[Mollusca • 2025] Hypselostoma pongrati & H. sichomphuense, ... • Two New Species of terrestrial Microsnails of the genus Hypselostoma W.H. Benson, 1856 (Gastropoda: Eupulmonata: Hypselostomatidae) from northeastern Thailand

 

A, B. Hypselostoma pongrati sp. nov. 
 C, D. Hypselostoma sichomphuense sp. nov.  

Tanmuangpak & S. Tumpeesuwan,

in Tanmuangpak, Nahok, Chanlabut, C. Tumpeesuwan et S. Tumpeesuwan, 2025.

 DOI: doi.org/10.3897/zookeys.1265.160661

Abstract

Two new species of hypselostomatid land microsnails, Hypselostoma pongrati Tanmuangpak & S. Tumpeesuwan, sp. nov. from Nong Bua Lamphu Province and H. sichomphuense Tanmuangpak & S. Tumpeesuwan, sp. nov. from Khon Kaen Province, are described based on the morphology of their shell, radula, and genital system. Both new species are very similar in shell shape to H. phupaman from Chaiyaphum Province, possessing a double-keeled last whorl. However, H. pongrati Tanmuangpak & S. Tumpeesuwan, sp. nov. is distinguished by the absence of apertural barriers, whereas H. sichomphuense Tanmuangpak & S. Tumpeesuwan, sp. nov. possesses three apertural barriers, and H. phupaman possesses six or seven. The three species were found on isolated limestone hills in the Chaiyaphum-Khon Kaen-Nong Bua Lamphu-Loei area.

Key words: Apertural barriers, double-keeled last whorl, genital system, limestone hills, radula

Taxonomy

Family Hypselostomatidae Zilch, 1959

Genus Hypselostoma W.H. Benson, 1856

Living Hypselostoma spp.
A, B. Hypselostoma pongrati sp. nov. paratype NHLRU015;
C, D. H. sichomphuense sp. nov. paratype NHLRU033.

 Hypselostoma pongrati Tanmuangpak & S. Tumpeesuwan, sp. nov.

Diagnosis. This new species has a prominent keel on the upper part of the last whorl and a weaker keel on the lower part. Apertural barriers absent (Fig. 3A, G, H, L). Terminal part of the last whorl is adnated to penultimate whorl.

Etymology. This new species is dedicated to the late Pongrat Dumrongrojwattana, our highly respected senior who was an expert on microsnails and who provided us with many land snails references, knowledge, and inspiration.

 Hypselostoma sichomphuense Tanmuangpak & S. Tumpeesuwan, sp. nov.

 

Diagnosis. This new species differs from Hypselostoma phupaman by the presence of a non-prominent lower keel on the last whorl and the absence of basal and parietal apertural barriers. Aperture has three smooth tooth-like swellings (Fig. 4A, G–I), whereas there are no apertural barriers in H. pongrati sp. nov. (Fig. 3A, G–I). Spire shorter than the spire of H. pongrati sp. nov.

Etymology. The specific epithet sichomphuense refers to Si Chomphu District, Khon Kaen Province, northeastern Thailand, where this species was discovered.

 Kitti Tanmuangpak, Benchawan Nahok, Utain Chanlabut, Chanidaporn Tumpeesuwan and Sakboworn Tumpeesuwan. 2025. Two New Species of terrestrial Microsnails of the genus Hypselostoma W.H. Benson, 1856 (Gastropoda, Eupulmonata, Hypselostomatidae) from northeastern Thailand. ZooKeys. 1265: 49-67. DOI: doi.org/10.3897/zookeys.1265.160661

[Mollusca • 2025] Georissa chatra & G. principalis • Phylogenetic and Morphological Evidence for Two New Species of Terrestrial Micro Snail Genus Georissa Blanford, 1864 (Neritimorpha: Hydrocenidae) from Central Thailand

 

หอยทากจิ๋วจุกแดงทรงเจดีย์ • Georissa principalis  Buathanom & Tongkerd, 
หอยทากจิ๋วจุกแดงทรงฉัตร • Georissa chatra  Buathanom & Pholyotha,  

in Buathanom, Tongkerd, Jirapatrasilp, Janjai, Mitchueachart, Annate, Panha, Sutcharit et Pholyotha, 2025. 

