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

Hassan Al-Razi,Sabir Bin Muzaffar,Marjan Maria

doi:10.3897/zookeys.927.48733

Abstract

Raorchestes is a speciose genus of bush frogs with high diversity occurring in the Western Ghats of India. Relatively fewer species have been recorded across India, through Bangladesh, southern China, into Vietnam and Peninsular Malaysia. Many bush frogs are morphologically cryptic and therefore remain undescribed. Here, a new species, Raorchestes rezakhanisp. nov., is described from northeastern Bangladesh based on morphological characters, genetics, and bioacoustics. The 16S rRNA gene distinguished this species from 48 known species of this genus. Bayesian Inference and Maximum Likelihood analyses indicated that the new species was most similar to R. tuberohumerus, a species found in the Western Ghats, and to R. gryllus, a species found in Vietnam. Bioacoustics indicated that their calls were similar in pattern to most Raorchestes species, although number of pulses, duration of pulses, pulse intervals and amplitude differentiated it from a few other species. It is suggested that northeastern India, Bangladesh, northern Myanmar, and southern China represent important, relatively unexplored areas that could yield additional species of Raorchestes. Since many remaining habitat patches in Bangladesh are under severe threat from deforestation, efforts should be made to protect these last patches from further degradation.

Highlights

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 ML and BI analyses resulted in essentially identical topologies and were integrated in the consensus tree (Fig. 2), in which the maximum nodes were sufficiently supported with the Bayesian posterior probabilities (BPP) > 0.90 and the bootstrap supports (BS) for maximum likelihood analysis > 70 and a few poorly supported basal nodes
The uncorrected p-distances for the 16S rRNA gene that are interpreted as interspecific distances were lowest between R. bombayensis Annandale 1919 and R. sanctisilvaticus Das and Chanda 1997 (p = 1.4%, Table 2)

Summary

Introduction

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). 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). 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.. 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)

Methods

Results

Conclusion