Filling the BINs of life: Report of an amphibian and reptile survey of the Tanintharyi (Tenasserim) Region of Myanmar, with DNA barcode data

Abstract

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).

DNA barcoding elucidates the new altitude record and range-extension of lesser-known bullfrog (Hoplobatrachus litoralis) in northeast India

“…All the studied Hoplobatrachus species showed monophyletic clustering in the BA phylogeny with high posterior probability support (Figure 1(C)). The targeted species, H. litoralis depicted sister relationship with H. tigerinus, as suggested in the previous studies (Hasan et al 2012;Sultana et al 2017;Mulcahy et al 2018). The generated sequence of H. litoralis from northeast India showed 1.5% genetic distance from the generated sequences from Bangladesh.…”

“…The morphological characters often create confusion to identify the H. litoralis from their close relative H. tigerinus in different life stages. In this instance, the utility of mitochondrial genes (16S rRNA and Cytb) were evidenced to identify the species accurately and effectively discriminated H. litoralis from the sister species H. tigerinus (Mulcahy et al 2018).…”

“…Based on the morphological observation the species was recorded from three different states (Assam, Tripura and West Bengal) in eastern and northeastern India (Purkayastha and Basak 2018;Mondal et al 2018;Bohra et al 2019) (Figure 1(A)). Besides the taxonomic studies, the molecular data of H. litoralis was also generated from Bangladesh and Myanmar (Hasan et al 2012;Sultana et al 2017;Mulcahy et al 2018). The morphological characters often create confusion to identify the H. litoralis from their close relative H. tigerinus in different life stages.…”

The discovery of Rock Geckos Cnemaspis Strauch, 1887 (Squamata: Gekkonidae) in the Tanintharyi Region, Myanmar with the description of two new species

“…We also sequenced the DNA barcode markers COI and 16S, following previously published protocols (Mulcahy et al 2018), in order to initially verify the identities of our specimens. These data will be published elsewhere in a larger report of amphibians and reptiles from the Tanintharyi Region (Mulcahy et al unpublished).…”

“…Because major portions of the country remain unexplored, there is tremendous potential for both new species discoveries and range extensions (Wogan et al 2008;Wilkinson et al 2012;Lee et al 2015Lee et al , 2018Connette et al 2017;Grismer et al 2017a,b;Grismer et al 2018a,b,c;Mulcahy et al 2017Mulcahy et al , 2018Zug et al 2017;Zaw et al 2019). Recent surveys in remote and understudied areas of Myanmar, such as the Tanintharyi, have yielded numerous herpetofaunal specimens that increase our knowledge of biodiversity in that region (Zug et al 2017;Lee et al 2018;Mulcahy et al 2018), a region under studied since the late 19 th century (Theobald 1868). The Tanintharyi Region is the southernmost administrative unit of Myanmar; it is bordered on its eastern edge by Thailand, on its western edge by the Andaman Sea, and to the north by Mon State.…”