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

Order : Nudibranchia Suborder : Euctenidiacea Superfamily : Doridoidea Family : Chromodorididae Distribution : Western Indian Ocean. Maximal size : 40 mm Abundance : Seldom on the fore reef zone Species characteristics : Mantle ground color translucent orange brown, with a border of pale violet, and five parallel lines of the same color run down the dorsum.    Indistinct creamy yellow patches run between the violet lines of the dorsum form a network    The gills are orange-red and orange-red rhinophores have an opaque white apex H. centenculus is paler in color than H. maridadilus.
	Showing species characteristics...	Photo Sophie Darnis Reunion, La cheminée, Saint Gilles, 26 m, 18 October 2008, size 30 mm

See more about : Chromodoris centunculus (whitei?) variability in Southwest Indian ocean
   See more about : Sightening and mating periods

Remarks :

Identification confirmed by Nathalie Yonow
    For Nathalie Yonow it's a distinct species. H. Centunculus is paler in colours, and has the almost glistening patches in between the light pinky red lines.  H. maridadilus is usually vivid, deep cream and magenta only.  Rhinophores less contrasting in colour than in H. maridadilus
    For Gosliner and Johnson (1999), H. centuculus is regarded as a junior synonym of H. whitei.
    For others H. centunculus H. whitei and H. maridadilus are considered as extreme variation of only one species.... all with five lines and varying amounts of white on gills and rhinophores.
    Synonymous : (according Worms) Worms considered than is a junior synonym of H. whitei For Nathalie Yonow it's a distinct species
          - Goniodoris whitei, A. Adams & Reeve, 1850
          - Hypselodoris centenculus, Yonow, 1994

Bibliographic data :

The ground colour of this species is translucent orange brown, overlain by longitudinal stripes of pale violet and patches of creamy yellow.
    The mantle is spatula-shaped, the anterior end rounded and a little wider than the rest of the mantle. There is a slight overlap of the mantle along the sides.
    Five dorsum lines description (as H. maridadilus):
- The median line begins just behind the rhinophores and go back to the gills pocket
- A pair of lines on each side of the median line run from each rhinophore pocket to the posterior end of the dorsum. The inner one of each pair runs around the gills pocket joining the midline.
- A thick curve line runs between the rhinophores and a purple border around each of the rhinophores pockets and the gills pockets
    Foot lines description (as H. maridadilus) :
- The two reddish violet lines run along the side of the foot on each side, one in the middle another at the junction of the foot and the underside of the mantle.
- The two lines on each side join in the posterior midline to form a single line on the posterior part of the foot
- The sole of the foot is white
    The eight gills and rhinophores are red orange, with an increase in pigment along the edges of the lamellae.
    The rhinophores bear 13-14 lamellae and the tips are opaque white.
    It looks like Hypselodoris emma, but H. emma has only 3 longitudinal purple lines on the mantle, while H. centenculus have 5 longitudinal lines.
    It looks that there are a pair of sibling species, one in the Indian Ocean (H. maridadilus ) and one in the western Pacific ( H. whitei ). Nathalie Yonow described a similar species H. centunculus from Maldives Island with white tips on the rhinophores (for Gosliner and Johnson (1999) it was a synonymous of H.whitei)

References :

Bill Rudman Sea slug site : Sea Slug Forum : Hypselodoris maridadilus

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
    Gosliner, T.M. & Johnson, R.F. (1999) Phylogeny of Hypselodoris with a review of the monophyletic clade of Indo-Pacific species, including descriptions of twelve new species. Zoological Journal of the Linnean Society, 125 : 1-114.
    Rudman, W.B. (1977) Chromodorid opisthobranch Mollusca from East Africa and the tropical West Pacific. Zoological Journal of the Linnean Society, 61 : 351-397.
    Yonow, N. (1994) Opisthobranchs from the Maldive Islands, including descriptions of seven new species (Mollusca: Gastropoda). Revue fr. Aquariol., 20(4) : 97-130.

Other photos of Hypselodoris centunculus (whitei?) :

Jean-Marie Gradot Seychelles, Anse Lazio, Praslin, April 2018

Sophie Darnis Reunion, La cheminée, Saint Gilles, 26 m, 18 October 2008, size 30 mm Rhinophores détail : The opaque white apex of the rhinophores is more extensive and obvious.     Gills detail : The gills are entirely orange-red with an increase in pigment along the edges of the lamellae

Sophie Darnis Reunion, Petites gorgones de Boucan, 17 September 2006, size : 20-25 mm H. centunculus is paler in colours, and has the almost glistening patches in between the light pinky red lines

Sully Bachel Flic en flac, Mauritius, 14m, January 2009, size : 25 mm

Richard Lai cheong Trou aux biches, Mauritius, 17 m, 12 December 2008. According Nathalie Yonow : "it looks like H. centunculus when I enlarge it (small looks like H. maridadilus with the darker rhino + gills……!), I can see two clear patches behind the rhinophores"

Sylvain Le Bris Mayotte, 2 December 2008 Exactly the same pattern than Eva Fontaine specimen

Mathias Deuss Mayotte, 23 december 2010, size : 30 mm   4 specimens found under a rock, two of them mating

See more about : Chromodoris centunculus (whitei?) variability in Southwest Indian ocean

 Mayotte, atypical Hypselodoris centunculus, at mbouenatsa, by Eva Fontaine

Mayotte, Hypselodoris centenculus with deep coloration of rhinophores, at M'Bouini, by Matthias Deuss  

Madagascar, Hypselodoris centenculus, at Nosy Bé, by Alain-Benoît Rassat