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1.
Nature ; 605(7909): 285-290, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35477765

RESUMEN

Comprehensive assessments of species' extinction risks have documented the extinction crisis1 and underpinned strategies for reducing those risks2. Global assessments reveal that, among tetrapods, 40.7% of amphibians, 25.4% of mammals and 13.6% of birds are threatened with extinction3. Because global assessments have been lacking, reptiles have been omitted from conservation-prioritization analyses that encompass other tetrapods4-7. Reptiles are unusually diverse in arid regions, suggesting that they may have different conservation needs6. Here we provide a comprehensive extinction-risk assessment of reptiles and show that at least 1,829 out of 10,196 species (21.1%) are threatened-confirming a previous extrapolation8 and representing 15.6 billion years of phylogenetic diversity. Reptiles are threatened by the same major factors that threaten other tetrapods-agriculture, logging, urban development and invasive species-although the threat posed by climate change remains uncertain. Reptiles inhabiting forests, where these threats are strongest, are more threatened than those in arid habitats, contrary to our prediction. Birds, mammals and amphibians are unexpectedly good surrogates for the conservation of reptiles, although threatened reptiles with the smallest ranges tend to be isolated from other threatened tetrapods. Although some reptiles-including most species of crocodiles and turtles-require urgent, targeted action to prevent extinctions, efforts to protect other tetrapods, such as habitat preservation and control of trade and invasive species, will probably also benefit many reptiles.


Asunto(s)
Conservación de los Recursos Naturales , Extinción Biológica , Reptiles , Caimanes y Cocodrilos , Anfibios , Animales , Biodiversidad , Aves , Mamíferos , Filogenia , Reptiles/clasificación , Medición de Riesgo , Tortugas
2.
Mol Ecol ; 31(15): 3979-3998, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-34516675

RESUMEN

Secondary sympatry amongst sister lineages is strongly associated with genetic and ecological divergence. This pattern suggests that for closely related species to coexist in secondary sympatry, they must accumulate differences in traits that mediate ecological and/or reproductive isolation. Here, we characterized inter- and intraspecific divergence in three giant tree frog species whose distributions stretch across West and Central Africa. Using genome-wide single-nucleotide polymorphism data, we demonstrated that species-level divergence coincides temporally and geographically with a period of large-scale forest fragmentation during the late Pliocene. Our environmental niche models further supported a dynamic history of climatic suitability and stability, and indicated that all three species occupy distinct environmental niches. We found modest morphological differentiation amongst the species with significant divergence in tympanum diameter and male advertisement call. In addition, we confirmed that two species occur in secondary sympatry in Central Africa but found no evidence of hybridization. These patterns support the hypothesis that cycles of genetic exchange and isolation across West and Central Africa have contributed to globally significant biodiversity. Furthermore, divergence in both ecology and reproductive traits appear to have played important roles in maintaining distinct lineages. At the intraspecific level, we found that climatic refugia, precipitation gradients, marine incursions, and potentially riverine barriers generated phylogeographic structure throughout the Pleistocene and into the Holocene. Further studies examining phenotypic divergence and secondary contact amongst these geographically structured populations may demonstrate how smaller scale and more recent biogeographic barriers contribute to regional diversification.


