Gymnodoris ceylonica ( Kelaart, 1858 )

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


Order : Nudibranchia
Suborder : Euctenidiacea
Superfamily : Polyceroidea
Family : Gymnodorididae
Distribution : Indo-West Pacific
Maximal size : usualy 60 mm but sometimes 120 mm
Abundance : (Run) From time to time (May and Mau) May be present in large population during spawning event


Species characteristics :

Translucent white body with small bright orange-red spots.

The small rhinophores have pale orange tips.

The 9 to 10 very large gills with an orange line up the outer face, form a circle

A yellow line round the edge of the foot

Gymnodoris ceylonica
Showing species characteristics...

Photo Philibert Bidgrain
In a pool at "Kélonia center" a Marine
Turtle Center. Saint Leu, Réunion,
size 80-90 mm, 15 November 2005.

See more about : Sightening and mating periods

See more about : Gymnodoris ceylonica variability in Southwest Indian ocean

See more about : Gymnodoris ceylonica feeding behavior, a seahare predator

Remarks :

Identification confirmed by Hsini Lin and Bill Rudman
    Synonymous : (according Worms)
               - Trevelyana ceylonica Bergh, 1858
               - Trevelyana zeylanica Bergh, 1858

Bibliographic data :

The body which is very soft, lacks a notal brim separating the mantle from the sides of the foot. The foot is larger than the mantle.
    The largest spots which are on the center of the back, are usually raised on low pustules
    G ceylonica is commonly found in shallow grass beds and sandy habitats. It is nocturnal.
    The yellow-orange eggs are arranged in clusters of 20-40 as described by Johnson & Boucher (1983), in loosely spiralled masses.
    The genital aperture is situated on the right side half way between the rhinophore and the gills.
    Breeding aggregation have been observed in Queensland and the Salomon Islands and now from Mauritius and Mayotte Islads (see below...)
    Species of Gymnodoris are voracious predators of other opistobranches, G.ceylonica commonly feeds upon the sea hare Stylocheilus striatus.
    It has similarities in colour pattern to G. impudica but in G. impudica the orange spots are much larger and more densely arranged, the body is more elongated. In G.ceylonica there is only one orange or red line in each gill but some bifurcated lines can be observed in G impudica. There are also major anatomical differences

References :

Bill Rudman Seaslug site : Sea Slug Forum : Gymnodoris ceylonica
   Nudipixel Gymnodoris ceylonica

Publications :

Kelaart, E.F. (1858). Description of a new Ceylonese nudibranch. Annals & Magazine of Natural History, (Ser.3), 1(4) : 257-258, Pl. 10B.
    Yonow N. (2011) Results of the Rumphius Biohistorical Expedition to Ambon (1990). Part 15. The suborder Doridina (Mollusca, Gastropoda, Opisthobranchia, Nudibranchia). Zoologische Mededelingen 85(17): 905-956.

Other photos of Gymnodoris ceylonica :

Philibert Bidgrain

This specimen was observed in a pool at "Kélonia center" a Marine Turtle Center in Saint Leu. Réunion,

You can see the genital aperture, situated on the right side half way between the rhinophore and the gills.

Saint Leu, size 80-90 mm, 15 November 2005.

Gymnodoris ceylonica

spawning behavior

François Beudard

This species spawns in November in a pool at "Kélonia center" Réunion,

The yellow-orange eggs are arranged in clusters, in loosely spiralled masses.

spawn filament

Philibert Bidgrain

This species spawns in November in a pool at "Kélonia center" Réunion,

The yellow-orange eggs are arranged in clusters of 20-40 as described by Johnson & Boucher (1983), in loosely spiralled masses.

gymnodoris ceylonica

Philibert Bidgrain

This specimen was observed in a pool at "Kélonia center" a Marine Turtle Center in Saint Leu. Réunion,

Size 70 mm , 18 November 2005

The orange spots are small and numerous, compared to the three other specimens found during this period.

Eva Fontaine

mtsanga Mbouéanatsa at Mayotte, on the reef flat zone, less 1 m, 2 August 2008

A few specimens aggregate probably for spawn...

 

A very large number of G ceylonica was observed on the reef flat zone during this period, with numerous spawns.

 Gymnodoris ceylonica

This species spawns.

The yellow-orange eggs are arranged in clusters, in loosely spiralled masses.

Yann Von Arnim

Ferme Marine de Mahebourg, Mauritius, 3 October 2008, 22m,

A large number of G. ceylonica was observed during one week ( 3 to 10 October). After this week the population decreased. During the last dive ( 17 October )we observed only a few specimens and some dead animals.

See also Fabrice Bettex observation in December 2008...

During this swarning events,

This species spawns...The yellow-orange eggs are arranged in clusters, in loosely spiralled masses.

During this swarning events,

This species eats... some Stylocheilus striatus

 More photos from Indian Ocean

See more about : Gymnodoris ceylonica variability in Southwest Indian ocean

See more about : Gymnodoris ceylonica feeding behavior, a sea hare predator

Mauritius, Gymnodoris ceylonica, at Récif des murènes, by Mathieu Bayon.

Mayotte, two differents patterns of Gymnodoris ceylonica, at Mbouéanatsa, by Eva Fontaine 

Mayotte, anormal coloration of Gymnodoris ceylonica, at Mbouéanatsa, by Eva Fontaine 

Mauritius, aggregate of Gymnodoris ceylonica, at Grand Baie, by Fabrice Bettex 

Reunion, Gymnodoris ceylonica on seagrass, at Saint Gilles, "Parc Marin" 

Reunion, Gymnodoris ceylonica eating a Stylocheilus striatus, at Saint Paul, by Alain Diringer  

Seychelles, Gymnodoris ceylonica, at Mahé, by Christophe Mason-Parker 

Madagascar, Gymnodoris ceylonica mating, at Nosy Bé, by Michel Touze