Piyoros Tongkerd
Chulalongkorn University
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Featured researches published by Piyoros Tongkerd.
Molecular Phylogenetics and Evolution | 2014
Nattawadee Nantarat; Piyoros Tongkerd; Chirasak Sutcharit; Christopher M. Wade; Fred Naggs; Somsak Panha
Operculate land snails of the genus Cyclophorus are distributed widely in sub-tropical and tropical Asia. Shell morphology is traditionally used for species identification in Cyclophorus but their shells exhibit considerable variation both within and between populations; species limits have been extremely difficult to determine and are poorly understood. Many currently recognized species have discontinuous distributions over large ranges but geographical barriers and low mobility of snails are likely to have led to long periods of isolation resulting in cryptic speciation of allopatric populations. As a contribution towards solving these problems, we reconstructed the molecular phylogeny of 87 Cyclophorus specimens, representing 29 nominal species (of which one was represented by four subspecies), plus three related out-group species. Molecular phylogenetic analyses were used to investigate geographic limits and speciation scenarios. The analyses of COI, 16S rRNA and 28S rRNA gene fragments were performed using neighbour-joining (NJ), maximum likelihood (ML), and Bayesian inference (BI) methods. All the obtained phylogenetic trees were congruent with each other and in most cases confirmed the species level classification. However, at least three nominate species were polyphyletic. Both C. fulguratus and C. volvulus appear to be species complexes, suggesting that populations of these species from different geographical areas of Thailand are cryptic species. C. aurantiacus pernobilis is distinct and likely to be a different species from the other members of the C. aurantiacus species complex.
ZooKeys | 2011
Ueangfa Bantaowong; Ratmanee Chanabun; Piyoros Tongkerd; Chirasak Sutcharit; Samuel W. James; Somsak Panha
Abstract Four new species of terrestrial earthworms from the zebrus-group in the genus Amynthas Kinberg, 1867, are described from Nan province, north Thailand: Amynthas phatubensis sp. n., from Tham Pha Tub Arboretum, Amynthas tontong sp. n., from Tontong Waterfall, Amynthas borealis sp. n., from Chaloemprakiat district, and Amynthas srinan sp. n., from Srinan National Park.After comparing with the two closely related Laos species Amynthas chandyi Hong, 2008 and Amynthas namphouinensis Hong, 2008, the four new species show clear morphological differences, and also it is confirmed that there are no previous records of the species described here. Amynthas phatubensis sp. n. is the largest (longest) sized of these earthworms and is the only species that lives in limestone habitats. The genital characters are different among them and also from the two Laotian species. Molecular systematics would be a good method for further analysis of the diversity and species boundaries in SE Asian Amynthas.
ZooKeys | 2016
Warut Siriwut; Gregory D. Edgecombe; Chirasak Sutcharit; Piyoros Tongkerd; Somsak Panha
Abstract The centipede genus Scolopendra in mainland Southeast Asia is reviewed taxonomically based on morphological characters, informed by a molecular phylogenetic analysis using sequences from three mitochondrial and nuclear genes (COI, 16S rRNA and 28S rRNA). Eight nominal species of Scolopendra, namely Scolopendra morsitans Linnaeus, 1758, Scolopendra subspinipes Leach, 1816, Scolopendra dehaani Brandt, 1840, Scolopendra multidens Newport, 1844, Scolopendra calcarata Porat, 1876, Scolopendra japonica Koch, 1878, Scolopendra pinguis Pocock, 1891, and Scolopendra dawydoffi Kronmüller, 2012, are redescribed together with some revision of type materials. Geographical variation in each species has been compiled with reference to samples that span their distribution ranges in Southeast Asia and some parts of neighbouring areas such as East Asia, the Indian Ocean, and Africa. Comparative study of traditional taxonomic characters from external morphology provides further information to distinguish some closely related species. Scolopendra cataracta Siriwut, Edgecombe & Panha, sp. n., is described from the southern part of Laos, with additional records in Thailand and Vietnam. The phylogenetic framework for Southeast Asian Scolopendra recognizes Scolopendra calcarata + Scolopendra pinguis, Scolopendra morsitans, and a Scolopendra subspinipes group that unites the other six species as the main clades. Within the Scolopendra subspinipes group, two monophyletic groups can be distinguished by having either slender or short, thick ultimate leg prefemora and different numbers of apical spines on the coxopleuron. Scolopendra arborea Lewis, 1982, is placed in subjective synonymy with Scolopendra dehaani. A survey of external morphology of the genital segments confirms its potential for improving species identification in Scolopendra. Some observations on biology and behaviour are recorded based on field surveys in this area.
ZooKeys | 2014
Nattawadee Nantarat; Chirasak Sutcharit; Piyoros Tongkerd; Jonathan D. Ablett; Fred Naggs; Somsak Panha
Abstract The collection of land caenogastropod snails in the genus Cyclophorus Monfort, 1810 housed in the Natural History Museum, London (NHM), includes 52 type lots. Lectotypes have been designated for 43 available species-level names to stabilize existing nomenclature, two previously designated lectotype, two holotypes, one paratype, one syntype, one possible syntype and two paralectotypes are also listed. A complete catalogue of the Cyclophorus types in NHM, London is provided for the first time.