La sympatrie secondaire parmi les espèces sœurs est fortement associée à la divergence génétique et écologique. Ce modèle suggère que pour que des espèces étroitement liées coexistent en sympatrie secondaire, elles doivent accumuler des différences dans les traits qui contribuent à l'isolement écologique ou reproductif. Ici, nous avons caractérisé la divergence inter- et intra-spécifique chez trois espèces de grenouilles arboricoles géantes dont les distributions s'étendent à travers l'Afrique de l'Ouest et Centrale. Avec des données génétiques, nous avons démontré que la divergence au niveau des espèces coïncide temporellement et géographiquement avec une période de fragmentation forestière à la fin du Pliocène. Nos modèles de niches environnementales ont soutenu une histoire dynamique de stabilité climatique, et ont indiqué que les trois espèces occupent des niches environnementales distinctes. Nous avons trouvé une différenciation morphologique modeste parmi les trois espèces mais une divergence significative dans le diamètre du tympan et les cris des mâles. De plus, nous avons confirmé que deux espèces sont présentes en sympatrie secondaire en Afrique Centrale mais n'avons trouvé aucune preuve d'hybridation. Ces résultats soutiennent l'hypothèse que les cycles d'échange génétique et d'isolement à travers l'Afrique de l'Ouest et Centrale ont contribué à une profonde concentration de biodiversité dans la région. De plus, la divergence des traits écologiques et reproducteurs semble avoir joué un rôle important dans le maintien de lignées distinctes. Au niveau intra-spécifique, nous avons constaté que les refuges climatiques, les gradients de précipitation, les incursions marines et potentiellement les barrières fluviales ont généré une structure phylogéographique pendant le Pléistocène et jusqu'à l'Holocène. Des études examinant la divergence phénotypique et le contact secondaire entre ces populations géographiquement structurées pourraient démontrer comment des barrières biogéographiques à échelle plus petite et plus récentes contribuent à la diversification régionale.


Asunto(s)
Anuros , Biodiversidad , África Central , Animales , Anuros/genética , ADN Mitocondrial/genética , Bosques , Variación Genética , Masculino , Filogenia , Filogeografía , Ranidae/genética
3.
Mol Phylogenet Evol ; 145: 106722, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31874235

RESUMEN

The most ubiquitous, abundant, and invasive turtle on Earth, Trachemys scripta elegans (TSE, "red-eared slider"), is one of four taxa in a clade that is native to the USA and adjacent Mexico (three subspecies of Trachemys scripta plus Trachemys gaigeae). The present range-wide study of this clade is based on 173 known-locality mtDNA sequences combined with ddRAD libraries for 43 samples emphasizing the western part of the range of TSE, its contact with that of T. gaigeae, and anthropogenic hybrids between TSE and T. s. scripta. The data presented here are the first to sample the TSE × T. s. scripta intergrade zone or TSE × T. s. scripta crosses from introduced turtles. In the western part of its range (New Mexico and Texas), most samples of TSE from the Pecos River have mtDNA haplotypes matching T. gaigeae. Structure analysis of SNPs from the ddRAD show evidence of genetic admixture between T. gaigeae and TSE in all included samples from the Rio Grande and Pecos River. These populations also exhibit T. gaigeae-like head stripes, i.e., a postorbital marking that does not reach the eye. The genetic and morphological data are thereby reconciled, as both suggest that these TSE are intergrades. We recommend that these populations continue to be considered TSE, despite the admixture with T. gaigeae. In the Eastern United States, some samples of the morphologically intermediate subspecies T. s. troostii are not genetically distinct from TSE and some samples share morphological characters and genetic affinities with T. s. scripta. Based on these observations we conclude that the taxon T. s. troostii represents intergrades between TSE and T. s. scripta and should not be considered a valid taxon. Near the already established part of the intergrade zone between TSE and T. s. scripta, TSE mtDNA haplotypes have naturally introgressed into typical-looking samples of T. s. scripta in Georgia. Hybrids between introduced TSE and T. s. scripta are also confirmed deeper within the natural range of T. s. scripta in South Carolina and Virginia. Given the examples of feral hybrids deep within its range shown here and elsewhere, the threat of genetic pollution of T. s. scripta by feral TSE is established.


Asunto(s)
Variación Genética , Tortugas/genética , Animales , ADN Mitocondrial/genética , Biblioteca de Genes , Filogenia , Polimorfismo de Nucleótido Simple , Tortugas/clasificación , Estados Unidos
4.
Mol Phylogenet Evol ; 145: 106724, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31881327

