The family Rhacophoridae (Order:Anura) is a diverse group composed of arboreal frogs with ca. 300 species in 9 genera spread over two continents. The members of the genera, Buergeria, Chirixalus, Kurixalus, Nyctixalus, Philautus, Polypedates, Rhacophorus and Theloderma are from South Asia, and Chiromantis is from Sub-Saharan Africa. Due to their highly conserved body plan and convergence in reproductive modes, their phylogeny has remained unresolved for more than half a century. This study addresses questions related to systematics and biogeography of the members of the family Rhacophoridae with emphasis on the evolution of the mode of reproduction. Samples of Rhacophoridae from Western Ghats, Eastern Ghats, Western Himalayas and north eastern India were used. DNA sequences from samples were obtained for two mitochondrial (416bp, 546bp) and three nuclear (530bp, 316bp, 175bp) domains. In order to have representative taxa from different geographical regions, sequences from the gene bank were used. The sequence data was screened and standard protocol for analysis was adopted. Akaike’s Information Criteria (AIC) and base factors were used to arrive at a parsimonious selection of an evolutionary model. Parametric bootstrapping and Markov Chain Monte Carlo simulations were used to generate a maximum likelihood trees. A single consensus tree was obtained and the relationship between the members of the family Rhacophoridae was inferred. Our data supports the monophyly of the family Rhacophoridae. The members of the genus “Philautus” in the Western Ghats and Sri Lanka are monophyletic. It implies that the Western Ghats and Sri Lanka is a single biogeographic unit for amphibians. Philautus of North East India, Eastern Ghats of Orissa forms a different clade along with South & SE Asia. “Philautus” of Western Ghats and Sri Lanka have an independent radiation from a shared ancestry with African Chiromantis. The results indicated that shared morphological and reproductive modes are the result of convergent evolution in Philautus coinciding with the evolution of monsoons in the region. The systematics for Rhacophoridae needs revision based on these findings. There are important conservation implications for the Biodiversity Hotspots that harbor large diversity of Rhacophoridae.
 

Dr. Karthikeyan Vasudevan,WII and Dr. Ramesh Aggarwal, CCMB

Department of Biotechnology, Ministry of Science and Technology, Govt. of India
Collaborators : Centre for Cellular and Molecular Biology, Hyderabad