Researchers discover three new species of rare jumping spiders

Three new species of rare jumping spiders, genus Onomastus, have been discovered by a team of researchers from India and Sri Lanka, with two found in the Brahmagiri Hills, Wayanad, and Silent Valley National Park, Palakkad, and the third in the mountain forests of Sri Lanka.

The new species of rare jumping spiders discovered by researchers.
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The team comprising Athira Jose, a PhD scholar at Christ College, Irinjalakuda, and Prof. A.V. Sudhikumar, in collaboration with Prof. S.P. Benjamin of the National Institute of Fundamental Studies (NIFS), Sri Lanka, also rediscovered a fourth species of the same spider family in Tamil Nadu, which remained unseen by humans for more than a hundred years.  

The new species of rare jumping spiders discovered by researchers.
| Photo Credit:
Special arrangement

The study, published in the journal Zootaxa, describes Onomastus brahmagiri from the Brahmagiri Hills; O. silentvalley from the shola forests of Silent Valley National Park, representing endemism to the respective hills; and O. wijesinghei from the montane forests of Sri Lanka. The re-described O. patellaris was rediscovered from the Pampadum Shola National Park, part of the type locality Kodaikanal-High Range shola landscape. The discovery has shed light on the unique evolutionary history of the montane forests of the Western Ghats, according to a release.

Onomastus belongs to one of the oldest lineages of jumping spiders and is restricted to the Oriental region. Along with the taxonomic discoveries, the researchers carried out a morphological phylogenetic analysis, which recovered a distinct Indian lineage of Onomastus and supported the separation of highly diverse montane South Asian and less diverse lowland Southeast Asian evolutionary lineages.

According to the researchers, the findings support the “sky island” concept, in which isolated montane habitats act as natural islands, promoting long-term geographic isolation, speciation, and high levels of endemism. The Western Ghats shola forests provide ideal conditions for such evolutionary processes due to the extensive grasslands and low-elevation valleys.

The newly described species are known only from isolated montane forests and are believed to have limited dispersal ability. Because of 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 say the findings highlight the need to conserve the shola forest ecosystems, which harbour evolutionarily distinct species found nowhere else.