RESUMEN

Rhacophoridae are one of the most speciose and ecologically diverse families of amphibians. Resolution of their evolutionary relationships is key to understanding the accumulation of biodiversity, yet previous hypotheses based on Sanger sequencing exhibit much discordance amongst generic relationships. This conflict precludes the making of sound macroevolutionary conclusions. Herein, we conduct the first phylogenomic study using broad-scale sampling and sequences of 352 nuclear DNA loci obtained using anchored hybrid enrichment targeted sequencing. The robust time-calibrated phylogenetic hypothesis clarifies several long-disputed relationships and facilitates the testing of evolutionary hypotheses on spatiotemporal diversification and reproductive modes. The major extant lineages of Rhacophoridae appear to have radiated in mainland Asia, and the spatiotemporal process corresponds with several common accumulations of biodiversity in Asia. Analyses do not detect any case of "Out of Himalaya" in Rhacophoridae. All transitions of reproductive modes appear to have evolved in an ordered, gradual sequence associated with gaining independence of standing water for larval development. The different reproductive modes are phylogenetically conserved and the completion of their transitions appear to have occurred over a period of ~30 Ma, which does not fit a pattern of a rapid burst of diversification. Innovations in reproductive modes associate statistically with the uneven distribution of species-richness between clades, where higher diversification is linked to increased terrestrial modes of reproduction. These results strengthen the hypothesis that breeding innovations drive diversification by providing new opportunities for ecological release and dispersion.


Asunto(s)
Anuros/clasificación , Evolución Biológica , Animales , Anuros/genética , Anuros/crecimiento & desarrollo , Teorema de Bayes , Biodiversidad , Núcleo Celular/genética , Filogenia , Filogeografía , Reproducción
5.
Mol Phylogenet Evol ; 148: 106789, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32173414

RESUMEN

The genus Amolops ("torrent frogs") is one of the most species-rich genera in Ranidae, with 59 recognized species. This genus currently includes six species groups diagnosed mainly by morphology. Several recent molecular studies indicated that the classification of species groups within Amolops remains controversial, and key nodes in the phylogeny have been inadequately resolved. In addition, the diversity of Amolops remains poorly understood, especially for those from incompletely sampled regions. Herein, we investigate species-level diversity within the genus Amolops throughout southern China and Southeast Asia, and infer evolutionary relationships among the species using mtDNA data (16S, COI, and ND2). Molecular analyses indicate nine unnamed species, mostly distributed in the Himalayas. We then utilized anchored hybrid enrichment to generate a dataset representing the major mitochondrial lineages to resolve phylogenetic relationships, biogeography, and pattern of species diversification. Our resulting phylogeny strongly supports the monophyly of four previously identified species groups (the A. ricketti, A. daiyunensis, A. hainanensis, and A. monticola groups), but paraphyly for the A. mantzorum and A. marmoratus groups, as previously defined. We erect one new species group, the A. viridimaculatus group, and recognize Dubois' (1992) subgenus Amo as the A. larutensis species group. Biogeographic analysis suggests that Amolops originated on the Indo-Burma/Thai-Malay Peninsula at the Eocene/Oligocene boundary, and dispersed outward, exemplifying a common pattern observed for the origin of Asian biodiversity. The early divergence within Amolops coincides with the Himalayan uplift and the lateral extrusion of Indochina at the Oligocene/Miocene boundary. Our results show that paleoclimatic and geomorphological events have profoundly influenced the patterns of lineage diversification within Amolops.


Asunto(s)
Biodiversidad , Núcleo Celular/genética , ADN Mitocondrial/genética , Filogenia , Filogeografía , Ranidae/genética , Animales , Asia Sudoriental , Secuencia de Bases , Teorema de Bayes , Análisis Espacio-Temporal , Especificidad de la Especie
6.
Mol Phylogenet Evol ; 124: 162-171, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29530499

RESUMEN

Southeast Asia and southern China (SEA-SC) harbor a highly diverse and endemic flora and fauna that is under increasing threat. An understanding of the biogeographical history and drivers of this diversity is lacking, especially in some of the most diverse and threatened groups. The Asian leaf-litter frog genus Leptolalax Dubois 1980 is a forest-dependent genus distributed throughout SEA-SC, making it an ideal study group to examine specific biogeographic hypotheses. In addition, the diversity of this genus remains poorly understood, and the phylogenetic relationships among species of Leptolalax and closely related Leptobrachella Smith 1928 remain unclear. Herein, we evaluate species-level diversity based on 48 of the 53 described species from throughout the distribution of Leptolalax. Molecular analyses reveal many undescribed species, mostly in southern China and Indochina. Our well-resolved phylogeny based on multiple nuclear DNA markers shows that Leptolalax is not monophyletic with respect to Leptobrachella and, thus, we assign the former to being a junior synonym of the latter. Similarly, analyses reject monophyly of the two subgenera of Leptolalax. The diversification pattern of the group is complex, involving a high degree of sympatry and prevalence of microendemic species. Northern Sundaland (Borneo) and eastern Indochina (Vietnam) appear to have played pivotal roles as geographical centers of diversification, and paleoclimatic changes and tectonic movements seem to have driven the major divergence of clades. Analyses fail to reject an "upstream" colonization hypothesis, and, thus, the genus appears to have originated in Sundaland and then colonized mainland Asia. Our results reveal that both vicariance and dispersal are responsible for current distribution patterns in the genus.


