Elysia ornata ( Swainson, 1840 )

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


Order : Sacoglossa
Superfamily : Elysioidea
Family : Elysiidae
Distribution : Circum-tropical: Caribbean and Indo-West Pacific.
Maximal size : 50 mm
Abundance : From time to time on the reef flat zone and seldom on the rocky coast


Species characteristics :

The animal is usually a translucent green colour with a black parapodial margin and a submarginal yellow or orange band.
   The tip of the rhinophores often have the same colour bands
   There are also numerous black and white dots all over the body

 Elysia ornata
Showing species characteristics...

Photo Alain Barrére
Reunion, Saint Pierre lagoon, floating on the water at 8 p.m, 01 June 2005, size :15-17 mm

See more about : Sightening and mating periods
   See more about : Elysia ornata variability in Southwest Indian ocean

Remarks :

Identification confirmed by Kathe Jensen and Bill Rudman

Bibliographic data :

The animal is usually a translucent green colour with a black parapodial margin and a submarginal yellow or orange band. Sometimes there is a white line between the orange and black bands
    Elysia ornata was originally described from the Caribbean. Recent anatomical studies suggest that Elysia marginata (Pease, 1871) from the Indo-West Pacific is the same species
    A very similarly coloured species, from the Indo-West Pacific, Elysia grandifolia, It grows to a very large size, 10 cm or more, the parapodia are large and very thin, and the black and orange bands at the edge of the parapodia are not separated by white.
    Jensen (1992) reports that E. ornata feeds on Bryopsis in both the Caribbean and the Indo West Pacific. The Sacoglossans are unique in their very specialised feeding mechanism, they pierce a hole in the algae and suck out the cell contents.
    Typical for this genus, the rudimentary eyes are located behind the rhinophores.

References :

Bill Rudman Seaslug site : Sea Slug Forum : Elysia ornata
   Nudipixel Elysia ornata

Publications :

Jensen, K.R. (1992) Anatomy of some Indo-Pacific Elysiidae (Opisthobranchia: Sacoglossa (=Ascoglossa), with a discussion of the generic division and phylogeny. Journal of Molluscan Studies, 58(3) : 257-296

Other photos of Elysia ornata :

 

Eva Fontaine

Mayotte, Mtsanga Tanaraki, less 1 m, 25 Jully 2011, size : 15 mm

Some specimens from Mayotte Island have some constant pattern variations :

- Presence of a white line (a) between the orange and black bands

- Presence of large diffuse white patches (b) just under the marginals band

- Absence of small white dots on the body wall, just only black spots...

We need other photo from Mayotte to confirm this observation

Elysia ornata

Philibert Bidgrain

Found in a pool at "Kélonia center" a Marine Turtle Center in Saint Leu. Réunion, 20 March 2010, size : 20-25 mm

A specimen with a coloration pattern very clear.

The parapodial margin is bright yellow and black

 

Philibert Bidgrain

Reunion, Etang salé les bains, on the rocky coast

17 October 2005, size : 20mm

 Elysia ornata

 

Philibert Bidgrain

Reunion, Etang salé lagoon, under a rock, less 1 m, 3 February 2007, size 15-18 mm

Fabrice Schubert

Mayotte, Mliha, 3m, 17 January 2010, size : 30 mm

The animal is usually a translucent green colour with a black parapodial margin and a submarginal orange band.

In this specimen there is a white line (a) between the orange and black bands

Specimen with very few white spots on the parapodia

Philibert Bidgrain

Reunion, Trou d'eau lagoon, less 1 m, 2 July 2010, size 8 mm

An anormal or partially eaten specimen with only a partial parapodia

Stéphane Ciccione

Found in a pool at "Kélonia center" a Marine Turtle Center in Saint Leu. Réunion, 23 August 2010, size : 45 mm

Pericardium (a) and blood dorsal vessels (b).

 

 

Philibert Bidgrain

Mayotte, mtsanga M'titi Sada , less 1 m, 17 July 2010, size 15 mm

 

Christophe Mason-Parker

Seychelles, baie Ternay, Mahé, 1 m, 14 November 2010

The animal is mottle green colour with a black parapodial margin and a faint submarginal yellow/orange band on parapodial margin and rhinophores

 

 

Pierre Conchylinet

Mauritius, 20 m

Presence of a white line (a) between the orange and black bands

Presence of a large dark green area (b) near the marginal bands

 More photos from Indian Ocean

See more about : Elysia ornata variability in Southwest Indian ocean

Reunion, three Elysia species in the same area, at Etang salé, by Philibert Bidgrain

Reunion, friendly meeting between two Elysia species, at Etang salé, by Philibert Bidgrain

Reunion, Elysia ornata, at Saint Paul, by Alain Diringer

Reunion, Elysia ornata, at Trou d'eau, by Philibert Bidgrain

Mauritius, dark green Elysia ornata, at Mahebourg, by Yann von Arnim