Leucosyrinx madagascarensis Ardovini, 2022

Kantor, Yuri I., Fedosov, Alexander & Puillandre, Nicolas, 2025, Revision of the Indo-Pacific species of the genus Leucosyrinx Dall, 1889 (Neogastropoda: Conoidea: Pseudomelatomidae), European Journal of Taxonomy 999, pp. 1-126 : 68-69

Leucosyrinx madagascarensis Ardovini, 2022

Fig. 22F–L

Comitas eurina (E.A. Smith, 1899) – Robin 2008: 449, fig. 10 (not Smith, 1899).

Leucosyrinx madagascarensis Ardovini, 2022: 7 , text figs.

Leucosyrinx sp. E – Kantor & Puillandre 2021: pl. 13g.

Type material

Holotype

MADAGASCAR • west coast of Madagascar ; depth 600–700 m; MMM.

Material examined (all sequenced)

MADAGASCAR • 2 lv; off Majunga ; 15°22′ S, 46°00′ E; depth 493–662 m; MIRIKY, stn CP3250; MNHN-IM-2009-16897, MNHN-IM-2009-16898 .

Non-sequenced material

NW MADAGASCAR • 16 dd; 15°27′ S, 46°0′ E; depth 403–750 m; MIRIKY, stn CP3250 • 2 dd; 14°27′ S, 47°25′ E; depth 347–408 m; MIRIKY, stn CP3291

SW MADAGASCAR • 1 dd; 22°10′ S, 43°05′ E; depth 525 m; Campagne crevettière 1986, stn 79; MNHN-IM-2016-4823 • 1 dd; 22°23′ S, 43°03′ E; depth 525 m; Campagne crevettière 1986, stn 81; MNHN-IM-2016-4824.

Description

SHELL. Large, reaching 50.6 mm, strong, from narrow to medium broad fusiform, with high spire, light orange. Protoconch small, bulbous, paucispiral. Teleoconch whorls distinctly obtusely angular on shoulder, subsutural ramp distinctly concave on all whorls, from narrow to medium broad. Distinct impressed suture. 19–21 strong, slightly oblique to nearly ortocline axial folds on and below shoulder on last whorl, 16–20 on penultimate whorl, reach lower suture on teleoconch whorls and disappear shortly below shoulder on last whorl. Intervals between folds narrower than folds’ width. Very distinct spiral sculpture of similar width, closely spaced, rounded cords, over entire shell. On subsutural ramp cords weaker than on shoulder and below. Intervals between cords usually half of cords’ width, rarely equal to the cords’ width. About 30 cords on the last whorl on and below shoulder. Shell base strongly convex, quickly narrows at passing to medium-long rather narrow, slightly inclined leftwards canal. Rather broad, elongate-oval aperture, well differentiated from canal. Well-developed, white or light yellowish columellar and parietal callus. Medium deep, subsutural, arcuate anal sinus extends across subsutural ramp, confluent with large forward extension of outer lip.

RADULA (studied in MNHN-IM-2009-16897). Comprising about 25 rows of teeth, 11 nascent. Marginal teeth duplex, ~360 µm in length (2.2% of AL without canal). Major limb medium broad lanceolate, strongly curved. Accessory limb twice as narrow, ~0.7 of total tooth length, inserted into deep distinct socket on dorsal side of major limb.

DNA diagnosis (based on 2 cox 1 sequences)

‘G’ in site 79, ‘C’ in site 347, ‘G’ in site 355, ‘C’ in site 418.

Remarks

Our sequenced specimens are very similar to the holotype and paratypes, illustrated by Ardovini (2022) and were mentioned as conspecific in the original description. Ardovini (2022) did not provide the exact collection site of his specimens, originating from the fishery boats stationed in the Tulear harbor but operating in the sea area north until the city of Morondava. Our specimens originated from off Majunga, much farther north from Morondava.

The species is most similar to Leucosyrinx eurina (E.A. Smith, 1899) , but differs in having a slenderer light-orange shell compared to the white-greyish shell shell of L. eurina (E.A. Smith 1899; Tan & Islami 2021).

Distribution

Madagascar, 347– 600 m.

Figures

Fig. 22. A–E. Leucosyrinx bolognai(Bozzetti, 2001). A. Holotype, MNHN-IM-2000-2819, SL 82.9 mm. B. MNHN-IM-2009-16896, Madagascasr, 493–662 m, SL 69.4 mm. C. MNHN-IM-2009-16899, Madagascar, 493–662 m, SL 44.9 mm. D–E. MNHN-IM-2009-16895, Madagascar, 620–637 m, SL 43.3 mm. F–L. Leucosyrinx madagascarensis Ardovini, 2022. F. Holotype, MMM, SL 41 mm. G. Paratype 3, Ardovini collection, SL 46 mm. H–I. MNHN-IM-2009-16897, Madagascar, 493–662 m, SL 46.1 mm. J–L. MNHN-IM-2009-16898, same locality, SL 50.6 mm. All shells at the same scale. F–G photos courtesy of R. Ardovini.