Pandalosia subfirmata (O. Boettger, 1887 )

Qi, Lu, Liu, Songyuan, Sun, Shengming, Kong, Lingfeng & Ma, Zhenhua, 2025, Zebinidae (Caenogastropoda, Rissooidea) from Hainan Island, China, with re-description of four species, Biodiversity Data Journal 13, pp. e 165463-e 165463 : e165463-

Pandalosia subfirmata (O. Boettger, 1887)

Materials

Type status: Other material. Occurrence: catalogNumber: STGY 71 ; recordedBy: Qi Lu; individualCount: 2; lifeStage: adult; occurrenceID: EDBBA5C5-74AE-557C-B169-350D9E4314E3; Taxon: taxonID: Native; scientificName: Pandalosia subfirmata ; originalNameUsage: Costalynia decapitata Laseron, 1956 , Costalynia truncata Laseron, 1956 , Pandalosia darwinensis Laseron, 1956 , Pandalosia excelsis Laseron, 1956 , Pandalosia subulata Laseron, 1956 , Rissoina ( Schwartziella) subfirmata O. Boettger, 1887 , Schwartziella ( Pandalosia) darwinensis ( Laseron, 1956) ; Location: country: China; stateProvince: Hainan; locality: Wenchang ; Identification: identifiedBy: Qi Lu; dateIdentified: 2023

Description

Shell minute (3 ± 0.15 mm in height, 1 ± 0.02 mm in width), conical, white, glossy, translucent (Fig. 2 A-D). Protoconch with 3.5 whorls, conical, slender, smooth, transition to teleoconch poorly defined (Fig. 2 G 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. 2 C-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. 2 F).

Diagnosis

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).

Distribution

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

Taxon discussion

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.

Figures

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.