Tropical Natural History. Supplement 8 (2025): 

Abstract

This paper introduces two newly discovered endemic micro snails, Georissa chatra Buathanom & Pholyotha, sp. nov. and G. principalis Buathanom & Tongkerd, sp. nov., from limestone hills of Uthai Thani and Nakhon Sawan Provinces in central Thailand. These findings expand the number of Georissa species recorded in Thailand to seven. The taxonomic status and species boundaries of these new species were determined through a comprehensive analysis of comparative morphology and mitochondrial genetics. Georissa chatra sp. nov. is distinguished by a conical shell with tall and prominent carinas. Georissa principalis sp. nov. is characterized by an elongate conical or turreted shell with prominent cord-like spiral ridges, and an operculum with two layers. The cytochrome c oxidase subunit I (COI) phylogeny supports the monophyly of both lineages, but the relationships with other congeners remain unresolved. The analysis also revealed interspecific genetic distances among examined species ranging from 6.8% to 18.6%. Additionally, intraspecific genetic distances are surprisingly high, with 6.1% for G. chatra sp. nov. and 7.5% for G. principalis sp. nov. The observed high intraspecific genetic divergences are likely due to the significant endemism and fragmented distribution of populations within karst ecosystems. As a result, the discovery of these two new species significantly advances our understanding of micro snail diversity and represents a crucial first step in establishing a comprehensive DNA barcode reference library for micro snails in Thailand.

Keywords: COI, Endemic, Limestone, Operculated snail, Morphology, Systematics, Taxonomy, Hydrocenoidea 

Subclass Neritimorpha Koken, 1896

Order Cycloneritida Frýda, 1998

Superfamily Hydrocenoidea Troschel, 1857

Family Hydrocenidae Troschel, 1857

Genus Georissa Blanford, 1864

Living Georissa chatra sp. nov. from a limestone hill near Wat Si Uthum Phon, Nakhon Sawan.
A, B.snails in microhabitats on the limestone wall; insets showing close-up views of (A) a snail hiding in a small crevice and (B) a snail on a bare wall. C–F.four different individuals while climbing slowly on moist tissue paper.

Georissa chatra Buathanom & Pholyotha, sp. nov.

 หอยทากจิ๋วจุกแดงทรงฉัตร

Diagnosis.− Shell minute, conical, dark orange, with tall and prominent carinas: one on upper periphery and one on below periphery.

Etymology.− The specific epithet “chatra” refers to a dome or umbrella-like structure sometimes with multiple tiers or layers, which is used in several Asian royal or state ceremonies, reflecting the distinctive shell shape of this new species.

Shells of Georissa principalis sp. nov.
A–C.paratype CUMZ 15273 from Wat Khao Mano, Nakhon Sawan.

Living Georissa principalis sp. nov.
 A.snail in a microhabitat on the limestone wall at Tham Khao Kaji, Uthai Thani; an inset showing a close-up view of a snail among lichen on a bare wall. B–E.four different individuals while climbing slowly on moist tissue paper, (B, C)from Wat Khao Ruea, Nakhon Sawan and (D, E)from Wat Khao Mano, Nakhon Sawan.

Georissa principalis Buathanom & Tongkerd, sp. nov.

หอยทากจิ๋วจุกแดงทรงเจดีย์

Diagnosis.− Shell minute, elongate, turreted, yellow-orange to light brownish, with about six to seven prominentspiral ridges at the periphery, and operculum with 2 layers.

Etymology.− The name “principalis” is derived from the Latin word meaning “chief” or “leader” and is chosen to honor Her Royal Highness Princess Maha Chakri Sirindhorn for her outstanding leadership in biodiversity conservation in Thailand.

Paniwat BUATHANOM, Piyoros Tongkerd, Parin Jirapatrasilp, Teerangkul Janjai, Bowornluk Mitchueachart, Supunya Annate, Somsak Panha, Chirasak Sutcharit and Arthit Pholyotha. 2025. Phylogenetic and Morphological Evidence for Two New Species of Terrestrial Micro Snail Genus Georissa Blanford, 1864 (Neritimorpha: Hydrocenidae) from Central Thailand. Tropical Natural History. Supplement 8 (2025): 62-78. DOI: 10.58837/tnh.25.8.267040

https://li01.tci-thaijo.org/index.php/tnh/article/view/267040

[Mollusca • 2025] Dicharax devraivasi • A New Micro-snail Species of the Genus Dicharax Kobelt & Möllendorff, 1900 (Caenogastropoda: Cyclophoridae: Alycaeinae), from sacred groves in the northern Western Ghats, India

 

 Dicharax devraivasi

Bhosale, Thackeray, Yadav & Khandekar, 2025

DOI: doi.org/10.61733/jconch/4543

 Researchgate.net/publication/390521141

 

