Abstract. – A new whip spider species of the genus Sarax Simon, 1892 is described based on three specimens collected in Koh Pha Ngan island, Southern Thailand. The new species, Sarax kosulici sp. nov., represents the second species of the genus Sarax described from Thailand, and the sixth species of Amblypygi reported from the country. The new taxon described here raises the total number of currently recognized species for the genus Sarax to 39.
Curcuma gracillima Gagnep. is a rare species and it has been found in Cambodia, Laos, Thailand, and some regions of southern Vietnam. This study provided the micro-morphological and molecular data of this species collected from Xuyen Moc Commune, Ho Chi Minh City, Vietnam for the first time. As a result, the Internal Transcribe Spacer (ITS) and trnL intron of C. gracillima were successfully amplified and sequenced. These sequences were also successfully deposited on the NCBI database with the accession numbers PQ813594 and PQ821005. The genetic relationship of C. gracillima in this study with other taxa of this species from different habitats was also reported. The pairwise alignment of C. gracillima from this study and its taxa from the prior reports showed the genetic variation in the ITS and trnL intron regions among C. gracillima collected from the different locations. In addition, the details of the anatomical characteristics of C. gracillima leaf, leaf sheath, petiole, root, and rhizome were first investigated.
Sermyla riquetii, a thiarid gastropod, serves as an intermediate host for various trematodes in brackish and coastal habitats. This study examined 6,137 S. riquetii specimens from 29 sites across 16 Thai provinces to identify larval trematodes using morphological and molecular approaches. Cercariae were detected in 35 snails (0.57%) and assigned to three morphological types: (i) pleurolophocercous (including Centrocestus formosanus and Stellantchasmus falcatus), (ii) parapleurolophocercous (Procerovum cheni), and (iii) furcocercous (Transversotrema laruei). The pleurolophocercous type was the most prevalent. Phylogenetic analysis of the ITS2 region confirmed the identities of C. formosanus, S. falcatus, and P. cheni, which clustered with corresponding GenBank sequences. Molecular data could not differentiate between pleurolophocercous and parapleurolophocercous types. This is the first report of S. riquetii as a host for C. formosanus and P. cheni in Thailand. The findings provide important baseline data on trematode-snail associations and support the potential role of S. riquetii in the transmission of zoonotic trematodes. This study contributes to the understanding of parasite biodiversity in tropical estuarine ecosystems and highlights the need for monitoring snail populations in disease risk assessments.
The study investigated the diversity and the spatial distribution of seaweed in the intertidal zone during three periods including December 2022, March 2023, and May 2023 at Tu Thien seaweed field, Phuoc Dinh commune, Thuan Nam district, Ninh Thuan province. Samples were hand collected through wading surveys of the intertidal zone during low tide periods. The coverage was assessed based using the line transect-quadrat method of Saito and Atobe. The investigation recorded 59 species of seaweeds belonging to 3 phyla, 3 classes and 34 genera. Among all families, Sargassaceae was the most species-rich with 11 species, followed by Gracilariaceae with 9 species. The Rhodophyta accounted for the highest proportion of species composition. The highest coverage of seaweed was measured in March 2023 (103.36 to 343.19). Ulva reticulata was the dominant species, with the Simpson dominance index ranging from 0.7 to 0.9 at most sites in March. Simultaneously, the coverage of this species reached 80% during the March survey period. The Cheney index of 2.28, the Tu Thien seaweed community was classified as temperate. It is inferred that seaweed exhibits substantial diversity and abundance at optimal times of the year, particularly during the first half, before gradually diminishing in the latter half. The baseline data generated in this study will serve as the first foundational reference, not only for the scientific assessment of seaweed coverage but also for documenting the occurrence of seaweed species in the Tu Thien seaweed field, Ninh Thuan.
Populations of large fruit bats such as flying foxes are declining globally, particularly due to hunting. Monitoring population changes as well as roost characteristics are vital for conservation planning. The distribution and population size of flying foxes (Pteropus spp.) in Myanmar were assessed in the Mandalay Region, Sagaing Region, Mon State (Mawlamyine Township and Kyaikami Township), and Tanintharyi Region (Myeik Township, Thayetchaung Township, Thae Phyu Island) from February 2020 to January 2021. The survey found 12 colonies of P. medius and 3 colonies of P. hypomelanus roosting in 17 tree species. Direct roost counts were used to estimate the population size of these species. The total number of individuals across all study sites was 73,876 for P. medius and 20,458 for P. hypomelanus. The roosting sites of P. medius and P. hypomelanus were at an average elevation of 59.25 m and 25 m, respectively, and close to bodies of water. In total, 66% of P. medius and 61% of P. hypomelanus populations were located within Buddhist temples and public land, respectively. In addition, one-third of their populations occupied private land. Approximately 56% of the total flying fox population was found in areas classified as well-protected and 44% as disturbed. Temples play a crucial role in providing safe roosting habitats for flying foxes in Myanmar as hunting is prohibited in temples. Tall, large canopy trees offer optimum roost sites for flying foxes as they provide more heat dissipation on hot days when flying foxes often experience hyperthermia in full sunlight. Some colonies were found to suffer from hunting or roost tree cutting. Private land is also vital for flying fox survival and conservation efforts need to involve collaboration with private landowners to ensure their protection and survival. This study identifies ecologically important roost characteristics and provides an update on the distribution and population status of Pteropus species in Myanmar.
