Order : Sacoglossa
Superfamily : Plakobranchoidea
Family : Plakobranchidae
Distribution : Indo-West Pacific
Maximal size : 50 mm
Abundance : Seldom if ever on the fore reef zone

Species characteristics :

The general body color is olive green
   The parapodia are held high and open and when they are closed the undulating lobes form openings. The parapodial margins are orange or pink to light red.
   The body is extremely papillose, and many of the papillae, especially those along the parapodial margins, but also on the external parapodial surface, are branched

This is more or less covered by tiny white dots which may form larger white spots especially on the head and the distal part of the inner parapodial surface. Small orange brown dots are scattered on the body surface as are numerous small black dots, some of which are ocellate.There may be some opalescent, light blue dots
    In some specimen there is a black line on the inside and outside of the parapodia, along the inside edge of the pink parapodial margin.
    The rhinophores are olive green or reddish brown
    The eye are small, rounded, and located behind the rhinophores
    On the internal parapodial surface, six or seven pairs of branching dorsal vessels enter the reno-pericardium opposite one another, distally the branches of the vessels anastomose.
    There is an anterior transverse groove across the foot. The sole foot is uniformly olive green.
    It feeds on Caulerpa ( C. taxifolia, C. racemosa, C. serrulata...) in shallow sublittoral and intertidal reef flats
    Egg ribbon: a sinuous yellow streak.

References :

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

Barbara Bini

Madagascar, Nosy bé, 16 m, 120 November 2017, size : 20 mm

Photo Philibert Bidgrain
Reunion, Saint Leu, Kelonia, 15 April 2009, size : 25 mm

This is more or less covered by tiny white dots

The sole foot is uniformly olive green.

The body is extremely papillose

Philibert Bidgrain

Mtsanga Mboueanatsa, Mayotte, on the reef flat zone, less 1 m, 24 July 2008, size : 30 mm

In this specimen there is a dark red line (a) on the inside and outside of the parapodia, along the inside edge of the pink parapodial margin (b).

There are very long papillae (c) on the parapodial margin.

On the internal parapodial surface, six or seven pairs of branching dorsal vessels (a) enter the reno-pericardium opposite one another, distally the branches of the vessels anastomose.

Photo Christophe Cadet

Reunion, Etang salé, on the rocky coast, less 1 m, 23 November 2010, size : 25 mm

Photo Christophe Cadet

Reunion, Etang salé, on the rocky coast, less 1 m, 14 December 2011, size : 8 mm

A juvenile form ...

Photo Christophe Cadet

Reunion, Etang salé, on the rocky coast, less 1 m, 20 October 2012, size : 10 mm

Another juvenile form ...

Photo Christophe Cadet

Reunion, Etang salé, on the rocky coast, less 1 m, 30 November 2010

According Kathe Jensen " With 6-7 branching vessels I am as sure as I can be that it is E. tomentosa."