Genetic variation and differentiation in Indirana beddomii frogs endemic to the Western Ghats biodiversity hotspot

Abstract

Understanding of biodiversity on a local scale is extremely important for effective conservation measures, especially in biodiversity hotpsots hosting diverse endemic flora and fauna and subject to strong anthropogenic influences. Little is known about patterns of local biodiversity and the processes generating it in the Western Ghats biodiversity hotspot: the patterns of genetic diversity and biogeographic affinities are poorly known for most of the species from this region. We studied the genetic diversity and population structuring of an endemic frog Indirana cf beddomii, from 12 localities of Western Ghats using 15 polymorphic microsatellite loci. The genetic diversity as measured by mean expected heterozygosity (HE = 0.83) or allelic richness (Ar = 10.41) was high and similar in all localities. Significant genetic differentiation (mean FST = 0.075) with a strong pattern of isolation by distance (IBD) across the localities was observed. Clearest genetic discontinuities in the data corresponded to topographic gaps suggesting that apart from IBD, genetic structuring in this species is strongly influenced by habitat matrix. In general, the results provide novel insight into factors that may impact the genetic diversity and population structuring of endemic amphibians in this biodiversity hotspot.