The millipede genus Yuennanina Attems, 1936 has been known so far only from Yunnan Province, southwestern China. Currently, it comprises three species: Y. ceratogaster Attems, 1936, Y. aceratogaster Zhang & Li, 1977, and Y. petalolobodes Chang & Zhang, 1989. Herein, we describe Y. sirindhornae sp. nov., from Huai Nam Dang, Chiang Mai Province, northern Thailand, representing the first formal record of this genus not only from Thailand, but also from entire Southeast Asia. The new species is characterized by its unique gonopodal solenophore the shape of which resembles a young fern frond with fimbriate edges. A detailed redescription of the type species, Y. ceratogaster, is provided based on a revision of type material. An updated identification key to all four presently known Yuennanina species is also provided.
Temnothorax Mayr, 1861, a large ant genus with 502 valid species, 33 valid subspecies, and one valid fossil species (inclu-ding the new species), is predominantly found in temperate regions of the Old and New Worlds. The genus is represented in Thailand by two named species: Temnothorax barrettoi Hamer & Guénard, 2023, and T. sirindhornae Phosrithong, Ignatius & Samung, sp. nov. Herein, Temnothorax sirindhornae sp. nov. is described based on worker and dealate queen castes from the highlands of western Thailand, and T. barrettoi is newly recorded from the country's lowlands. Notably, both species nest in dead twigs on trees.
We present a taxonomic revision of Brachylophon (Malpighiaceae) in Thailand, Southeast Asia, based on herbarium collections and a field trip conducted in 2024. Two previously accepted species, B. anatomosans Craib and B. curtisii Oliv., are reported, alongside the new species, B. sirindhorniae Chaisongkram & Ruchis., described and illustrated for the first time. The new species is characterized by having white petals, pedicels 2–5 mm long; filaments 1.5–2.5 mm long; and mericarp 6–7 mm long. A detailed description, illustrations, and a comparison with closely related species are provided to aid in its identification. The discovery of this new species highlights the ongoing need for further exploration and taxonomic study of the genus in Southeast Asia to fully understand its diversity and distribution.
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.
Debaratania gen. nov. is described from Thailand, with Debaratania bellula sp. nov. designated as the type species. The new genus is characterized by its colorful forewing pattern, sexual dimorphism in the shape of both the fore- and the hindwing, and distinctive male hindwing venation, where M3 and CuA1 are short-stalked both proximally and distally, with three distinct anal veins. The male genitalia feature a prominent leaf-like uncus and a large tubular phallus with long, narrow cornuti. In the female genitalia, a conspicuous sclerotized plate with a strongly developed thorn-like process is present at the anterior end of ductus bursae. Living and pinned specimens, wing venation, and genitalia are illustrated. Structural features support placement in the tribe Enarmoniini.
The new helicarionoidean land snail genus Siamopotaxis Pholyotha, gen. nov. is described for two new species, Siamopotaxis principalis Pholyotha, sp. nov. and Siamopotaxis thailandensis Pholyotha, sp. nov., both from Thailand. The new genus is characterised by a medium-sized, globose, high-spired, cream-coloured shell, with one or two supraperipheral bands, a rounded last whorl, a short epiphallic caecum, an elongated dart apparatus, and many radular teeth with pectiniform cusps. Siamopotaxis principalis sp. nov. differs from S. thailandensis sp. nov. by the presence of one spiral band, whereas the latter species has two spiral bands. A DNA sequence analysis of mitochondrial COI and 16S DNA, and nuclear 28S DNA gene fragments, supports the systematic placement of these new taxa and confirms that Siamopotaxis gen. nov. as a distinct clade within the Helicarionidae.
A species new to science, belonging to Strobilanthes from Thailand is described. Strobilanthes sirindhorniae Kladwong & Chantar., sp. nov. is found on limestone in northern Thailand. It is morphologically similar to S. maxwellii J.R.I.Wood and S. rosea Nees. A comparison table with similar and closely related species and a distribution map, and an illustration of S. sirindhorniae sp. nov. are provided.
Dicnecidia narathiwatensis Thonongtor and Pinkaew sp. nov. is described based on a single male specimen from Narathiwat Province, southernmost Thailand. In addition, D. fumidana Kuznetzov, 1997, previously recorded only from Vietnam, is recorded for the first time from Thailand and Laos. Illustrations of adults and genitalia are provided. The discovery of the new species increases the total number of described Dicnecidia to four.
