A new study published in the journal BMC Evolutionary Biology has revealed that water is no obstacle for spiders, and they can travel across water. Spiders can control their speed, and travel across water by using the legs as sails and the silk as anchor.
Spiders or arachnids use a technique called as ballooning, to spread their silk over a wide area, and allow the wind to catch them. This allows them to travel miles to reach a destination. However, for a long time it was considered that spiders would drown in the water. But, a new study has revealed that spiders use this newly discovered technique, to travel vast distances and migrate.
“If landing on water poses no problem, then in a week or two they could be a long way away from where they started,” said Sara Goodacre, co-author, University of Nottingham, UK.
Scientists collected about 321 adult spiders belonging to 21 small islands from nature reserves in Nottinghamshire, UK. The team observed the behavior of spiders on tray of water with pump generated air. The study then compared to the reactions on dry surfaces. The spiders used several postures like lifting the legs, and take advantage of the wind current on the water surface. This allowed the spiders to sail in turbulent, fresh and salt water conditions.
They further observed that silk was released into the water to act as anchors that would slow down movement, and may even act as a drag-line for water-trapped spider to reach the shore. This adapting ability could allow the spider to survive in aquatic bodies. Though the adapting ability of spiders differed from species to species, researchers found that the one that used ballooning method, were the best suited for water landing. The study reveals that the two characteristics could be linked together in spiders, allowing them to travel over long distances.