Zootaxa | 2015
Warut Siriwut; Gregory D. Edgecombe; Chirasak Sutcharit; Piyoros Tongkerd; Somsak Panha
The first Southeast Asian record of the scolopendrid centipede Digitipes Attems, 1930, has been collected and analyzed based on a new species from Myanmar, males possessing a distomedial process on the ultimate leg femur that is diagnostic of the genus. Digitipes kalewaensis n. sp., described herein, is distinguished from other members of Digitipes by its 2.5 to 2.7 dorsally glabrous antennal articles, an unusually long basal suture on the tooth-plates, absence of a lateral spine on the coxopleural process, and a lack of median and dorso-median spines on the ultimate leg prefemur. Maximum likelihood and Bayesian analyses of two molecular markers (mitochondrial COI and 16S rRNA) supported the proposal of a new species from Myanmar. The phylogenetic tree identifies Digitipes barnabasi from the Western Ghats, India, in a polytomy with members of other genera of Otostigminae (Otostigmus, Ethmostigmus and Rhysida) and a robust Indian-Burmese Digitipes clade in which D. kalewaensis n. sp. is resolved as sister group to a clade composed of most Indian species. Available molecular dates for the diversification of Indian Digitipes are consistent with introduction of the genus into SE Asia when the Indian subcontinent made contact with Myanmar in the early Palaeogene.
ZooKeys | 2013
Ratmanee Chanabun; Chirasak Sutcharit; Piyoros Tongkerd; Somsak Panha
Abstract The semi-aquatic freshwater earthworm genus Glyphidrilus Horst, 1889 from Thailand was investigated based on extensive recent collecting. The species in this genus were characterized by their external and internal morphological characters of the location of wings, genital openings, genital organ structures and their locations, as well as the dimensions of body length and number of segments. Several type specimens were compared with both previous and newly collected materials. Ten new species are described from several river systems in Thailand; as Glyphidrilus borealis sp. n., Glyphidrilus chaophraya sp. n., Glyphidrilus chiensis sp. n., Glyphidrilus huailuangensis sp. n., Glyphidrilus kratuensis sp. n., Glyphidrilus quadratus sp. n., Glyphidrilus trangensis sp. n., Glyphidrilus wararamensis sp. n., Glyphidrilus vangthongensis sp. n. and Glyphidrilus vesper sp. n. Each species is endemic to a single river system. All 26 previously described species are re-described, and eight lectotypes have been designated. An identification key and a morphological comparison summary are provided.
Invertebrate Systematics | 2018
Warut Siriwut; Gregory D. Edgecombe; Chirasak Sutcharit; Piyoros Tongkerd; Somsak Panha
Abstract. Phylogenetic relationships of two morphologically similar scolopendrid genera, Rhysida Wood, 1862, and Alluropus Silvestri, 1912, were investigated based on broad-scale taxonomic sampling from SE Asia, India and Australia. Morphological revision and molecular phylogenetics using three loci validate seven Rhysida species in SE Asia and Australia: R. lithobioides (Newport, 1845), R. longipes (Newport, 1845), R. immarginata (Porat, 1876), R. nuda (Newport, 1845), R. carinulata (Haase, 1887), R. singaporiensis Verhoeff, 1937 and R. polyacantha Koch, 1985. The nominal SE Asian species R. leviventer Attems, 1953 and R. marginata Attems, 1953 are placed in junior subjective synonymy with R. lithobioides and Alluropus calcaratus (Pocock, 1891), respectively. The monotypic genus Alluropus is redescribed, molecular phylogeny recovering it nesting together with Indo-Australian Rhysida. Taxonomic revision reassigned R. calcarata Pocock, 1891 to Alluropus based on its morphological and molecular similarity to the type, A. demangei Silvestri, 1912, the differences between putative species being sexual variation. Two morphologically distinct allopatric populations of A. calcaratus, comb. nov. (= A. demangei, syn. nov.) were found in the Indochina subregion. Phylogenetic relationships in Otostigminae remain unsettled because clades within several genera lack significant support, although Rhysida consistently falls into two clades that are not each other’s closest relative.
ZooKeys | 2015
Chirasak Sutcharit; Jonathan D. Ablett; Piyoros Tongkerd; Fred Naggs; Somsak Panha
Abstract The collection of the Southeast Asian tree snail genus Amphidromus Albers, 1850 at the Natural History Museum, London includes more than 100 lots of type specimens representing 85 name-bearing types, 9 paratypes and 6 paralectotypes, and one nomen nudum. Lectotypes are here designated for Amphidromus cambojiensis, Amphidromus perakensis globosus, Amphidromus columellaris gloriosa, Amphidromus maculiferus inflata, Amphidromus lepidus, Amphidromus sinistralis lutea, Amphidromus moniliferus, Amphidromus maculiferus obscura, Amphidromus sinistralis rosea and Amphidromus sinensi vicaria. In addition, the missing types of A.A. Gould were discovered and their type status is discussed. A complete catalogue of these types, including colour photographs is provided for the first time. After examining these type specimens, two new Amphidromus species, Amphidromus (Syndromus) globonevilli Sutcharit & Panha, sp. n. and Amphidromus (Syndromus) principalis Sutcharit & Panha, sp. n. were recognized and are described herein.
Journal of Molluscan Studies | 2004
Piyoros Tongkerd; Taehwan Lee; Somsak Panha; John B. Burch; Diarmaid Ó Foighil
Biochemical Systematics and Ecology | 2008
Pongpun Prasankok; Chirasak Sutcharit; Piyoros Tongkerd; Somsak Panha