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

Order : Nudibranchia Suborder : Dexiarchia Superfamily : Tritonioidea Family : Bornellidae Distribution : Indo-West Pacific. Maximal size : 80 mm Abundance : Seldom : on the fore reef zone Species characteristics : It has a very characteristic mosaic-like colour pattern with orange, yellow and white spots. Presence of appendages along the animal.
	Showing species characteristics...	Photo Geoffrey Bertrand Reunion, "Cap la Houssaye" at Saint Paul, 5-6 m, 21 January 2011, size : 70 mm

See more about : Sightening and mating periods

Remarks :

Identification confirmed by Bill Rudman and Nathalie Yonow
    Synonymous : (according Worms)
               - No other name

Bibliographic data :

Its name (anguilla = eel) refers to its method of swimming. While most species of Bornella can swim by a lateral flexion of their body, in B. anguilla a muscular wave travels down the body to produce an eel-like motion. When disrupted, it swims with a sideways ondulation of its entire body.
    It is noctural and is reported by Johnson to feed on the hydroid Plumularia.
    The appendages formed by an association of secondary gills and the paired "cerata", similar to the small gills found in some species of Doto. In species of Bornella they don't have a defensive function (like the cerata).
   The anus opens on the right side just below and between the first and second cerata.
   The reproductive opening is further forward on the right side, below and between the rhinophore and the first cerata.

Material examined by Nathalie Yonow ( see reference/publications).

One specimen collected from Le morne (Mauritius), 18 October 1985, size : 45 mm. One other from Belle mare (Mauritius), 27 February 1990, size : 49 mm. And one other from Trou aux Biches (Mauritius), 2 March 1990, size : 31 mm

References :

Bill Rudman Seaslug site : Sea Slug Forum : Bornella anguilla
   Nudipixel Bornella anguilla

Publications :

Johnson, S. (1984) A new Indo-West pacific species of the dendronotacean nudibranch Bornella (Mollusca: Opisthobranchia) with anguilliform swimming behaviour. Micronesica, 19(1) : 17-26. [for 1983]
   Yonow, N. and Hayward , P. J. (1991). Opistobranches de l'île Maurice, avec la description de deux espèces nouvelles (Mollusca : Opistobranchia) Revue française d'aquariologie herpétologie, 18 (1), 1-30

Other photos of Bornella anguilla :

Geoffrey Bertrand Reunion, "Cap la Houssaye" at Saint Paul, 5-6 m, 21 January 2011, size : 70 mm It has lobe-like digitate oral tentacles (a) on each side of the mouth The rhinophore complex (b) The first pair of dorso-lateral processes (c) with the gills (d)

Maurice Jay Reunion, A specimen with less black background coloration on the mantle.

Emmanuelle Aigle Mayotte, Mliha, 4 m, 20 December 2009, size : 20 mm During the night, it is a nocturnal seaslug...

Thierry Peres Reunion, Cap la Houssaye, 3 July 2010, size : 30-40 mm You can see the video on YouTube While most species of Bornella can swim by a lateral flexion of their body, in B. anguilla a muscular wave travels down the body to produce an eel-like motion.

Mauritius, drawing of an Bornella anguilla specimen, from Le Morne, by Nathalie Yonow

Tanzania, Bornella anguilla, at Pemba, by Maria Efremova-Holmes 

Madagascar, Bornella anguilla, at Nosy Bé, by Alain-Benoît Rassat