Shell minute (3.4 ± 0.25 mm in height; 1.5 ± 0.01 mm in width), fusiform-ovate in shape, white, solid and translucent (Fig. 1A and B). Seven whorls, body whorl height greater than spire (Fig. 1C and D); teleoconch whorls 4, inflated, sculptured exclusively by axial ribs with wide intercostal spaces (approximately twice the width of ribs), axial ribs on body whorl constricted at base (Fig. 1C-F); shell surface with fine microsculpture (Fig. 1F). Suture distinct, but shallow (Fig. 1F). Aperture large, D-shaped, angulated posteriorly, without anterior channel; outer lip prosocline, thick, with varix, bearing fine growth lines on edge; inner lip and columellar lip forming straight line, thick, broad, everted at columella; interior of aperture with delicate annular sculpture (Fig. 1E). Base lacking folds. Umbilicus absent. Protoconch of 3 whorls, eroded (Fig. 1G and H).

Figure 1.  

Schwartziella triticea (Pease, 1861). A, B shell illustration in colour; C scanning electron micrographs of frontal view of shell; D scanning electron micrographs of lateral view of shell; E detail of aperture; F detail of teleoconch surface; G scanning electron micrographs of lateral view of protoconch; H scanning electron micrographs of apical view of protoconch.

Shell somewhat fusiformly ovate; ribs nine, prominent, smooth, continuous over the sutures; aperture ovate (Pease 1861).

Schwartziella triticea exhibits a broad tropical distribution, ranging from the Red Sea across the Indian Ocean. It is also recorded from Hainan Island (China) and Hawaiian waters (Sleurs and Strack 2021).

The genus Schwartziella Nevill, 1881 is primarily characterised by prominent axial ribs on the shell surface, with ribs on the body whorl extending continuously to the base. It differs from Rissoina in lacking an anterior canal in the aperture and possessing an inner operculum without peg-like projections. When compared to Zebina H. Adams & A. Adams, 1854, Schwartziella Nevill, 1881 shows minimal anatomical distinctions, but exhibits more robust axial ribbing. S. triticea closely resembles S. laseroni (C.-K. Chang & W.-L. Wu, 2004); however, the latter can be distinguished by the presence of basal plicae and a narrower columellar lip.

Shell minute (3 ± 0.15 mm in height, 1 ± 0.02 mm in width), conical, white, glossy, translucent (Fig. 2A-D). Protoconch with 3.5 whorls, conical, slender, smooth, transition to teleoconch poorly defined (Fig. 2G and H). Teleoconch comprising approximately 5 whorls, each convex with deeply impressed sutures; sculpture consisting of prosocline axial ribs, lacking spiral elements; axial ribs sparsely distributed, intercostal spaces exceeding rib width (Fig. 2C-E). Base with prominent plica. Aperture D-shaped, posteriorly angulate, lacking distinct anterior canal; outer lip thickened, varix bearing longitudinal striae; interior of aperture with delicate spiral lirae (Fig. 2F).

Figure 2.  

Pandalosia subfirmata (O. Boettger, 1887). A, B shell illustration in colour; C scanning electron micrographs of frontal view of shell; D scanning electron micrographs of lateral view of shell; E detail of teleoconch surface; F detail of aperture; G scanning electron micrographs of lateral view of protoconch; H scanning electron micrographs of apical view of protoconch.

Whorls growing fairly rapidly, rather convex, separated by a deep suture; initial whorls smooth, the others strongly ribbed, with rounded, oblique ribs and smooth interspaces. Aperture oblique, narrowly ovate (Boettger 1887).

Tropical Indo-Pacific Region (China, Japan, Australia); including tropical western America (Sleurs and Strack 2021).

The genus Pandalosia was segregated from Schwartziella (Laseron 1956), characterised by smaller and more slender shells; protoconch comparatively large and elongate, surface smooth, lacking microsculpture, base bearing a prominent plica. Pandalosia subfirmata (O. Boettger, 1887) is not a new record from Chinese waters, as it had been previously identified in Taiwanese waters as Pandalosia darwinensis Laseron,1956 (Liu 2008). Currently, Pandalosia darwinensis Laseron, 1956 is treated as a synonym of P. subfirmata in the World Register of Marine Species (WoRMS). Two additional species, Pandalosia moerchiella C.-K. Chang & W.-L. Wu, 2004 and Pandalosia lutaoi C.-K. Chang & W.-L. Wu, 2004, have also been reported from Taiwanese waters, though their taxonomic status remains uncertain. These two species are clearly distinguishable from P. subfirmata in shell sculpture: P. moerchiella possesses a smooth shell surface lacking prominent axial ribs, while P. lutaoi exhibits much weaker and less distinct axial ribs compared to those of P. subfirmata (Chang and Wu 2004). A comprehensive taxonomic revision of the genus Pandalosia in Chinese waters is warranted in the future.

