Phyllidia ocellata     Cuvier, 1804

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


Order : Nudibranchia
Suborder : Euctenidiacea
Superfamily : Phyllidioidea
Family : Phyllidiidae
Distribution : Tropical Indo-West Pacific, including Red Sea.
Maximal size : 70 mm
Abundance : Frequently on the fore reef zone

Species characteristics :

The rhinophores of this sea slug are gold in colour

The dorsum has a gold background.

Variant 1 : The coalescent black area (undulating lines in that specimen) is bordered with white area.

sea slug phyllidia ocellata E.Eby

Showing species characteristics...

Photo Emmanuel Eby
Variant 1: Reunion, Saint-Leu 6 May 2004.

 

 

Other variants of Phyllidia ocellata :


sea slug phyllidia ocellata F.Trentin

Florence Trentin

Variant 2 :

The 8 to 10 black areas, bordered with white aren't coalescent.

Reunion,


Olivier Aubrespine

Reunion, Saint Pierre lagoon, 29 April 2003, size 20-30 mm.

Variant 3 :

The 8 to 10 black areas are included in a large white coalescent area.

The black areas aren't coalescent

phyllidia ocellata


Emmanuel Eby

Reunion, Saint Leu, 24 March 2004

Variant 4 :

The 8 to 10 black rings (each with a central white and yellow tubercle), bordered with white aren't coalescent.

sea slug phyllidia ocellata E.Eby


sea slug Phyllidia ocellata F.Trentin

Florence Trentin

Reunion, Saint Leu, 11 May 2004

Variant 5 : The 8 to 10 black rings (each with a central white and yellow tubercle) are included in a large white coalescent area.

The black rings (each with a central white and yellow tubercle) aren't coalescent.


Erwan Meyer

Reunion, Saint Leu, 27 August 2005

 

Variant 6 : The 8 to 10 black rings (each with a central white and yellow tubercle) taking shape of a partial black coalescent area bordered with white.

phyllidia ocellata


Alain-Benoît Rassat

Madagascar, Nosy Bé, Plateau des arches, 17 m, 21 April 2012, size : 50 mm

 

Variant 7 : The tubercules are yellow and surrounded by a white border. The rest of the mantle is black

Le tubercules sont de couleur jaune et entouré d'une bordure blanche . Le reste du manteau est noir


Alain-Benoît Rassat

Madagascar, Nosy Bé, 20 m, 1 May 2012,

 

Variant 8 : Tubercles yellow, some of them are surrounded by a small ring white and black. In fact a variant 4 with a few white and black marking.

The coat is uniformly yellow.

See more about : Sightening and mating periods
   See more about : Phyllidia ocellata in association with Brittle star
   See more about : Phyllidia ocellata variability in Southwest Indian ocean

Remarks :

Identification confirmed by Bill Rudman
    Synonymous (according worms) :
          - Phyllidia baccata Pruvol-Fol, 1957                                       - Phyllidia tuberculata Baba, 1930
          - Phyllidia japonica Baba, 1937                                            - Phyllidiopsis carinata , Eliot, 1910
          - Phyllidia ocellata undula Yonow, 1986                 

Bibliographic data :

There is little ontogenetic variation in external pattern (juveniles resemble the adults), however considerable individual variation in dorsal pattern occurs in this sea slug species.
    In Reunion Island we can find six kinds of variants (see upper photos).

Material examined by David J.Brunckhorst ( see references/publications).

30, 28 & 15 mm specimens, Reunion Island, 5-20m depth, 1989, M.Jay
    50, 45 & 40 mm specimens, Reunion Island, 1-20m depth, 1987, M.Jay

Other external morphology characteristics

Live specimens ranged in length from 16-70 mm and the average being 39 mm.
    The rhinophores of this sea slug are gold in colour, and each rhinophoral clavus possesses 27 to 30 lamellae (specimens greater than 40mm).
    The rounded or conical tubercles are usually isolated and may be gold, or white in colour, their surface is often irregular because of the underlying matrix of supporting spicules. Some tubercles are compound in some specimens, but generally they do not coalesce into continuous ridges.
    Often the median tubercles appear to line up longitudinally, almost joining as a ridge.
    The foot sole is paler towards the margin and lacks any distinctive marking.

Similar species

It appears to be closest in colour to the sea slug Phyllidia flava, but P. flava does not have any black pigmentation.
    Phyllidia varicosa , Phyllidia tula , and Phyllidia coelestris have yellow capped tubercles, but all have blue-grey pigmentation and the two ( P. varicosa and P. tula ) have a black stripe on the foot sole.

