Envis Centre, Ministry of Environment & Forest, Govt. of India

Printed Date: Thursday, April 18, 2024

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Eight-eyed and everywhere (Source: The Hindu 23-02-2019)

                  At least five new species of jumping spiders have been discovered from different parts of India over the past year Last week, a group of arachnologists from Thrissur came across a spider that had never been reported before. Hidden in the crevices of the bark of teak trees, Cocalus lacinia are hairy, yellow-brown spiders with a distinctive v-shaped mark on their head. They happen to be closely related to a species of spider in Australia, adding to the theory that the continents were once united. A couple of year earlier, this time in Assam, another researcher stumbled upon a large, hairy eight-eyed arachnid that had made a nest for itself between two leaves.

 

                   He snapped a picture and posted it on Instagram, and last December, it was established that this was Hyllus diardi, a spider known to be so ‘friendly’, it’s kept as a pet in parts of the world. In the middle of last year, in West Bengal, a wildlife photographer chanced upon a bunch of very tiny spiders lurking in an orchard. They were identified later as belonging to the genus Neobrettus, which lives, hunts and breeds in the dried leaves of the banana plant. They are related to another genus, Portia, found across south and southeast Asia, Africa and Australia and known for their remarkably intelligent hunting behaviour and their penchant for feeding on other spiders.

 

                   Around the same time, a student from Gujarat discovered a genus of spiders in Kerala that he decided to famously name Icius vikrambatrai, after a martyred Kargil war hero, Capt. Vikram Batra. Indeed, jostling for column space among reports of new snakes, reptiles and frogs discovered, are a particularly delightful and large group of spiders called jumping spiders, because well, they jump rather than crawl. In the past year, at least five new species of jumping spiders have been discovered from different parts of India. Jumping spiders are the most abundant and diverse family of spiders in the world with more than 5,200 species described so far, found not just in forests but in urban built-up landscapes too.

 

               Laboratories around the world have used them for a range of behavioural experiments, especially to understand systematics and evolution. As for me, I find in them perfect specimens to introduce children (and adults) to the world of arachnids. They are almost cute with those large inquisitive middle eyes. And they are clever. They behave rather differently to other spiders: most do not build webs, but stalk, crouch and hunt their prey like a cat would. Their silken retreats become refuges where they rest or hide. Their vision is excellent and has been a subject of much study: the median eyes are the ‘image forming’ eyes with movable retina, and the three pairs of surrounding eyes are motion detection eyes. All put together, they get an almost 360 degree vision. These little arachnids are also known for their astonishing array of cognitive abilities and are considered model organisms to study behaviour, as well as answer theoretical questions about communication, foraging, courtship, mating and parental care. But arachnologists will tell you how it’s often difficult to study them: when they are confined together in close proximity in labs they may dine on their companions, given as they are to cannibalism. The male jumping spider can be brilliantly coloured, even iridescent, and exhibits elaborate courtship dances, the most famous being that of the peacock jumping spider found in Australia and now a YouTube sensation (with 7.3 million views to date). They move and wave their legs in elaborate movements, and even tap their feet.

 

                We don’t know how the infamous insect apocalypse is impacting spiders yet, but there is some evidence to suggest that our use of insecticides at home, offices and in agricultural fields might affect populations. Yet, jumping spiders are resilient inhabitants of natural habitats as well as concrete jungles. They serve important biological functions as predators that keep a check on the populations of certain insects. Spiders are thus indicators of ecosystem health or vegetation change. Of the 45,000 different species of spiders documented across the world, more than 1,400 have been found in India so far. These numbers seem large, almost mind-boggling, but most natural historians and spider taxonomists believe there are far more spider types that we don’t know about yet simply because many parts of the world are yet to be sampled for the creatures. In India, there are are far too few of us out in the field looking for them — but you can be sure that there’s definitely an eight-eyed creature living somewhere in your house, office or garden. The writer works with the Nature Conservation Foundation in Bengaluru and takes unsuspecting people for spider walks.