Shell minute (6.2 ± 0.02 mm in height, 3.8 ± 0.11 mm in width), thick-walled, solid, opaque-white, smooth and glossy, ovate-conical (Fig. 3A and B). Whorls approximately 7 (protoconch missing); body whorl inflated, its height exceeding that of spire; teleoconch whorls 1-3 with axial ribs, whorls 4 to body whorl smooth (Fig. 3C, D and F). Aperture elliptical, slightly prosocline, anteriorly rounded and posteriorly angulate; outer lip lacking external varix, but internally thickened, with a single small denticle on anterior interior edge; inner lip smooth; peristome with fine axial striations (Fig. 3E). Sutures indistinct.

Figure 3.  

Zebina tridentata (Michaud, 1830). A, B shell illustration in colour; C scanning electron micrographs of frontal view of shell; D scanning electron micrographs of lateral view of shell; E detail of aperture; F scanning electron micrographs of lateral view of protoconch.

Shell conical，white, smooth and glossy; aperture ovate, oblique and somewhat channelled; outer lip swollen, with three teeth on the inner side; columella with a distinct callus at the upper part (Michaud 1830).

Tropical and subtropical Indo-West Pacific (Hainan and Taiwan, China; Kyushu, Japan; Philippines), ranging from the Red Sea and Mozambique to Hawaii and Tuamotu Archipelago (Sleurs and Strack 2021).

Species of Zebina resemble those of the family Eulimidae, but are distinguished by distinct apertural features, typically exhibiting a robust outer lip varix and posterior channel. Additionally, Zebina shells tend to be thicker and more opaque. The diagnostic character of Z. tridentata is the presence of three denticles on the anterior interior edge of the outer lip (Michaud 1830). However, Cernohorsky (1978) noted that this species may exhibit 1–3 denticles. Therefore, we conclude that the denticle number in Z. tridentata exhibits intraspecific variation. In this study, the examined specimen possesses only a single denticle (Fig. 3E), yet consistent with other diagnostic features, we identify it as Z. tridentata.

Shell minute (4 ± 0.01 mm in height, 1.9 ± 0.03 mm in width), thick-walled, white, but frequently stained pale reddish-brown by iron deposits (Fig. 4A and B). Whorls approximately 7, body whorl height greater than spire; teleoconch sculptured exclusively by strong spiral cords with axial lamellae between cords, interspaces about twice the width of cord (Fig. 4G); body whorl bearing 4 spiral cords (Fig. 4C and D). Sutures indistinct, shallow (Fig. 4F). Base with 3 spiral cords. Aperture elliptical, anteriorly canaliculate, posteriorly angulate; outer lip with strong external varix bearing spiral cords, interior smooth, but with 3 weakly-developed tubercular ridges; inner lip smooth to anterior canal, slightly arcuate, broad; peristome thickened (Fig. 4E). Protoconch multispiral (approximately 2.5 whorls), distinctly demarcated from teleoconch; clear boundary between first and second protoconch whorls, smooth (Fig. 4H and I).

Figure 4.  

Stosicia annulata (Dunker, 1860). A, B shell illustration in colour; C scanning electron micrographs of frontal view of shell; D scanning electron micrographs of lateral view of shell; E detail of aperture; F, G detail of teleoconch surface; H scanning electron micrographs of lateral view of protoconch; I scanning electron micrographs of apical view of protoconch.

A species distinguished by its transverse ribs, of which seven are present on the last whorl (Dunker 1860).

Widely distributed, currently known from the Bōsō and Noto Peninsulas to Kyushu (Japan), Southeast Asia, India, East Africa and Hainan Island (China) (Gajera et al. 2024).

The genus Stosicia Brusina, 1871 was divided by Ponder (1985) into two subgenera: Stosicia s.s. (with only spiral cords and multispiral protoconch) and Isseliella (with cancellate sculpture formed by axial and spiral ribs and paucispiral protoconch). These two subgenera have now been elevated to separate genera. S. annulata is reported from China for the first time and is, therefore, identified as a new record for the country.