THRISSUR: Shedding new lights on the evolution of Indian spiders, the Centre for Animal Taxonomy (CATE) and Ecology at Christ College, Irinjalakuda, has spotted eight new species in Parambikulam Tiger Reserve.
The species were spotted in a study conducted by the Centre under the initiative of the Forest Department.
This is the first time that a study on the diversity of spiders is being conducted by the Forest Department in the state, said Sudhikumar A V, head, CATE, who led the study.
The newly-spotted species are net casting spider of genus Deinopis family, fishing spider of the genus Dolomedes, bird dropping spider of the genus Calaenea, new species of the genus Haploclastus, another new species of the genus Stenaelurillus, green spotted Neoscona spider of the family Araneidae, Hasarious of family Salticidea, and Stenochilus of family Stenochilidea.
Among these, net casting spider is the most interesting one since it is very difficult to spot it as the twig-like is well camouflaged in the fields.
It spreads its web in its four front legs and waits for the prey to come. The spider catches the prey by throwing the web onto it when it comes close.
The fishing spider lives in vegetation near water bodies and catches small fishes from the water bodies. It is also capable of living under the water for a few minutes.
The bird dropping spider which is dark in colour usually remains immobile like a bird dropping. It catches the prey by ambushing on it. Spotting of other species of this genus has been reported only from Australia so far, Sudhikumar said.
The newly-found species of the genus Haploclastus is an inhabitant of the evergreen forests.
This spider, which usually lives in potholes made in the ground, stretches out a silk thread from the burrow which detects the presence of any prey in the surrounding area. The species of genus Stenaelurillus is special for its contrasting red and blue lines in the forehead as all other species of this genus are darker.
They exhibit these contrasting colours during their nuptial dance to attract its female partner. Green spotted Neoscona spider of the family Araneidae is also new to science, he said.
The three-week survey has prepared an inventory of over 200 species of spiders. Though some species are endemic to the Western Ghats region, some species are showing similarity with those in the African and the Malayan regions.
This creates confusion about the evolutionary origin of spiders in the Indian subcontinent.
More studies based on the profiling of nucleic acids are required to reveal the truth of the evolutionary changes in the spider fauna of the Indian subcontinent, Sudhikumar said.