This species has been observed on Reunion, Mauritius, Mayotte and Madagascar Islands
Order : Nudibranchia
Suborder : Euctenidiacea
Superfamily : Doridoidea
Family : Discodorididae
Distribution :
Indo-West Pacific.
Maximal size :
max 200 mm
Abundance : Frequently on the reef flat zone
Species characteristics :
The large and high branchial pocket make the gills stand erect.
The
mantle is covered with small yellow/orange spots and brownish lines
forming a large irregular reticulate. Near the edge of the mantle there
are several broken, longitudinal white lines.
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Showing species characteristics... |
Photo Philibert Bidgrain
Réunion, Etang salé les bains lagoon, 220 mm
01 January 2005
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See more about : Sightening and mating periods
See more about : Mating behavior and spawn event, Jorunna rubescens
See more about : A sponge predator, Jorunna rubescens
See more about : Excretion, Jorunna rubescens
See more about : Jorunna rubescens abnormality
See more about : Annual change in population
of Jorunna rubescens in l'Hermitage lagoon
Remarks :
Identification confirmed by Bill Rudman
We observed also according NSSI 2018 Jorunna rubecens juvenile pattern
Synonymous : (according Worms)
- Kentrodoris rubescens, Bergh, 1876
Bibliographic data :
The body is elongate, narrow and very elevated. The texture is soft and
velvety. The dorsum is entirely covered with long spiculate papillae
(caryophyllidia), about 130 µm in length which are characteristic of
that genus.
The general colour of the living animals varies from cream to pale
orange. Normally, the anterior and posterior edges of the notum, as
well as the edges of the rhinophoral and branchial sheaths, are darker,
sometimes almost black.
The entire dorsum is covered with
numerous longitudinal dark brown streaks. Among them, there are several
yellow/orange low protuberances, which are also present in the
rhinophoral and branchial sheaths.
The mantle margin is wide, but stays close to the laterals of the foot.
The foot has the same colour as the dorsum, with an irregular pattern
of broken brown streaks and some white lines.
The rhinophoral and branchial sheaths are very elevated and regular.
- There are
seven, branchial leaves, forming a circle, posteriorly closed by the
anal papilla. The branchial leaves have the same colour as the dorsum,
except for the rachis, which is white proximally and dark brown
distally. The rachis of the secondary and tertiary branches is also
dark brown.
- The rhinophores
are elongate, with 25 lamellae in a 38 mm preserved length specimen.
The rhinophores are dark brown with the apex white. They may have dark
brown spots near the apex.
The egg mass is a pink convoluted ribbon.
Bill Rudman would have suggested, that Jorunna rubescens
was a spasmodic visitor rather than a permanent resident. He has only
seen it alive a few times, the first time was in Tanzania, where he
came across a very large population in a relatively shallow reefal
lagoon with mixed sand, sea grass and coral heads. Most were large
animals and there were many egg ribbons. Within a month they had all
gone. That is the only time he has seen more than two at a time.
In Reunion Island I observed sometimes J. rubescens
crawling or laying in "Etang salé les bains lagoon" and "La Saline
lagoon" during all the year with a maximum in summer (November to
February).
Emmanuel Eby observed a pair of Jorunna rubescens ( see photo below) mating on Saint Leu reef (15 m) in late December.
References :
Bill Rudman Seaslug site : Sea Slug Forum : Jorunna rubescens
Nudipixel Jorunna rubescens
Publications :
Bergh, L.S.R. (1876). Malacologische Untersuchengen. In: C.G. Semper,
Reisen im Archipel der Philippinen, Wissenschaftliche Resultate, 10:
377-427
Camacho-García Y.E. & Gosliner T.M. (2008). Systematic revision of Jorunna Bergh, 1876 (Nudibranchia: Discodorididae) with a morphological phylogenetic analysis. Journal of Molluscan Studies 74 : 143-181
Valdes, A. and Gosliner, T. M. (2001). Systematics and phylogeny of the
caryophyllidia bearing dorids (Mollusca, Nudibranchia), with
descriptions of a new genus and four new species from Indo-Pacific deep
waters Zoological Journal of the Linnean Society, 133: 103–198.
Other photos of Jorunna rubescens :
Philibert Bidgrain
Réunion, Etang salé les bains lagoon, 220 mm
01 January 2005
This specimen (the same as the upper photo) presents on posterial position an abnormal excroissance of its body. |
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Florence Trentin
Réunion, Etang salé les bains lagoon
02 February 2006
Spawn diameter, about 6 to 8 cm.
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Christine Bottin
Réunion, Etang salé les bains lagoon, 17 December 2006 at 9 a.m
The egg mass is a pink convoluted ribbon. |
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Philibert Bidgrain
Réunion, "Saint Pierre lagoon", 1 December 2006, size 100-120 mm
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1 : The dorsum is entirely covered with long spiculate papillae (caryophyllidia), about 130 µm in length which are characteristic of that genus.
2 : The branchial leaves
have the same colour as the dorsum, except for the rachis, which is
white proximally and dark brown distally. The rachis of the secondary
and tertiary branches is also dark brown.
3 : The rhinophores are dark brown with the apex white. They may have dark brown spots near the apex.
You can see the mouth between the two mantle flap... |
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Emmanuel Eby
Réunion, A pair of Jorunna rubescens mating on Saint Leu reef (15 m)
"Maison verte" at Saint Leu, 26 December 04
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Hugues Flodrops
Réunion, Etang salé les bains lagoon, 60 cm, temperature 26°C, 28 October 2005 (17h45).
size 110 mm A Specimen eating a sponge during the day...
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Philibert Bidgrain
Réunion, Etang salé les bains lagoon
The foot has the same colour as the dorsum, with an irregular pattern of broken brown streaks and some white lines. |
More photos from Indian Ocean
See more about : Mating behavior and spawn event, Jorunna rubescens
See more about : A sponge predator, Jorunna rubescens
See more about : Excretion, Jorunna rubescens
See more about : Jorunna rubescens abnormality
Reunion, Jorunna rubescens, in Saint Pierre lagoon, by Alain Barrère.
Mauritius, Jorunna rubescens, at Recif corsaire, by Mathieu Bayon
Reunion, Jorunna rubescens beside his spawn, in Etang salé lagoon, by Hugues Flodrops
Reunion, Jorunna rubescens smile, at Etang salé, by Hugues Flodrops
Reunion, 6 Jorunna rubescens on a sponge, at Saint Gilles, by Eva Fontaine
Reunion, Jorunna rubescens, at Saint Benoît, by Sully Bachel
Mauritius, Jorunna rubescens, at Trou aux Biches, by Richard Lai cheong
Mayotte, J. rubescens crawling on a sandy substrate, at Passe en S, by Freddy Fuentes and Nathalie Geffriaud
Réunion, Jorunna rubescens mating, at Etang salé, by Florence Trentin
Réunion, Jorunna rubescens spawning, at Etang salé, Jean-Jacques Giordan
Réunion, Jorunna rubescens, at Etang salé, by Carole Nussbaumer
Reunion, importante population of Jorunna rubescens, at Saint Gilles, by Eva Fontaine
Reunion , video on "you tube" of Jorunna rubescens and its spawn, by Thierry Peres
Madagascar, Jorunna rubescens, at Antongil, by Olivier Fournajoux
Mauritius, Jorunna rubescens with its spawn, at Point d'esny, by Geoffrey Summers
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