Asunto(s)
Anuros/clasificación , Biodiversidad , Filogenia , Animales , Asia , Secuencia de Bases , Teorema de Bayes , Filogeografía , Especificidad de la Especie , Factores de Tiempo
7.
Mol Ecol ; 26(19): 5223-5244, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28753250

RESUMEN

Organismal traits interact with environmental variation to mediate how species respond to shared landscapes. Thus, differences in traits related to dispersal ability or physiological tolerance may result in phylogeographic discordance among co-distributed taxa, even when they are responding to common barriers. We quantified climatic suitability and stability, and phylogeographic divergence within three reed frog species complexes across the Guineo-Congolian forests and Gulf of Guinea archipelago of Central Africa to investigate how they responded to a shared climatic and geological history. Our species-specific estimates of climatic suitability through time are consistent with temporal and spatial heterogeneity in diversification among the species complexes, indicating that differences in ecological breadth may partly explain these idiosyncratic patterns. Likewise, we demonstrated that fluctuating sea levels periodically exposed a land bridge connecting Bioko Island with the mainland Guineo-Congolian forest and that habitats across the exposed land bridge likely enabled dispersal in some species, but not in others. We did not find evidence that rivers are biogeographic barriers across any of the species complexes. Despite marked differences in the geographic extent of stable climates and temporal estimates of divergence among the species complexes, we recovered a shared pattern of intermittent climatic suitability with recent population connectivity and demographic expansion across the Congo Basin. This pattern supports the hypothesis that genetic exchange across the Congo Basin during humid periods, followed by vicariance during arid periods, has shaped regional diversity. Finally, we identified many distinct lineages among our focal taxa, some of which may reflect incipient or unrecognized species.


Asunto(s)
Anuros/clasificación , Evolución Biológica , Cambio Climático , Bosques , Filogenia , África Central , Animales , Núcleo Celular/genética , ADN Mitocondrial/genética , Femenino , Guinea , Islas , Masculino , Modelos Biológicos , Fenotipo , Filogeografía
8.
Mol Phylogenet Evol ; 106: 28-43, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27622725

RESUMEN

The horned toad assemblage, genus Megophrys sensu lato, currently includes three groups previously recognized as the genera Atympanophrys, Xenophrys and Megophrys sensu stricto. The taxonomic status and species composition of the three groups remain controversial due to conflicting phenotypic analyses and insufficient phylogenetic reconstruction; likewise, the position of the monotypic Borneophrys remains uncertain with respect to the horned toads. Further, the diversity of the horned toads remains poorly understood, especially for widespread species. Herein, we evaluate species-level diversity based on 45 of the 57 described species from throughout southern China, Southeast Asia and the Himalayas using Bayesian inference trees and the Generalized Mixed Yule Coalescent (GMYC) approach. We estimate the phylogeny using both mitochondrial and nuclear DNA data. Analyses reveal statistically significant mito-nuclear discordance. All analyses resolve paraphyly for horned toads involving multiple strongly supported clades. These clades correspond with geography. We resurrect the genera Atympanophrys and Xenophrys from the synonymy of Megophrys to eliminate paraphyly of Megophrys s.l. and to account for the morphological, molecular and biogeographic differences among these groups, but we also provide an alternative option. Our study suggests that Borneophrys is junior synonym of Megophrys sensu stricto. We provide an estimation of timeframe for the horned toads. The mitochondrial and nuclear trees indicate the presence of many putative undescribed species. Widespread species, such as Xenophrys major and X. minor, likely have dramatically underestimated diversity. The integration of morphological and molecular evidence can validate this discovery. Montane forest dynamics appear to play a significant role in driving diversification of horned toads.


