This species has been observed on Mayotte and Madagascar Islands

Order : Nudibranchia Suborder : Euctenidiacea Superfamily : Polyceroidea Family : Polyceridae Distribution : Tropical Indo-West Pacific Maximal size : 30 mm Abundance : Species characteristics : This seaslug is characterised by the presence of longitudinal brown to black lines of irregular width and large diffuse patches of yellow and orange. The ground colour of the body is white or cream white. The edge of the foot is generally blue or purple Red pigment on rhinophores and gills, both with a purple/blue base
	Showing species characteristics...	Photo Yvon Gildas Mayotte, Passe en S, buoy n°6, 15 m, 6 March 2009.

See more about : Sightening and mating periods

Remarks :

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

Bibliographic data :

Usually, the lines are arranged as follows:
         - One broad mid-dorsal line between the rhinophores and the gills and two shorter ones of similar width on each side of the middle line
         - There is also a similar line outside these, at the edge of the mantle, which  runs outside the gills and then behind them to converge with the corresponding line on the otherside to form a single line which runs back to the posterior end of the foot. Anteriorly this line runs around the rhinophores to join its counterpart in the anterior midline.
         - There are also similar lines running down each side of the body.
    In some animals the brown bands can be very wide and can even coalesce to form an almost solid brown dorsal patch., while in others the lines can be thin and more numerous making the animal look more like N. lineolata.
    There is a large dorsal orange to orange-brown background patch or yellow patch between the gills and the rhinophores and another large dorsal orange patch behind the gills. Often the rest of the dorsal background can be bright yellow, or parts of it have yellow patches. 
    There can also be distinctive blue or purple markings, but in some animals these are only very faint. They can be present on the oral tentacles, the margin of the foot, the base of the rhinophore sheaths, and the base of the gills.
    The rhinophores are red. The  rhinophore sheaths range from white to blue to purple, and in some specimens are edges with dark brown.
    The gills are red and their stalks white or blue to purple.
    Found on coloniales tunicates on shallow water reefs 10-15 m depth
    N. aurea have similarity with
            - N. purpureolineata but the main colour difference between the two species is that N. aurea has two dorsal orange patches, one in front of the gills and one behind
            - N. lineolata, but N. aurea has two dorsal orange patches, one in front of the gills and one behind and has red rhinophores (red with white apex in N. lineolata)

References :

Bill Rudman Seaslug site : Sea Slug Forum : Nembrotha aurea
    Nudipixel Nembrotha aurea

Publications :

Pola, M., Cervera, J.L. and Gosliner, T.M. 2008. Revision of the Indo-Pacific genus Nembrotha (Nudibranchia: Dorididae: Polyceridae), with description of two new species. Scientia Marina 72(1): 145-183

Other photos of Nembrotha aurea :

Olivier Le Bris Mayotte, Nurserie, 8 m, 4 December 2008 Red pigment (a) on rhinophores and gills, both with a purple/blue (b) base There are longitudinal brown to black lines (c) running down each side of the body.

Alain-Benoît Rassat Madagascar, Nosy be, Bobosse, 22 m, 12 May 2013, size : 50 mm