Leucosyrinx farhatorum Kantor & Fedosov & Puillandre 2025, sp. nov.

Leucosyrinx farhatorum sp. nov. urn:lsid:zoobank.org:act: 2935C93B-7AE1-4EDD-AC64-D1F18F5C30B9 Figs 4K–P, 5B–C Leucosyrinx sp. C – Kantor & Puillandre 2021: figs 11f, 13j. Etymology The species is named after Sarah Farhat, member of the ERC “HYPERDIVERSE” team, and her family for her contribution to the knowledge of the genome evolution of neogastropods. Material examined Holotype (sequenced) SOLOMON ISLANDS • New Georgia; 7°58′ S, 157°34′ E; depth 650–836 m; SALOMON 2, stn CP2219; MNHN-IM-2007-42503. Other material (all sequenced) SOLOMON ISLANDS • 1 lv; 7°43′ S, 156°24′ E; depth 664–682 m; SALOMON 2, stn CP2246; MNHN-IM-2009-16752. VANUATU • 2 lv; SE Malékula I.; 16°22′ S, 167°50′ E; depth 637–644 m; SANTO 2006, stn AT130; MNHN-IM-2009-13498, MNHN-IM-2009-13499. Description MEASUREMENTS (holotype). SL 41.2 mm, AL (with canal) 19.7 mm, AL (without canal) 12.8 mm, SW 12.7 mm. SHELL (holotype). Medium-sized, fusiform, with a high spire, fragile, uniform light tan in color. 11+ teleoconch whorls, uppermost whorls and protoconch missing. Teleoconch whorls roundly angled at shoulder, with flat subsutural ramp. Shallow but distinct, narrowly canaliculate, and slightly wavy suture. 16 strong, oblique, medium broad, and rounded axial folds on body whorl, 17 on penultimate one. Folds fade on subsutural ramp, slightly weaken towards lower suture, disappear at body whorl slightly above periphery. Folds more closely spaced and distinct on upper teleoconch whorls, on posterior part of last whorl they weaken, nearly disappearing. Weak spiral sculpture of low, rounded, and indistinct narrow cords over entire shell. On subsutural ramp 12–13 cords on last whorl and 10 on penultimate whorl. Numerous thin growth lines, also prominent on subsutural ramp. Shell base weakly evenly convex, smooth transition to long, straight canal. Narrow, elongate-oval aperture, poorly differentiated from canal aperture. Inner lip slightly convex. Columellar and parietal sides with narrow, distinct callus. Moderately deep, subsutural, broadly arcuate anal sinus extends across subsutural ramp, confluent with large forward extension of outer lip. RADULA (Fig. 5B–C; studied in two specimens, holotype and MNHN-IM-2009-13498, Vanuatu). Similar in tooth morphology. Radula in holotype short, of 25 rows of teeth, 8–10 nascent. Marginal teeth duplex, short, ~215 µm in length (1.6% of AL without canal), broad. Major limb broadly lanceolate, slightly curved. Accessory limb nearly twice as narrow, rather flat, ~0.8 of total tooth length, inserted into shallow but distinct socket on dorsal side of major limb. Radula of the second specimen is very similar, with still smaller marginal teeth, ~150 µm in length (1.9% of AL without canal). DNA diagnosis (based on 4 cox 1 sequences) ‘C’ in site 121, ‘G’ in site 484, ‘G’ in site 520, ‘C’ in site 604. Remarks The best partition of the ASAP analysis combines L. farhatorum sp. nov. together with L. zucconi sp. nov. in a single PSH. Nevertheless, in the phylogenetic tree (Fig. 1, Supp. file 1) both species constitute monophyletic groups with high support that are not sister. Besides, they are rather distinct conchologically and have a slightly different shape of radular teeth. They both were found off the Solomon Is., although L. farhatorum is recorded at shallower depths. Therefore, we consider them as two independent species. The second-best ASAP partition recognized three PSHs, including two within L. farhatorum, which are nevertheless not monophyletic. Two specimens from Vanuatu (Fig. 4N–P) have a more slender shell with a less angulated shoulder. Radulae of specimens from Vanuatu and Solomon Is. are very similar and distinct from that of other species of Leucosyrinx in having relatively short and broad marginal teeth (Fig. 5B–C). The genetic distance between the two groups within L. farhatorum could be linked to geographic variation. The largest specimen measures SL 42.7 mm. Both available specimens from the Solomon Is. (Fig. 4K– M) are similar in sculpture pattern and shell shape. The new species somewhat resembles Sibogasyrinx pyramidalis, differing in a shorter canal, more pronounced axial folds on shoulder, absence of subsutural row of nodules. From the similar L. floraecharlottae sp. nov. it differs in having a straight vs slightly concave subsutural ramp, better pronounced spiral cords on the ramp, as well as in much shorter and relatively broader radular marginal teeth. It is somewhat similar to L. archibenthalis, differing in a broader shell with more pronounced sutural knobs and in broader and shorter marginal radular teeth. Distribution Solomon Is., Vanuatu, 637– 646 m.