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

Leucosyrinx gaelae sp. nov. urn:lsid:zoobank.org:act: 6C0EDDB0-1001-4E86-BE55-1A86D875D745 Fig. 12I–M Etymology The species is named after Priscillia Gaël Bourguignon, member of the marine invertebrate team in the MNHN. Material examined Holotype (sequenced) PAPUA NEW GUINEA • New Britain, north of Rabaul; 4°4′ S, 151°50′ E; depth 702–724 m; BIOPAPUA, stn CP3672; MNHN-IM-2009-17135. Other material (all sequenced) PAPUA NEW GUINEA • 3 lv; New Britain, north of Rabaul; 4°3′ S, 151°50′ E; depth 788–805 m; BIOPAPUA, stn CP3674; MNHN-IM-2009-16996, MNHN-IM-2009-16997, MNHN-IM-2009-17001 • 2 lv; same data as for holotype; IM-2009-17138, IM-2009-17211. Description MEASUREMENTS (holotype). SL 21.9 mm, AL (with canal) 9.46 mm, AL (without canal) 6.3 mm, SW 6.4 mm. SHELL (holotype). Shell small, narrow fusiform, with high spire, very light tan in color, thin, semitransparent, fragile. 8.5 distinctly roundly angulated at shoulder teleoconch whorls. Upper part of protoconch missing. Subsutural ramp weakly concave on upper whorls, nearly straight on last and penultimate whorls. Shallow and impressed suture. Strong, oblique, broad, and rounded axial folds on shoulder of teleoconch whorls, forming nearly orthocline knobs, increasing in number from 9–10 on first whorl to 12 on penultimate and last whorls. Folds fade on subsutural ramp, do not reach lower suture, disappear below shoulder on last whorl. Weak, hardly discernible spiral sculpture of closely spaced, low, rounded cords over entire shell except subsutural ramp. Intervals between cords narrower than cords’ width. Numerous thin, visible on subsutural ramp growth lines. Shell base weakly convex, passes smoothly into long and straight canal. Narrow, elongate-oval aperture, poorly differentiated from canal, outer lip fragile, partially broken. Inner lip is nearly straight, outer lip very thin and fragile. Columellar and parietal sides with narrow, distinct callus, of same color as remaining part of last whorl. Moderately deep, subsutural, broadly arcuate anal sinus extends across subsutural ramp, confluent with large forward extension of outer lip. RADULA. Not examined. DNA diagnosis (based on 6 cox 1 sequences) ‘A’ in site 163, ‘G’ in site 169, ‘C’ in site 448, ‘C’ in site 548. Remarks The protoconch, retained in one specimen (MNHN-IM-2009-16997), is paucispiral, of about 1.75 strongly convex whorls, light brown. The transition between the protoconch and teleoconch is marked by the emergence of a shoulder keel. The species is weakly variable. Most of the shells are partially broken due to the fragility. The number of knobs on the last whorl can reach 14–15. The species is most similar to L. claviforma and to Leucosyrinx sp. 12, differing in broader spaced axial folds, more like knobs, on the shoulder and a relatively lower spire. There is a certain similarity in shell outline to Sibogasyrinx suluensis (Powell, 1969), differing in less pronounced and more closely spaced spiral cords below the shoulder on the last whorl, as well as in the absence of a subsutural row of knobs. The specimen presented by Sysoev (1996: 11, fig. 28) as Leucosyrinx claviforma off Maldive Is. from depths of 786–1170 m may belong to L. gaelae sp. nov., which is found at greater depths than L. claviforma – 702–788 vs 370– 500 m. Distribution Papua New Guinea, 702– 788 m.