Abstract

 We describe a new micro-snail species of the genus Dicharax based on 16 specimens collected from three sacred groves in Kolhapur District, in the northern Western Ghats of Maharashtra State, India. This species can be easily distinguished from its congeners in several non-overlapping morphological characters: R2 with closely spaced, blunt, elevated ribs; R3 with an inflated, blunt swelling; and basal part of the outer peristome (part close to the umbilicus) is more expanded than the rest of the outer peristome. We also describe and illustrate the living animal, operculum, radula, and jaw. This is the first report of the genus from the northern Western Ghats and extends its known geographic distribution in the Western Ghats by 370 km north. The new species highlights the importance of sacred groves as a biodiversity reservoir and emphasizes the need for in-depth investigations to uncover largely unknown biodiversity at these sites. We also discuss the need for systematic, fine-scale sampling in the northern Western Ghats to reveal mostly unknown land-snail diversity.

Key words. Biodiversity hotspot, Devrai, endemic, Dicharax devraivasi n. sp.,  taxonomy

Living snail of Dicharax devraivasi n. sp.
A, male, holotype NRC-AA-8454. B, female, paratype NRC-AA-8457. C, immature male (not collected) showing semitransparent shell. D, immature male, showing penis (at arrow).

Dicharax devraivasi n. sp.

Etymology. The specific epithet is used as a noun in apposition. It is derived from the Marathi word “devrai”, meaning “sacred grove”, and Sanskrit word “vasi”, meaning “inhabitant of”, as the new species has so far only been reported from multiple sacred grove forests in Kolhapur District, northern Western Ghats of Maharashtra. The suggested English common name is Devrai micro-snail.

Amrut Bhosale, Tejas Thackeray, Omkar Yadav and Akshay Khandekar. 2025. A New Micro-snail Species of the Genus Dicharax Kobelt & Möllendorff, 1900 (Caenogastropoda: Cyclophoridae: Alycaeinae), from sacred groves in the northern Western Ghats, India. Journal of Conchology. 45(3); DOI: doi.org/10.61733/jconch/4543  [5 April 2025]

 Researchgate.net/publication/390521141_A_new_micro-snail_species_of_the_genus_Dicharax_from_the_northern_Western_Ghats_India

[Mollusca • 2025] Clostophis udayaditinus • First Rrecord of the Microsnail Genus Clostophis Benson, 1860 (Eupulmonata: Pupilloidea: Hypselostomatidae) from Cambodia, with Description of A New Species

Clostophis udayaditinus Sutcharit & Panha,

in Sutcharit, Thi, Chantha, Chourn, Sophea, Jeratthitikul, Pholyotha, Siriwut, Srisonchai et Panha, 2025. 

Journal of Conchology. 45(3); 

 facebook.com/ASRUChula

Abstract

 Specimens of a new species of hypselostomatid microsnail, Clostophis udayaditinus Sutcharit & Panha, n. sp., were collected from the limestone hills area in Battambang Province, western Cambodia. Besides being a species new to science, this discovery represents a new country record for the genus. The new species differs from all other congeners by its concave-conical shell, with apertural dentition four in number, and hooked parietal and columellar lamellae. Living snails were found crawling on the walls in a cave, and the snails have a colourless, semitransparent soft body.

Key words. Angkor Kingdom, endemic species, limestone, pulmonates, taxonomy

Clostophis udayaditinus n. sp.  from the type locality.
A–C, paratype CUMZ 14466 of living snails crawling on wet tissue paper (three snails at different angles; all shell widths about 1.3 mm). D, light microscope image of paratype CUMZ 14467 with enlarged aperture at different angles.

 Abbreviations: c = columellar lamella, ip = infraparietal lamella, p = parietal lamella, pl = palatal plica.

Clostophis udayaditinus n. sp. from Battambang, Cambodia.
A, holotype CUMZ 14441 with enlarged aperture at different angles, and enlarged columellar lamella and palatal plica, and B, C, protoconch. D, paratype CUMZ 14446 from the type locality.

 Abbreviations: c = columellar lamella, ip = infraparietal lamella, p = parietal lamella, pl = palatal plica.

Family Hypselostomatidae Zilch, 1959 

Clostophis Benson, 1860

 Type species. Clostophis sankeyi Benson, 1860, by monotypy. 

Remarks. Until now, the genus Clostophis has been known to be widely distributed from Peninsular Malaysia to Myanmar, mainland Indochina, and southern China (Páll-Gergely et al. 2020; Páll-Gergely & Hunyadi 2022; MolluscaBase Eds 2024). There are 20 species known from Cambodia, including the new species, described here.

Clostophis udayaditinus Sutcharit & Panha, n. sp. 

