Version française...

This species has been observed on Mayotte and Madagascar Islands

Order : Nudibranchia Suborder : Euctenidiacea Superfamily : Phyllidioidea Family : Phyllidiidae Distribution : Tropical Indo-West Pacific. Maximal size : 110 mm Abundance : Species characteristics : The dorsum is generally a very pale shade of pink, grey or blue It is distinctive, on account of its mid-dorsal crest which is triangular in cross section ( the body is not dorsoventrally flattened as in other phyllidiids) Encircling the perimeter of the visceral hump is a black band. In most specimens, four small black lines radiate out from it in opposite directions and at right angles to each other. The rhinophores are pale salmon pink
	Showing species characteristics...	Photo Matthias Deuss Mayotte, Passe en S Buoy n°8, 20 m, 23 December 2008, size : 60 mm

See more about : Sightening and mating periods

Remarks :

Identification confirmed by Bill Rudman and Nathalie Yonow
    Synonymous : (according Worms)
          - No other name

Bibliographic data :

Phyllidiopsis shireenae is elongate in shape and possesses a relatively soft, but firm body.
    Encircling the perimeter of the visceral hump is a black band.
            - In most specimens, four black lines diverge from the black band and run to the mantle edge. One black line occurs anteriorly and one at the posterior extremity. Two lines arise laterally, one on either side of the dorsal crest.
            - Minor variations of this pattern include : a diverging black line which does not run right to the mantle edge, a black line running across the dorsal crest, a second transverse black line across all of the mantle or a few, small, irregularly shaped, black patches on the dorsal crest.
    A number of small, rounded tubercles occur on the mantle skirt. Larger tubercles with angular edges are sparsely scattered over the dorsal crest.
    The rhinophores are pale salmon pink and each clavus possesses 17-20 lamellae (specimens greater than 40 mm).
    The anus opens at the posterior end of the crest
    Ventrally, the hyponotum, foot and oral tentacles are white. The fused oral tentacles have a broad base and are short with broad, rounded tips. The gills are dark grey. There is a black band behind the gills where the notum meets the sides of the foot.
    P. shireenae looks like other phyllidiid but no other phyllidiid possesses a large dorsal crest and salmon pink rhinophores
            - Phyllidiopsis gemmata is grey-pink to grey-blue with three tuberculate ridges, black rhinophores
            - Phyllidiopsis krempfi has multicompound pink tubercles, black and pink rhinophores, and possesses 26-28 lamellae on each rhinophoral clavus (17-20 in P. shireenae)
            - Phyllidiopsis pipeki, Phyllidiopsis burni and Phyllidiopsis fissurata differ from P. shireenae in having large compound tubercles, black and pink rhinophores and pink to grey ventral coloration (white in P. shireenae).

References :

Bill Rudman Seaslug site : Sea Slug Forum : Phyllidiopsis shireenae
   Nudipixel Phyllidiopsis shireenae

Publications :

Brunckhorst, D.J., 1990. Description of a new species of Phillidiopsis Bergh (Nudibranchia: Doridoidea: Phyllidiidae) from the tropical western Pacific, with comments on the Atlantic species. Journal of Molluscan Studies 56: 577-584
    Brunckhorst, D.J. (1993) The systematics and phylogeny of Phyllidiid Nudibranchs (Doridoidea). Records of the Australian Museum, Supplement 16 : 1-107.

Other photos of Phyllidiopsis shireenae :

Yvon Gildas Mayotte, Passe en S, 6 m, 11 November 2008 The rhinophores (a) are pale salmon pink It is distinctive, on account of its mid-dorsal crest (b), which is triangular in cross section Encircling the perimeter of the visceral hump is a black band (c). In this specimen, four black lines diverge from the black band and run to the mantle edge. One black line occurs anteriorly (d) and one at the posterior extremity. Two lines arise laterally, one on either side (e) of the dorsal crest. Minor variations of this pattern include : a few, small, irregularly shaped, black patches on the dorsal crest.

.

Ventrally : - The hyponotum, foot (a) and oral tentacles are white    -The gills are dark grey (b). There is a black band behind the gills where the notum meets the sides of the foot.

Hugues Flodrops Mayotte, Tombant de l'arche, Sakouli, 26 m, 2 May 2009, size : 40 mm Minor variations of this pattern include : a few, small, irregularly shaped, black patches on the dorsal crest.

.

Alain-Benoît Rassat Madagascar, Nosy Bé, Pterois, 17 m, 18 November 2010, size : 70 mm   Minor variations of this pattern include : a few, small, irregularly shaped, black patches on the dorsal crest.

Mayotte, Phyllidiopsis shireenae without posterior black line, at Passe en S, by Hugues Flodrops

Mayotte, Phyllidiopsis shireenae without black patches on the dorsal crest, at Passe en S, by Matthias Deuss