Laotia christahemmenae phami, Páll-Gergely & Hunyadi, 2021

Páll-Gergely, Barna & Hunyadi, András, 2021, A new species and a new subspecies of Laotia Saurin, 1953 (Gastropoda: Caenogastropoda: Alycaeidae) from Sơn La Province, Vietnam, Raffles Bulletin of Zoology 69, pp. 118-123 : 120-121

Laotia christahemmenae phami , new subspecies

( Fig. 1B–D )

Type material. Holotype (VNMN-Z-Inv.000218, D: 5.1 mm, H: 3.5 mm), Vietnam, SƠn La Province, Thu ận Châu District, Co M ạ, Pha Khuȏng , rock wall above Chuyên Nga Motel , 1,270 m a.s.l., 21°21.385′N, 103°31.175′E (locality code: 2020/17), coll. A. Hunyadi, H. V. Luong, J.U. Otani & S. V. Pham, 8 February 2020.

Paratypes. 1 shell (VNMN-Z-Inv.000219), same data as holotype ; 9 shells (coll. HA), same data as holotype ; 1 paratype with operculum (photographed), (coll. HA), same data as holotype ; 5 adult dead shells (coll. JUO), same data as holotype ; 2 adult dead shells (coll. JUO), Vietnam, SƠn La Province, Thu ận Châu District, Co M ạ, Pha Khuȏng , along rd. 108, 1,260 m a.s.l., 21°21.36′N, 103°31.4526′E (locality code: 20200208B), coll. A. Hunyadi, H. V. Luong, J.U. Otani & S. V. Pham, 8 February 2020 .

Additional material. 1 juvenile shell (coll. HA), same data as holotype .

Differential diagnosis. This subspecies differs from the nominotypical subspecies in the more elevated spire and the narrower umbilicus (umbilicus width ca. one fifth of the small shell diameter in the new subspecies, whereas it is ca. one fourth in the nominotypical subspecies).

Measurements (in mm). D: 4.9–5.3, H: 3.5 (smallest and largest shells measured).

Operculum. Outer side: funnel shaped with a single, multispiral calcareous lamina bent towards the nucleus. Inner side: glossy, without central nipple, with shallow, wide spiral grooves corresponding with the position of the elevated lamina of the outer side. This is the first report of an operculum in Laotia .

Etymology. This new species is dedicated to and named after our much-valued friend, Sáng Văn Phạm, who helped during field collection.

Distribution. Laotia christahemmenae phami , new subspecies, is known from two nearby occurring localities in SƠn La Province, Vietnam ( Fig. 2 ). Practically a single population is known.

RAFFLES BULLETIN OF ZOOLOGY 2021

Figures

Fig. 1. Shells of Laotia Saurin, 1953 species. A, Laotia christahemmenae christahemmenae Páll-Gergely, 2014 (20200210A, VNMN-Z- Inv.000221); B–D, Laotia christahemmenae phami, new subspecies. B, holotype (VNMN-Z-Inv.000218); C, outer side of the operculum, coll. HA, paratypes; D, inner side of the operculum, coll. HA, paratype. All photos: B. Páll-Gergely.

Fig. 2. Distribution of Laotia Saurin, 1953 species in Vietnam. Triangle: Laotia christahemmenae phami, new subspecies; inverse triangle: Laotia luongi, new species; square:Laotia christahemmenae christahemmenae Páll-Gergely, 2014 (filled square represents the type locality).