Diagnosis. Shell concave-conical, with long, descending tuba and expanded peristome. Apertural dentition four: consisting of one hooked parietal lamella, one small infraparietal lamella, one large, strong palatal plica, and one hooked columellar lamella. Umbilicus wide.

Etymology. The species name udayaditinus is from “udayadit-”, and the suffix “-inus”, meaning possession or belonging to. This name is a memorial to King Udayadityavarman II, who ruled the Angkor Kingdom around 1100 A.D. He also ordered the building of the Bannan Temple (Higham 2014), which became the name of the hill—the type locality of this new species.

Chirasak Sutcharit, Sothearen Thi, Nasak Chantha, Phyroum Chourn, Chhin Sophea, Ekgachai Jeratthitikul, Arthit Pholyotha, Warut Siriwut, Ruttapon Srisonchai and Somsak Panha. 2025. First Rrecord of the Microsnail Genus Clostophis Benson, 1860 (Eupulmonata: Pupilloidea) from Cambodia, with Description of A New Species. Journal of Conchology. 45(3); DOI. doi.org/10.61733/jconch/4538  [23 February 2025] 

 facebook.com/ASRUChula/posts/1067704748707587

[Mollusca • 2020] Diplommatina fusiformis, D. burapha, ... • A Review of Diplommatina Species (Gastropoda: Diplommatinidae) in eastern Thailand with the Descriptions of Five New Species

[A] Diplommatina fusiformis spec. nov. หอยกระสวยจิ๋ว,  

[B-E] D. khwantongae spec. nov. หอยกระสวยจิ๋วคณิตา, 

D. crispata khaochamaoensis Panha et al., 1998, 

  หอยกระสวยจิ๋วบูรพา D. burapha sp. n.,   

หอยกระสวยจิ๋วชฎาทอง D. chadathongae Kamtuptim, Dumrongrojwattana & Wongkamhaeng sp. nov.  

หอยกระสวยจิ๋วจันทบุรี  D. chantaburiensis sp. n. 

 in Dumrongrojwattana, Kamtuptim & Wongkamhaeng, 2020

 DOI: 10.3897/BDJ.8.e57689

Abstract

Background: Microsnails in the genus Diplommatina Benson, 1849 from eastern Thailand are revised, based on the collection of the Zoological Research Collection, Burapha University, Chonburi Province, Thailand and on recently-collected materials.

New information: Five new species, Diplommatina burapha sp. n., D. chadathongae sp. n., D. chantaburiensis sp. n., D. fusiformis sp. n. and D. khwantongae sp. n., are described as new to science. The geographic distribution of these eastern species is presented.

Keywords: Diplommatina, Diplommatinidae, taxonomy, Thailand

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.

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.

  

 Pongrat Dumrongrojwattana, Chanakarn Kamtuptim and Koraon Wongkamhaeng. 2020. A Review of Diplommatina Species in eastern Thailand with the Descriptions of Five New Species. Biodiversity Data Journal. 8: e57689. DOI: 10.3897/BDJ.8.e57689

  facebook.com/BiologyBurapha/posts/1459708384224424

 สด ๆ ร้อน ๆ หอยกระสวยจิ๋วชนิดใหม่ของโลก 5 ชนิด จากภาคตะวันออก ได้แก่ 

1. หอยกระสวยจิ๋วบูรพา (Diplommatina burapha Dumrongrojwattana, Kamtuptim & Wongkamhaeng, 2020) จากจังหวัดสระแก้ว ตั้งตามภูมิภาคที่พบ คือ ภาคตะวันออกและสอดคล้องกับชื่อมหาวิทยาลัย "บูรพา"

2. หอยกระสวยจิ๋วชฎาทอง (Diplommatina chadathongae Kamtuptim et al., 2020 in Dumrongrojwattana et al., 2020) หอยชนิดนี้ตั้งชื่อเพื่อเป็นเกียรติและระลึกถึงคุณแม่ของนางสาวชนากานต์ ขำทับทิม นิสิตชั้นปีที่ 4 ภาควิชาชีววิทยา หนึ่งในผู้ร่วมงานวิจัยชิ้นนี้

3. หอยกระสวยจิ๋วจันทบุรี (Diplommatina chantaburiensis Dumrongrojwattana et al., 2020) ตั้งชื่อตามจังหวัดจันทบุรี ที่ซึ่งพบหอยกระสวยจิ๋วชนิดนี้เป็นครั้งแรก

4. หอยกระสวยจิ๋ว (Diplommatina fusiformis Dumrongrojwattana et al., 2020) ตั้งชื่อตามรูปทรงเปลือกหอยที่เป็นทรงกระสวย

