Leucosyrinx breviplicata (E.A. Smith, 1899 ), 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 : 78-80

Leucosyrinx breviplicata (E.A. Smith, 1899) comb. nov.

Figs 20H , 26A–K

Pleurotoma (Surcula) breviplicata E.A. Smith, 1899: 238–239 .

Pleurotoma (Surcula) breviplicata – Annandale & Stewart 1909: pl. 9 fig. 3–3a.

Comitas breviplicata – Powell 1969: 272 (23-284), pl. 219 figs 3–4. — Kosuge 1992: 165, fig. 2, pl. 58 fig. 4.

Type material

Holotype

ANDAMAN ISLANDS • SL 25.1 mm; 13°17′15″ N, 93°10′ E; depth 185 ftm (= 338 m); ZSI, M 923 /1.

Material examined (sequenced)

SOLOMON ISLANDS • 1 lv; NW of Santa Isabel I.; 7°39′ S, 157°43′ E; depth 495–650 m; SALOMON 2, stn CP2213; MNHN-IM-2007-35063 • 1 lv; Choiseul; 6°39′ S, 156°14′ E; depth 490– 520 m; SALOMON 2, stn CP2226; MNHN-IM-2009-16803 • 1 lv; Choiseul; 6°37′ S, 156°13′ E; depth 508–522 m; SALOMON 2, stn CP2227; MNHN-IM-2007-42499 • 5 lv; Choiseul; 6°35′ S, 156°11′ E; depth 609–625 m; SALOMON 2, stn CP2228; MNHN-IM-2007-17933, MNHN-IM-2007-42525 to MNHN-IM-2007-42527, MNHN-IM-2009-16786 • 2 lv; Vella Gulf ; 7°55′ S, 156°51′ E; depth 485– 520 m; SALOMON 2, stn CP2263; MNHN-IM-2009-16810, MNHN-IM-2009-16814 . • 1 lv; Rendova ; 8°38′ S, 157°22′ E; depth 195–197 m; SALOMON 2, stn CP2284; MNHN-IM-2009-16788 .

SOLOMON SEA • 1 lv; SE of Tuam Is ; 6°04′ S, 148°12′ E; depth 500–575 m; PAPUA NIUGINI, stn CP4009; MNHN-IM-2013-19930 • 1 lv; Ainto Bay ; 6°08′ S, 149°17′ E; depth 410–614 m; MADEEP, stn CP4338; MNHN-IM-2013-46381 .

Description

SHELL. Medium-sized, nearly reaching 50 mm, thin but strong, narrow fusiform, with high spire, from off-white to light cream. Small paucispiral protoconch of 1.5–1.75 strongly convex microshagreened whorls. Protoconch-teleoconch transition indistinct, marked by appearance of definitive sculpture. Teleoconch whorls obtusely angular on shoulder, subsutural ramp weakly to moderately concave, in larger specimens nearly flat on last whorl. Distinct, impressed suture. 13–14 strong oblique axial folds on and below shoulder on last whorl in specimens with SL over 40 mm. Folds mostly do not reach lower suture on teleoconch whorls, disappear shortly below shoulder, rarely extend to periphery. Well-developed spiral sculpture. 3–5 variously developed spiral cords on subsutural ramp, on upper whorls below ramp thin cords separated by intervals exceeding the cords’ width, on last and penultimate whorls cords relatively broader with intervals narrower than cords. Immediately on shoulder 4–5 more narrow cords, crossing folds and distinct on their summits, below shoulder spiral cords broadly-spaced, with intervals 1–3 times as wide as cords. On shell base and canal cords more closely spaced and broader than on periphery. 30–37 cords on last whorl below shoulder. Shell base weakly to strongly convex, gradually or rapidly narrows passing into long sinuous canal. Narrow elongate-oval aperture, well differentiated from canal. Well-developed white columellar and parietal callus. Deep, subsutural, broadly arcuate anal sinus extends across subsutural ramp, confluent with large forward extension of outer lip.

