Vol.:(0123456789) 1 3 Organisms Diversity & Evolution https://doi.org/10.1007/s13127-022-00577-5 ORIGINAL ARTICLE A widespread commensal loses its identity: suggested taxonomic revision for Indotyphlops braminus (Scolecophidia: Typhlopidae) based on molecular data Chinta Sidharthan 1,2  · Pragyadeep Roy 1,3  · Surya Narayanan 2  · K. Praveen Karanth 1 Received: 9 November 2021 / Accepted: 20 July 2022 © Gesellschaft für Biologische Systematik 2022 Abstract The widespread human commensal blindsnake species Indotyphlops braminus is currently the only known obligate partheno- genetic snake species. It is also known to be triploid. However, much of these data is from specimens collected outside India which is the native range of this species. Polyploidy and parthenogenesis are often associated with hybridization in amphib- ians and lizards. In this study, we generated nuclear and mitochondrial data from multiple Indotyphlops lineages from across peninsular India and investigated the possible hybrid origin of I. braminus. Species delimitation suggested three putative species, one of which was I. pammeces and the other two morphologically matched I. braminus. One of these was confned to the wet zone (high rainfall areas) while the other was largely distributed in the dry zone. There was wide discordance in the relationships between these lineages across markers and diferent tree building approaches suggesting past or ongoing genefow. The statistical test for hybridization also implied genefow across these three lineages. Furthermore, the dry zone I. braminus appears to be true I. braminus as the topotypic material falls within this clade. These results suggest that the widespread, commensal, and parthenogenetic Indotyphlops is a separate species from I. braminus, and further investigation is required to determine diagnostic morphological characters for a species description. Keywords Typhlopidae · Hybridization · Phylogenetics · Parthenogenesis Introduction While interspecifc hybridization and polyploidy is quite common in plants (Alix et al., 2017; Chen, 2010), for the longest time, interspecifc hybridization in animals was considered of minor signifcance to evolution (Mayr, 1963; Schwenk et al., 2008). Hybridization not only contradicted the biological species concept but was thought to result in sterile ofspring or hybrids, which could not persist in the population. Based on empirical evidence gathered between the 1950s and the 1980s, Harrison (1993) suggested that multiple evolutionary pathways were responsible for hybrid- ization between species, and no one model could explain every case. One of the outcomes of interspecifc hybridiza- tion is polyploidy with diverse unisexual modes of reproduc- tion (Neaves & Baumann, 2011). Further, there is growing evidence of correlation between parthenogenesis and poly- ploidy in the animal kingdom (Bogart, 1980; Cole et al., 2014; Ghiselli et al., 2007; Saura et al., 1993; Schultz, 1969; Smith, 1971). In squamates, there are 10 reported cases of polyploid parthenogenetic lizard species (Bogart, 1980; Grismer et al., 2014; Hall, 1970; Kluge & Eckardt, 1969; Lowe & Wright, 1966; Pennock, 1965; Wright & Lowe, 1968). Parthenogenesis has been reported from over 80 animal taxa, including amphibians, reptiles, teleost fshes, and arthropods (Ghiselli et al., 2007; Neaves & Baumann, 2011; Saura et al., 1993; Schultz, 1969; Smith, 1971). All known cases of parthenogenesis in teleost fshes arose from interspecifc hybridization. Most parthenogenetic lineages * Chinta Sidharthan chinta.sidharthan@gmail.com 1 Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560012, India 2 SMS Foundation Centre for Biodiversity and Conservation, Ashoka Trust for Research in Ecology and the Environment (ATREE), Royal Enclave, Srirampura, Jakkur PO 560064, India 3 Laboratory for Conservation of Endangered Species (LaCONES), Centre for Cellular and Molecular Biology (CCMB), Sai Hills Colony, Attapur, Hyderabad 500048, India