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This species has been observed on Mayotte and Madagascar Islands

Order : Nudibranchia Suborder : Dexiarchia Superfamily : Tritonioidea Family : Tritiniidae Distribution : Indonesia, Philippines, Palau and now Mayotte Maximal size : 70 mm Abundance : (May) From time to time on the fore reef zone Species characteristics : The sides and foot are white to pale yellowish-white, as is the background color of the notum. A series of fine, reddish-brown lines form a reticulate network on the notum . Four pairs of velar tentacles that are simple or divided at their tips Narrow rhinophoral sheaths with a serie of longitudinal lines at their apex
	Showing species characteristics...	Yvon Gildas Passe en S, Mayotte, 9 June 2008

See more about : Sightening and mating periods

Remarks :

Identification confirmed by Terry Gosliner, Nathalie Yonow and Hsini Lin
    Synonymous : (according Worms)
               - No other name

Bibliographic data :

Portions of the notum may exhibit a reddish tint.
    A series of fine, reddish-brown lines form a reticulate network on the notum . The reticulations are strongest in rectangular sections between the secondary gills, and between the ‘‘gills'' and rhinophores.
    A longitudinal strip runs down the center of the notum. This strip is paler in color, with less defined reticulations. Similar pale areas extend laterally from the central area to the base of each ‘‘gill'' branch.
    The branchial plumes "gills" are whitish at their bases, becoming greenish yellow where they begin to ramify. The divisions of the "gills" vary in color from reddish-brown to greenish, with the finest terminal divisions tipped in white. The ‘‘gills'' are relatively short. The trunks of the ‘‘gills'' divide into four main branches. Each main branch divides into two smaller branches multiple times, terminating in somewhat blunt apices
    The coloration of the rhinophore sheaths resembles that of the branchial plumes, with greenish bases becoming reddish with some darker red lines or spots approaching the margins. The rhinophoral sheath margins have some fine white spots.
    The rhinophores each have a terminal digitiform projection with numerous branched subterminal excrescences. The shafts of the rhinophores have similar coloration to the branchial plumes; the tips of the central clavi colored white.
    The dorsal pattern of lines or reticulations extends onto the proximal surface of the oral veil, but it does not extend out to the digitiform projections, which show a pattern of reddish brown dots, some projections with white apices.
    There are four digitiform projections on each lobe of the velum, with the outermost on each side being the distally grooved or spatulate oral tentacle. The most medial projection of each lobe is usually simple and always the shortest, with the next two outermost each longer and apically bi- or trifid. The oral tentacles are nearly equal in length to the medial projections.
    The gonopore is on the right side, between the second and third branchial plumes, medially between the notum and foot
    It feeds on gorgonians of the Elisellidae
    Etymology : The specific epithet is descriptive of characteristics of the species. Elongo refers to the elongated form of the living animal, and reticulata refers to the reticulated pattern on the notum.
    Marionia elongoreticulata and M. elongoviridis share many similarities but :
               - In M. elongoreticulata, the reticulate pattern of lines forms polygons covering the notum and in Marionia elongoviridis the lines are transverse across most of the notum

References :

Nudipixel Marionia elongoreticulata

Publications :

Smith, Victor G.; Gosliner, Terrence M. 2007-01-25. Two new species of Marionia (Mollusca : Nudibranchia) from the Indo-Pacific region. The Veliger 48 (4): 260-275.

Other photos of Marionia elongoreticulata :

Yvon Gildas Passe en S, Mayotte, 9 June 2008   A series of fine, reddish-brown lines form a reticulate network on the notum . The reticulations are strongest in rectangular sections between the secondary gills (a), and between the ‘‘gills'' and rhinophores (b). The rhinophoral sheath margins have some fine white spots (c).

The branchial plumes "gills" are whitish at their bases (a), becoming greenish yellow where they begin to ramify (b) . The divisions of the "gills" vary in color from reddish-brown to greenish. A longitudinal strip (c) runs down the center of the notum. This strip is paler in color, with less defined reticulations. Similar pale areas extend laterally (d) from the central area to the base of each ‘‘gill'' branch.

Yvon Gildas Mayotte, 10 September 2009 There are four digitiform projections (1 to 4) on each lobe of the velum, with the outermost on each side being the distally grooved or spatulate oral tentacle. The most medial projection (1) of each lobe is usually simple and always the shortest, with the next two outermost (2 and 3) each longer and apically bi- or trifid. The oral tentacles (4) are nearly equal in length to the medial projections. The gonopore (b) is on the right side, between the second and third branchial plumes, medially between the notum and foot

Robert Verneau "îlots des 4 frères", Mayotte, on a fringing reef, 3m, 16 September 2007 on a soft coral... The divisions of the "gills" vary in color from reddish-brown to greenish.

Yvon Gildas Mayotte, Passe en S, buoy n°3, 9 m, 22 February 2010 During a night dive... Always on its food...

There are four digitiform projections (a) The coloration of the rhinophore sheaths (b) resembles that of the branchial plumes, with greenish bases becoming reddish with some darker red lines or spots approaching the margins. The rhinophoral sheath margins have some fine white spots (c). The rhinophores each have a terminal digitiform projection (d) with numerous branched subterminal excrescences. The shafts of the rhinophores have similar coloration to the branchial plumes; the tips of the central clavi colored white (e).

Yvon Gildas Mayotte, Passe en S, buoy n°3, 9 m, 22 February 2010 During a night dive... Always on its food... A juvenile form ???

Nathalie Bazard   Madagascar, Nosy bé, , 20 m, novembre 2016, taille : 25 mm

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