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1.
Mol Phylogenet Evol ; : 106754, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32028030

RESUMO

Recognizing species-level diversity is important for studying evolutionary patterns across biological disciplines and is critical for conservation efforts. However, challenges remain in delimiting species-level diversity, especially in cryptic radiations where species are genetically divergent but show little morphological differentiation. Using multilocus molecular data, phylogenetic analyses, species delimitation analyses, and morphological data, we examine lineage diversification in a cryptic radiation of Riopa skinks in Myanmar. Four species of Riopa skinks are currently recognized from Myanmar based on morphological traits, but the boundaries between three of these species, R. anguina, R. lineolata, and R. popae are not well-defined. We find high levels of genetic diversity within these three species, and analyses suggest that they may comprise as many as 12 independently evolving lineages, which highlights the extent to which species diversity in the region is underestimated. However, quantitative trait data suggest that these lineages have not differentiated morphologically, possibly indicating that this cryptic radiation represents non-adaptive evolution, although additional data is needed to corroborate this.

2.
Zootaxa ; 4661(1): zootaxa.4661.1.2, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31716716

RESUMO

We report the first occurrence of the Asian Rock Gecko genus Cnemaspis Strauch, 1887 from mainland Myanmar based on a series of specimens recently collected from the Tanintharyi Region. These records come from several localities in the Tanintharyi Region and fill a significant sampling gap for the genus. Molecular phylogenetic analyses using the mitochondrial gene ND2 identify two distinct clades, the first includes Cnemaspis siamensis of the Southeast Asian Cnemaspis group and the second includes two new species belonging to the South Asian Cnemaspis kandiana group. These two species are morphologically distinct and are distinguished from all other members in the C. kandiana group by a combination of character states. The first species, Cnemaspis tanintharyi sp. nov. occurs on the mainland in southern Tanintharyi and is distinguished from all congeners by the possession of keeled pectoral scales; smooth ventral scales and abdominal scales; 2-4 precloacal pores; 4-5 femoral pores on each leg; smooth subcaudal scales with the median row enlarged; coloration of the gular region beige, dark gray-brown with dark blue hueing towards throat; 15-18 subdigital lamellae on the 4th toe; and 21-23 ventral scales at midbody. The other, Cnemaspis thayawthadangyi sp. nov. is known only from the island group of Thayawthadangyi, in the Myeik Archipelago and is distinguished from all congeners by the possession of keeled pectoral scales; keeled ventral scales and abdominal scales; three precloacal pores; four femoral pores on each leg; smooth subcaudal scales, scales on median row enlarged; coloration of the gular region silver with dark-gray irregularly shaped streaks; 16-18 subdigital lamellae on the 4th toe; and 18-20 ventral scales at midbody. In addition, we address the taxonomic status of populations referred to as C. kandiana (a species now restricted to Sri Lanka) found in peninsular Thailand and provisionally assign them as C. cf. tanintharyi sp. nov. until further analysis can be conducted. Finally, we briefly discuss the biogeography of the South Asian clade of Cnemaspis.


Assuntos
Lagartos , Distribuição Animal , Estruturas Animais , Animais , Ecossistema , Ilhas , Mianmar , Filogenia , Sri Lanka , Tailândia
3.
Zookeys ; (757): 85-152, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29780268

RESUMO

Despite threats of species extinctions, taxonomic crises, and technological advances in genomics and natural history database informatics, we are still distant from cataloguing all of the species of life on earth. Amphibians and reptiles are no exceptions; in fact new species are described nearly every day and many species face possible extinction. The number of described species continues to climb as new areas of the world are explored and as species complexes are examined more thoroughly. The use of DNA barcoding provides a mechanism for rapidly estimating the number of species at a given site and has the potential to record all of the species of life on Earth. Though DNA barcoding has its caveats, it can be useful to estimate the number of species in a more systematic and efficient manner, to be followed in combination with more traditional, morphology-based identifications and species descriptions. Herein, we report the results of a voucher-based herpetological expedition to the Tanintharyi (Tenasserim) Region of Myanmar, enhanced with DNA barcode data. Our main surveys took place in the currently proposed Tanintharyi National Park. We combine our results with photographs and observational data from the Chaung-nauk-pyan forest reserve. Additionally, we provide the first checklist of amphibians and reptiles of the region, with species based on the literature and museum. Amphibians, anurans in particular, are one of the most poorly known groups of vertebrates in terms of taxonomy and the number of known species, particularly in Southeast Asia. Our rapid-assessment program combined with DNA barcoding and use of Barcode Index Numbers (BINs) of voucher specimens reveals the depth of taxonomic diversity in the southern Tanintharyi herpetofauna even though only a third of the potential amphibians and reptiles were seen. A total of 51 putative species (one caecilian, 25 frogs, 13 lizards, 10 snakes, and two turtles) were detected, several of which represent potentially undescribed species. Several of these species were detected by DNA barcode data alone. Furthermore, five species were recorded for the first time in Myanmar, two amphibians (Ichthyophis cf. kohtaoensis and Chalcorana eschatia) and three snakes (Ahaetulla mycterizans, Boiga dendrophila, and Boiga drapiezii).

4.
Zootaxa ; 4347(2): 301-315, 2017 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-29245596

RESUMO

The taxonomic identity of the Trimeresurus (Popeia) popeiorum complex from the Isthmus of Kra and to the north was investigated. Several studies over the last decade have produced several specimens and associated mtDNA sequence data for a variety of individuals of the T. popeiorum and "T. sabahi" complexes. Here, we combine four mitochondrial genes (12S, 16S, ND4, and CytB) from all available specimens in GenBank with the addition of five new specimens collected from the mainland, Tanintharyi Region of Myanmar. Maximum Likelihood and Bayesian analyses identified that T. popeiorum sensu lato is paraphyletic with two geographically distinct clades: a northern clade representing populations from northern Myanmar, Laos and northern Thailand and a southern clade representing samples from the Tanintharyi Region and adjacent west Thailand. While the two clades have considerable genetic distance, they appear to be morphologically identical, leading to the hypothesis that the southern clade represents a cryptic, undescribed species. Because they appear to be cryptic species and the limitation of only five specimens from the southern lineage, this does not permit us to formally describe the new species. In accordance to past molecular studies, we uncovered paraphyly and lack of genetic support for the validity of taxa within the T. sabahi complex. However, we suggest recognizing these populations as subspecies within T. sabahi.


Assuntos
Trimeresurus , Animais , Teorema de Bayes , DNA Mitocondrial , Laos , Mianmar , Filogenia , Análise de Sequência de DNA , Tailândia
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