Mourgona/Polybranchia sp. 1

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This species has been observed on Reunion Island

Order : Sacoglossa
Superfamily : Limapontioidea
Family : Caliphyllidae
Distribution : Reunion, Hawaii...
Maximal size : 20 mm
Abundance :

Species characteristics :

Mature animals of this species have flattened leaf-like cerata covered with small tubercles.

The body is translucent whitish, liberally flecked with white, orange and dark purple.

The rhinophores are long, forked (bifurcated) with the same pattern of the body and cerata

Mourgona/Polybranchia sp. 1
Showing species characteristics...

Photo Alexandre Laporte
Reunion, Etang salé les bains lagoon, less 1 m, 10 January 2016, size : 10-15  mm

Remarks :

According Kathe Jensen " This species has digestive gland branches in the cerata, which will most likely make it a Polybranchia or a Mourgona species. Actually the regular branching pattern of digestive gland shown in your close-up of cerata makes Mourgona more likely, but only dissection to show absence of pharyngeal pouches will definitely separate the 2 genera. Too bad there is no photo of the foot-sole, because Cyerce has a distinct transverse groove in the foor-sole."
    This species looks like Cyerce sp. 3 in NSSI, Nudibranch & Sea Slug Identification, Indo-Pacific, Gosliner, Valdés & Behrens, 2015
    Or may be a variant of Polybranchia orientalis

Bibliographic data :

There is a cluster of more prominent purple spots on top of the head behind the eye spots (non observed on this photo...)
    Greenish-brown branches of the digestive gland can be seen in the bases of the cerata.
    Very young animals have smoother and more cylindrical cerata with more prominent branches of the digestive gland and fewer purple, orange and white spots. Also, the cluster of spots on their heads tends to be reddish-purple.

References :

Seaslufg of Hawaii: Cyerce sp. 1
   Seaslufg of Hawaii: Mourgona osumi

Other photos of Mourgona/Polybranchia sp. 1 :

Philibert Bidgrain

Reunion, Etang salé les bains, 06 October 2005, size :15 mm

Cerata detail of the upper specimen.

The back covered in leaf-like cerata contain fine branching digestive gland ducts.

The cerata and glands along the edge of the cerata produce sticky secretions.

polybranchia orirentalis

The rhinophores are long, forked (bifurcated) (a) and transparent with a faint green pattern and small white pustules


Christophe Cadet

Reunion, Etang salé lagoon, less 1 m, 29 October 2009, size : 6 mm

It contain fine branching digestive gland ducts

Christophe Cadet

Reunion, Etang salé lagoon, less 1 m, 2 February 2018, size : 10 mm


Christophe Cadet

Reunion, 27 december 2015


The smallest.... 5mm


  More photos from Indian Ocean

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