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

Order : Nudibranchia Suborder : Euctenidiacea Superfamily : Doridoidea Family : Chromodorididae Distribution : Found throughout the tropical and subtropical Pacific and Indian Oceans. Maximal size : 60 mm Abundance : From time to time on the fore reef zone and on the rocky coast Species caracteristics : It is characterized by the black line bordering the sinuous mantle edge, the black edge to the rhinophore pockets, the black rhinophore clubs and the black edging to the simple gills The small rhinophores are thin, with a pale beige stalk, a white axis and blue black lamellae
	Showing species characteristics...	Photo Philibert Bidgrain Reunion, Etang salé les bains rocky coast, 50 cm, 4 October 2005, size 18 mm

See more about : Sightening and mating periods
   See more about : Doriprismatica atromarginata variability in Southwest Indian ocean

Remarks :

  There are clearly 2 different populations : one population from Mayotte/Seychelles and another population from Reunion/Mauritius.
          - Specimens from Mayotte/seychelles looks like to D. plumbea
          - Specimens from Reunion/Mauritius are closer to the species D. atromarginata or D. sibogae....
      So I use the older name for this group of seaslug : Doriprismatica atromarginata group

Population from Mayotte/Seychelles	Population from Reunion/Mauritius
Thin black margin and thick submarginal white band Notum vivid yellow brown with numerous large dots	Large black margin and submarginal white band Notum pale brown with numerous small whitish dots
Bill Rudman Seaslug : Glossodoris plumbea     Kenya seaslug: Doriprismatica plumlbea	Seaslug of Hawai Doriprismatica atromarginata     Bill Rudman Seaslug : Glossodoris atromarginata     Philippines Nudibranchs : Doriprismatica sibogae

Identification confirmed by Nathalie Yonow
    Synonymous (according worms) :
          - Casela atromarginata, (Cuvier, 1804)                    - Doris maccarthyi, Kelaart, 1859
          - Casela atromarginata var. pallida, Bergh, 1905    - Glossodoris atromarginata, (Cuvier, 1804)  
          - Casela maccarthyi, (Kelaart, 1859)                       - Glossodoris maccarthyi, (Kelaart, 1859)
          - Casela philippiensis, Bergh, 1874                        - Goniodoris atromarginata, (Cuvier, 1804)
          - Doris atromarginata, Cuvier, 1804

Bibliographic data :

This common species ranges in colour from creamy-white to a pale brown.
The unipinnated gills are arranged in a horseshoe around the anterior and lateral edges of the anal papilla, which is relatively large, and cover with relatively tight lamellae
    The gills often rhythmically wave as the animal crawls along
    It is eating sponge ( fasciospongia.sp )

Material examined by Nathalie Yonow ( see reference/publications).

One specimen collected from Flic en Flac (Mauritius), 19 October 1985, size : 27 mm. Another specimen collected from Le Morne (Mauritius), 20 October 1985, size : 25 mm

References :

Bill Rudman Seaslug site : Sea Slug Forum : Glossodoris atromarginata
   Nudipixel Glossodoris atromarginata

Publications :

Johnson R.F. & Gosliner T.M. (2012) Traditional taxonomic groupings mask evolutionary history: A molecular phylogeny and new classification of the chromodorid nudibranchs. PLoS ONE 7(4): e33479
    Rudman, W.B. (1986) The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: the genus Glossodoris Ehrenberg (= Casella , H.& A. Adams). Zoological Journal of the Linnean Society, 86 : 101-184.
    Yonow, N. and Hayward , P. J. (1991). Opistobranches de l'île Maurice, avec la description de deux espèces nouvelles (Mollusca : Opistobranchia) Revue française d'aquariologie herpétologie, 18 (1), 1-30

Other photos of Doriprismatica atromarginata :

Eva Fontaine mtsanga Guini at Mayotte , crawling on the substate, on the reef flat zone, 1m, 27 July 2008, size : 60 mm.         Gills detail with the black edging to the simple gills

Monika Bachel Reunion, "Route en corniche" , Saint Denis, 5m, 3 may 2009, size : 15-20 mm. In the Eudoridoidea the gills can be withdrawn into a pocket for protection . Another name for the superfamily is the "Cryptobranchia" which basically means "hidden gills".   (a)  Gills extended (b) Gills retracted

.

Emmanuel Eby Reunion, St-Leu Particular specimen with background colour a bright brownish yellow, a little like G.sibogae

Florence trentin Reunion, Saint Leu.

Christophe Mason-Parker Seychelles, Mahé, Corsaire Reef, 12 m, July, 2013, size : 30 mm

See more about : Doriprismatica atromarginata variability in Southwest Indian ocean
   Reunion, Hypselodoris bullocki and Doriprismatica atromarginata, at Saint Leu, by Erwan Meyer
   Mauritius, Doriprismatica atromarginata, at Stella Maru, by Mathieu Bayon
   Reunion, Doriprismatica atromarginata, by David Caron
   Mayotte, aggregation of de 5 or 6 Doriprismatica atromarginata, at Tanaraki, by Eva Fontaine 
   Reunion, Doriprismatica atromarginata, at Saint Paul, by Sully Bachel  
   Mayotte, Doriprismatica atromarginata on a sea ursin test, at Sakouli, by Hugues Flodrops  
   Reunion, Doriprismatica atromarginata, at Etang salé, by Christophe Cadet 
   Reunion, Doriprismatica atromarginata, at N'Gouja, by Rachel Lebatard 
   Reunion, Doriprismatica atromarginata, at Etang salé, by Christophe Cadet
   Reunion, Doriprismatica atromarginata, at Saint Leu, by Isabelle Ruffin
   Mayotte, Doriprismatica atromarginata, at Mtsanga Sakouli, by Matthias Deuss
   Mayotte, a smaller Doriprismatica atromarginata, at Mtsanga Sakouli, by Matthias Deuss