Lost, forgotten, and overlooked: systematic reassessment of two lesser-known toad species (Anura, Bufonidae) from Peninsular India and another wide-ranging northern species

Abstract

We rediscovered two species of toads, Bufo stomaticus peninsularis and Bufo brevirostris, which were described from Peninsular India 84 and 101 years ago, respectively, but have not been reported since. Because the name-bearing types of both species are either damaged or lost, we provide detailed redescriptions, morphological comparisons, and insights into phylogenetic relationships with closely related members of the genus Duttaphrynus sensu lato, based on new material from the type locality of each species. We clarify and validate the identity of D. brevirostris, which was rediscovered from multiple localities in the Malenadu and adjoining coastal regions of Karnataka. We also demonstrate that Bufo stomaticus peninsularis, which was considered a synonym of Duttaphrynus scaber, is a distinct species. Bufo stomaticus peninsularis differs from Duttaphrynus scaber morphologically and genetically, and is more closely related to members of the Duttaphrynus stomaticus group. We also clarify the identity of the namesake species of the Duttaphrynus stomaticus group, which is reported widely in India and neighbouring countries, but lacks sufficient taxonomic information due to its brief original description and reportedly untraceable type material. We located and studied the complete syntype series of D. stomaticus, probably for the first time in over a century, and we report on the status of available specimens, provide detailed description of a potential type, compare it to related species, and clarify the species’ geographical range. Our molecular analyses suggest that D. stomaticus is minimally divergent from, and possibly conspecific with, D. olivaceus. Our analyses also clarify its relationship to the closely-related D. peninsulariscomb. nov., with which it was previously confused. Finally, our study provides other insights into the phylogenetic relationships and genetic differentiation among various species of Duttaphrynus toads.

On the edge of the Shivaliks: An insight into the origin and taxonomic position of Pakistani toads from the Duttaphrynus melanostictus complex (Amphibia, Bufonidae)

“…The newly generated sequences of 16S, tRNAGly-ND3, and Rho from Pakistan belong to one, well-supported, monophyletic group in all investigated markers (Figs 1-3). This clade is known from previous studies, particularly Wogan et al (2016), Vences et al (2017) and Bisht et al (2021).…”

“…We amplified a fragment of the nuclear (nDNA) rhodopsin (Rho) gene (~316 bp), of the 16S rRNA (~560 bp), and approximately 469 bp of mitochondrial DNA (mtDNA) that encodes part of the cytochrome oxidase c subunit III (COIII), tRNA glycine (tRNAGly), and part of the NADH dehydrogenase subunit 3 (ND3) using the primers and PCR conditions following previous studies (Vences et al 2017;Hofmann et al 2019;Bisht et al 2021). PCR products were Sanger-sequenced in both directions by Macrogen Europe (Amsterdam, The Netherlands; http://www.…”

“…material 1: Table S1). We mostly followed datasets provided by Wogan et al (2016), Vences et al (2017), andBisht et al (2021) as well as others with available sequences for D. melanostictus. To map the phylogeographic pattern of detected clades, we used published georeferenced localities of the sequence origin.…”

“…We followed Vences et al (2017) and trimmed the mitochondrial sequences, retaining 411 bp corresponding to 71 bp of tRNA-Gly and 340 bp of ND3. We excluded the following three 16S sequences of the data set of Bisht et al (2021) due to low data quality and potential sequencing errors: EU071741, U52798, EU071765. Also, one sequence (AY458592) was excluded from the data set of Vences et al (2017) due to uncertain geographic origin.…”

“…According to Khan (2001), the type locality has a wider range and is defined as "Ooghi, Mansehra and Datta, Hazara Division, eastern NWFP, Pakistan", i.e., covering several villages and districts in northern Pakistan where these toads occur. Recent molecular studies focusing on the genus Duttaphrynus were based on dense sampling, covering a wide range of South-East Asia (mostly), and different DNA markers for D. melanostictus (see Hasan et al 2014;Wogan et al 2016;Reilly et al 2017;Vences et al 2017;Othman et al 2020;Soorae et al 2020;Bisht et al 2021). Because the resulting DNA sequence variation showed deep genetic structuring, we reviewed and reanalysed these data together with new sequence data of D. melanostictus from different localities of Pakistan, including the locality of "hazarensis" (Datta, Khyber Pakhtunkhwa;34.2962°N, 73.2649°E).…”