Thuridilla multimarginata Gosliner, 1995

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This species has been observed on Reunion and Mauritius Islands


Order : Sacoglossa
Superfamily : Plakobranchoidea
Family : Plakobranchidae
Distribution : Indo-West Pacific
Maximal size : 12 mm
Abundance : Seldom if ever on the reef flat zone


Species characteristics :

The animal is orange or light to dark green with white colour markings on the head.

There is a narrow white line at the parapodial margin and it is enlarged at regular intervals. Below this line are consecutive, narrow stripes of orange, black, pale blue, and black, all wavy

The head and most of the rhinophores have opaque white pigment with sometimes orange marks. The tips of the rhinophores are black ( diffuse black pigment)

Showing species characteristics...

Photo Christophe Cadet
La Saline lagoon, less 1 m, 30 December 2009, size : 12 mm

See more about : Sightening and mating periods
   See more about : Thuridilla phylogeny by Gosliner 1995
   See more about : Thuridilla multimarginata variability in Southwest Indian ocean

Remarks :

Identification confirmed by Terry Gosliner and Kathe Jensen
    Synonymous : (according Worms)
               - No other name

Bibliographic data :

The parapodia completely cover the body and meet in a straight line along the dorsal midline
    The specimen from South Africa has more diffuse black pigment on the tip of the rhinophore while the Hawaiian specimens have some green and opaque white on most of the rhinophores with black at the apex.
    The anterior margin of the foot has orange, black, blue and black lines
    This species is named for the multiple bands of pigmen found on and below the parapodial margins
    In external morphology, T multimarginata most closely resembles to T. indopacifica and T. livida.
            - All three species have orange, black and blue parapodial lines.
            - But T indopacifica hasn't marginal white pigment and it has only a thin brownish black edge, then a broad band of yellow or orange, then a band of black and then a broken bright blue band.
            - But T livida hasn't marginal white pigment and it has only a series of longitudinal lines of orange, black and blue.
    Comparative data of the five Thuridilla with black, orange and blue margin found in our area...

 

T. multimarginata

T. indopacifica

T. livida

T. hoffae

T. undula

Parapodial margin

Narrow white edge enlarged at regular intervals, then a narrow stripes of orange, black, pale blue, and black.

Thin brownish black edge, then a broad band of yellow-orange, and an irregular band of black. In the spaces between the blackish extensions are bright blue

Black edge followed by lines of orange, black and narrow iridescent blue

Bright yellow-orange edge, followed by a thin black line and a diffuse broad light blue to blue green band.

Broad burnt orange edge, followed by lines of black and vivid blue

Head

Opaque white pigment with sometimes orange marks

Blue with a centrally placed Y-shaped opaque white patch

Dark brown to black

Black to dark blue

Black and reflective blue pigment.

Rhinophores

They have opaque white pigment with sometimes orange marks
    The tips of the rhinophores are black

The base are whitish to pale blue. At the tips are bands of blue, black, orange-yellow and black.
   Not observed in our specimens

They are dark brown to black
    The apical half has opaque white pigment

They are light blue except for the tip which is dark-blue

The base are turquoise bluish green. At the middle are narrow bands of blue and black. The apex is orange

Body

Orange or light to dark green

Translucent green with scattered opaque white spots

Dark brown to black

Black to dark blue

Turquoise bluish green

Anterior margin of the foot

It has orange, black, blue and black lines

It has black, orange-yellow , black and blue bands

It has black, orange and blue lines .

It hasn't blue and orange lines

It has orange, black and blues bands.

References :

Bill Rudman Seaslug site : Sea Slug Forum : Thuridilla multimarginata
   Nudipixel Thuridilla multimarginata

Publications :

  Gosliner, T.M. (1995) The genus Thuridilla (Opisthobranchia: Elysiidae) from the tropical Indo-Pacific, with a revision of the phylogeny and systematics of the Elysiidae. Proceedings of the California Academy of Sciences, 49(1) : 1-54.
    Jensen, K.R. (2007). Biogeography of the Sacoglossa (Mollusca, Opisthobranchia). Bonner Zoologische Beiträge. 55: 255281.

Other photos of Thuridilla multimarginata :


Christophe Cadet

La Saline lagoon, less 1 m, 24 December 2009, size : 12 mm

There narrow white line (a) at the parapodial margin is very thin in this specimen. Below this line are consecutive, narrow stripes of orange (b), black (c), pale blue (d) and black (e), all wavy


Christophe Cadet

Etang salé lagoon, less 1 m, 26 May 2010, size : 12 mm

A specimen with an importante white line (a) at the parapodial margin

The head and most of the rhinophores have opaque white pigment with orange marks (b)

 


Christophe Cadet

Etang salé lagoon, less 1 m, 30 May 2010, size : 10 mm

The animal body is brown-orange to dark green-orange with white colour markings on the head.

 


 

 

Christophe Cadet

Etang salé lagoon, less 1 m, 26 May 2010, size : 10 mm

The animal body is bright-orange with white colour markings on the head.


 More photos from Indian Ocean

See more about : Thuridilla phylogeny by Gosliner 1995

See more about : Thuridilla multimarginata variability in Southwest Indian ocean

Reunion, Thuridilla multimarginata with rhinophores like a bull, at La Saline, by Christophe Cadet

Mauritius, Thuridilla multimarginata at Pointe d'Esny, by Geoffrey Summers