Recent floods could have affected survival of rare spiders, claims arachnologist

Kerala is home to around six species of large, hairy spiders called tarantulas. But a four-year Statewide survey by a team from Kuravilangad’s Deva Matha College now shows that Kerala may be home to more than 11 species of these often iridescently-coloured arachnids.

New genus and species

The research project, for which a team led by Sunil K. Jose (assistant professor at Deva Matha College) surveyed several districts including Kasaragod, Kollam and Ernakulam for tarantulas, has identified four genus of the large spiders (Sahydroaraneus, Chilobrachys, Neoheterophrictus and Thrigmopoeus) that have not been recorded in the State before.

Poecilotheria hanumavilasumica from Chinnar in Kerala

For instance, the team recorded Chilobrachys fimbiratus (also called the Indian violet spider, which is endemic to the Western Ghats of Karnataka and Maharashtra) in Kasaragod district.

Similarly, they spotted the Rameshwaram Parachute Spider (Poecilotheria hanumavilasumica) which has so far been recorded only from Tamil Nadu’s Ramanathapuram district (found only on the Rameshwaram Island and Mandapam area here) from Chinnar in Kerala. This tarantula has been classified as critically endangered by the International Union for the Conservation of Nature’s Red List. Totally, tarantulas from seven genus have now been recorded in the State.

Poecilotheria rufilata that the team recorded from Achenkovil

The range extensions of the genus and species had been described in the report submitted to the University Grants Commission, which funded the work that focused on studying spiders belonging to the family Theraphosidae, said Dr. Jose. He also presented the results at the recently-concluded international conference of the Asian Society of Arachnology at Bangkok, Thailand.

Kerala floods

While deforestation was one of the threats that the forest-dwelling tarantulas faced along the Western Ghats, the recent floods that Kerala witnessed could have affected the species in those areas too, said Dr. Jose.

“All tarantulas seen in Kerala except those in the genus Poecilotheria [tiger spiders] live in burrows in the ground. These would have become submerged during the floods,” he said.

Yet another threat that tarantulas face is collection for the illegal pet trade across the world. Kerala’s colourful tarantulas belonging to the genus Poecilotheria and Haploclastus were collected illegally and were available for sale on the internet for as high as $275, he added.

Tarantulas are a group of large, hairy spiders that can live up to 10 to 20 years.