A second species of the rogadine braconid wasp genus, Batothecoides Watanabe, 1958 is described from Thailand, the genus having been known only from the type species for the past 66 years. The new species, Batothecoides sirindhornae Ranjith, Butcher & Quicke, sp. nov., is distinguished from the type species of the genus, B. yakushimensis (Watanabe, 1938), by morphology, color and DNA sequence data. The type species is redescribed based on images of the holotype. A molecular phylogeny of all members of the subtribe Spinariina for which barcode data are available is presented.
Tetraponera Smith, 1852, a large ant genus comprising 87 extant and seven fossil species, is primarily distributed in the Afrotropical, Oriental, and Australasian regions. A new species, T. sirindhornae Yodprasit, Tasen & Jaitrong, sp. nov., is described from southern Thailand based on worker, dealate queen, and male castes. The new species exhibits worker dimorphism and is morphologically similar to T. binghami (Forel, 1902), T. connectens Ward, 2001, and T. notabilis Ward, 2001 in possessing an elongated head, but differs by the presence of a distinct mandibular gap between masticatory margins when the mandibles are closed (in the case of major worker and queen). The new species was found nesting in a dead rubber tree branch on a tree within a rubber plantation near a stream.
Two new earthworm species are described from the Mekong River, Thailand, namely Amynthas septuaginta Bantaowong & Panha, sp. nov. and Metaphire fidelis Bantaowong & Panha, sp. nov. The former is a small Mekong earthworm in the A. aeruginosus species group with two pairs of spermathecal pores in 7/8-8/9. It is mainly distinguished from other Amynthas from the Mekong River by its small size (less than 50 mm), and with no genital markings at the male pore region. The latter is distinguished by having four pairs of spermathecal pores in 5/6-8/9, genital markings paired on xvii, ampulla paddle-shaped, and with diverticulum as a slender tube with a loose loop. Morphological description, taxonomic comments, illustrations, and distribution are provided.
Two new cladocera species of the family Chydoridae (Crustacea: Cladocera) are described from Southeast Asia. Populations of Paralona sirindhornae sp. nov. were found in Thailand and Cambodia, while Karualona cambodiaensis sp. nov. was detected in Cambodia only. Paralona sirindhornae sp. nov. differs from the only other species of the genus Paralona Šramek-Hušek, Strašcraba et Brtek, 1962, namely, Holarctic P. pigra (Sars, 1862), in its smaller size, different position of the head pores, and the morphology of thoracic limbs III–V. Our data suggest that the populations of Paralona from South America and Africa also belong to independent species rather than P. pigra. Karualona cambodiaensis sp. nov. differs from other species of the genus in the unique morphology of the posteroventral angle of the valves, as well as in the body shape and morphology of the antenna. The morphology and taxonomic position of two new species are discussed. Both new species appear to be extremely rare in Southeast Asia, and their discovery is a result of recent intensive sampling efforts.
The dobsonfly genus Protohermes van der Weele, 1907 is the most diverse genus within the family Corydalidae of the order Megaloptera. In the present study, we describe a new species of Protohermes, namely Protohermes sirindhornae Piraonapicha, Chomphuphuang & Liu, sp. nov., and report three additional species newly recorded from Thailand: P. cangyuanensis Yang & Yang, 1988, P. impunctatus Liu, Hayashi & Yang, 2008, and P. striatulus Navás, 1926. These findings are based on an integrative approach that combines both morphological and molecular data. A key to the males of Thai Protohermes species is provided.
A new species of burrowing mayfly, Ephoron debaratana sp. nov., is described based on the larval stage. The morphological characteristics distinguished the new species from other known Ephoron species are the followings: 1) pigmented lateral tracheal branches on the abdominal gills, 2) number of tubercles on the tusk, and 3) triangular frontal process. The morphological evidence presented in this study is strongly supported by cytochrome c oxidase subunit I (COI) gene data. This new species was found in a headwater stream in Kanchanaburi Province, Thailand. The habitat information and a comparison to the known species of Thai larvae are also presented.
In the present study, a new species of the genus Teloganopsis Ulmer, 1939, T. sirindhornae sp. nov., is described based on specimens collected and reared in Thailand. The new species is distinguished from other Thai Teloganopsis species by its abdominal color pattern, which is consistent across all developmental stages. Both morphology characteristics and molecular analysis support its designation as a new species. A concatenated phylogenetic tree based on COI and 28S rDNA confirms its monophyly and clearly separates it from other Teloganopsis species. Additionally, a description of the chorionic structure of T. sirindhornae sp. nov., a distribution map of known Teloganopsis species in Thailand and a dichotomous key for both larval and imaginal stages of known Oriental Teloganopsis species are provided.
