoological Journal of the Linnean Society 52(3) : 175-199.
    Yonow, N. (1984). Doridacean nudibranchs from Sri Lanka, with descriptions of four new species. The Veliger, 26(4) : 214-228.

Other photos of Goniobranchus conchyliatus :

Philibert Bidgrain Reunion, Etang salé les bains, November 2005 The rhinophore are uniformly red or reddish-orange with a with white stalk.

Alain Barrère Reunion, Etang salé les bains, 8 November 2005 Ventrally, the head, the simple oral tentacles, and the foot are white. In lateral view, a longitudinal dark violet line can be seen between the foot and the mantle. Orange and purple coloring to the ventral surface of the anterior mantle.

Philibert Bidgrain Reunion, Etang salé les bains, 8 November 2005 at 6 p.m The spawn  looks quite similar to that of C. geometrica, a common species in the western Pacific, which is very similar in colour pattern and body shape. An other spawning event was observed by Hugues Flodrops (see message in bottom of the page ) in May 2007

This spawn, was photographied the next day, early on the morning. The diameter is about 30 to 35 mm. During October and November 2005, I observed several spawns of this species. Always approximatively the same size and the same color...

Photo below : microscopic observations, five days after the spawn event. You can observed capsule with one or two larvae.

Philibert Bidgrain Reunion, Etang salé on a rocky coast, less 1 m, 10 December 2005 These 3 specimens have eaten about 80% of the purple sponge, frequent in this area. The sponge is probably Chelonaplysilla violacea Chromodoris geometrica (the sibling species from the Western Pacific) also eat this sponge.   Rq : This species has a purple patch on the underside (see Alain Barrère photo) of the anterior mantle. Five other species with the same purple patch also feed on this sponge...

An evidence.... This species eat Chelonaplysilla violacea	Philibert Bidgrain Reunion, Etang salé on a rocky coast, less 1 m, 16 November 2005

Philibert Bidgrain Reunion, Etang salé, on the rocky coast, less 1 m, 22 November 2010, size : 20-25 mm A specimen with small and numerous creamy pustules and red gills

Hugues Flodrops Reunion, Etang salé on a rocky coast, less 1 m, 3 December 2010, size : 25-35 mm Three different pattern of this species eating on the same sponge The sponge is probably Chelonaplysilla violacea

Alain-Benît Rassat Madagascar, plateau des arches, 19 m, 26 July 2015, size : 15 mm     A small specimen

See more about : Goniobranchus conchyliatus variability in Southwest Indian ocean

Reunion, Goniobranchus conchyliatus, at Etang salé les bains, by Alain Barrère

Reunion, mirror effect with Goniobranchus conchyliatus, at Etang salé, by Hugues Flodrops

Reunion, Goniobranchus conchyliatus spawning, at Etang salé, by Hugues Flodrops 

Reunion, Goniobranchus conchyliatus feeding observation, at Etang salé, by Hugues Flodrops  

Reunion, Goniobranchus conchyliatus, at Saint Paul, by Sully Bachel  

Mayotte, Goniobranchus conchyliatus, at Longoni, by Emmanuel Eby  

Reunion, rhinophore detail of Goniobranchus conchyliatus, at Etang salé, by Christophe Cadet 

Reunion, when G conchyliatus meet C. cf geminus, at Etang salé, by Hugues Flodrops

Madagascar, Goniobranchus conchyliatus, at Antongil, by Olivier Fournajoux

Seychelles, Goniobranchus conchyliatus, at Conception Island, by Christophe Mason-Parker

Mauritius, Goniobranchus conchyliatus, at Riviere Noire, by Pierre Périès