Zafra thaanumi, Monsecour & Raines, 2024

Monsecour, Kevin & Raines, Bret K., 2024, New species and genus of Columbellidae (Gastropoda: Buccinoidea) from the Western Pacific, Zootaxa 5514 (4), pp. 353-367 : 364

Zafra thaanumi sp. nov.

Figures 5 A–H

Type Material. Holotype LACM 3857, 8 Paratypes LACM 3858, 8 Paratypes MNHN-IM-2018-1784, 8 Paratypes CKM, 8 Paratypes MSF fa183.

Type Locality. Wake Atoll , off west side of Wilkes Island, 19.2921 o N, 166.6084 o E, 30–35 m deep .

Additional Material Examined. 15 specimens from type locality, and 35 specimens from off northwest side of Wilkes Island , 25–30 m deep .

Distribution. Only known from around Wilkes Island at depths of 25–35 m deep.

Description. Shell of average size for genus, up to 3.2 mm; fusiform, elongate. Protoconch paucispiral, of 1.5 smooth whorls. Transition to teleoconch clearly visible. Teleoconch of 3.25–4.0 whorls, slightly shouldered; suture not impressed. Axial sculpture of about 13 strong ribs, wider than interspaces. Spiral sculpture obsolete on early whorls; subsutural cord becomes visible on latter whorls, extending to just above mid-apertural height. Intersections of axial ribs and basal cords giving abapical edge of dorsal side of shell crenulate appearance. Aperture narrow, 42–46% of shell height. Outer lip slightly thickened, with continuation of basal cords abapically. Inside with sinus on adapical end and 4–5 denticles, diminishing in strength toward abapical end, adapical two denticles partially fused. Columellar callus with pronounced sharp edge, not denticulate, basal cords emerging through. Parietal callus thin. Siphonal canal short, open, slightly recurved. Teleoconch whorls pale brown to brown with network of paler spade-shaped spots, clearly present white subsutural spiral band and weak white band at mid-height of last whorl. Protoconch off-white to cream. Aperture and columella white. Radula not studied. Height of holotype: 3.1 mm.

Remarks. Paratypes show some variation in shell size, number of teleoconch whorls and darkness of the color pattern. Zafra thaanumi has a comparable color pattern with the widespread Indo-Pacific Zafra ocellatula ( Hervier, 1900) (figs 5 I–J). However, Z. thaanumi is smaller in size, has a paucispiral protoconch, fewer teleoconch whorls and greater number of larger spots in the color pattern.

Etymology. Named after Ditlev Thaanum, who was the amateur malacologist on the first biological survey of Wake Atoll as part of the Tanager Expedition in 1923 (see Rehder 1969).

Figures

FIGURE 5. A–H, Zafra thaanumi sp. nov.; A–B, Holotype. LACM 3857, 3.1 mm; C–D, Paratype 1. LACM 3858, 2.6 mm; E–F, Paratype 2. MNHN-IM-2018-1784, 3.4 mm; G–H, Paratype 3. CKM, 2.7 mm; I–J, Zafra ocellatula (Hervier, 1900), Papua New Guinea, New Ireland, Kavieng, CKM, 4.0 mm; K–P, Zafra spadicea sp. nov.; K–L, Holotype. LACM 3372, 3.0 mm; M–N, Paratype 1. LACM 3373, 2.9 mm; O–P, Paratype 2. MNHN-IM-2018-1785, 3.2 mm.