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

Materials

Type status: Holotype. Occurrence: catalogNumber: ZRCBUU-0190 ; recordedBy: Kanita Khwantong; individualCount: 1; lifeStage: adult; preparations: dry shell material; Taxon: scientificName: Diplommatinakhwantongae; Location: country: Thailand; stateProvince: Chonburi; locality: Lub Lae Cave, Bothong district, Chonburi Province ; verbatimCoordinates: 13°09'09.9"N 101°35'52.4"E; georeferenceProtocol: GPS; Identification: identifiedBy: Kanita Khwantong; dateIdentified: 2015; Event: samplingProtocol: hand collecting; eventDate: 2020; habitat: limestone hills; Record Level: language: en; collectionCode: Mollusc; basisOfRecord: PreservedSpecimen Type status: Paratype. Occurrence: catalogNumber: ZRCBUU-0102 ; recordedBy: Kanita Khwantong; individualCount: 5; lifeStage: adult; preparations: dry shell material; Taxon: scientificName: Diplommatinakhwantongae; Location: country: Thailand; stateProvince: Chonburi; locality: Lub Lae Cave, Bothong district, Chonburi Province ; verbatimCoordinates: 13°09'09.9"N 101°35'52.4"E; georeferenceProtocol: GPS; Identification: identifiedBy: Kanita Khwantong; dateIdentified: 2015; Event: samplingProtocol: hand collecting; eventDate: 2020; habitat: limestone hills; Record Level: language: en; collectionCode: Mollusc; basisOfRecord: PreservedSpecimen Type status: Paratype. Occurrence: catalogNumber: ZRCBUU-0757 ; recordedBy: Rattanawadee Tekavong; individualCount: 5; lifeStage: adult; preparations: dry shell material; Taxon: scientificName: Diplommatinakhwantongae; Location: country: Thailand; stateProvince: Chonburi; locality: Lub Lae Cave, Bothong district, Chonburi Province ; verbatimCoordinates: 13°09'09.9"N 101°35'52.4"E; georeferenceProtocol: GPS; Identification: identifiedBy: Pongrat Dumrongroiwattana; dateIdentified: 2015; Event: samplingProtocol: hand collecting; eventDate: 2020; year: 2020; month: 7; day: 11; habitat: limestone hills; Record Level: language: en; collectionCode: Mollusc; basisOfRecord: PreservedSpecimen Type status: Other material. Occurrence: catalogNumber: ZRCBUU-0759 ; occurrenceRemarks: Three live specimens were collected and reared in the laboratory for few months. All specimens were preserved in ethanol.; recordedBy: Rattanawadee Tekavong; individualCount: 3; lifeStage: adult; Taxon: scientificName: Diplommatinakhwantongae; Location: country: Thailand; stateProvince: Chonburi; locality: Lub Lae Cave, Bothong district, Chonburi Province ; verbatimCoordinates: 13°09'09.9"N 101°35'52.4"E; georeferenceProtocol: GPS; Identification: identifiedBy: Pongrat Dumrongroiwattana; dateIdentified: 2015; Event: samplingProtocol: hand collecting; eventDate: 2020; year: 2020; month: 7; day: 11; habitat: limestone hills; Record Level: language: en; collectionCode: Mollusc; basisOfRecord: PreservedSpecimen

Description

Holotype - Shell height 3.59 mm, shell width 1.91 mm. Aperture height 0.93 mm, aperture width 1.86 mm. Shell width/shell height ratio = 0.53. Aperture width/aperture height ratio = 1.15. (Fig. 3 B-E).

Paratypes: (6 shells). Shell height 1.68-1.76 mm (1.69 ± 0.04 mm), shell width 0.78-0.81 mm (0.81 ± 0.04 mm). Aperture height 0.46-0.58 mm (0.53 ± 0.04 mm). Aperture width 0.53-0.61 mm (0.59 ± 0.03 mm). Shell width/shell height ratio = 0.48 ± 0.03. Aperture width/aperture height ratio = 1.12 ± 0.07.

Shell minute dextral, cylindrical, light orange, with about 7 whorls that increase regularly in size and diameter until the last whorl; protoconch orange, smooth, consisting of 1 ¼ whorls, covered with minute pits; teleoconch light orange, consisting of about 5 ¾ whorls; spires shouldered; sculpture consists of rather even and widely-spaced thin radial ribs with discernible spiral striae between the ribs; there are about 8 ribs/mm on the penultimate whorl and about 6 ribs/mm on the body whorl; sutures deep; umbilicus closed; aperture round; peristome thickened and expanded and doubled; columellar lamella rather bluntly rounded.

Animal. Living animals had a greyish body, head, tentacles and foot, with an orange eye located at the base of each tentacle (Fig. 3 C-E). The operculum was round and corneous. Snails were found living in leaf litter and plant debris in the limestone hills. Due to the small population of each species, the live specimens of all species found in this study are hard to find. More observation and further study on anatomy are needed.

Diagnosis

Shell minute, dextral, cylindrical, light orange, teleoconch sculpture of widely-spaced and high radial ribs, aperture rounded, columellar lamella well developed, peristome thickened and expanded.

Etymology

We named this new species " khwantongae " in memory of Ms. Kanita Khwantong, who made the first discovery of this new species.

Distribution

This species is known only from the limestone hills in Chonburi and Rayong Provinces.

Taxon discussion

The shell shape of Diplommatina is generally fusiform or tower-shaped with mostly low and strong radial ribs, which are formed as tubular projections in some species and mostly rounded or angular periphery whorls. For example, the shell of D. hidagai is fusiform covered with low and strong radial ribs or the shell of D. nimannandhi Panha et al., 2002 has tower-shaped, radial ribs forming as semi-tubular peripheral projections. In this new species, Diplommatina khwantongae sp. n. is a very distinct species of epitoniid snail due to its cylindrical, thin radial ribs and shouldered whorls.

Figures

Figure 3. Two Diplommatina species from eastern Thailand. A) D. fusiformis spec. nov., B-E) D. khwantongae spec. nov., B) Holotype, C-D) Living snail. (Photos by Ms. Rattanawadee Tekavong). 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.