tubastraea Phestilla melanobrachia : Reunion island (Indian Ocean)

Tenellia melanobrachia Bergh, 1874

This species has been observed on Reunion, Mayotte Maurice and Madagascar Islands

Order : Nudibranchia
Suborder : Dexiarchia
Superfamily : Fionoidea
Family : Fionidae
Distribution : From southern Japan, Hawaii, northeastern Australia, and South Africa suggesting an Indo western Pacific distribution
Maximal size : 40 mm
Abundance : Seldom if ever...

Species characteristics :

The translucent pale orange body has many short plumb cerata which varie in colour depending upon the diet, but always with an orange or white tips. Colour varies from bright to dull orange, brown and black

The rhinophores and oral tentacles are both long, smooth and translucent orange deepening in colour towards the tips

Showing species characteristics...

Photo Sophie Darnis
Reunion, Saint Gilles, "vallée aux Mérous", 37 m, 12 December 2010, size : 10-15 mm

See more about : Sightening and mating periods

Remarks :

Identification confirmed by Bill Rudman
Synonymous : (according Worms)
- Phestilla melanobranchia Bergh, 1874

Bibliographic data :

A central band along the body is clear of cerata
    The foot is large and the corners are rounded anteriorly
    The rhinophores which araised from a common base are smooth and relatively short
    It has both black and bright orange/yellow colour forms, the colour matching the colour of the Dendrophylliid coral on which specimens are feeding. Studies by Larry Harris (1968) showed that pigments in the coral tissue are taken up in the digestive gland, giving the nudibranch a coloration similar to its food.The orange/yellow colour form on Tubastraea coccinea, T. faulkneri or Dendrophyllia sp and the dark green/black form on T. micrantha and T. diaphana
    Tenellia melanobrachia is observed in Tubastraea coral habitat on the undersides of shaded overhangs or in caverns. It has also been found on the undersides of rocks. It lives in moderately protected to highly exposed areas from 2-43 m
    The nudibranchs are typically concealed in adjacent cracks during the day. They emerge at night to feed.
    Larry Harris reported many years ago that this aeolid seemed to prefer feeding on pieces of coral that had broken off and were lying on the bottom below the main colony.
    The spawn consists of numerous creamish, cup-shaped spirals attached to the host coral by their narrow end
    Species of Tenellia are closely related to Cuthona, but lack a sac at the tip of the cerata to store nematocysts

References :

Bill Rudman Seaslug site : Sea Slug Forum : Phestilla melanobrachia
Nudipixel Phestilla melanobrachia

Publications :

Cella, K; Carmona Barnosi, L.; Ekimova, I; Chichvarkhin, A; Schepetov, D; Gosliner, T. M. (2016). A radical solution: The phylogeny of the nudibranch family Fionidae. PLoS ONE. 11(12): e0167800.
    Harris, L.G. (1968) Notes on the biology and distribution of the aeolid nudibranch (Gastropoda), Phestilla melanobrachia Bergh, 1874. Publications of the Seto Marine Biological Laboratory, 16 : 193-198,2Pls.
    Harris, L.G. (1975) Studies on the life history of two coral-eating nudibranches of the genus Phestilla . Biol. Bull., 149(3) : 539-550.
    Gosliner.T. (1980) The systematics of the Aeolidacea of the Hawiian Islands with the descriptions of two new species. Pacif. Sci 31 : 37-77
    Rudman, W.B. (1981a) Further studies on the anatomy and ecology of opisthobranch molluscs feeding on the scleractinian coral Porites . Zoological Journal of the Linnean Society, 71 : 373-412

Other photos of Tenellia melanobrachia :

Alain-Benoît Rassat

Madagascar, Nosy bé, 21 m, 15 September 2014, size : 40 mm

Three specimen on the same coral.

Colour varies from bright to dull orange, brown and black

Sophie Darnis

Reunion, Saint Gilles, "vallée aux Mérous", 37 m, 12 December 2010, size : 10-15 mm

Studies by Larry Harris (1968) showed that pigments in the coral tissue are taken up in the digestive gland (a), giving the nudibranch a coloration similar to its food.

Maurice Jay

Reunion, T.melanobrachia on its food : Tubastraea sp