Contributions to the taxonomic status and molecular phylogeny of Asian Bronzeback Snakes (Colubridae, Ahaetuliinae, Dendrelaphis Boulenger, 1890), from Mizoram State, Northeast India

Abstract

We evaluate the presence of three sympatric species of Asian Bronzeback Snakes (genus Dendrelaphis Boulenger, 1890) from Mizoram State, India. These are taxonomically complicated species that were recently, either resurrected (D. proarchos Wall, 1909, D. biloreatus Wall, 1908) or redefined (D. cyanochloris (Wall, 1921)). In the light of morphological and molecular data, we confirm the validity of D. proarchos from Mizoram, Northeast India, and subsequently confer the specimen of D. pictus (Gmelin, 1789) (CHS791) from Hainan (China) to D. proarchos. We also provide the first molecular phylogenetic data for the lesser-known species D. biloreatus as well as the first molecular samples of D. cyanochloris from Mizoram, Northeast India which seems to be the closest sample from Darjeeling, India (type locality). Apart from this, we also affirm the southwestern population in the distribution range of the latter species as D. cyanochloris sensu stricto, while conferring the southern population from Pinag Island, Malaysia to D. vogeli Jiang, Ren, Guo, Wang, Ding & Li, 2020, and the northeastern populations comprising Kachin (Myanmar), Tibet, Yunnan and Hainan (China) to D. ngansonensis (Bourret, 1935). Our present mitochondrial gene trees using the genes 16S rRNA, COI, and Cytb suggest the presence of cryptic diversity within several Dendrelaphis species, which will require rigorous genetic sampling and integrative taxonomic analysis to examine whether these lineages represent distinct species. This study also presents natural history and additional data on the distributional localities of Dendrelaphis species from Mizoram State, Northeast India.