Search

Based on several field investigations, many molluscan shells and chondrichthyan teeth, together with other invertebrate and actinopterygian remains were found from the marine Bangkok Clay deposits in Ongkharak, Nakhon Nayok, at a depth of ~ 5–7 m below the topsoil surface. Animal macrofossils recovered from these Holocene marine deposits were identified and their chronological context was investigated in order to reconstruct the paleoenvironments of the area at that time. The majority of marine fossils recovered from the site consist of molluscs, with a total of 63 species identified. Other invertebrate species include a stony coral, a mud lobster, barnacles, and a sea urchin. The vertebrates are represented by fish remains, including carcharhinid shark teeth from at least nine species, stingray and trichiurid teeth, and one sciaenid otolith. The molluscan fauna indicates that the paleoenvironments of the area corresponded to intertidal to sublittoral zones, where some areas were mangrove forests and intertidal mudflats. The fish fauna is dominated by the river shark Glyphis, indicating freshwater influences and possibly occasional brackish conditions. The carbon-14 analysis of mollusc and charcoal remains shows that deposition of the marine sediment sequence began during the mid-Holocene, spanning approximately from 8,800 to 5,300 cal yr BP. This study provides in-depth insights into the diversity of fishes, marine molluscs, and other invertebrates from the Bangkok Clay deposits, supporting the existence of a marine transgression onto the Lower Central Plain of Thailand during the mid-Holocene. [ABSTRACT FROM AUTHOR]

This paper reassesses the taxonomy and systematics of 11 arboreal snail species in the genus Amphidromus from Vietnam, Cambodia, Indonesia and Laos (A. bozhii Wang, 2019, A. buelowi Fruhstorfer, 1905, A. costifer Smith, 1893, A. haematostoma Möllendorff, 1898, A. ingens Möllendorff, 1900, A. madelineae Thach, 2020, A. metabletus Möllendorff, 1900, A. pankowskianus Thach, 2020, A. placostylus Möllendorff, 1900, A. roseolabiatus Fulton, 1896, and A. thachi Huber, 2015). The taxonomic validity of each species is supported by a phylogenetic analysis of mitochondrial COI and 16S rRNA gene fragments from 17 ingroup taxa. Amphidromus buelowi was found to comprise two populations from two distant localities, one from Mount Singgalang, West Sumatra, Indonesia and the other from southern Vietnam. The samples from southern Vietnam were previously described as A. asper Haas, 1934 and A. franzhuberi Thach, 2016, but they are now treated as junior synonyms of A. buelowi in this study. In addition, two species from Vietnam are described as new to science, viz. A. asperoides Jirapatrasilp & Lee, sp. nov. and A. ingensoides Jirapatrasilp & Lee, sp. nov., each of which is conchologically comparable to A. buelowi and A. ingens, respectively. [ABSTRACT FROM AUTHOR]

Thailand is located at the crossroads of several biogeographical regions, and boasts a high level of biodiversity, especially among the malacofauna. The most recent checklist of land snail species in Thailand was compiled more than twenty years ago, and so this checklist needs revision and the addition of newly discovered taxa. This study updates the taxonomy and species list of the operculated land snail family Pupinidae from Thailand. This snail family is diverse and abundant, and can be found in various natural habitats in Southeast Asia. Although the taxonomy of some Southeast Asian pupinid genera has been reviewed, studies of Pupina Vignard, 1829, which contains the highest number of species, and a lesser-known genus Pupinella Gray, 1850 are still lacking. Herein we present an annotated checklist with an up-to-date systematic framework of the Pupinidae in Thailand based on both field investigations and literature surveys, and include the taxonomic treatment of all Pupina and Pupinella species from mainland Southeast Asia. This annotated checklist contains 30 nominal species and two subspecies from seven genera currently known to occur in Thailand. We describe two species of Pseudopomatias (P. doiangkhangensis Jirapatrasilp, sp. nov. and P. pallgergelyi Jirapatrasilp, sp. nov.), five species and one subspecies of Pupina (P. bensoni Jirapatrasilp, sp. nov., P. bilabiata Jirapatrasilp, sp. nov., P. godwinausteni Jirapatrasilp, sp. nov., P. latisulci Jirapatrasilp, sp. nov., P. stoliczkai Jirapatrasilp, sp. nov., and P. dorri isanensis Jirapatrasilp, ssp. nov.) as new to science. New records of Coptocheilus sumatranus, Pupinella mansuyi, and Rhaphaulus tonkinensis are also reported from Thailand. The mainland Southeast Asian Pupina species are classified into three species groups (Pupina artata group, Pupina arula group, and Pupina aureola group) based on the distinction of shell teeth and canals, and operculum. Three species formerly in Pupina from Vietnam are allocated to Pupinella (P. illustris comb. nov., P. sonlaensis comb. nov., and P. thaitranbaii comb. nov.) due to the presence of a funnel-like anterior canal. [ABSTRACT FROM AUTHOR]

