Records of two toads Duttaphrynus scaber and D. stomaticus (Amphibia: Anura: Bufonidae) from southeastern India

Abstract

We document two toad species Duttaphrynus scaber and D. stomaticus from southeastern India, in the Coromandel Coastal Plains. Owing to incorrect data presented in previous reports denoting the occurrence of these toad species, their occurrence in the said region has remained obscure. Our results, presented here, on both the species are based on morphological data from 15 preserved voucher specimens and direct field observations made by the authors in situ. In this work, we report D. scaber from Chengelpet and D. stomaticus from Thoothukudi. We revisited these places after studying the labeled specimens in Chennai Snake Park Trust Museum, to confirm their occurrences in the respective region and provide natural history notes based on our field observations.

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

“…The species were also found in secondary forest patches adjacent to human settlements. Ganesh et al (2020) reported this species as D. stomaticus from Tuticorin, Tamil Nadu. ZMUC 131366 [ex 199] from "Hoogly," ZMUC 131363 [ex 193] from "Calcutta," and ZMUC 131364 [ex 194] from "Calcutta."…”

“…Hence, records of D. stomaticus from Peninsular India (south of Maharashtra and possibly Odisha) are currently presumed to be doubtful and will require verification of all known populations (see D. peninsularis for discussion). The reports of D. stomaticus from Karnataka and Tamil Nadu States (Hegde 2012;Ramachandra et al 2012;Seshadri et al 2012;Ganesh et al 2020) likely refer to D. peninsularis. A report of D. olivaceus from Gurgaon, India (Ray and Deuti 2008) is also questionable (Heydari and Rastegar-Pouyani 2010) and considered to represent D. stomaticus based on our fresh collections from Delhi and surrounding North Indian regions.…”

“…Among the Indian Duttaphrynus species, nine occur in Peninsular India and of these, six are endemic to the region. Although the wide-ranging species (D. melanostictus, D. stomaticus, D. hololius, and D. scaber) are frequently studied and reported from Peninsular India (Sarkar et al 1993;Dutta 1997;Biju 2001;Chanda 2002;Van Bocxlaer et al 2009;Dinesh et al 2009;Srinivasulu et al 2013;Ganesh et al 2020), the taxonomic status of the endemic species has not been thoroughly investigated subsequent to their original descriptions (Dubois and Ohler 1999;Biju 2001). These include five recognised species-D. beddomii (Günther, 1876), D. brevirostris (Rao, 1937), D. microtympanum (Boulenger, 1882), D. parietalis (Boulenger, 1882), and D. silentvalleyensis (Pillai, 1981).…”

“…Another four available names from Peninsular Indian regions exist as junior subjective synonyms (Dubois and Ohler 1999). Given such complex nomenclatural histories, misidentifications of Duttaphrynus species in museum specimens (S.D.B., personal observation) and regional biodiversity reports (Ray and Deuti 2008;Gururaja 2012;Hegde 2012;Seshadri et al 2012;Ganesh et al 2020) are frequent.…”

“…(not Duttaphrynus stomaticus peninsularis) as "D. stomaticus," which was implicitly considered as the transfer of Bufo stomaticus peninsularis into the synonymy of Duttaphrynus scaber (Schneider, 1799) by Frost (2021). However, most recently Ganesh et al (2020) made a cursory statement referring to the identity of this taxon as "status: incertae sedis" without any clarification.…”