RADULAE ( Fig. 20H ; examined in MNHN-IM-2007-42499, MNHN-IM-2007-17933, MNHN- IM-2007-42526, MNHN-IM-2007-35063, MNHN-IM-2009-16810). comprising 25–38 rows of teeth, 8–12 nascent. Marginal teeth similar in studied specimens, duplex, ~370–415 µm in length (3.4–3.5% AL without canal). Major limb narrow to medium lanceolate in dorsal view, strongly curved. Accessory limb about half of tooth width, inserted into distinct socket on dorsal side of major limb.

DNA diagnosis (based on 10 cox 1 sequences)

‘G’ in site 148, ‘C’ in site 346, ‘G’ in site 388, ‘T’ in site 517.

Remarks

Most ASAP partitions (Supp. file 2) suggest the presence of two molecularly distinct sister PSHs within L. breviplicata . However, in the BA tree (Supp. file 1), one of the two PSHs is not monophyletic. Both PSHs have nearly identical shells, with no clear boundary to distinguish them. As a result, we treat these PSHs as a single species. This species shows considerable variability in shell slenderness, but its spiral sculpture pattern is consistent, characterized by distinct, broadly-spaced cords on the periphery and most of the shell base.

We tentatively apply the name breviplicata to this species. First, the holotype is much smaller (SL 26 mm) than our specimens, although it may represent an immature individual. Second, the holotype was described from the Andaman Is., whereas all our specimens were collected from the Solomon Is. and Papua New Guinea. Nonetheless, Kosuge (1992) illustrated a dead shell collected off Western Australia (18°40′ S, 117°13′ E, 396–398 m), an intermediate locality, which closely resembles both the holotype and our specimens. This shell is larger than the holotype (SL 40.7 mm), comparable in size to our specimens. Therefore, we consider L. breviplicata to be a broadly distributed species, found at depths of 195– 609 m.

This species is well differentiated from its congeners by its spiral sculpture pattern, yet it closely resembles L. kirai ( Powell, 1969) , Leucosyrtinx sp. 26 and Leucosyrinx sp. 7 (see below for comparative remarks).

Distribution

From Andaman Is., to Western Australia and Solomon Is., 195– 609 m.

Figures

Fig. 20. Radulae of species of Leucosyrinx Dall, 1889. A. Leucosyrinx sp. 2, MNHN-IM-2009-16783, SL 27.9 mm. B. Leucosyrinx sp. 16, MNHN-IM-2009-13401, SL 25.7 mm. C–D. L. bernardeti sp. nov. C. Holotype, MNHN-IM-2013-48121, SL 34.4 mm. D. MNHN-IM-2007-17846, SL 27.3 mm. E. L. bolognai (Bozzetti, 2001), MNHN-IM-2009-16895, SL 43.3 mm. F. L. luzonica (Powell, 1969), MNHN-IM-2009-13444, SL 23.1 mm. G. L. quinetae sp. nov., MNHN-IM-2013-59549, SL 53.8 mm. H. L. breviplicata (E.A. Smith, 1899), MNHN-IM-2007-35063, SL 44 mm. I. Leucosyrinx sp. 26, MNHN-IM-2013-58381, SL 18.5 mm. Scale bars = 100 µm.

Fig. 26. A–K. Leucosyrinx breviplicata (E.A. Smith, 1899) comb. nov. All specimens, except holotype, from the Solomon Is. A–B. Holotype, ZSI, M 923/1, SL 25.1 mm (from ZSI, https:// zsicollections.in/specimen/ZSI0000003966). C. MNHN-IM-2007-42525, 609–625 m, SL 33.4 mm. D. MNHN-IM-2007-17933, SL 33.1 mm. E. MNHN-IM-2009-16803, 490–520 m, SL 33.7 mm. F. MNHN-IM-2009-16788, 195–197 m, SL 44.5 mm. G. MNHN-IM-2013-19930, 500–575 m, SL 26.8 mm. H–J. MNHN-IM-2009-16810, 485–520 m, SL 45.1 mm. K. MNHN-IM-2009-16814, 485–520 m, SL 46.8 mm. L. Leucosyrinx kirai (Powell, 1969) comb. nov., holotype ANSP 232552, SL 35.3 mm (photo from ANSP website http://clade.ansp.org/malacology/collections/details. php?mode=details&catalognumber=232552). All shells at the same scale.