Elysia sp. 1

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


Order : Sacoglossa
Superfamily : Plakobranchoidea
Family : Plakobranchidae
Distribution : ?
Maximal size : 20 mm
Abundance : Seldom if ever on the rocky coast


Species characteristics :

This Elysia is usually a translucent green colour with numerous white dots scattered all over the body

There is a white to cream margin. Below this line are a few small black dots

Ther is an orange coloration and a black line on the anterior border of the foot

The tip of the rhinophore is washy purple

Elysia sp1
Showing species characteristics...

Photo Christophe Cadet
Reunion, trou d'eau, less 1 m, 7 March 2012, size : 13-15 mm

See more about : Sightening and mating periods

Remarks :

Identification confirmed by Kathe Jensen and Hsini Lin
    The photo of Elysia sp. 27 in NSSI, Nudibranch & Sea Slug Identification, Indo-Pacific, Gosliner, Valdés & Behrens, 2015 corresponded of Kevin Bourdon Photo in this web page...

Bibliographic data :

Typical for this genus, the rudimentary eyes are located behind the rhinophores.
    One way the genera can be distinguished externally (in most cases) is that in Thuridilla there is usually a bright colour pattern, the pigments being quite opaque, while in Elysia, there may be colourful markings but the background colour is usually translucent with the green of the branching internal digestive gland showing through.
    There is a large white mark on the head and numerous smaller white dots on the rhinophores
    The row of raised white spots along each side of the parapodia are similar to Thuridilla kathae, but
              - This specimen hasn't a Y-shaped opaque white mark on head that extends on to the base of the rhinophores and then a second patch of opaque white on the tip of the rhinophore
              - The rhinophores aren't distinctly rolled like in Thuridilla but are more grooved like Elysia

References :

Bill Rudman Seaslug site : Sea Slug Forum : Elysia spp

Other photos of Elysia sp. 1 :

 

Alain-Benoît Rassat

Madagascar, Nosy bé, 20 m, 8 octobre 2017, taille : 10 mm

 

Monika Bachel

Reunion, La Possession, 6m, 28 December 2008, size : 20 mm

 

 

 

 

 

 

In this species the rhinophores aren't meeting at the bases like in Thuridella but they appear to be located more laterally (a) like in Elysia

The rhinophores aren't distinctly rolled like in Thuridilla but are more grooved (b) like in Elysia

The rudimentary eyes (c) are located behind the rhinophores.

 

Sophie Darnis

Reunion, Ravine à Jacques, 5 m, 13 April 2009, size : < 10 mm

In this specimen there is an orange coloration on the parapodia

There is a cream margin. Below this line are a few small black dots

The tip of the rhinophore is washy purple

Sophie Darnis

Reunion, La barge, Saint Paul, 24 m, 20 March 2010

In this specimen there is an orange coloration on the parapodia

The rhinophore have an important washy purple coloration

In this specimen we can see
an orange coloration and a black line on the anterior border of the foot

Christophe Cadet

Reunion, Etang salé on the rocky coast, less 1 m, 20 December 2010, size : 10 mm

Philibert Bidgrain

Mayotte, Mtsanga Tanaraki, less 1 m , 25 Jully 2010, size : 13-15 mm

In this specimen we can see an orange coloration and a black line on the anterior border of the foot

 

 

 

 

Kevin Bourdon

Reunion, Saint Paul, 21 September 2013

 

 More photos from Indian Ocean

Reunion, head detail of Elysia sp 1, at Le Port, by Sully Bachel

Mayotte, head detail of Elysia sp1, at Sakouli, by Philibert Bidgrain