Diversidoris crocea    (Rudman, 1986)

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This species has been observed on Mayotte and Madagascar Islands

Order : Nudibranchia
Suborder : Euctenidiacea
Superfamily : Doridoidea
Family : Chromodorididae
Distribution : Western pacific and now Mayotte
Maximal size : 25 mm
Abundance : Seldom if ever on the fore reef zone

Species characteristics :

The whole of the body, including the gills and the rhinophores, is yellow except for a pale almost white band around the mantle margin.

At the extreme edge of the mantle outside the white band is a thin yellow line

In the undulating mantle margin, the number and position of the waves in the mantle margin change continuously exept for the single semi-permanent fold half-way along each side.

Noumea norba
Showing species characteristics...
Photo Matthias Deuss
Mayotte, ilots d'Hajangoua, 6-8 m, 1 January 2012, size : 10-15 mm

See more about : Sightening and mating periods

Remarks :

Identification confirmed by Nathalie Yonow and Hsini Lin
    Synonymous (according worms) :
          - Noumea crocea, Rudman, 1986

Bibliographic data :

As in Diversidoris flava, the mantle fold halfway along each side is more characteristic of Thorunna than Diversidoris but the buccal armature and reproductive system, both very similar to those of D. flava, clearly place this species in the genus Diversidoris
     The foot is uniformly yellow
    The six or 12, long, simple gills form a complete circle around the anus. They are uniformly yellow. They do not vibrate
    The long rhinophores are lamellate. They are yellow with sometimes a faint white streak up both axes
    The long tail is visible when the animal is crawling
    It's one of a number of yellow species of chromodorid, which are very well camouflaged on their food sponges. N. crocea feeds on bright yellow species of Darwinella.
    Lays a yellow eg ribbon
    It looks like Diversidoris flava, but D. flava as a thin, bright red or orange-red marginal band that widens to give a pattern of regularly semicircular spots
    It looks like some specimens of Glossodoris pallida but D. crocea has a vivid uniformly yellow mantle and foot and the gills are longer

References :

Bill Rudman Seaslug site : Sea Slug Forum : Noumea crocea
   Nudipixel Noumea crocea

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: Noumea flava colour group. Zoological Journal of the Linnean Society, 88 : 377-404.

Other photos of Diversidoris crocea :

Matthias Deuss

Mayotte, ilots d'Hajangoua, 6-8 m, 1 January 2012, size : 10-15 mm

In fact three specimens on its favorite yellow sponge... Darwinella sp

Fabrice Schubert

Mayotte, Sakouli, 12 m, 14 October 2009, size : 10 mm

The long tail is visible when the animal is crawling

A pale specimen...

 More photos from Indian Ocean

Madagascar, Diversidoris crocea, at Nosy Bé, by Alain-Benoît Rassat