5. หอยกระสวยจิ๋วคณิตา (Diplommatina khwantongae Dumrongrojwattana et al., 2020) ตั้งชื่อให้เป็นเกียรติและแสดงความระลึกถึง นางสาวคณิตา ขวานทอง หรือ พะลอย ของอาจารย์และเพื่อน ๆ ร่วมรุ่น นิสิตผู้ทำการศึกษาและค้นพบหอยกระสวยจิ๋วชนิดนี้ ผู้จากไปก่อนวัยอันควร

ผลการศึกษาครั้งนี้ ทำให้จำนวนชนิดของหอยกระสวยจิ๋วในภาคตะวันออก เพิ่มขึ้นจากเดิมที่รายงานไว้เพียง 1 ชนิด คือ หอยกระสวยจิ๋วเขาชะเมา (Diplommatina crispata khaochamaoensis) เพิ่มขึ้นเป็น 6 ชนิด

[Mollusca • 2023] Sohtsuia diting • Integrative Taxonomy revealing A Troglobitic New Genus of Diplommatinidae (Gastropoda: Caenogastropoda: Cyclophoroidea) from Jiangxi, China

Sohtsuia Z.-Y. Chen,
Sohtsuia diting Chen, Lyu & Chen, 2023 

DOI: 10.11646/zootaxa.5231.4.10 

 Researchgate.net/publication/367636325

Abstract

A new subterranean diplommatinid snail is described and illustrated from Jiangxi, China. The species is diagnosed by its cylindrical-fusiform shell and absence of internal columellar lamellae and parietal folds. The morphological and molecular phylogenetic characterization of the new species supports the erection of a new genus, Sohtsuia Z.-Y. Chen, gen. nov. A molecular phylogeny of representative East Asian continental species of Diplommatina Benson, 1949 is provided and the relationships of the new genus are discussed. Sohtsuia diting sp. nov. is described as new species.

Keywords: Gastropoda, China, Diplommatinidae, new genus, new species, systematics, taxonomy 

 

Shell of Sohtsuia diting gen. & sp. nov. Scale bar: 1 mm

Sohtsuia diting sp. nov.  

 

  Type locality (A) and living specimens (b) of Sohtsuia diting gen. & sp. nov.  

Zhe-Yu Chen, Zhi-Tong Lyu and Hui-Ming Chen. 2023. Integrative Taxonomy revealing A Troglobitic New Genus of Diplommatinidae from Jiangxi, China (Gastropoda: Caenogastropoda: Cyclophoroidea). Zootaxa. 5231(4); 491-500. DOI: 10.11646/zootaxa.5231.4.10

  Researchgate.net/publication/367636325_Integrative_taxonomy_revealing_a_troglobitic_new_genus_of_Diplommatinidae_from_Jiangxi_China

[Mollusca • 2023] Gyliotrachela khmeriana • Notes on the hypselostomatid snails (Gastropoda: Heterobranchia) from limestone hills in Western Cambodia with a new record and a new species

Gyliotrachela khmeriana Sutcharit & Panha,

in Sutcharit, Ngor, Páll-Gergely, Jeratthitikul, Siriwut, Srisonchai, Ng, Jirapatrasilp et Panha, 2023. 

DOI: 10.1080/00222933.2023.2223386 

  facebook.com/ASRUChula

 

ABSTRACT

Thirteen hypselostomatid microsnails have been reported so far from Cambodia: 10 species from the Mekong Delta karsts in the south and three species from the Sisophon-Battambang limestone hills in the west. Herein, Gyliotrachela torticollis Benthem Jutting, 1962, the only species previously reported from the Battambang, is redescribed based on near-type locality specimens. We describe a new species, Gyliotrachela khmeriana sp. nov., from the Cambodian Sisophon-Battambang limestone hills. This new species differs from all other known hypselostomatid species in having a short and straight tuba, protoconch sculptures with shallow pits and spiral striations, and apertural dentition with parietal, angular, and four other lamellae on the palatal wall. In addition, specimens of ‘Anauchen srakeoensis Panha and Burch, 2004’, previously recorded only in Thailand, were collected from limestone hills in Sisophon, redescribed based on shell morphology and taxonomically relocated as a member of the Hypselostoma.

 

KEYWORDS: Micro, snails, Indochina, endemic, Mekong, pupillids

Gyliotrachela khmeriana sp. nov. 

