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Ellepola, Herath, Manamendra-Arachchi, et al., 2021. |
Abstract
Sri Lanka is an amphibian hotspot of global significance. Its anuran fauna is dominated by the shrub frogs of the genus Pseudophilautus. Except for one small clade of four species in Peninsular India, these cool-wet adapted frogs, numbering some 59 extant species, are distributed mainly across the montane and lowland rain forests of the island. With species described primarily by morphological means, the diversification has never yet been subjected to a molecular species delimitation analysis, a procedure now routinely applied in taxonomy. Here we test the species boundaries of Pseudophilautus in the context of the phylogenetic species concept (PSC). We use all the putative species for which credible molecular data are available (nDNA–Rag-1; mt-DNA– 12S rRNA, 16S rRNA) to build a well resolved phylogeny, which is subjected to species delimitation analyses. The ABGD, bPTP, mPTP and bGMYC species delimitation methods applied to the 16S rRNA frog barcoding gene (for all species), 12S rRNA and Rag-1 nDNA grouped P. procax and P. abundus; P. hallidayi and P. fergusonianus; P. reticulatus and P. pappilosus; P. pleurotaenia and P. hoipolloi; P. hoffmani and P. asankai; P. silvaticus and P. limbus; P. dilmah and P. hankeni; P. fulvus and P. silus.. Surprisingly, all analyses recovered 14 unidentified potential new species as well. The geophylogeny affirms a distribution across the island’s aseasonal ‘wet zone’ and its three principal hill ranges, suggestive of allopatric speciation playing a dominant role, especially between mountain masses. Among the species that are merged by the delimitation analyses, a pattern leading towards a model of parapatric speciation emerges–ongoing speciation in the presence of gene flow. This delimitation analysis reinforces the species hypotheses, paving the way to a reasonable understanding of Sri Lankan Pseudophilautus, enabling both deeper analyses and conservation efforts of this remarkable diversification.
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| Delimitation summary results. Molecular phylogenetic relationships of Pseudophilautus, based on Bayesian inference of the concatenated data set of the 16S rRNA + 12S rRNA + Rag1 (2189bp) loci. Asterisks (*) above nodes represent ≥ 95% Bayesian posterior probabilities. The scale bar represents number of changes per site. Recovered species delimitation based on overall significance of results for molecular species delimitation methods (ABGD, bPTP, mPTP and bGMYC) using 16S rRNA, 12S rRNA, Rag-1 nDNA loci and the concatenated data set are shown as black rectangles on the right. Six major clades of Pseudophilautus, A-F, are shaded in different colours on the phylogeny. Images of frogs indicate species suggestive of synonymyzation based on recovered species delimitations. Rectangles indicated by * in similar colours represent species pairs that were recovered as close relatives or recovered in different clades based on their relative position on the concatenated tree. |
Gajaba Ellepola, Jayampathi Herath, Kelum Manamendra-Arachchi, Nayana Wijayathilaka, Gayani Senevirathne, Rohan Pethiyagoda and Madhava Meegaskumbura. 2021. Molecular Species Delimitation of Shrub Frogs of the Genus Pseudophilautus (Anura, Rhacophoridae). PLoS ONE. 16(10): e0258594. DOI: 10.1371/journal.pone.0258594
