Investigating the efficacy of skin swabbing as a minimally invasive method of genetic sampling from Indian amphibians

Amphibians are facing an unprecedented extinction crisis, 41% of species are currently on the verge of extinction, making them among the most threatened vertebrates. One of the integral components in amphibian conservation is genetic research, which provides vital insights into their fitness and long-term persistence. Molecular studies on amphibians most often use invasive methods that are detrimental to them. Instead, minimally invasive methods such as cloacal, buccal, and skin swabbing can be effective. In this study, we collected skin swab samples from multiple anuran species in the Western Ghats biodiversity hotspot and the urban areas of Bengaluru, India, to assess the efficacy of skin swabs for generating genetic data without compromising animal welfare. Two extraction methods (salt vs Qiagen™ DNeasy kit) and two swab storage conditions (dry vs wet) were assessed. There was no significant difference in DNA yield between the two DNA extraction methods, whereas kit-based extractions consistently yielded DNA within the ideal purity range (A260/280 = 1.8–2.0). Swab storage did not significantly affect DNA concentration, but dry swabs provided significantly higher purity. Samples showed 86.36% amplification success on the gel, and 67.05% yielded high-quality DNA sequences suitable for downstream analyses. Our results demonstrate that minimally invasive skin swabs are a non-lethal technique that can be replicated in anurans using less DNA. This is the first study from the Indian tropical region to utilise multiple species of varying body sizes to demonstrate the feasibility of minimally invasive skin swabbing as a method for anuran research and conservation.