Tropical Natural History

Leaf Epidermal Anatomy of Some Crotalaria L. (Fabaceae) Species in Thailand

Sakuntala Ninkaew — 2024-01-25

The leaf epidermal anatomy of 23 Crotalaria species was studied. The leaf epidermis was prepared by peeling and clearing methods and observed by a light microscope. The results of the leaf epidermis showed that the shape of an epidermal cell is polygonal, irregular or jigsaw-like and the anticlinal wall is straight, curved or undulated. There are two stomatal types: anomocytic and anisocytic, while the trichome is uniseriate. The papillae are presented in C. acicularis. The leaf epidermal anatomical characteristics cannot be used for species identification, however the shape and anticlinal wall of the epidermal cell and the presence of trichomes can be used to determine species pairs.

Wildlife Species Recorded by Camera Traps in Reforested Lowland Rainforest and Peat Swamp Forest of Gunung Palung National Park, Indonesia

Sandy Leo — 2024-04-29

We quantified wildlife presence in two reforestation areas of Gunung Palung National Park (GPNP), one of the top biodiversity hotspots in Indonesian Borneo. Wildlife species were monitored using camera traps in two reforested ecosystems: lowland dipterocarp forest and peat swamp forest. The GPNP authority and the non-profit organization Alam Sehat Lestari (ASRI), in affiliation with the non-profit organization Health in Harmony (HIH), have conducted reforestation in the lowland dipterocarp forest since 2009 and the peat swamp forest since 2012. Cameras were placed at 13 locations from December 2020 to August 2022 using point and grid methods. Forty-seven wildlife species were recorded, including mammals (31 species), birds (14 species), and reptiles (2 species). Eighteen of these species are listed as Vulnerable, Endangered, or Critically Endangered by the International Union for Conservation of Nature. The wildlife documented in this study indicate that a reforestation approach emphasizing community engagement, long-term partnerships, and ecosystem functioning can support the restoration of heavily degraded lowland rainforest and peat swamp forest to viable habitat.

Polychaetes of the Coral Triangle: Told and Untold Richness

Cirilo Ybanez Jr — 2024-05-03

This paper comprehensively reviews polychaete species in the Coral Triangle (CT), documenting 750 species across 60 families. The Philippines stands out for the highest species diversity, reflecting more extensive exploration than in other ecoregions. Limited publications in specific regions result from heightened sampling needs and taxonomic expertise. Nereididae and Syllidae, each constituting 11% of the total, are prominent polychaete families, alongside others like Polynoidae, Terebellidae, Eunicidae, Spionidae, and Sigalionidae. The genus Syllis is the most speciose, contributing 4% to the overall tally. Since 1750, polychaete species and publication numbers in the CT show an upward trend, reaching its peak from 2000 to the present. Increased marine biodiversity awareness, using SCUBA diving and ROVs, and advanced technology for species identification have significantly contributed to the continuous increase in recorded species. Despite these advancements, polychaetes in the CT remain relatively understudied compared to other taxa, underscoring the need for additional focused research on polychaetes within the region.

Exploring Pliocene Vegetation Variability through Wood Fossil Analysis from Jasinga, Indonesia

Danni Gathot Harbowo — 2024-05-26

Residents of Jasinga, West Java, consistently reported the presence of an abundance of wood fossils. We examined geological settings and wood fossils to investigate the paleovegetation types in the region. This research aims to map the distribution of wood fossils and interpret the paleoenvironment based on paleontological evidence. Lithostratigraphic measurements were performed, followed by a description of wood fossil anatomy in micro-thin section observations, isolation of palynological fossils from the host rock through chemical preparation techniques, and geochemical analysis using X-ray fluorescence spectroscopy. Our findings indicate that the area comprises Pliocene fluvial-volcanoclastic deposits containing several dipterocarp wood fossils, including Parashoreoxylon, Dryobalaonoxylon, Shoreoxylon, Anisopteroxylon, and Dipterocarpoxylon. There were also non-dipterocarp wood fossils from Apocynaceae, Combretaceae, Fabaceae, and Olacaceae. Most wood fossils in these deposits were silicified (SiO₂: 92.7 ± 1.88%), preserving the wood tissue structures. Additionally, the wood fossil-rich strata contains fossilized palynomorphs, including pollen fossils from Dipterocarpaceae, Convolvulaceae, and Florschuetzia, and spore fossils from Stenochlaenidites, Verrucatosporites, and Lygodium, indicating the presence of a more diverse paleovegetation. These results support the existence of paleotropical rainforests. Our study suggests that paleoclimatic and paleovolcanic settings have significantly shaped the paleotropical rainforest ecosystems in the southern part of Sundaland during the Early Pliocene.

