Diplommatina chadathongae Kamtuptim, Dumrongrojwattana & Wongkamhaeng 2020

Dumrongrojwattana, Pongrat, Kamtuptim, Chanakarn & Wongkamhaeng, Koraon, 2020, A review of Diplommatina species in eastern Thailand with the descriptions of five new species, Biodiversity Data Journal 8, pp. 57689-57689 : 57689

Diplommatina chadathongae Kamtuptim, Dumrongrojwattana & Wongkamhaeng 2020 sp. n.

Materials

Type status: Holotype. Occurrence: catalogNumber: ZRCBUU-0092 ; recordedBy: Pongrat Dumrongrojwattana; individualCount: 1; lifeStage: adult; preparations: dry shell material; Taxon: scientificName: Diplommatinachadathongae; Location: country: Thailand; stateProvince: Chanthaburi; locality: Wat Khaowongkotrujiwongsaram, Kanghaengmaeo District ; verbatimCoordinates: 12°53'11.4"N 101°49'06.2"E; georeferenceProtocol: GPS; Identification: identifiedBy: Pongrat Dumrongrojwattana; dateIdentified: 2012; Event: samplingProtocol: hand collecting; eventDate: 2020; habitat: limestone hills; Record Level: language: en; collectionCode: Mollusc; basisOfRecord: PreservedSpecimen Type status: Paratype. Occurrence: catalogNumber: ZRCBUU-0093 ; recordedBy: Pongrat Dumrongrojwattana; individualCount: 29; lifeStage: adult; preparations: dry shell material; Taxon: scientificName: Diplommatinachadathongae; Location: country: Thailand; stateProvince: Chanthaburi; locality: Wat Tam Khaochan, Khaochakan District ; verbatimCoordinates: 12°53'11.4"N 101°49'06.2"E; georeferenceProtocol: GPS; Identification: identifiedBy: Pongrat Dumrongrojwattana; dateIdentified: 2012; Event: samplingProtocol: hand collecting; eventDate: 2020; habitat: limestone hills; Record Level: language: en; collectionCode: Mollusc; basisOfRecord: PreservedSpecimen

Description

Holotype. Shell height 1.61 mm, shell width 0.78 mm. Aperture height 0.50 mm, aperture width 0.60 mm. Shell width/shell height ratio = 0.49. Aperture width/aperture height ratio = 1.21 (Fig. 2 C).

Paratypes (6 shells). Shell height 1.93-2.07 mm (1.98 ± 0.05 mm), shell width 0.84-0.93 mm (0.88 ± 0.03 mm). Aperture height 0.51-0.63 mm (0.58 ± 0.05 mm). Aperture width 0.59-0.67 mm (0.63 ± 0.02 mm). Shell width/shell height ratio = 0.45 ± 0.01. Aperture width/aperture height ratio = 1.09 ± 0.07.

Shell minute dextral, cylindrical, translucent, whitish, with about 5 ¾ whorls that increase regularly in size and diameter until the last whorl; protoconch orange, smooth, consisting of 1 ½ whorls; teleoconch light orange, consisting of about 4 ¼ keeled whorls; sculpture consists of strong, rather narrowly-spaced radial ribs which are about 20 ribs/mm on the penultimate whorl and about 14 ribs/mm on the body whorl; sutures well impressed; umbilicus closed; aperture round; peristome thickened and expanded and doubled; columellar lamella well developed and directed anteriorly (Fig. 4 ).

Diagnosis

Shell minute, dextral, cylindrical, translucent, whitish, teleoconch sculpture of narrowly-spaced axial ribs, whorls aperture rounded, columellar lamella well developed, peristome thickened, expanded and doubled.

Etymology

We named this new species " chadathongae " in memory of the second author's beloved mother, Ms. Wiang Chadathong.

Distribution

Only known from the type locality.

Taxon discussion

Diplommatina chadathongae sp. n. is another one of the Thai smallest Diplommatina species (average shell height = 1.69 ± 0.04 mm) and same size as D. krabiensis Panha & Burch, 1998 (shell height of type specimens are 1.6-1.7 mm and average shell height = 1.69 ± 0.04 mm). This new species differs from D. krabiensis by its dextral, cylindrical, narrowly-fine radial ribs, while the smallest species is sinistral, shell fusiform or ovate with widely-spaced radial ribs. This new species differs from Diplommatina miriensis Godwin-Austen, 1917 from Nepal by its shell being more slender and columellar lamella well developed.

Figures

Figure 2. Four Diplommatina species from eastern Thailand. A) Diplommatina crispata khaochamaoensis Panha et al., 1998, B) D. burapha sp. n., C) D. chadathongae sp. nov. and D) D. chantaburiensis sp. n. Each species shows a frontal view, lateral view, dorsal view and the number of ribs per 0.5 mm on the penultimate whorl and body whorl, respectively.

Figure 4. Synopsis of eastern diplommatind species. A) Diplommatina crispata khaochamaoensis, B-C) Holotype and paratypes of D. burapha sp. n., D-E) Holotype and paratypes of D. chadathongae sp. n., F-G) Holotype and paratypes of D. chantaburiensis sp. n., H-I) Holotype and paratypes of D. fusiformis sp. n. and J-K) Holotype and paratypes of D. khwantongae sp. n. Scale bar = 1 mm.