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This species has been observed on Mauritius and Madagascar Islands

Order : Nudibranchia Suborder : Euctenidiacea Superfamily : Polyceroidea Family : Polyceridae Distribution : Indo West Pacific Maximal size : 100 mm Abundance : Species characteristics : Body dark green, blue or more commonly black with blue markings on the head, notum and foot border The five, large, branched gills are black with sometimes greenish or blue pigment on the rachis and the base. The lamellate rhinophores are black
	Showing species characteristics...	Photo Patrick Millar Mauritius, "7 Patches", 10 m, 18 August 2007, size : 30 mm

See more about : Sightening and mating periods

Remarks :

Identification confirmed by Nathalie Yonow
    Synonymous : (according Worms)
               - Nembrotha morosa Bergh, 1877
               - Tambja kushimotoensis Baba, 1987

Bibliographic data :

The front margin of the head and the foot edge have blue lines. There are usualy bright blue markings ( round blue spots sometimes fused or blue streak) on the back.
    Below the rhinophore there is a long black ridged structure corresponded to the sensory organ. Usually all we see is a dark line, or groove along the side of the head. But in some photo the sensory organ is 'half open' and in other it is fully everted to show its structure of compound ridges.
    Quite a lot of these "long-tailed" nudibranchs can swim by this vigorous lateral movement of the body simultaneously bending the head and tail to one side, then to the other
    Like all species of Tambja, it feeds on arborescent bryozoan colonies.

Material examined by Nathalie Yonow ( see reference/publications).

1 specimen. Trou aux biches ( H. Debelius) ; 4 March 1990 ; 25 m  ; 26x9 mm. Under the name T. kushimotoensis

References :

Bill Rudman Seaslug site : Sea Slug Forum : Tambja morosa
   Nudipixel Tambja morosa

Publications :

Baba, K. (1987) Two new green colored species of Tambja from Japan (Nudibranchia: Polyceridae). Venus, The Japanese Journal of Malacology, 46(1) : 13-18.
    Bergh, L.S.R. (1877). Malacologische Untersuchengen. In C.G. Semper, Reisen im Archipel der Philippinen, Wissenscaftliche Resultate, 11 : 429-494, pls 54-57
    Pola M., Cervera J.L. & Gosliner T.M. (2006) Taxonomic revision and phylogenetic analysis of the genus Tambja Burn, 1962 (Mollusca, Nudibranchia, Polyceridae). Zoologica Scripta 35(5):491-530.
   Yonow, N. and Hayward , P. J. (1991). Opistobranches de l'île Maurice, avec la description de deux espèces nouvelles (Mollusca : Opistobranchia) Revue française d'aquariologie herpétologie, 18 (1), 1-30, Figs1-13

Other photos of Tambja morosa :

Vanessa Béchard Mauritius, Sirius and Troumoutou, 20 m, 19 September 2012, size : 40 mm Below the rhinophore there is a long black ridged structure corresponded to the sensory organ. Usually all we see is a dark line, or groove along the side of the head. But in some photo the sensory organ is 'half open' and in other it is fully everted to show its structure of compound ridges. The five, large, branched gills are black with sometimes greenish or blue pigment on the rachis and the base.

   More photos from Indian Ocean

 Madagascar, Tambja morosa, at Nosy Bé, by Nathalie Bazard