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This species has been observed on Reunion and Madagascar Islands

Order : Nudibranchia Suborder : Euctenidiacea Superfamily : Doridoidea Family : Discodorididae Distribution : Indian West Pacific Maximal size : 30 mm Abundance : Species characteristics : The ground color of the dorsum and foot is lemon yellow to orange The ridges are linen in white, with additional short lines or dots of white spinkled of the dorsum among the ridges. Brown dots, which outline the ridges and are scattered along the mantle edge can be seen on some specimen The upright rhinophores are tapered towards the tip with brown coloration on the posterior side near the base, black subapical coloration and a translucent white background color The six branchial leaves are highly pinnate. The gills have black-lined branches and the undersides are white.
	Showing species characteristics...	Photo Cédric Peneau Reunion, Cap la Houssaye, 8-10 m, 18 December 2017

Remarks :

Identification confirmed by Erwin Koehler and Lindy Warren
    Synonymous : (according Worms)
          - No other name

Bibliographic data :

The body profile is relatevely low and the dorsum has a series of angled ridges arranged in a reticulate pattern. Ther are no conical tubercles at the jonction.
    Some light brown pigment spots on the ventral side of the mantle near the margins of the foot, are retained on the preserved animals
    H. dalanghita feeds on unidentified orange sponges and that the three specimens from the Philippines were almost entirely embedded in a lobate orange sponge on which they had been feeding
    Etymology : Fahey & Gosliner (1999) named the species based on the color of the animals from a Tagalog name (the holotype was collected from the Batangas Province, Luzon, Philippines), dalanghita , having reference to a small orange fruit

References :

Bill Rudman Seaslug site : Sea Slug Forum : Halgerda dalanghita
   Slugsite Halgerda dalanghita

Publications :

Fahey S.J. & Gosliner T.M. 1999. Description of three new species of Halgerda from the western Indian Ocean with a redescription of Halgerda formosa Bergh, 1880. Proceedings of the California Academy of Sciences , (4) 51(8): 365-383

Other photos of Halgerda dalanghita :

Nathalie Bazard Madagascar, Nosy Bé, 15 m, size : 20 mm   Probably the same species with numerous brown dots on the dorsum and an orange background...