Vermeijius costuliferus sp. nov.

urn:lsid:zoobank.org:act: BE85E445-E29C-4EA1-87D8-F0221F0433F0

Figs 44–45, 82G, 85U

Etymology

The Latin adjective ‘ costuliferus ’ means ‘rib-bearing’ or ‘having ribs’. It combines the Latin words ‘ costula ’ (meaning ‘small rib’ or ‘riblet’) and ‘ ferre ’ (meaning ‘to bear’ or ‘to carry’). Therefore, ‘ costuliferus ’ literally describes something that has or bears ribs or rib-like structures, referring to the axial sculpture of this new species.

Material examined

Holotype VANUATU • dd; W of Malo; 15°43′ S, 167°04′ E; depth 309–402 m; BOA 1, stn CP2414; MNHN-IM-2023-1043 (Figs 44A–D, 82G).

Paratype VANUATU • 1 dd, SL 34.0 mm, ShW 15.5 mm; Vanuatu, W of Malo; 15°43′ S, 167°02′ E; depth 314– 547 m; BOA 0, stn CP2328; MNHN-IM-2023-1044 (Figs 44E–I, 85U).

Sequenced material

None sequenced.

Description

Measurements (holotype): SL 51.0 mm, ShW 22.8 mm.

Shell large for genus (up to 51.0 mm SL), fusiform, with broad, short spire, comprising 1.75 protoconch and 8 teleoconch whorls. Protoconch paucispiral (Figs 44I, 85U), consisting of 1.5 smooth, bulbous whorls followed by 0.25 whorl with very fine axial growth lines. Transition to teleoconch marked by onset of spiral sculpture. Protoconch diameter 1.1 mm, exposed height ~ 0.9 mm. Teleoconch whorls strongly convex, conspicuously inflated; unkeeled on upper whorls, occasionally with indistinct central keel on later whorls. Suture deeply impressed, slightly undulating, following axial sculpture of preceding whorl. Axial sculpture of strong, raised, narrow ribs extending from suture to suture; 7–8 on spire whorls, 8–9 on last whorl. Interspaces deep, about twice rib width on later whorls. Spiral sculpture of 5 strong primary cords on early whorls; from second whorl onwards, fine sixth cord appears adapically below suture; from third whorl onwards, fine secondary threads intercalated between primary cords; on penultimate and last whorl, fine tertiary threads present on both sides of secondary ones. Central primary cord often slightly stronger, forming indistinct keel. Prominent axial growth lines intersect spiral cords, producing reticulate pattern. Base and siphonal canal with numerous weaker spiral threads, coarse and fine, fading towards canal tip. Siphonal canal relatively long, slightly longer than aperture length, open, slightly curved. Aperture large, almost round. Outer lip strongly lirate internally; subadult specimens with shallow internal grooves corresponding to external spiral cords. Inner lip fully adherent to columella, forming thin, glossy, smooth columellar callus; columellar plicae absent. At base of siphonal canal, labral side with strongly calloused elongate teeth; parietal side with 1–2 irregular teeth. Broad, shallow parietal tooth present. Umbilicus absent. Protoconch white. Shell whitish to cream, with yellowish-tinged interspaces between axial ribs; aperture white; base and canal pale. Periostracum light brown, bearing small, relatively long thorns at intersections of axial growth lines and spiral sculpture. Operculum and radula unknown.

Distribution

Known only from Vanuatu (Fig. 45). Empty shells at depths of 314– 402 m.

Remarks

Vermeijius costuliferus sp. nov. was recorded at BOA 1 station CP2414, in syntopy with V. pallidus. The latter differs notably by its multispiral protoconch, and further by having a more slender shell profile, a proportionally higher spire, less inflated whorls, and typically more numerous and closely spaced axial ribs.

Vermeijius papuaensis sp. nov. (Papua New Guinea) is also comparable, but can be distinguished by its higher and more slender spire, smaller spire angle, weaker axial ribs, and narrower, more widely spaced spiral cords.

Juvenile specimens of V. admirabilis sp. nov. (Solomon Islands) may resemble V. costuliferus sp. nov., but differ in their longer and more slender spire, less convex whorls, less deeply incised suture, less pronounced axial ribs, and somewhat weaker spiral sculpture.

Specimens of V. snyderi sp. nov. (Philippines) are overall not likely to be confused due to their smaller adult size, lighter and more slender shells, and finer axial sculpture. However, one morphological form displays axial sculpture similar to V. costuliferus sp. nov., along with a deeply incised suture and strongly convex whorls. Even this form is clearly separable by its smaller adult size, longer and slimmer spire, less inflated whorls, and slightly stronger primary spiral cords.