 

 

Chirasak Sutcharit, Peng Bun Ngor, Barna Páll-Gergely, Ekgachai Jeratthitikul, Warut Siriwut, Ruttapon Srisonchai, Ting Hui Ng, Parin Jirapatrasilp and Somsak Panha. 2023. Notes on the hypselostomatid snails (Gastropoda: Heterobranchia) from limestone hills in Western Cambodia with a new record and a new species. Journal of Natural History. 57(25-28); 1287-1303. DOI: 10.1080/00222933.2023.2223386 

  facebook.com/ASRUChula/posts/715357547275644

[Mollusca • 2023] Opisthostoma platyconcha & O. somsakpanhai • Two New Species of Opisthostoma (Caenogastropoda: Diplommatinidae) from Southern Thailand

Opisthostoma somsakpanhai

Dumrongrojwattana, Jaroonpongsawat & Tekavong, 2023

 Tropil History. Supplement 7

tci-thaijo.org/index.php/TNH

Abstract

Opisthostoma platyconcha sp. nov. and Opisthostoma somsakpanhai sp. nov. are described from limestone hills in the South of Thailand. These new species can be distinguished from their congeners by prominent shell characters: shape, number of radial ribs per 0.5 millimeters, and distinct constriction. This is the first report of Opisthostoma species in Phatthalung and Chumphon provinces; there are now three species of this genus in Thailand.

Keywords: diversity, leaf litter, limestone, microsnail, Prosobranchia

Opisthostoma somsakpanhai sp. nov.
A.–E. Holotype ZRCBUU0789: A. left lateral view, B. top view, C. Protoconch with spiral striae, D. straight radial ribs on the penultimate whorl, and E. slightly curved radial ribs on the body whorl.
 F.–H. Paratype ZRCBUU 0796: F.left lateral view, G. right lateral view, and H. bottom view.
I., J. O. somsakpanhai sp. nov. in natural habitat.

Scale bar = 0.5 mm.

Pongrat Dumrongrojwattana, Saruttaya Jaroonpongsawat and Rattanawadee Tekavong. 2023. Two New Species of Opisthostoma (Caenogastropoda: Diplommatinidae) from Southern Thailand. Tropical Natural History. Supplement 7; 181-186

 li01.tci-thaijo.org/index.php/TNH/article/view/258827

[Mollusca • 2022] Gyliotrachela cultura • A New Species of Terrestrial Microsnail (Gastropoda: Eupulmonata: Vertiginidae) from Thailand

Gyliotrachela cultura 

Tanmuangpak & Dumrongrojwattana, 2022

RAFFLES BULLETIN OF ZOOLOGY. 70

  facebook.com/oldsnails

Abstract

A new species of terrestrial microsnail, Gyliotrachela cultura, from a limestone karst within the integrated agricultural area in Loei province, Northeastern Thailand, is described based on the shell and radula morphology, and genital system. This new species differs from its closest congener G. saraburiensis in both number and position of apertural barriers. An infraparietal lamella, interpalatal plicae, two infrapalatal plicae, a subcolumellar lamella are present in the new species while three infraparietal, two supracolumellar, three subcolumellar, five infrapalatal, three interpalatal, five suprapalatal, and two parallel barriers are present in G. saraburiensis. 

Key words. Gyliotrachela, Vertiginidae, microsnail, northeastern Thailand

Gyliotrachela cultura, new species.
 A–F, holotype (NHLRU011), apertural view (A), protoconch (B, C), basal view (D), lateral view (E), and apertural teeth detail (F).
G–L, paratype (ZRCBUU 0750), apertural view (G), protoconch (H, I), basal view (J), lateral view (K), and apertural teeth detail (L).

Abbreviations for apertural teeth: P = parietal lamella; A = angular lamella; T = twin; SupPL = suprapalatal plica; UPL = upper palatal plica; IPL = interpalatal plicae; LPL = lower palatal plica; InPL = infrapalatal plica; SubC = subcollumellar lamella; C = columellar lamella; SupC = supracolumellar plica; Infp = infraparietal lamella.

  Live Gyliotrachela cultura, new species, in situ.

Gyliotrachela cultura, new species

Diagnosis. Shell small, trumpet-shaped last whorl with free short tuba, peristome expanded; aperture with 26 teeth, the angular lamella, parietal lamella, upper and lower palatal plicae, and columellar lamella being most prominent.

Type locality. Agricultural areas in Mueang Loei District, Loei Province, Thailand.

 Etymology. The specific epithet “cultura” refers to agriculture, where this new species was discovered. 