References :

Bill Rudman Seaslug site : Sea Slug Forum : Phyllidia ocellata

Publications :

Brunckhorst, D.J. (1993) The systematics and phylogeny of Phyllidiid Nudibranchs (Doridoidea). Records of the Australian Museum, Supplement 16: 1-107.

Other photos of Phyllidia ocellata :


Alain-Benoît Rassat

Madagascar, Nosy Bé, Pterois, 15 m, 14 September 2013 : size 20 mm for the smaller.

 

 

Mating between two different pattern variant 1 and variant 8


 

 

Florence Trentin

Reunion, 13 April 2008

Mating between two different pattern variant 3 and variant 1


Maurice Jay Reunion, Cap La Houssaye, 10-20 m.

Variant 1 Variant 2
sea slug phyllidia ocellata M.Jay sea slug phyllidia ocellata M.Jay


Emmanuel Eby

Variant 1

Reunion, Saint Leu, 11 May 2004

sea slug phyllidia ocellata E.Eby


sea slug Phyllidia ocellata F.Trentin

Florence Trentin

Variant 1

Reunion, Saint Leu

The black areas aren't completely coalescent.


Sandrine Flodrops

Reunion, "Sec Jaune" at Saint Leu, 15m, 3 November 2008, size : 30 and 45 mm

This seaslug has been reported feeding on the orange sponge Higginsia massalis by Dave Brunckhorst (1993) so it could be this species...

Variant 4


Raphaël Roland Gosselin

 

Reunion, Les kiosques, Saint Leu, 31 October 2008.

 

Variant 2 :

Absence of large tubercles and presence in middle position of "three ridges " formed by small tubercles

A strange specimen...

 


Matthias Deuss

Mayotte, Banc du Boa, Ilots Choizil, 20 m, 2 September 2009, size : 25 mm

.Partial Variant 6 : The 8 to 10 black rings (each with a central white and yellow tubercle) taking shape of a partial black coalescent area bordered with white.

A very tuberculated specimen...


   More photos from Indian Ocean
   See more about : Phyllidia ocellata in association with Brittle star
   See more about : Phyllidia ocellata variability in Southwest Indian ocean
   Reunion, two Phyllidia ocellata variant 2 (mating), at Saint Pierre, by Olivier Aubrespin
   Reunion, P. ocellata var 4 with numerous small black and white spots, at Saint Leu, by Philibert Bidgrain
   Mauritius Island, P. ocellata var 1 without completely coalescent black area, at Recif corsaire, by M. Bayon
   Mauritius, Phyllidia ocellata variant 4, at Grand Baie, by Mathieu Bayon
   Reunion, P. ocellata var 1 with posterior bilateral coalescence, at Saint Gilles, by Fabien Michenet
   Mauritius, Phyllidia ocellata variant 4, at Mahebourg, by David Caron
   Mauritius, P. ocellata var 4-5 with numerous black and white spots, at Pereybere, by M. Poddubetskaia
   Mauritius, Phyllidia ocellata variant 2 with some black area, at Pereybere , by Marina Poddubetskaia
   Reunion, Phyllidia ocellata variant 3 with anterior bilateral coalescence, at Saint Leu, by Florence Trentin
   Reunion, Phyllidia ocellata variant 1 with middle bilateral coalescence, at Saint Leu, by Hugues Flodrops
   Reunion, Phyllidia ocellata variant 4 with white tiped tubercle, at Saint Leu, by Guillaume Boeye
   Reunion, P. ocellata var 1 with large posterior bilateral coalescence, at Saint Leu, by Sophie Darnis
   Reunion, heavy bkack coloration in Phyllidia ocellata variant 1, at Saint Gilles, by Alain Martinat
   Reunion, symmetric front dorsal view of P. ocellata variant 1, at Saint Paul, by Sebastien Flouvat 
   Reunion, P. ocellata var 4-5 with numerous black and white spots, at Saint Gilles, by Sophie Darnis
   Reunion, Phyllidia ocellata variant 4 with white tiped tubercles, at Saint Leu, by Jean Louis Fabry
   Mayotte, Phyllidia ocellata variant 4, at Passe en S, by Matthias Deuss
   Reunion, Phyllidia ocellata var 1 with invasive black area, at Etang salé, by Raphaël Roland Gosselin
   Reunion, Phyllidia ocellata partial variant 1, at Saint Paul, by Jean-Marc Ferrand
   Seychelles, Phyllidia ocellata variant 2, at Mahé, by Christophe Mason-Parker
   Reunion, mating between variant 2 and 3 of Phyllidia ocellata, at Saint Gilles, by Nathalie Rodrigues