Three New Jumping Spider Species Found in Western Ghats and Sri Lanka
A team of researchers from India and Sri Lanka has discovered three new species of rare jumping spiders belonging to the genus Onomastus. Two of these were found in the Brahmagiri Hills in Wayanad and Silent Valley National Park in Palakkad, while the third was discovered in the mountain forests of Sri Lanka. The findings, published in the journal Zootaxa, also include the rediscovery of a fourth species of the same spider family in Tamil Nadu, unseen by humans for over a century.
The newly described species are named Onomastus brahmagiri, Onomastus silentvalley, and Onomastus wijesinghei. The first two are endemic to their respective hill ranges in the Western Ghats. The fourth species, Onomastus patellaris, was rediscovered in the Pampadum Shola National Park, part of the Kodaikanal-High Range shola landscape. According to the researchers, this discovery sheds light on the unique evolutionary history of the montane forests of the Western Ghats.
The team included Athira Jose, a PhD scholar at Christ College in Irinjalakuda, Professor A.V. Sudhikumar, and Professor S.P. Benjamin of the National Institute of Fundamental Studies in Sri Lanka. Together, they conducted a morphological phylogenetic analysis, which revealed a distinct Indian lineage within the Onomastus genus. This analysis supports the separation of highly diverse montane South Asian evolutionary lineages from the less diverse lowland Southeast Asian ones.
Onomastus is one of the oldest lineages of jumping spiders and is found only in the Oriental region. The study’s findings support the 'sky island' concept, where isolated montane habitats act as natural islands. This promotes long-term geographic isolation, speciation, and high levels of endemism. The shola forests of the Western Ghats, with their extensive grasslands and low-elevation valleys, provide ideal conditions for such evolutionary processes.
The newly described species are known only from isolated montane forests and are believed to have limited dispersal ability. Due to their highly restricted distributions in these misty highland habitats, they may be particularly vulnerable to rising temperatures, habitat degradation, and other impacts of climate change and human activities. The researchers emphasize that these findings highlight the need to conserve shola forest ecosystems, which harbour evolutionarily distinct species found nowhere else.