Kitti Tanmuangpak and Pongrat Dumrongrojwattana. 2022. Gyliotrachela cultura, A New Species of Terrestrial Microsnail (Gastropoda: Eupulmonata: Vertiginidae) from Thailand. RAFFLES BULLETIN OF ZOOLOGY. 70: 407–416.   

 facebook.com/oldsnails/posts/10159945506682310

[Mollusca • 2021] Angustopila coprologos & A. psammion • The World’s Tiniest Land Snails (Gastropoda, Pulmonata, Hypselostomatidae) from Laos and Vietnam

Angustopila coprologos Páll-Gergely, Jochum & Hunyadi; 

 Angustopila psammion Páll-Gergely, Vermeulen & Anker;

Angustopila pallgergelyi, Acmella nana, Notharinia micro 

in Páll-Gergely, Jochum, Vermeulen, Anker, Hunyadi, et al., 2022.

DOI: 10.1163/18759866-bja10025 

 facebook.com/PallGergelyBarna

Abstract

Two new, extremely small land snail species, Angustopila coprologos Páll-Gergely, Jochum & Hunyadi n. sp. and Angustopila psammion Páll-Gergely, Vermeulen & Anker n. sp. are described from northern Vietnam and northern Laos, respectively. The former is characterized by a rough surface sculpture and bears tiny mud granules arranged in a pattern of radial lines on its shell surface. The latter species is the new global record-holder of the tiniest land snail title, with a shell width of 0.6–0.68 mm and a shell height of 0.46–0.57 mm. These measurements surpass the former records of Angustopila pallgergelyi and Acmella nana.

Keywords: Acmella; Angustopila; Arinia; miniaturization; shell; ornamentation

Systematic descriptions

Family Hypselostomatidae Zilch, 1959

Genus Angustopila Jochum, Slapnik & Páll-Gergely, 2014

Angustopila Jochum, Slapnik & Páll-Gergely, 2014; Jochum et al., 2014: 410: 26.

Type species: Systenostoma tamlod Panha & Burch, 1999, by original designation.

Angustopila coprologos Páll-Gergely, Jochum & Hunyadi n. sp.

 

Diagnosis: A strongly depressed-globular Angustopila species with a wide umbilicus, strong spiral sculpture consisting of a series of coarse elevations (flat-topped beads) in a chain-like pattern and four well-developed teeth (1 parietal, 2 palatal, 1 basal).

Differential diagnosis: Angustopila coprologos n. sp. can be easily distinguished from all other Angustopila species by its depressed shell, the four apertural denticles and the pronounced sculpture.

Etymology: The specific epithet coprologos (Ancient Greek for dung gatherer) refers to the mud granules (here assumed to be faeces) placed on this species’ shell. Used as a noun in apposition.

Distribution: This species is known only from the type locality in Bolikhamsay Province, Laos: ca. 13 km southeast (in a straight line) from the town Lak Sao (see also supplementary figs S1–S2).

Angustopila psammion Páll-Gergely, Anker & Vermeulen, n. sp.

 

Diagnosis: An Angustopila species with a depressed-globular shell with dome-shaped spire, thick spiral striae, kidney-shaped aperture with single parietal denticle not reaching parietal callus.

Differential diagnosis: Angustopila pallgergelyi Dumrongrojwattana, Chuenit & Wongkamhaeng, 2021 is similar in shell and aperture shape, but is larger, has a prominent palatal tooth (absent in Angustopila psammion n. sp.) and a stronger parietal tooth. Angustopila coprologos n. sp. is slightly larger, has a rough shell surface, and has an additional subcolumellar tooth and two palatal teeth.

Etymology: The specific epithet (ψαμμίον) means a grain of sand in Greek and is used as a noun in apposition.

Distribution: This new species is known only from the type locality, Cap La Cave, Ha Long Bay, Quang Ninh Province, Vietnam.

Size comparisons of the former record holders,
Angustopila pallgergelyi, Acmella nana, Notharinia micro, the smallest marine snail, Ammonicera minortalis, and the two new species [Angustopila coprologos n. sp. and Angustopila psammion n. sp.] described herein.
 The image of Ammonicera minortalis Rolán, 1992 is from Oliver et al. (2012), whereas the other images (Acmella nana and Arinia micro) are from their respective original descriptions. The figure of Acmella nana is adjusted to scale with the measurement of the smallest specimen, whereas for Angustopila coprologos n. sp. and Angustopila psammion n. sp., the holotypes (not the tiniest shells) are shown.

