A faunal survey by the Zoological Survey of India (ZSI) in Megamalai Wildlife Sanctuary, Western Ghats, has identified nine species new to science. They include the jumping spider Stenaelurillus megamalai, the mayflies Edmundsula meghamalaiensis and Thraulus vellimalaiensis, the damselfly Protosticta sholai, the cockroach Allacta vellimalai and the bark louse Lachesilla vellimalai. In all, 977 species from 21 faunal groups were recorded: 511 vertebrates (286 birds, 97 reptiles, 77 mammals, 36 amphibians, 15 fish) and 466 invertebrates. The sanctuary is part of the Srivilliputhur–Megamalai Tiger Reserve, India's 51st, notified in 2021 over about 1,016 sq km. Many recorded species serve as bio-indicators of water quality.