Description of the Larva of Argiocnemis rubescens rubeola Selys, 1877 (Odonata, Coenagrionidae, Agriocnemidinae) from Thailand with Systematic Notes on the Subfamily Agriocnemidinae

Tosaphol Saetung Keetapithchayakul — 2024-05-29

The final stadium larvae of Argiocnemis rubescens rubeola are described in the present study. The adult–larva association along with the taxonomic remarks on the subfamily Agriocneminae, is established by employing the cytochrome oxidase subunit I gene (COI). The larva is characterized by the ovate shape of the caudal lamella, the lack of a band on the caudal lamella, a rounded postocular lobe outline, three pairs of premental setae, and four palpal setae. Taxonomic notes suggest the COI data consistently aligns with both larval and adult characteristics, offering a comprehensive perspective.

Studies on the Gesneriaceae in Laos I: Three New Species of Microchirita from Khammouane Karstarst

Keooudone Souvannakhoummane — 2024-06-07

TThree new species of Microchirita from the Khammouane Karst are here described as part of studies on the family Gesneriaceae in Laos. The description, habitat, phenology, vernacular name, initial IUCN assessment, illustration, and photographs of the new taxa are provided.

Mitigating Human-Elephant Conflict in Southeast Asia

Poldej Kochprapa — 2024-06-12

Human-elephant conflict (HEC) poses serious threats to humans and to elephants, and while HEC in Southeast Asia is increasing, mitigation effectiveness data are lacking. Previous assessments of available mitigation options have not compared relative benefits and impacts of each on a practical level to identify which factors should be considered by local agricultural communities and/or other stakeholders when choosing among mitigation options. Understanding which mitigation approach to apply in a given context is crucial for effective mitigation planning and can aid in the development of more holistic methods. We reviewed the literature regarding the strengths and weaknesses of 14 currently applied HEC mitigation methods in Southeast Asia, considering five key factors for each mitigation option: 1) effectiveness at reducing crop damage, 2) initial start-up costs, 3) maintenance/long-term costs, 4) potential impacts on humans and 5) potential impacts on elephants. Our results suggest there are considerable tradeoffs among these five factors for any given mitigation option and that none of the available mitigation methods are simultaneously highly effective in preventing crop damage and low cost while presenting minimal impact to people and elephants. Although our metric of comparison is not comprehensive, it may offer an initial set of guidelines for decision making.

The First Occurrence of a Basal Tyrannosauroid in Southeast Asia: Dental Evidence from the Upper Jurassic of Northeastern Thailand

Wongwech Chowchuvech — 2024-06-12

Isolated theropod teeth are one of the most common vertebrate fossils that have been found in the Khorat Group of Thailand. Furthermore, several isolated teeth have been discovered from the Upper Jurassic Phu Kradung Formation, located in Phu Noi locality of Kalasin Province, Northeastern Thailand. Three of those theropod teeth from the Phu Noi locality show unique dental features that can be distinguished from previous discovered metriacanthosaurid theropod, including the lateral teeth with mesiolingual twisted mesial carinae extending above the cervix line and braided enamel surface texture. Morphological examination with cladistics and morphometric analyses show that these isolated teeth exhibit the synapomorphies of basal tyrannosauroids, closely related to Guanlong wucaii and Proceratosaurus bradleyi from the Jurassic Period. This paper notes the first report of a basal tyrannosauroid in Southeast Asia as well as significantly contributes to our understanding of paleoecology of the Upper Jurassic Phu Kradung Formation and paleobiogeography of Tyrannosauroidea during the Jurassic Period.

Qualitative Ethnobotany of Hermitism Karen in Ban Le Tong Ku, Unique Cultural Karen Community in Thailand

Apichart Songsangchun — 2024-06-12

Ban Le Tong Ku is a Karen community comprising Pwo and Sgaw subgroups, each with its own distinct culture and traditions. Both subgroups adhere to the hermitism of the Talaku sect, a belief system that sets them apart from other Karen communities in Thailand. This raises the intriguing question of whether their ethnobotanical knowledge aligns with that of other Karen groups in Thailand. Qualitative ethnobotanical surveys involving six key informants revealed a total of 218 plant species used by the community: 145 by Pwo and 142 by Sgaw. The Fabaceae family stood out with the highest number of species utilized by both groups. Herbs and trees were the most commonly used plant types, with leaves being a predominant choice for both subgroups. Approximately two-thirds of the species served as food or traditional medicine, often prepared fresh or boiled. While Pwo and Sgaw shared knowledge on traditional plant use for 69 species, it is noteworthy that this knowledge was not exchanged between the two subgroups. For instance, Phytocrene macrophylla var. macrophylla was exclusively used for medicinal purposes by Pwo, whereas Saraca thailandica was solely utilized as food by Sgaw. Furthermore, this study represents the first documentation of ethnobotanical uses of Phytocrene macrophylla var. macrophylla, Impatiens purpureoscorpioides, and Grewia multiflora among the Karen community in Thailand.