The luminous earthworm Pontodrilus litoralis (Grube, 1855) occurs in a very wide range of subtropical and tropical coastal areas. Morphometrics on size variation (number of segments, body length and diameter) and genetic analysis using the mitochondrial cytochrome c oxidase subunit 1 (COI) gene sequence were conducted on 14 populations of P. litoralis from Southeast Asia and Japan. Statistical inference on morphometric data revealed significantly different size variations in the body length and diameter among these 14 populations of P. litoralis. However, discordance between the morphometric and mitochondrial COI gene-based phylogenetic analyses was evident, where the size variations in P. litoralis showed a different pattern from the COI genetic differences. The update on the current distribution of P. litoralis is reported and revealed different aspects of the littoral habitat characteristics between Southeast Asia and Japan. [ABSTRACT FROM AUTHOR]

This paper reassesses the taxonomy and systematics of 11 arboreal snail species in the genus Amphidromus from Vietnam, Cambodia, Indonesia and Laos ( A.bozhii Wang, 2019, A.buelowi Fruhstorfer, 1905, A.costifer Smith, 1893, A.haematostoma Möllendorff, 1898, A.ingens Möllendorff, 1900, A.madelineae Thach, 2020, A.metabletus Möllendorff, 1900, A.pankowskianus Thach, 2020, A.placostylus Möllendorff, 1900, A.roseolabiatus Fulton, 1896, and A.thachi Huber, 2015). The taxonomic validity of each species is supported by a phylogenetic analysis of mitochondrial COI and 16S rRNA gene fragments from 17 ingroup taxa. Amphidromusbuelowi was found to comprise two populations from two distant localities, one from Mount Singgalang, West Sumatra, Indonesia and the other from southern Vietnam. The samples from southern Vietnam were previously described as A.asper Haas, 1934 and A.franzhuberi Thach, 2016, but they are now treated as junior synonyms of A.buelowi in this study. In addition, two species from Vietnam are described as new to science, viz. A.asperoides Jirapatrasilp & Lee, sp. nov. and A.ingensoides Jirapatrasilp & Lee, sp. nov. , each of which is conchologically comparable to A.buelowi and A.ingens , respectively., Competing Interests: The authors have declared that no competing interests exist., (Parin Jirapatrasilp, Chih-Wei Huang, Chirasak Sutcharit, Chi-Tse Lee.)

The luminous earthworm Pontodriluslitoralis (Grube, 1855) occurs in a very wide range of subtropical and tropical coastal areas. Morphometrics on size variation (number of segments, body length and diameter) and genetic analysis using the mitochondrial cytochrome c oxidase subunit 1 (COI) gene sequence were conducted on 14 populations of P.litoralis from Southeast Asia and Japan. Statistical inference on morphometric data revealed significantly different size variations in the body length and diameter among these 14 populations of P.litoralis . However, discordance between the morphometric and mitochondrial COI gene-based phylogenetic analyses was evident, where the size variations in P.litoralis showed a different pattern from the COI genetic differences. The update on the current distribution of P.litoralis is reported and revealed different aspects of the littoral habitat characteristics between Southeast Asia and Japan.