Asunto(s)
Anuros/clasificación , Animales , Anuros/genética , Teorema de Bayes , Bufonidae/clasificación , Bufonidae/genética , China , ADN/química , ADN/aislamiento & purificación , ADN/metabolismo , ADN Mitocondrial/clasificación , ADN Mitocondrial/genética , Filogenia , Filogeografía , ARN Ribosómico 16S/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
9.
Biol Lett ; 12(1): 20150807, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26763213

RESUMEN

The Asian common toad (Duttaphrynus melanostictus) is a human commensal species that occupies a wide variety of habitats across tropical Southeast Asia. We test the hypothesis that genetic variation in D. melanostictus is weakly associated with geography owing to natural and human-mediated dispersal facilitated by its commensal nature. Phylogenetic and population genetic analyses of mitochondrial and nuclear DNA sequence variation, and predictive species distribution modelling, unexpectedly recovered three distinct evolutionary lineages that differ genetically and ecologically, corresponding to the Asian mainland, coastal Myanmar and the Sundaic islands. The persistence of these three divergent lineages, despite ample opportunities for recent human-mediated and geological dispersal, suggests that D. melanostictus actually consists of multiple species, each having narrower geographical ranges and ecological niches, and higher conservation value, than is currently recognized. These findings also have implications for the invasion potential of this human commensal elsewhere, such as in its recently introduced ranges on the islands of Borneo, Sulawesi, Seram and Madagascar.


Asunto(s)
Bufonidae/genética , Distribución Animal , Animales , Asia Sudoriental , Bufonidae/clasificación , ADN Mitocondrial/genética , Ecosistema , Variación Genética , Especies Introducidas , Filogeografía
10.
Mol Phylogenet Evol ; 92: 266-79, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26162672

RESUMEN

Using multiple markers and multiple analytical approaches is critical for establishing species boundaries reliably, especially so in the case of cryptic species. Despite development of new and powerful analytical methods, most studies continue to adopt a few, with the choice often being subjective. One such example is routine analysis of Amplified Fragment Length Polymorphism (AFLP) data using population genetic models despite disparity between method assumptions and data properties. The application of newly developed methods for analyzing this dominant marker may not be entirely clear in the context of species delimitation. In this study, we use AFLPs and mtDNA to investigate cryptic speciation in the Trimeresurus macrops complex that belongs to a taxonomically difficult lineage of Asian pitvipers. We analyze AFLPs using population genetic, phylogenetic, multivariate statistical, and Bayes Factor Delimitation methods. A gene tree from three mtDNA markers provided additional evidence. Our results show that the inferences about species boundaries that can be derived from population genetic analysis of AFLPs have certain limitations. In contrast, four multivariate statistical analyses produced clear clusters that are consistent with each other, as well as with Bayes Factor Delimitation results, and with mtDNA and total evidence phylogenies. Furthermore, our results concur with allopatric distributions and patterns of variation in individual morphological characters previously identified in the three proposed species: T. macrops sensu stricto, T. cardamomensis, and T. rubeus. Our study provides evidence for reproductive isolation and genetic distinctiveness that define these taxa as full species. In addition, we re-emphasize the importance of examining congruence of results from multiple methods of AFLP analysis for inferring species diversity.


Asunto(s)
Viperidae/genética , Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Animales , Asia , Teorema de Bayes , Análisis por Conglomerados , ADN Mitocondrial/genética , Flujo Génico , Marcadores Genéticos , Genética de Población , Geografía , Análisis Multivariante , Filogenia
11.
Sci Rep ; 14(1): 4727, 2024 03 12.
Artículo en Inglés | MEDLINE | ID: mdl-38472264

