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This species has been observed on Reunion, Mauritius and Mayotte Islands

Order : Nudibranchia Suborder : Euctenidiacea Superfamily : Doridoidea Family : Discodorididae Distribution : Tropical Indo-West Pacific Maximal size : 250 mm Abundance : From time to time : on the reef flat zone. Species characteristics : Brownish body with large, irregular tubercles, being larger in the central part of the body. The tubercles in the centre of the dorsum are lined up and fused together forming a longitudinal ridge. Other tubercles may be fused in groups of two or three. In the mantle margin, the tubercles may be fused together forming concentric ridges.    The mantle edge is very wavy and when an animal is crawling these edges are rippled.    The body is flat, wide, with a rigid, gelatinous texture
	Showing species characteristics...	Photo Philibert Bidgrain Reunion, "Etang sale les bains" lagoon, under a rock, 25 January 2005, size : 80 mm

See more about : Asteronotus cespitosus variability in Southwest Indian ocean
   See more about : Asteronotus cespitosus mating behavior and spawn event in Southwest Indian ocean
   See more about : Sightening and mating periods
   See more about : Asteronotus cespitosus with a commensal shrimp ?

Remarks :

Identification confirmed by Nathalie Yonow
    Synonymous (according worms) :
          - Asteronotus brassica, Allan, 1932
          - Asteronotus fuscus, O.Donoghue, 1924
          - Asteronotus hemprichi, Ehrenberg, 1831
          - Jorunna marchadi, Risbec, 1956

Bibliographic data

The color varies in specimens from different localities. They could have a dark-red, dull yellow or pale green tint. May be these color forms correspond to different species !!!
- In some specimens there are white rings encircling the tubercles.
- In others the border of the mantle margin has a distinct paler line around it.
- In the darkest specimens the tubercles may be paler than the rest of the dorsum.
    The ventral colour is the same as the dorsum.
    The rhinophoral and branchial sheaths are elevated and irregular.
    The gills are brownish or reddish with paler tips.The opening of the branchial sheath has six large lobes pointing towards the centre of the gill. There are six tripinnate branchial leaves, forming a circle which form a complete circle around the anus. Each branchial leaf protrudes through the space between two lobes.
    The rhinophores have normally the same colour as the dorsum.
    The spawn. It consists of three whorls, is 11 cm in maximum diameter, and is speckled pink or orange in colour. A more detailed description of the spawn, as well as the development and behaviour of the larvae of this species, is given by Gohar & Soliman (1967).
    It presumably feeds upon sponge.
    For some reason early naturalists found this animal rather repulsive, giving it a number of names likening it to unattractive body organs (the brain and liver ; Doris cerebralis Gould, 1852; et Doris hepatica Abraham, 1877) or descriptive terms denoting its unattractiveness (Doris foetida Pease, 1860)... Kelaart (1858), when describing it from Ceylon as Doris exanthemata stated : "The whole animal gives one more the idea of a horrid disease than the charms of sea nymph"

References :

Bill Rudman Seaslug site : Sea Slug Forum : Asteronotus cespitosus
   Nudipixel Asteronotus cespitosus

Publications :

Hasselt, J.C.v. (1824). In: Andre Férussac. Extrait d'une lettre du Dr. J.C. van Hasselt au Prof. van Swinderen sur mollusques de Java (traduit de l'Allgem. konst en letterbode, 1824, nos. 2,3,4) Tjuringe (ile Java) le 25 Mai 1823 (1). Bulletin des Sciences Naturelle et de Geologie, 3 : 237-248.
    Gohar, H.A.F. & Soliman, G.N. The biology and development of Asteronotus cespitosus (Van Hasselt) (Gastropoda, Nudibranchia). Publications of the Marine Biological Station Al-Ghardaqa, Red sea no. 14: 177-195
    Valdes. A and Gosliner.T.M. Systematics and phylogeny of the caryophyllidiabearing dorids (Mollusca, Nudibranchia), with descriptions of a new genus and four new species from Indo-Pacific deep waters. Zoological Journal of the Linnean Society (2001), 133: 103–198.

