This species has been observed on Reunion and Mayotte
Order : Nudibranchia
Sous ordre : Euctenidiacea
Super famille : Doridoidea
Family : Chromodorididae
Indo West Pacific
Maximal size : 20 mm
Abundance : Seldom if ever on the reef flat zone and the rocky coast.
Species characteristics :
white body with characteristic broad white longitudinal lines the one
along the midline often forming a “Y” just in front of the gills. These
lines contain purple spots
There are large purple and small spots scattered over the dorsum
White edge mantle, followed by orange-brown
The rhinophores are a translucent straw colour with an opaque white core and the simple gills are similary coloured.
|Showing species characteristics...
Photo Philibert Bidgrain
Reunion, Etang salÚ on the rocky coast, less 1 m, 8 November 2005, size : 15-20 mm
See more about : Sightening and mating periods
Identification confirmed by Nathalie Yonow
Synonymous : (according
- Chromodoris decora,
- Doris decora, Pease, 1860
- Glossodoris ndukuei, (Risbec, 1928)
- Chromodoris ndukuei, Risbec, 1928
- Glossodoris decora, (Pease, 1860)
Bibliographic data :
Mantle description :
- The mantle is translucent with an orange band just in front of the edge.
There is a thin opaque white line which runs around the mantle and
parallel to the edge, just encircling the rhinophores and gills
Between these intense white line and the orange border the mantle is
pigmented white but not so intensely as the thin line
From between the rhinophores a thin line runs down the dorsal midline
to midway where it bifurcates to form a loop around the gill pocket
Right at the edge the mantle is transparent, and the outer edge of the
white mantle glands appear as a serie of white streaks or in some
places a continuous white line
- On the orange band is a line of small purple spots
Another row of much larger purple spots, diffuse at the edges, is found
outside the thin white ring on the whitish submarginal band
There is some variation in colour pattern :
- Sometimes the purple spots on the orange border are few or absent.
Also, the region between the orange band and the white line
encircling the gills and rhinophores varies from being as unpigmented
as the central region to almost as heavily pigmented as the white line
In other specimens the Y-shaped white line and the encircling white
line can be scattered with purple spots, and in others the Y-shaped
line can be broken or have extra branches
On the underside of the mantle the orange border is visible and at the
junction of the mantle and the side of the body there is a row of small
purple spots. Elsewhere the foot is white and translucent
The egg mass is pale yellow.
This species closely looks like Goniobranchus lekker, but G. lekker have opaque white spots on the dorsal surface of mantle (notum) and Goniobranchus decorus possesses a typical colour form with white Y-shaped pattern on the notum or purple spots in centre of back.
similar is Goniobranchus setoensis
which differs by having
purple spots also in the greyish mid-dorsal region, and by having
purple spots in the white 'Y".
Bill Rudman Seaslug site : Sea Slug Forum : Chromodoris decora
Nudipixel Chromodoris decora
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.
Pease, W.H. (1860). Descriptions of new species of mollusca from the Sandwich Islands. Proceedings of the Zoological Society of London, 28 : 18-37
Rudman, W.B. (1984) The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: a review of the genera. Zoological Journal of the Linnean Society 81 : 115-273
Rudman, W. B. (1986) The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: Noumea purpurea and Chromodoris decora colour groups. Zoological Journal of the Linnean Society 86(4) : 309-353
Other photos of Goniobranchus decorus :
Mayotte, Le Rocher, Dzaoudzi, less 1 m, 21 September 2012, size : 10 mm
Translucent white body with characteristic broad white longitudinal lines the one along the midline often forming a “Y” (a) just in front of the gills. These lines contain purple spots (b)
The characteristic pattern of this species
Mayotte, Mtsanga Sakouli, less 1 m, 14 April 2012, size : 8 mm
Right at the edge the mantle is transparent, and the outer edge of the white mantle glands (a) appear as a serie of white streaks or in some places a continuous white line
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