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

Order : Nudibranchia Suborder : Dexiarchia Superfamily : Flabellinoidea Family : Samlidae Distribution : Indo-West Pacific Maximal size : 50 mm Abundance : Seldom if ever on the fore reef zone Species characteristics : The general body color is translucent white. There is an orange tinge on either lateral side of the head The cerata have red and white rings near the tips and opaque white or cream bands near the bases A serie of sky-blue to whitish diamond or lozenge-shaped patches is present medially on the notum. These patches may be continuous or well separated
	Showing species characteristics...	Photo Rozenn Gildas Mayotte, Longoni harbourg, La cardinale, 15 m, 26 Jully 2009, size : 50 mm

See more about : Sightening and mating periods

Remarks :

Identification confirmed by Terry Gosliner and Nathalie Yonow
    Synonymous : (according Worms)
               - Flabellina bilas Gosliner & Willan, 1991

Bibliographic data :

The notal brim gives rise to a series of pedunculate cerata.There are 6-7 pairs of ceratal rows with 4 to 1 cerata in each ceratal cluster     Cerata coloration :             - At the translucent base of some cerata a thin blood-red digestive diverticulum is visible             - More distally, are two broad areas of opaque cream separated by a small area of translucence.             - Subapically, a broad red ring is bordered on either side by a thinner irregular band of opaque white     The oral tentacles bear two opaque white areas, separating the translucent base, median region and apex. They are thin and elongate, approximately three times the length of the rhinophores. The distal third of these tentacles is broadly expanded and paddlelike     The perfoliate rhinophores are translucent basally, medially and apically. They posses two bands of cream pigment and a sharply defined subapical blood red ring. They bear 25-28 densely packed lamellae     The foot corners are short and tentacular, and are held nearly perpendicularly to the longitudinal axis of the body, or they may be recurved posteriorly. Opaque white pigment is present on the foot corners and as a series of ovoid patches along either side of the body extending from the head to the tail.     The gonogore is located immediately ventral to the preanal ceratal arch while the anus is situated slightly anterior to the median of the interhepatic space, below the notal brim     The specific epithet “bilas” is a New Guinea Pidgin word meaning “decoration”, referring to the brillant crimson and blue markings of this species

           Found on Eudendrium hydroids on steep reef slopes and walls in moderate depths of 20-30 m
     It can be readily distinguished from other species with perfoliate rhinophores by its unique pattern of coloration. It is the only species with red bands on the cerata and rhinophores, a single precardiac ceratal row and whitish or bluish markings on the notum between the cerata

References :

Bill Rudman Seaslug site : Sea Slug Forum : Flabellina bilas
   Nudipixel Flabellina bilas

Publications :

Gosliner,T.M. & Willan,R.C. (1991) Review of the Flabellinidae (Nudibranchia: Aeolidacea) from the tropical Indo-Pacific, with the descriptions of five new species. The Veliger, 34(2) : 97-133.
     Korshunova, T.; Martynov, A.; Bakken, T.; Evertsen, J.; Fletcher, K.; Mudianta, W.; Saito, H.; Lundin, K.; Schrödl, M.; Picton, B. (2017). Polyphyly of the traditional family Flabellinidae affects a major group of Nudibranchia: aeolidacean taxonomic reassessment with descriptions of several new families, genera, and species (Mollusca, Gastropoda). ZooKeys. 717: 1-139.

Other photos of Samla bilas :

Rozenn Gildas Mayotte, Longoni harbourg, La cardinale, 15 m, 26 Jully 2009, size : 50 mm The perfoliate rhinophores are translucent basally, medially and apically. They posses two bands of cream (a) pigment and a sharply defined subapical blood red ring (b) Opaque white pigment is present on the foot corners (c) and as a series of ovoid patches (d) along either side of the body extending from the head to the tail.

Cerata coloration :             - At the translucent base of some cerata a thin blood-red (e) digestive diverticulum is visible             - More distally, are two broad areas (f) of opaque cream separated by a small area of translucence.             - Subapically, a broad crimson ring (g) is bordered on either side by a thinner irregular band of opaque white (h)   The orange mass (i), which is clear in the photo, will be the lobes of the ovotestis

Erwan Meyer Reunion, La Barge, Saint Paul, 25 m, 27 April 2007, Found on Eudendrium hydroids in moderate depths of 20-30 m It is the only species with red bands on the cerata and rhinophores, a single precardiac ceratal row and whitish or bluish markings on the notum between the cerata

Alain-Benoît Rassat Madagascar, La licorne, Nosy bé, 15 m, July 2012, size : 40 mm

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