RESUMEN

Divergence dating analyses in systematics provide a framework to develop and test biogeographic hypotheses regarding speciation. However, as molecular datasets grow from multilocus to genomic, sample sizes decrease due to computational burdens, and the testing of fine-scale biogeographic hypotheses becomes difficult. In this study, we use coalescent demographic models to investigate the diversification of poorly known rice paddy snakes from Southeast Asia (Homalopsidae: Hypsiscopus), which have conflicting dates of origin based on previous studies. We use coalescent modeling to test the hypothesis that Hypsiscopus diversified 2.5 mya during the Khorat Plateau uplift in Thailand. Additionally, we use ecological niche analyses to identify potential differences in the niche space of the two most widely distributed species in the past and present. Our results suggest Hypsiscopus diversified ~ 2.4 mya, supporting that the Khorat Plateau may have initiated the diversification of rice paddy snakes. We also find significant niche differentiation and shifts between species of Hypsiscopus, indicating that environmental differences may have sustained differentiation of this genus after the Khorat Plateau uplift. Our study expands on the diversification history of snakes in Southeast Asia, and highlights how results from smaller multilocus datasets can be useful in developing and testing biogeographic hypotheses alongside genomic datasets.


Asunto(s)
Oryza , Filogenia , Ecosistema , Asia Sudoriental , Tailandia , Filogeografía
12.
Zootaxa ; 3702: 545-65, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-26146745

RESUMEN

We describe a new species of Southeast Asian rhacophorid frog belonging to the Polypedates leucomystax species complex from Songkhla Province, southern Thailand. Polypedates discantus sp. nov. is distinguished from its congeners by the combination of having the skin of the head not co-ossified with the skull; absent or indistinct white dots on the back of the thigh; paired-vocal sac openings; and a round tubercle on the tibiotarsal articulation. The new species is also distinguished from P. leucomystax and P. megacephalus in univariate and multivariate analyses of quantitative morphometric characters, and has uncorrected pairwise distances of 6.61-7.16% from its closest relative, P. leucomystax, in the mitochondrial 16S rRNA gene. The new species has four distinct male advertisement call types, consisting of one-note, two-note, three-note and staccato calls. The new species occurs syntopically with P leucomystax at the type locality.


Asunto(s)
Anuros/anatomía & histología , Anuros/clasificación , Animales , Anuros/fisiología , Ecosistema , Femenino , Masculino , Tailandia , Árboles , Vocalización Animal
13.
Zootaxa ; 3745: 73-83, 2013 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-25113339

RESUMEN

The small rhacophorid frog Philautus abditus is geographically restricted to central Vietnam and adjacent Cambodia. Our fieldwork in northern Laos resulted in the discovery of a Philautus species that very closely resembles P. abditus, but is at least 330 km from the nearest known locality of that species. The Laos population differs from P. abditus in mitochondrial DNA and coloration, and is described here as a new species. Philautus nianeae sp. nov. is distinguished from its congeners by having the combination of a hidden tympanum; no nuptial pads; smooth skin; large black spots on the hidden surfaces of the hind limbs; light venter with dark spotting; and a bronze iris. A second species of Philautus from northern Laos, P. petilus, is transferred on the basis of morphology to the genus Theloderma. 


Asunto(s)
Anuros/clasificación , Distribución Animal , Estructuras Animales/anatomía & histología , Animales , Anuros/anatomía & histología , Anuros/genética , Anuros/fisiología , Ecosistema , Femenino , Laos , Masculino , Datos de Secuencia Molecular , Filogenia , Vocalización Animal
14.
Mol Ecol Resour ; 23(5): 1124-1141, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36924341

RESUMEN

DNA barcoding has greatly facilitated studies of taxonomy, biodiversity, biological conservation, and ecology. Here, we establish a reliable DNA barcoding library for Chinese snakes, unveiling hidden diversity with implications for taxonomy, and provide a standardized tool for conservation management. Our comprehensive study includes 1638 cytochrome c oxidase subunit I (COI) sequences from Chinese snakes that correspond to 17 families, 65 genera, 228 named species (80.6% of named species) and 36 candidate species. A barcode gap analysis reveals gaps, where all nearest neighbour distances exceed maximum intraspecific distances, in 217 named species and all candidate species. Three species-delimitation methods (ABGD, sGMYC, and sPTP) recover 320 operational taxonomic units (OTUs), of which 192 OTUs correspond to named and candidate species. Twenty-eight other named species share OTUs, such as Azemiops feae and A. kharini, Gloydius halys, G. shedaoensis, and G. intermedius, and Bungarus multicinctus and B. candidus, representing inconsistencies most probably caused by imperfect taxonomy, recent and rapid speciation, weak taxonomic signal, introgressive hybridization, and/or inadequate phylogenetic signal. In contrast, 43 species and candidate species assign to two or more OTUs due to having large intraspecific distances. If most OTUs detected in this study reflect valid species, including the 36 candidate species, then 30% more species would exist than are currently recognized. Several OTU divergences associate with known biogeographic barriers, such as the Taiwan Strait. In addition to facilitating future studies, this reliable and relatively comprehensive reference database will play an important role in the future monitoring, conservation, and management of Chinese snakes.