Development of a Biofertilizer from Plant Growth Promoting Rhizobacteria Isolated from Millipede Fecal Pellets

Waraporn Sutthisa — 2024-06-13

Plant Growth Promoting Rhizobacteria (PGPR) are commonly used to produce biofertilizers. As such, the purpose of the present research was to develop a PGPR biofertilizer formulation from four Streptomyces strains isolated from millipede fecal pellets and to select suitable carriers for them. The four Streptomyces isolates were Streptomyces sp. KLS-AC04, S. zaomyceticus KLD-AC02-1, S. zaomyceticus KLD-AC16 and S. zaomyceticus KLD-AC30. Their compatibility was tested on Actinomycetes isolation agar by the cross-streak method and the results showed that the four isolates can coexist. A viability test was done with three different types of carriers: coconut coir, cow dung and peat moss. The best carrier for all isolates was peat moss (viability: 5.3 x 10⁴ − 8.5 x 10⁵ cfu/g). The isolate that exhibited the highest survival rate across the three carriers was Streptomyces sp. KLS-AC04. Seven PGPR biofertilizer formulations were developed, of which formulation 6 (cow dung: peat moss: KLS-AC04: KLD-AC02-1: KLD-AC16: KLD-AC30) showed the highest viability (6 x 10⁵ cfu/g). The effects of the PGPR biofertilizer formulations on plant growth were explored on Chinese kale. This showed that the use of the four Streptomyces strains had a significant positive effect on germination percentage (range 47.5% − 80.0%), fresh weight (range 0.060 − 0.086 g), shoot length (range 36.1 − 60.4 mm), and root length (range 15.3 − 30.8 mm).

The Diversity of Subterranean Dorylus Ants in the Agricultural Regions of Northern Thailand

Piyawan Suttiprapan — 2024-06-19

Thailand, primarily an agricultural nation, faces significant crop yield losses due to various pests. Members of the Dorylus Fabricius, 1793 ant genus are significant pests of both vegetables and cash crops. Despite extensive research on ant taxonomy in Thailand, a comprehensive understanding of ant diversity remains incomplete, with many species are undiscovered. This study examines the diversity of subterranean Dorylus ants in the agricultural regions of Northern Thailand, predominantly occupied by hill tribes. Ant surveys were carried out in organic vegetable farms located in the Chiang Mai and Mae Hong Son provinces of Northern Thailand, by using palm oil baits in sieve buckets. The worker ants were identified through their morphological and molecular characters derived from the cytochrome oxidase subunit I (COI) region of the mitochondrial gene. Our findings revealed that two species, Dorylus laevigatus and D. orientalis, are major Dorylus ants that infest Brassicaceae and Fabaceae vegetable crops. This is the first record of these species infesting Chinese radish (Raphanus sativus L.). In addition, we present the first documentation of D. laevigatus in Pak choi (Brassica chinensis L.), and peanut (Arachis hypogaea L.) in Thailand. These pests burrow into the subterranean parts of crop roots, resulting in reduced growth yield. The damage manifests as an unhealthy appearance in the above-ground parts of the crops.

Changes in Tetragnatha Spider Abundance and Web Characteristics Throughout Rice Field Development

Venus Saksongmuang — 2024-06-20

Vegetation change is one of the major drivers affecting web-building spider species, causing them to vary in abundance and to adapt their web traits accordingly. Rice ecosystems are among the most important agricultural areas, and understanding the influence of vegetation complexity throughout rice development on common Tetragnatha spiders is crucial to developing sustainable management practices. Six sympatric species of Tetragnatha spiders, T. javana, T. mandibulata, T. maxillosa, T. nitens, T. praedonia and T. virescens, were found in rainfed lowland rice fields in southern Thailand. The abundance, web diameter and web height of each species were measured and compared across rice developmental stages. Overall, the number of Tetragnatha spiders was significantly higher in the tillering stage than the flowering stage, while abundance during the booting stage was not significantly different from either. The numbers of T. javana, T. mandibulata and T. maxillosa were higher than those of T. nitens, T. praedonia, and T. virescens during all rice stages. Throughout the rice growing season, vegetation complexity increased continuously while both web diameter and web height exhibited hump-shaped patterns for all spider species (i.e., webs were larger and built higher above ground level during the middle of the growing season). The diameter and height of Tetragnatha webs varied by species, but only web diameter was positively related to spider body length for almost all spider species. Our findings confirm that changes in vegetation complexity during rice development, as well as spider body length, affect the functional traits of Tetragnatha webs in rice ecosystems.

