Resolving pitfalls in pit viper systematics – A multi-criteria approach to species delimitation in pit vipers (Reptilia, Viperidae, Craspedocephalus) of Peninsular India reveals cryptic diversity

Abstract

Asian pit vipers belonging to the genus Craspedocephalus are a complex group of vipers, distributed in South and Southeast Asia. Their taxonomy is unresolved in many lineages across their distributional range. Here, we reassess the taxonomy and systematics of pit vipers of the genus Craspedocephalus in Peninsular India based on extensive field sampling, in particular in the Western Ghats. We build and expand on the previous findings of genetic relatedness between the peninsular Indian lineages with the Sundaic clade (C. puniceus complex) with greater evidence, based on additional taxa sequenced herein. We reconstruct the phylogeny of the group using three mitochondrial genes and delineated lineages using coalescent species delimitation methods. We then used multiple criteria including genetic divergence and separation in morphological and geographic space to designate taxonomic units. Our work revealed the presence of a South Asian radiation of the clade Craspedocephalus, with a few Sundaic members. Our study reveals the systematic relationships of four Peninsular Indian species of Craspedocephalus, including Peltopelor macrolepis and C. strigatus, sequenced here for the first time, that are classified or confirmed as members of Craspedocephalus. Hence, we place the genus Peltopelor in the synonymy of Craspedocephalus. Using our multi-criteria approach, we delimit four new cryptic evolutionary lineages within the Western Ghats escarpment of Peninsular India. These cryptic lineages belong to the C. malabaricus, C. gramineus and C. macrolepis complexes and are geographically and/or ecologically (in terms of habitat association) distinct from their sister lineages across their distributional range, while others are separated in morphological space. Our new phylogenetic tree and delimitation analysis thus reveals the presence of multiple clades with several cryptic lineages separated by geographical barriers or habitat association.

A checklist of herpetofauna of Telangana state, India

“…For the present checklist, we researched and critically analysed all published (both peer-reviewed and nonpeer-reviewed) literature, online databases (including iNaturalist, India Biodiversity Portal, HerpMapper) and also relied on field surveys conducted since 1995 in various parts of Telangana State (Srinivasulu 2003;Srinivasulu et al 2006Srinivasulu et al , 2009Srinivasulu et al , 2011Srinivasulu et al , 2014Srinivasulu et al , 2016Seetharamaraju et al 2008Seetharamaraju et al , 2011Seetharamaraju et al , 2019Srinivasulu & Das 2008;Seetharamaraju & Srinivasulu 2013;Kumar et al , 2017aSeetharamaraju 2015;Kumar 2018). We confirmed the species identities by consulting standard references (Daniel 2002;Das 2002;Whitaker & Captain 2004), incorporating further updates by more recent literature (Deepak et al 2016(Deepak et al , 2018(Deepak et al , 2021Lajmi et al 2016;Ganesh et al 2017;Mirza & Patel 2018;Pal et al 2018;Mallik et al 2020Mallik et al , 2021Bisht et al 2021;Gowande et al 2021;Bandara et al 2022). We have also provided explanation for deletion of the taxa earlier reported in literature, and appeal to future workers to collect voucher specimens or photographs to report additions to the herpetofauna diversity of Telangana.…”

A new species of Cyrtodactylus (Reptilia: Gekkonidae) from the southern Western Ghats of India

“…Description of yet another species of Cyrtodactylus from the Agasthyamalai landscape makes it the fourth Cyrtodactylus for Tamil Nadu state. The southern tip of the Western Ghats (Agasthyamalai) is known for its endemic reptilian fauna and multiple new species were described recently, both in the mountains (Krishnan 2008;Mallik et al 2019;Mallik et al 2021) as well as in the lowlands (Harikrishnan et al 2012;Srikanthan et al 2018;Narayanan et al 2021;Pal et al 2021;Khandekar et al 2022). This highlights the hidden species diversity in this landscape and shows the poor exploration of these wellknown hill ranges.…”

After 16 Years: An Update Checklist of Herpetofauna on the Natuna Islands, Indonesia

“…The population of Ptychozoon lionotum in Natuna Islands is now Gekko cicakterbang (Grismer et al, 2019). Trimeresurus puniceus is now included in Craspedocephalus lineage (Mallik et al, 2021).…”