Amphibian survey of Ko Pha-gnan in Surat Thani Province, Thailand.

Insular amphibian species are often overlooked, rendering them vulnerable to habitat encroachment and other anthropogenic threats. The aim of this study was to compile a comprehensive list of amphibian species on Ko Pha-ngan in Surat Thani Province, Thailand. Data were collected via transect surveys and drift line fence traps in three different habitat types from February 2021 to September 2023. Our efforts detected 12 unique amphibian species in each of the three habitat types. The highest number of detections was observed in the Ko Pha-ngan-Than Sadet National Park protected areas. The common tree frog (Polypedatesleucomystax) and the common Asian toad (Duttaphrynusmelanostictus) were the two most abundantly found species on the island, whereas the Koh Tao caecilian (Ichthyophiskohtaoensis) and the newly described false Doria's fanged frog (Limnonectespseudodoriae) where the least commonly found species. In addition, Microhylaheymonsi and Fejervaryalimnocharis tadpoles were observed developing in high-salinity water bodies. Many species have shown a high tolerance in human-dominated landscapes. This study sheds light on the need for additional monitoring to better understand the dynamics of endemic species in addition to the impact tourism-driven development and habitat destruction has on a species with an insularly finite habitat.

Complete mitochondrial genomes of the Southeast Asian freshwater pufferfishes, Pao abei (Roberts, 1998) and Pao suvattii (Sontirat and Soonthornsatit, 1985) (Tetraodontiformes: Tetraodontidae) and an insight into the taxonomic status of Pao species.

The complete mitochondrial genomes of the Southeast Asian freshwater pufferfishes, Pao abei and Pao suvattii, were reconstructed using the MGISEQ platform. The genomes were 16,448 bp and 16,449 bp in length, each made up of 37 mitochondrial genes (13 CDSs, 22 tRNAs, and two rRNAs) and putative control region. It is suggested that an accumulation of complete mitochondrial genome sequences can contribute to resolve the taxonomic status of Pao species.

Population Genetic and Social Structure Survey of Solenopsis geminata in Thailand.

Fire ants have long been known to be a major pest and have recently attracted renewed widespread attention due to the invasion of Solenopsis species, especially S. invicta, into many countries in Asia and Australia. Here, we surveyed fire ant specimens in Thailand with the aims of studying their colony biology and population structure. We sampled 38 colonies distributed in agricultural and urban areas throughout Thailand for species identification and found that all were S. geminata. We further genotyped 13 microsatellite loci from 576 workers from 23 of these colonies. Analysis of these genetic data revealed that all colonies were polygynous with only a few queens. Queens from the same colonies were highly genetically related. Population structure was partitioned into two clusters. Pairwise F ST values revealed very high genetic differentiation between colonies suggesting low gene flow among populations. This result suggests that queens were locally mated and founded colonies by a budding strategy. Isolation-by-distance among local populations was not significant.

Phylogenetic and morphological classification of Ophiocordyceps species on termites from Thailand.

Seven new species occurring on termites are added to Ophiocordyceps - O. asiatica, O. brunneirubra, O. khokpasiensis, O. mosingtoensis, O. pseudocommunis, O. pseudorhizoidea and O. termiticola, based on morphological and molecular phylogenetic evidence. O. brunneirubra possesses orange to reddish-brown immersed perithecia on cylindrical to clavate stromata. O. khokpasiensis, O. mosingtoensis and O. termiticola have pseudo-immersed perithecia while O. asiatica, O. pseudocommunis and O. pseudorhizoidea all possess superficial perithecia, reminiscent of O. communis and O. rhizoidea. Phylogenetic analyses based on a combined dataset comprising the internal transcribed spacer regions (ITS) and the largest subunit (LSU) of the ribosomal DNA, partial regions of the elongation factor 1-α (TEF) and the largest and second largest subunits for the RNA polymerase genes (RPB1, RPB2) strongly support the placement of these seven new species in Ophiocordyceps.

Phylogenetic Diversity and Single-Cell Genome Analysis of "Melainabacteria", a Non-Photosynthetic Cyanobacterial Group, in the Termite Gut.

Termite guts harbor diverse yet-uncultured bacteria, including a non-photosynthetic cyanobacterial group, the class "Melainabacteria". We herein reported the phylogenetic diversity of "Melainabacteria" in the guts of diverse termites and conducted a single-cell genome analysis of a melainabacterium obtained from the gut of the termite Termes propinquus. We performed amplicon sequencing of 16S rRNA genes from the guts of 60 termite and eight cockroach species, and detected melainabacterial sequences in 48 out of the 68 insect species, albeit with low abundances (0.02-1.90%). Most of the melainabacterial sequences obtained were assigned to the order "Gastranaerophilales" and appeared to form clusters unique to termites and cockroaches. A single-cell genome of a melainabacterium, designated phylotype Tpq-Mel-01, was obtained using a fluorescence-activated cell sorter and whole genome amplification. The genome shared basic features with other melainabacterial genomes previously reconstructed from the metagenomes of human and koala feces. The bacterium had a small genome (~1.6 Mb) and possessed fermentative pathways possibly using sugars and chitobiose as carbon and energy sources, while the pathways for photosynthesis and carbon fixation were not found. The genome contained genes for flagellar components and chemotaxis; therefore, the bacterium is likely motile. A fluorescence in situ hybridization analysis showed that the cells of Tpq-Mel-01 and/or its close relatives are short rods with the dimensions of 1.1±0.2 µm by 0.5±0.1 µm; for these bacteria, we propose the novel species, "Candidatus Gastranaerophilus termiticola". Our results provide fundamental information on "Melainabacteria" in the termite gut and expand our knowledge on this underrepresented, non-photosynthetic cyanobacterial group.

CO2 efflux from subterranean nests of ant communities in a seasonal tropical forest, Thailand.

Many ant species construct subterranean nests. The presence of their nests may explain soil respiration "hot spots", an important factor in the high CO2 efflux from tropical forests. However, no studies have directly measured CO2 efflux from ant nests. We established 61 experimental plots containing 13 subterranean ant species to evaluate the CO2 efflux from subterranean ant nests in a tropical seasonal forest, Thailand. We examined differences in nest CO2 efflux among ant species. We determined the effects of environmental factors on nest CO2 efflux and calculated an index of nest structure. The mean CO2 efflux from nests was significantly higher than those from the surrounding soil in the wet and dry seasons. The CO2 efflux was species-specific, showing significant differences among the 13 ant species. The soil moisture content significantly affected nest CO2 efflux, but there was no clear relationship between nest CO2 efflux and nest soil temperature. The diameter of the nest entrance hole affected CO2 efflux. However, there was no significant difference in CO2 efflux rates between single-hole and multiple-hole nests. Our results suggest that in a tropical forest ecosystem the increase in CO2 efflux from subterranean ant nests is caused by species-specific activity of ants, the nest soil environment, and nest structure.