Leucosyrinx modicae, 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 : 74-77

Leucosyrinx modicae sp. nov.

urn:lsid:zoobank.org:act:132350F5-084B-4182-9232-BF5B5C2CDEDF

Fig. 25A–F

Leucosyrinx sp. B – Kantor & Puillandre 2021: fig. 13i.

Etymology

The species is named after Maria Vittoria Modica, world known specialist in toxinology and systematics of Neogastropoda and our many years companion in expeditions organized by MNHN.

Material examined

Holotype (sequenced)

SOLOMON ISLANDS • SW Santa Isabel I.; 8°24′ N, 159°23′ E; depth 897–1057 m; SALOMON 2, stn CP2197; MNHN-IM-2009-13570.

Other material (all sequenced)

SOLOMON ISLANDS • 1 lv; Santa Isabel I.; 8°47′ N, 159°38′ E; depth 762–1060 m; SALOMON 2, stn CP2182; MNHN-IM-2009-16764 .

SOUTHERN NEW CALEDONIA • 1 lv; 22°19′ N, 167°22′ E; depth 815–870 m; EXBODI, stn CP3844; MNHN-IM-2013-52093.

Description

MEASUREMENTS (holotype). SL 31.8 mm, AL (with canal) 15.4 mm, AL (without canal) 10.0 mm, SW 11.3 mm.

SHELL (holotype). Shell medium-sized, thin, fragile, biconical, with high spire, very light-yellowish in color, nearly white. About 9 distinctly roundly angled at shoulder teleoconch whorls, with strongly concave on all whorls subsutural ramp. Protoconch missing, uppermost whorls strongly eroded. Distinct impressed suture. 13–14 strong, oblique axial folds on last and penultimate whorls. Folds fade on subsutural ramp, reach lower suture, extend to shell base. Intervals between folds 1.5–2 times exceed folds’ width on last and penultimate whorls. Very distinct spiral sculpture of similar (except subsutural ramp) in width, low, slightly wavy cords over entire shell surface, distinct on shoulder and on axial folds. Intervals between cords narrower than cords’ width, only between few cords intervals equal or even slightly exceed cords’ width. On subsutural ramp cords distinct, significantly vary in width, can be nearly twice as broad then on and below shoulder, 9 cords on subsutural ramp of last whorl, 7 on penultimate. Numerous thin but distinct growth lines. Shell base rounded, medium convex, gradually constricting and passing into medium long straight canal. Narrow elongate-oval aperture, poorly differentiated from canal, inner lip weakly convex. Columellar and parietal sides covered by narrow, distinct white callus. Deep, subsutural, broadly arcuate anal sinus extends across subsutural ramp, confluent with large forward extension of outer lip.

RADULA (examined in MNHN-IM-2013-52093). Typical of genus. Marginal teeth duplex, ~280 µm in length (4.7% AL without canal).

DNA diagnosis (based on 3 cox 1 sequences)

‘C’ in site 103, ‘T’ in site 145, ‘C’ in site 640.

Remarks

The protoconch is retained in one specimen (MNHN-IM-2013-52093). It is paucispiral, small, and bulbous, consisting of about 1.75 rounded, light brown, microshagreened whorls. The transition between the protoconch and teleoconch is indistinct, marked by the appearance of a shoulder keel. The holotype is the largest specimen.

The species is moderately variable: while the sculpture pattern is consistent across all available specimens, the slenderness of the shell varies (compare Fig. 25A and 25D ).

The new species is somewhat similar to L. bourgeoisae sp. nov., but differs in having distinct spiral cords on the subsutural ramp and narrower, more closely spaced cords on the last whorl below the shoulder. It also strongly resembles L. maestratii sp. nov., but differs in its larger size (SL up to 31.8 mm vs 24 mm). These species are not closely related in the phylogenetic tree.

Distribution

Southern New Caledonia and Solomon Is., 762– 897 m.

Figures

Fig. 25. A–F. Leucosyrinx modicae sp. nov. A–C. Holotype, MNHN-IM-2009-13570, SL 31.8 mm. D–E. MNHN-IM-2009-16764, Solomon Is., 762–1060 m, SL 29.9 mm. F. MNHN-IM-2013-52093, southern New Caledonia, 815–870 m, SL 23.3 mm.G–J. Leucosyrinx maestratii sp. nov.G–I. Holotype, MNHN-IM-2009-16770, SL 22.8 mm.J. MNHN-IM-2009-16789, Solomon Is., 970–1060 m, SL 24 mm. A–F at the same scale; G–J at the same scale.