Asunto(s)
Biodiversidad , Código de Barras del ADN Taxonómico , Humanos , Animales , Filogenia , Código de Barras del ADN Taxonómico/métodos , Serpientes/genética , Complejo IV de Transporte de Electrones/genética
16.
Zootaxa ; 5092(1): 116-126, 2022 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-35391218

RESUMEN

Limnonectes liui (Yang, 1983) is a poorly known frog from Yunnan Province, China, with a confusing taxonomic history. We use mitochondrial (mt) DNA sequence data from newly collected specimens to reconstruct the phylogenetic position of the species. Limnonectes liui was found to be deeply nested within the geographically widespread dicroglossid frog L. limborgi (Sclater, 1892), verifying its placement within the genus Limnonectes but casting doubt on its distinction as a species. Morphological comparisons of the holotype and newly collected specimens of L. liui to specimens of L. limborgi from across its range also corroborated the hypothesis that these two species are conspecific, and we recommend treating L. liui as a junior synonym of L. limborgi. Our study underscores the importance of making comparisons with species found beyond a countrys border when describing new species.


Asunto(s)
Anuros , Genes Mitocondriales , Animales , China , ADN Mitocondrial/genética , Filogenia
17.
Zookeys ; 1125: 115-158, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36761290

RESUMEN

Two new insular rock geckos in the genus Cnemaspis are described from Ko Samui in Surat Thani Province and Ko Similan in Phang-nga Province, southern Thailand, based on a combination of morphological and mitochondrial NADH dehydrogenase subunit 2 (ND2) data. Both new species represent divergent lineages within the Cnemaspissiamensis species group. Cnemaspissamui sp. nov. is distinguished from other species in the group by having eight or nine supralabial and infralabial scales; 5-8 pore-bearing precloacal scales in males, pores rounded; 25-27 paravertebral tubercles, arranged randomly; 22-25 subdigital lamellae under 4th toe; enlarged median subcaudal scale row present; gular region, abdomen, limbs and subcaudal region yellowish only in males, and uncorrected pairwise divergences of 8.86-26.83% from all other species in the C.siamensis species group. Cnemaspissimilan sp. nov. is distinguished from other species in the group by having eight or nine supralabial and seven or eight infralabial scales; one pore-bearing precloacal scale in males, pore rounded; 24 or 25 paravertebral tubercles, arranged randomly; 23 or 24 subdigital lamellae under 4th toe; no enlarged median subcaudal scale row; pale yellow reticulum on head, neck, flanks, belly and limbs in male only, and uncorrected pairwise divergences of 9.34-27.11% from all other species in the C.siamensis species group. Cnemaspissamui sp. nov. is found along granitic rocky stream outcrops of Hin Lad Waterfall, Ko Samui, Gulf of Thailand, while Cnemaspissimilan sp. nov. occurs in granitic rocky outcrops near Ao Nguang Chang Bay, Ko Similan, Andaman Sea. The phylogenetic analyses confirmed that C.chanardi and C.kamolnorranathi are also nested within the C.siamensis species group, as previously hypothesized from morphology and color pattern characters.

