Leucosyrinx boiteuxi, Kantor & Fedosov & Puillandre, 2025

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 : 41-42

Leucosyrinx boiteuxi sp. nov.

urn:lsid:zoobank.org:act:0CFCDF0C-8C7F-4990-AA08-C8413E768752

Figs 10I , 14A–D

Etymology

The species is named after Benoit Boiteux, a indespensible volunteer companion of many years of the MNHN expeditions.

Material examined

Holotype (sequenced)

BISMARCK SEA • NW Long I.; 5°12′ S, 146°59′ E; depth 470–508 m; PAPUA NIUGINI, stn DW3983; MNHN-IM-2013-19767.

Other material (all sequenced)

PAPUA NEW GUINEA • 1 lv; off Madang; 4°58′ S, 145°52′ E; depth 640–675 m; BIOPAPUA, stn CP3709; MNHN-IM-2013-52051 .

SOLOMON SEA • 1 lv; Vityaz Strait; 6°00′ S, 147°36′ E; depth 706–715 m; PAPUA NIUGINI, stn CP3995; MNHN-IM-2013-19848 .

Description

MEASUREMENTS (holotype). SL 57.4 mm, AL (with canal) 23.7 mm, AL (without canal) 16.4 mm, SW 17.4 mm.

SHELL (holotype). Shell large, fusiform, with high spire, greyish in color, thin but solid. Protoconch and uppermost teleoconch whorls missing, remaining teleoconch whorls 11.5, upper whorls distinctly roundly angled at shoulder, last and half of penultimate whorls with more rounded shoulder accentuated by low keel. Subsutural ramp concave on upper whorls and nearly flat on last and penultimate whorls. Deep, impressed suture. Strong, oblique, broad, rounded axial folds on shoulder of upper teleoconch whorls, fading on penultimate whorl and absent on last whorl. Folds fade on subsutural ramp, strongly weaken towards lower suture. Folds number increasing from 10 on first remaining whorl to 19 on anterpenultimate one. Weak spiral sculpture of low, rounded, wavy, and narrow cords over entire shell. Cords on subsutural ramp weaker than below shoulder, on shell base and canal intervals between cords equal or slightly exceed cords’ width. Numerous thin, prominent on subsutural ramp growth lines. Shell base convex, smooth transition to long and straight canal. Narrow, elongate-oval aperture, poorly differentiated from canal, inner lip slightly concave, nearly straight. Columellar and parietal sides with narrow, distinct callus, slightly lighter than remaining last whorl. Deep, subsutural, broadly arcuate anal sinus extends across subsutural ramp, confluent with large forward extension of outer lip.

RADULA ( Fig. 10I ; studied in MNHN-IM-2013-19848). Marginal teeth duplex, ~330 µm in length (2.5% AL without canal). Major limb lanceolate in dorsal view, curved. Accessory limb relatively broad, at tooth base equals total tooth width, ~0.75 of total tooth length, inserted into distinct deep socket on dorsal side of major limb

DNA diagnosis (based on 3 cox 1 sequences)

‘A’ in site 22, ‘T’ in site 67, ‘G’ in site 295, ‘G’ in site 568, ‘C’ in site 607.

Remarks

The two other studied specimens have a shell outline similar to the holotype, which is the largest specimen. In the smaller specimens (MNHN-IM-2013-52051, SL 36.9 mm; MNHN-IM-2013-19848, SL 46.5 mm), axial folds on the shoulder are present on the last whorl, although they progressively weaken on the last whorl in the latter specimen. This suggests that the fading of the folds occurs as the shell grows. The protoconch is present in the smallest specimen, but strong erosion makes it impossible to count the number of whorls.

The species bears some resemblance to Leucosyrinx palawanica ( Powell, 1969) , differing in having a straighter canal, a significantly lower last whorl and a larger size.

Distribution

Bismarck Sea, Solomon Sea, Papua New Guinea, 470– 706 m.

Figures

Fig. 10. Radulae of species of Leucosyrinx Dall, 1889. A. L. oliverioi sp. nov., holotype, MNHN- IM-2007-17928, SL 37.5 mm.B–C. L. claviforma, MNHN- IM-2013-58303, SL 19.1 mm.B. Dorsal view of the radula membrane. C. Bending plane, showing marginal teeth in different views. D–E. L. urbanae sp. nov., MNHN-IM- 2009-17215, SL 14.1 mm. D. Dorsal view of the radula membrane. E. Bending plane, showing marginal teeth in different views. F. Leucosyrinx sp. 24, MNHN-IM-2013-66098, SL 21.6 mm. G. Leucosyrinx sp. 22, MNHN-IM-2013-48155, SL 24.2 mm. H. Leucosyrinx sp. 8, MNHN-IM-2009-29323, SL 20.1 mm. I. L. boiteuxi sp. nov., MNHN-IM-2013-19848, SL 46.5 mm. Scale bars = 100 µm.

Fig. 14. A–D. Leucosyrinx boiteuxi sp. nov. A–C. Holotype, MNHN-IM-2013-19767, SL 57.4 mm. D. MNHN-IM-2013-19848, Solomon Sea, 706–715 m, SL 46.5 mm. E–L. Leucosyrinx margaritae (E.A. Smith, 1904). E–F. Holotype, ZSI, M 3061/1, SL 58.5 mm (from the site of ZSI, https://zsicollections.in/specimen/ZSI0000003727). G. MNHN-IM-2009-13446, Philippines, 944–1004 m, SL 40.9 mm. H–I. MNHN-IM-2013-45439, Solomon Sea, 575–616 m, SL 39.5 mm. J–L. MNHN- IM-2013-19747, Solomon Sea, 724 m, SL 53.1 mm. All shells at the same scale.