Other photos of Asteronotus cespitosus :

Philibert Bidgrain Gill detail : There are six tripinnate branchial leaves, forming a circle which form a complete circle around the anus.

Rhinophore detail : The rhinophoral sheaths are elevated and irregular.

Philibert Bidgrain Reunion, Etang salé lagoon, under a rock, 29 November 2009, size : 55 mm. The spawn consists of three whorls, is 11 cm in maximum diameter, and is speckled pink or orange in colour. (a) The gonopore

Maurice Jay Reunion, Saint Leu lagoon, with a particular brown-reddish coloration.
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Geoffrey Bertrand Reunion, Etang salé lagoon, 28 December 2014   with a particular brown-reddish coloration.

Philibert Bidgrain Reunion, Etang salé lagoon, under a rock, 15 December 2006, animal size : 55-60 mm.   In this specimen there are white patches encircling some tubercles. And In this darkest specimen the tubercles are paler than the rest of the dorsum. The spawn consists of three whorls, is 11 cm in maximum diameter, and is speckled pink or orange in colour.

Underside pattern coloration variability Photos : P. Bourjon et P. Bidgrain
Réunion, Saint Gilles, size : 40 mm		Réunion, Etang salé, size : 150 mm

Eva Fontaine mtsanga sakouli, Mayotte, reef flat zone, less 1 m, 20 October 2008, size : 15 cm In this large specimen there are white patches encircling some tubercles.

Philibert Bidgrain Reunion, "Etang sale les bains" lagoon, under a rock, 25 November 2005, size : 45 mm In this specimen there are white patches encircling some tubercles arranged in lines perpendicular to the edge of the mantle

Philibert Bidgrain Reunion, "Etang sale les bains" lagoon, under a rock, 25 January 2005, size : 35-40 mm The mantle is transparent at its edge.

Philibert Bidgrain Reunion, "La saline" lagoon, during the night, less 1 m, 23 November 2010, size : 130-150 mm In this large specimen there are many white patches encircling some tubercles.

Laurent Bardot Reunion, Trou d'eau lagoon, during the night, less 1 m, 18 November 2009   A specimen with a pale yellow brown coloration

Christophe Cadet Reunion, "Etang salé " lagoon, less 1 m, 24 January 2011, size : 130 mm A very strange spécimen with numerous extra tubercule all over the notum

Florence Trentin Reunion, Etang Salé lagoon, less 1 m, 18 January 2011, size : 60 mm   A specimen with a dark brown coloration     Spawn from another species... not the good coloration and shape...

   See more about : Asteronotus cespitosus variability in Southwest Indian ocean
   See more about : Asteronotus cespitosus mating behavior and spawn event in Southwest Indian ocean
   See more about : Asteronotus cespitosus with a commensal shrimp ?
   Reunion, Asteronotus cespitosus, at Etang salé, by Philibert Bidgrain
   Reunion, A. cespitosus with numerous white patches, at l'Hermitage, by Guillaume Nédellec et Sully Blancard
   Reunion, Asteronotus cespitosus and the urchin, at Etang salé, by Philibert Bidgrain  
   Reunion, Asteronotus cespitosus matting event, at Etang salé, by Philibert Bidgrain  
   Reunion, rhinophores details of Asteronotus cespitosus, at Etang salé, by Philibert Bidgrain  
   Reunion, Asteronotus cespitosus with some white patches, at Etang salé, by Philibert Bidgrain  
   Reunion, three Asteronotus cespitosus and two spawns, at Saint Gilles, by Philippe Bourjon
   Reunion, a very large Asteronotus cespitosus with white patches, at Etang salé, by Philibert Bidgrain
   Reunion, two spawns, Sclerodoris apiculata and Asteronotus cespitosus, at Etang salé, by Philibert Bidgrain

   Mauritius, Asteronotus cespitosus, at La Gaulette, by Pierre Périès