Integrative Taxonomic Approach for Describing a New Cryptic Species of Bush Frog (Raorchestes: Anura: Rhacophoridae) from the Western Ghats, India

Abstract

A new cryptic species of bush frog Raorchestes honnametti sp. nov. is described from the south-eastern part of the Western Ghats, India. This newly described species belongs to the Charius clade and is morphologically similar to other clade members—R. charius and R. griet. Therefore, an integrative taxonomic approach based on molecular and bioacoustic analysis along with morphology was used to delimit the new species. Raorchestes honnametti sp. nov., is currently known only from Biligiri Rangaswamy Temple Tiger Reserve, a part of Biligiri Rangaswamy horst mountain range (a mountain formed due movement of two faults) formed during the Late Quaternary period (1.8–2.58 Ma). Discovery of cryptic species from a highly speciose and well-studied genus Raorchestes hints at the possible existence of several more cryptic species in this genus. We discuss the possible reasons for crypsis and emphasize the need for continued systematic surveys of amphibians across the Western Ghats.

A new species of cryptic Bush frog (Anura, Rhacophoridae, Raorchestes) from northeastern Bangladesh

“…The region has undergone biodiversity loss along with changes in land use that has contributed towards the creation of geographic barriers within the last few decades (Gadgil 1996). The diversification of frogs in the Western Ghats has generally been attributed to long-term ecological change over extended geological time scales (Priti et al 2016). Due to its status as a biodiversity hotspot, considerable research attention has been placed on this region, resulting in more discoveries in the anuran fauna.…”

“…Raorchestes Biju et al, 2010, is a genus of bush frogs belonging to the family Rhacophoridae, that extends in distribution from southwestern India through northeastern India, Bangladesh, Myanmar, southern China, and into Laos, Vietnam, and Peninsular Malaysia (Biju and Bossuyt 2009;IUCN 2016;Vijayakumar et al 2016;Frost 2019). The genus is particularly speciose in the Western Ghats of India, where more than 50 of the 63 recorded species occur (Biju et al 2010;Vijayakumar et al 2014;Priti et al 2016;Vijayakumar et al 2016;Boruah et al 2018). In addition, a few species have been recorded from the Eastern Ghats, Eastern Himalayas, and northeastern India, southern China and adjoining regions (Vijayakumar et al 2016;Boruah et al 2018;Wu et al 2019, Frost 2020.…”

“…In addition, a few species have been recorded from the Eastern Ghats, Eastern Himalayas, and northeastern India, southern China and adjoining regions (Vijayakumar et al 2016;Boruah et al 2018;Wu et al 2019, Frost 2020. Many species in the genus are cryptic (morphologically difficult to distinguish from congenerics) and, as a result, remain undescribed (Priti et al 2016;Vijayakumar et al 2016;Boruah et al 2018;Wu et al 2019). The genus is characterized within the Rhacophoridae by small size (15-45 mm snout-vent length), absence of vomerine teeth, transparent gular pouch, and direct development (Biju et al 2010).…”

“…The genus is characterized within the Rhacophoridae by small size (15-45 mm snout-vent length), absence of vomerine teeth, transparent gular pouch, and direct development (Biju et al 2010). Their advertisement calls consists of repetitive 'treenk.. treenk.. treenk' with variation in number of pulses, duration of calls, interval between calls and amplitude, which may be used to distinguish between species (Priti et al 2016). Thus, an integrative approach using morphological traits, bioacoustics and molecular variation has been used to distinguish cryptic species (Priti et al 2016;Boruah et al 2018).…”

Elucidating cryptic sympatric speciation in terrestrial orchids

“…More recently, the use of DNA sequencing has been helpful in species identification and in recognizing cryptic species, since sequence divergence is usually lesser between individuals of a species than among closely related taxa (Herbert et al, 2004). Cryptic species occur in many groups of animals (Herbert et al, 2004;Priti et al, 2016), but also have been recorded in plants (Hollingsworth et al, 2009), including orchids (Pansarin and Amaral, 2006;Pace et al, 2017;Gale et al, 2018).…”