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

Order : Nudibranchia Suborder : Euctenidiacea Superfamily : Phyllidioidea Family : Phyllidiidae Distribution : Western Indian Ocean - known from Maldives and Mauritius. Maximal size : 50 mm Abundance : Frequently on the fore reef zone Species characteristics : This species is characterised by four longitudinal black.    The inner pair runs from behind the rhinophores to just in front of the anal papilla.    The external pair line on each side which runs from the anterior edge of the mantle back to behind the anal papilla.     The median row of tubercles are usually tipped with orange/yellow.     The rhinophores are yellow.
	Showing species characteristics...	Photo Florence Trentin Reunion, "Cap la Houssaye" at Saint Paul, 14 m, 17 January 2005, size : 18-20mm

See more about : Sightening and mating periods
   See more about : Phyllidia alyta variability in Southwest Indian ocean

Remarks :

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

Bibliographic data :

There is a solid black median line on the sole of the foot which is broken anteriorly into one or two patches.
    There is a median row of tubercles which are usually tipped with orange/yellow, and a second row of tubercles on each side which are rarely tipped in yellow/orange.
    Outside the longitudinal black lines are another row of tubercles and outside that row small irregularly scattered tubercles at the mantle edge. In some specimens this area is ornamented with some black horizontal lines.
    There is also usually a black tranverse band between the rhinophores.
    I seems that larger specimens may develop yellow-capped tubercles in the three central rows (see below ).

Similar species

This species has been confused with Phyllidia varicosa who also possesses a solid black median line on the sole of the foot. But P. varicosa has on all the rows, many yellow-capped notal tubercles ( only few and in the three inner rows in P.alyta ). P. varicosa hasn't the four caracteristics longitudinal blacklines , which are organized with a inner pair runs from behind the rhinophores to just in front of the anal papilla, and an external pair line on each side which runs from the anterior edge of the mantle back to behind the anal papilla...
    It looks like Phyllidiopsis gemmata, but in P.gemmata the rhinophores are not yellow.

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

One specimen collected from Pereybere (Mauritius), 29 October 1985, size : 38 mm. Another specimen collected from Belle Mare (Mauritius), 27 February 1990, size : 19mm

References :

Bill Rudman Seaslug site : Sea Slug Forum : Phyllidia alyta
   Nudipixel Phyllidia alyta

Publications :

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
   Yonow, N., (1996) Systematic Revision of the Family Phyllidiidae in the Indian Ocean Province: Part 1 (Opisthobranchia: Nudibranchia: Doridoidea). Journal of Conchology, 35: 483-516

Other photos of Phyllidia alyta :

Fabien Michenet Reunion, "Cap la Houssaye" at Saint Paul, 6m, 20 November 2005 Detail of rhinophores, gold in colour, and each rhinophoral clavus possesses about 18-20 lamellae

Emmanuel Eby Reunion, Saint Leu. A specimen without any tubercles tipped with orange/yellow.

Emmanuel Eby Reunion, Saint Leu May be a juvenile form.

Florence Trentin Reunion, "Cap la Houssaye " at Saint Paul, 14 m, 17 January 2005, 18-20 mm.
Upper view	There is a solid black median line on the sole of the foot which is broken anteriorly into one or two patches.

Alain Barrère Reunion, "Cap la Houssaye" at Saint Paul, 15 m, 18 January 2005. In this specimen the rhinophores and the rhinotubercules are yellow, and there are some more yellow-capped tubercles in the three inner tubercles rows.

Mathias Deuss Plage du préfet, Mayotte, on the refflat zone, 1.5 m, 9 August 2009, size : 45mm. A specimen with a very important amoung of yellow-capped tubercles in the three inner tubercles rows.

Florence Trentin N'Gouja, Mayotte, 1 August 2006 A small specimen with a strange pattern... The two inner black line are partialy coalescent.

Christophe Mason-Parker Seychelles, Lilot, Mahé, 13 m, 21 August 2012   Outside the longitudinal black lines are another row of tubercles and outside that row small irregularly scattered tubercles at the mantle edge. In this specimen this area isn't ornamented with some black horizontal lines.

Françoise Summers Mauritius, Flic en Flac, 16 May 2015

See more about : Phyllidia alyta variability in Southwest Indian ocean
   Reunion Island, mating between two P.alyta, at Saint Leu, by Emmanuel Eby
   Reunion, an abnormal Phyllidia alyta, at Etang salé, by Hugues Flodrops
   Reunion, P alyta without tipped yellow tubercles, at Saint gilles, by Sébastien Flouvat
   Mayotte, Phyllidia alyta with three rows of yellow-capped tubercle, at Sasiley, by Eva Fontaine
   Mauritius, drawing of a specimen of Phyllidia alyta, from Pereybere, by Nathalie Yonow  
   Reunion, Phyllidia alyta with one row of yellow-capped tubercle, at Etang salé, by Raphaël Roland Gosselin  
   Mayotte, Phyllidia alyta with inner interrupted black lines, at Passe en S, by Florence Trentin  
   Reunion, Phyllidia alyta with a pink background, at Etang salé, by Christine Bottin  
   Madagascar, Phyllidia alyta, at Nosy Bé, by Alain-Benoît Rassat