The Richest Diversity and Highest Abundance of Freshwater Bivalve Fossils from the New Fossil Locality of the Early Cretaceous Sao Khua Formation at Roi Et Province, Northeastern Thailand

Sakboworn Tumpeesuwan — 2024-10-28

A new fossil freshwater bivalves locality in the Sao Khua Formation was discovered at the top of a small hill named Phu Kum Khao in the Pho Chai District, Roi Et Province, northeastern Thailand. The fossils bed is a mud-nodule conglomeratic sandstone of the Sao Khua Formation and has proved to be both of high abundance and species diversity (6,637 specimens of nine species). The most abundant species is Pseudohyria (Matsumotoina) somanai Tumpeesuwan, Sato, and Nakhapadungrat, 2010, which is not only the dominant species of the Sao Khua Formation but also the index fossil representative of the Late Barremian age for the formation. The bivalves from this locality are preserved as both articulated and disarticulated shells. Associated vertebrate fossils are preserved as bone fragments and micro remains. According to the fossil assemblage and its taphonomy and orientation, lithology, and geometry, we interpret this fossil bed as having been deposited by a crevasse splay of a meandering river system.

The Family Bithyniidae Gray, 1857 (Gastropoda: Truncatelloidea) in Peninsular Malaysia and Singapore

Ting Hui Ng — 2024-11-06

Freshwater snails of the family Bithyniidae on mainland Southeast Asia are important intermediate hosts of zoonotic parasites. However, bithyniids in the southern tip of the mainland, in Peninsular Malaysia and Singapore, have remained largely overlooked. We review records of the bithyniids from this target region based on literature and museum material to verify species identities, statuses and distribution. Species identification was conducted mainly using shell characters and supplemented by analyses of the COI gene. We recorded four species—Digoniostoma siamensis siamensis, Gabbia minuta, Gabbia cf. stenothyroides, Wattebledia baschi. In Malaysia, G. minuta and W. baschi are only known from their type localities. Digoniostoma siamensis siamensis occurs in Peninsular Malaysia and was introduced to Singapore in recent decades. Gabbia cf. stenothyroides has also been introduced to Singapore. Molecular analyses indicated that D. siamensis siamensis shares the same clade with mainland Southeast Asian Bithynia spp., Gabbia cf. stenothyroides is sister to a bithyniid from Sulawesi, while Bithynia and Gabbia were recovered as non-monophyletic groups. Our study clarifies the presence of two introduced bithyniids in Singapore, reveals the lack of knowledge on native (including endemic) Malaysian species, and further emphasises the need for a revision of all bithyniids.

Genetic verification of Thai Calotes cf. versicolor (Squamata: Agamidae) within the putative Calotes irawadi species complex

Arpapan Prakobkarn — 2024-11-10

Since the designation of Calotes versicolor sensu stricto and its restricted distribution in India, the status of Calotes cf. versicolor has been the subject of several taxonomic studies throughout its former distribution range, including Thailand. Among recently described species, C. irawadi was alleged to have been distributed from eastern India to Indochina. Based on subsequent studies, genetic variation obtained from limited set of samples suggested the potential existence of a species complex rather than a single taxonomic unit. Calotes cf. versicolor is commonly found in various habitats throughout Thailand. Therefore, the clarification of its taxonomic status is of importance. In this study, the degree of genetic variation among Thai C. cf. versicolor was investigated and compared to C. irawadi using the mitochondrial 16S rRNA gene (438 bp) to ascertain its position within the C. irawadi complex. DNA samples of C. cf. versicolor specimens from various regions of Thailand were examined. Based on the ML and BI phylogenetic trees, Thai C. cf. versicolor formed several closely related subclades, some of which shared the same subclade with C. irawadi from Myanmar and India. Substantial uncorrected p-distances (0.46–3.09%) were detected among Thai C. cf. versicolor suggesting the presence of several taxonomical units within the putative C. irawadi species complex.

A New Amphipod Species of the Genus Cheriphotis (Amphipoda, Senticaudata) from Pulau Langkawi, Straits of Malacca, Malaysia with Notes on the Distribution of the Genus

Abdul Rahim Azman — 2024-11-10

A new species, Cheiriphotis selat n. sp., was described based on specimens collected from coral rubbles found at Kuah Beach, Pulau Langkawi, Malaysia. The newly discovered amphipod species can be distinguished from its closest relative by its smaller eyes; the basis of male gnathopod 2 is anterodistally notched; a distinctly longer peduncle than the ramus of uropod 3; the inner lobe of the maxilliped does not reach the apex of palp article 1; a shallower projection on the posteroventral of epimeron 3. An identification key for the 17 known species in the genus was updated.