18.
Zookeys ; 1103: 139-169, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36761785

RESUMEN

Cyrtodactylusmonilatus sp. nov. is described from Si Sawat District, Kanchanaburi Province, in western Thailand. The new species superficially resembles C.zebraicus Taylor, 1962 from southern Thailand. However, differences between the new species from C.zebraicus and other congeners were supported by an integrative taxonomic analysis of molecular and morphological data. Phylogenetic analyses based on the mitochondrial NADH dehydrogenase subunit 2 (ND2) gene showed that the new species is a member of the C.oldhami group and closely related to Cyrtodactylus sp. MT468911 from Thong Pha Phum National Park, Thong Pha Phum District, Kanchanaburi Province. Uncorrected pairwise genetic divergences (p-distances) between the new species and its congeners, including C.zebraicus, ranged from 7.7-17.7%. Cyrtodactylusmonilatus sp. nov. can also be distinguished from all members of the C.oldhami group by having a unique combination of morphological characters, including a snout to vent length of 53.7-63.3 mm in adult males and 58.6-75.8 mm in adult females; 22-34 paravertebral tubercles; 34-42 ventral scales; 30-39 enlarged contiguous femoroprecloacal scales; femoral pores and precloacal pores absent in both sexes; four or five rows of postprecloacal scales; enlarged median subcaudal scales absent; weak ventrolateral folds present; 4-7 rows of paired, paravertebral, dark-brown blotches edged in yellow or yellowish white; and two rows of small, diffuse, yellow or yellowish white spots on flanks. The new species occurs in a narrow range of forest at mid to low elevations associated with karst landscapes in the Tenasserim mountain range.

19.
Animals (Basel) ; 11(2)2021 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-33671629

RESUMEN

A new species in the dicroglossid frog genus Limnonectes is described from Ko Pha-ngan, Ko Samui, and Ko Lanta Yai Islands in southern Thailand. Males of Limnonectes pseudodoriae sp. nov. lack a caruncle on top of the head and very closely resemble L. doriae (Boulenger, 1887) from Myanmar and western and southern Thailand. However, the new species is distinguished from L. doriae and its congeners using an integrative taxonomic approach of morphology, mitochondrial DNA, and bioacoustics. Limnonectes pseudodoriae sp. nov. differs from L. doriae and its congeners by having a unique combination of morphological characters, including body size; skin texture of the interorbital region, dorsum, and shank; toe webbing; relative size of the inner metatarsal tubercle; and coloration of the tympanum, venter, and ova. The advertisement call of the new species is also readily differentiated from that of L. doriae in temporal parameters. Limnonectes pseudodoriae sp. nov. is highly divergent in mitochondrial DNA from L. doriae and its congeners, but its phylogenetic position within the genus is not resolved. The natural history of the new species is presented, and the geographic range of L. doriae in Thailand is clarified.

20.
Zootaxa ; 4834(4): zootaxa.4834.4.4, 2020 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-33056105

RESUMEN

The species-rich, megophryid frog genus Leptobrachella Smith, 1925 is distributed throughout the uplands of mainland Southeast Asia but is conspicuously absent from the Cardamom Mountains of southwestern Cambodia, where it has been known only by a single, undetermined metamorphic specimen collected nearly two decades ago. We report two adult female specimens of Leptobrachella collected a decade later at a second locality in the Cardamom Mountains and use mitochondrial DNA, nuclear DNA, and morphology to show that it represents a distinct species. Leptobrachella neangi sp. nov., named after its collector, is most closely related in mitochondrial and nuclear DNA to L. fuliginosa (Matsui, 2006) and L. melanoleuca (Matsui, 2006) from western Thailand, but has uncorrected pairwise distances of 8.69-10.99% in a mitochondrial 16S gene fragment from its two sister species. The new species is also readily distinguished from these and other congeners by having the combination of (1) SVL 35.4-36.3 mm in two adult females, (2) distinct dorsolateral glandular line absent, (2) belly transparent, immaculate purplish gray in life, creamy white in preservative, (3) dark inguinal blotch absent, (4) tympanum with black coloration extending from line under supratympanic fold, (5) dorsal skin with small, irregular bumps and ridges, and (6) iris coppery orange around pupil, fading to gold at periphery, not distinctly bicolored. The new species is the first named Leptobrachella from the Cardamom Mountains and the third from Cambodia.


Asunto(s)
Anuros , Animales , Cambodia , Femenino , Filogenia
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