Conclusions: 

Two species, Angustopila psammion Páll-Gergely, Vermeulen & Anker n. sp. and Angustopila coprologos Páll-Gergely, Jochum & Hunyadi n. sp. are described from northern Laos and northern Vietnam, respectively. With its shell width of 0.60–0.68 mm and shell height of 0.46–0.57 mm, Angustopila psammion n. sp. is the new global record-holder of the title of the tiniest land snail, surpassing the former two record-holders, Angustopila pallgergelyi and Acmella nana. The calculated volume for the smallest adult snail (including the shell) is 0.036 mm3. In the absence of extreme food specialization, miniaturization of land snails is probably driven by the accessibility of small spaces in the subsoil, although other scenarios, such as avoidance of larger predators, cannot be ruled out. The lower limit of adult shell size may be determined by the fact that it must accommodate at least one viable egg, the size of which in turn, may be limited by the minimum number of neurons to be functional in the hatchling. On the other hand, Angustopila coprologos n. sp. is characterized by a rough surface sculpture (most complex among all known and undescribed species of its genus), and minuscule mud granules arranged in radial lines on its shell surface. These granules may play a role in camouflage and mate recognition or function like mini sponges for water retention.

 

 Barna Páll-Gergely, Adrienne Jochum, Jaap J. Vermeulen, Katja Anker, András Hunyadi, Aydin Örstan, Ábel Szabó, László Dányi and Menno Schilthuizen. 2022. The World’s Tiniest Land Snails from Laos and Vietnam (Gastropoda, Pulmonata, Hypselostomatidae). Contributions to Zoology. DOI: 10.1163/18759866-bja10025 

 brill.com/view/journals/ctoz/aop/article-10.1163-18759866-bja10025/article-10.1163-18759866-bja10025.xml

 facebook.com/PallGergelyBarna/posts/10223153656523360

[Mollusca • 2021] Nineteen New Species of Alycaeidae (Gastropoda: Caenogastropoda: Cyclophoroidea) from Myanmar and Thailand

Nineteen new species of genera Chamalycaeus, Dicharax, and Metalycaeus 
from Thailand and Myanmar

 Páll-Gergely, Hunyadi, ... et Auffenberg, 2021.  

DOI: 10.11646/zootaxa.4973.1.1

Researchgate.net/publication/351658361 

  facebook.com/PallGergelyBarna 

Abstract

Nineteen new species of the alycaeid genera Chamalycaeus, Dicharax, and Metalycaeus are described from Thailand and Myanmar: Chamalycaeus buaboke Páll-Gergely & A. Reischütz, n. sp., C. erawan Páll-Gergely & Hunyadi, n. sp., C. hirpex Páll-Gergely & A. Reischütz, n. sp., C. irmatallus Páll-Gergely, n. sp., C. krabiensis Páll-Gergely & A. Reischütz, n. sp., C. serratus Páll-Gergely & Auffenberg, n. sp., C. spiratus Páll-Gergely, n. sp., Dicharax (?) admirandus Páll-Gergely & Auffenberg, n. sp., D. cyclostoma Páll-Gergely, n. sp., D. ebrius Páll-Gergely & Auffenberg, n. sp., D. (?) gnomus Páll-Gergely, n. sp., D. mirounga Páll-Gergely, n. sp., D. ovatus Páll-Gergely & Auffenberg, n. sp., D. subroseus Páll-Gergely, n. sp., D. verrucosus Páll-Gergely & Hunyadi, n. sp., Metalycaeus anas Páll-Gergely & A. Reischütz, n. sp., M. aries Páll-Gergely & Auffenberg, n. sp., M. bicarinatus Páll-Gergely & Hunyadi, n. sp., M. pygmachos Páll-Gergely & Hunyadi, n. sp.

Alycaeus kengtungensis Godwin-Austen, 1914 is moved to the synonymy of Metalycaeus heudei (Bavay & Dautzenberg, 1900). We also report exact localities of Dicharax ataranensis (Godwin-Austen, 1914), Dicharax notus (Godwin-Austen, 1914), and Dicharax omissus (Godwin-Austen, 1914). The new records extend the known distribution of Chamalycaeus and Metalycaeus in Thailand.

Keywords: Gastropoda, taxonomy, systematics, museum collections, biodiversity, shell

Dicharax sylheticus (Godwin-Austen, 1914)

in Páll-Gergely, Hunyadi, ... et Auffenberg, 2021. 

 DOI: 10.11646/zootaxa.4973.1.1

Barna Páll-Gergely, András Hunyadi, Jozef Grego, Alexander Reischütz and Kurt Auffenberg. 2021. Nineteen New Species of Alycaeidae from Myanmar and Thailand (Gastropoda: Caenogastropoda: Cyclophoroidea). Zootaxa. 4973(1); 1–61. DOI: 10.11646/zootaxa.4973.1.1

Researchgate.net/publication/351658361_Nineteen_new_species_of_Alycaeidae_from_Myanmar_and_Thailand

  facebook.com/PallGergelyBarna/posts/10221920565096845