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.

The identity of Nanorana yunnanensis (Anderson, 1879) from Thailand, with a description of its tadpole (Anura, Dicroglossidae).

Nanorana yunnanensis has been reported in Thailand for many years; however, no specimens have been verifiably described. To verify the identity of this species in Thailand, we observed Thai specimens formerly assigned to the species N. bourreti and N. yunnanensis. The 12S rRNA, 16S rRNA, and ND2 mitochondrial genes were used to clarify the taxonomic statuses of the Thai specimens. The results showed that our specimens formed a clade with N. yunnanensis, containing specimens from southern Yunnan and Vietnam. The respective mean sequence divergences of the 12S and 16S rRNA genes between populations from Thailand versus China were 0.59% and 1.09%, for populations from Thailand versus Vietnam were 0.57% and 0.61%, and for populations from China versus Vietnam were 0.59% and 1.09%. We provide descriptions of the tadpole and adult specimens of N. yunnanensis from Thailand.

A new caruncle-bearing fanged frog (Limnonectes, Dicroglossidae) from Laos and Thailand.

A new species of the dicroglossid frog genus Limnonectes is described from recent and historical museum specimens collected in central and southern Laos and northeastern Thailand. Limnonectessavan sp. nov. has males that bear a caruncle on top of the head, and most closely resembles L.dabanus from adjacent southern Vietnam and eastern Cambodia. However, the new species is readily distinguished from L.dabanus, and all other caruncle-bearing species of Limnonectes in mainland Southeast Asia, by its adult and larval morphology, mitochondrial DNA, and advertisement call. Its description brings the total number of caruncle-bearing species of Limnonectes to six.

Integrative Taxonomy of Southeast Asian Snail-Eating Turtles (Geoemydidae: Malayemys) Reveals a New Species and Mitochondrial Introgression.

Based on an integrative taxonomic approach, we examine the differentiation of Southeast Asian snail-eating turtles using information from 1863 bp of mitochondrial DNA, 12 microsatellite loci, morphology and a correlative species distribution model. Our analyses reveal three genetically distinct groups with limited mitochondrial introgression in one group. All three groups exhibit distinct nuclear gene pools and distinct morphology. Two of these groups correspond to the previously recognized species Malayemys macrocephala (Chao Phraya Basin) and M. subtrijuga (Lower Mekong Basin). The third and genetically most divergent group from the Khorat Basin represents a previously unrecognized species, which is described herein. Although Malayemys are extensively traded and used for religious release, only few studied turtles appear to be translocated by humans. Historic fluctuations in potential distributions were assessed using species distribution models (SDMs). The Last Glacial Maximum (LGM) projection of the predictive SDMs suggests two distinct glacial distribution ranges, implying that the divergence of M. macrocephala and M. subtrijuga occurred in allopatry and was triggered by Pleistocene climate fluctuations. Only the projection derived from the global circulation model MIROC reveals a distinct third glacial distribution range for the newly discovered Malayemys species.

Impending conservation crisis for Southeast Asian amphibians.

With an understudied amphibian fauna, the highest deforestation rate on the planet and high harvesting pressures, Southeast Asian amphibians are facing a conservation crisis. Owing to the overriding threat of habitat loss, the most critical conservation action required is the identification and strict protection of habitat assessed as having high amphibian species diversity and/or representing distinctive regional amphibian faunas. Long-term population monitoring, enhanced survey efforts, collection of basic biological and ecological information, continued taxonomic research and evaluation of the impact of commercial trade for food, medicine and pets are also needed. Strong involvement of regional stakeholders, students and professionals is essential to accomplish these actions.