DNA barcoding elucidates the population genetic diversity of venomous cobra species (Reptilia: Elapidae) in Indo-Bangladesh region

Abstract

The DNA barcode data of venomous cobra species (Naja naja and Naja kaouthia) are limited in the global database, especially from India and Bangladesh. Owing to the rapid success of DNA barcoding for discriminating a variety of species around the world, the present study aimed to generate the mitochondrial cytochrome c oxidase subunit I (COI) gene information of two morphologically identified deadly elapid species from the Mizoram state in northeast India and Rangpur in northern Bangladesh. The multiple species delimitation methods: Automatic Barcode Gap Discovery (ABGD), General Mixed Yule-Coalescent (GMYC), and Poisson-Tree-Processes (bPTP) revealed 14, 16, and 18 molecular operational taxonomic units (MOTUs) for 12 Naja species. The binocellate cobra, N. naja showed monophyletic clustering in both maximum-likelihood (ML) and Bayesian (BA) trees, single MOTU in ABGD and GMYC, and negligible intra-species genetic distance (0.2%) with two haplotypes. However, the monocellate cobra, N. kaouthia showed paraphyletic and polytomy in ML and BA phylogenies respectively; more than one MOTUs in ABGD, GMYC, and bPTP analyses; and sufficient intra-species genetic distances (0.6–2.3%) with five haplotypes related to the diverse geographical locations in Bangladesh, China, India, and Thailand. By superimposing the executed species delimitation criteria, the present molecular-based investigation concludes the presence of cryptic diversity of N. kaouthia in Indo-Bangladesh, China, and Thailand.