Spiders Can Sail and Anchor Over Seas

A new study claims to be the missing piece in the tale of spider-migration as it reveals how arachnoids made their away across oceans to colonize the world.

The spider's ability to throw its web and literally catch the wind, an act called ballooning, has been known for long now. Researchers however wondered how spiders navigated water as they would have little control once airborne when they balloon. It turns out the crawlers have more control than previously thought.

The study published in the journal Evolutionary Biology claims that spiders can sail like ships using their acrobatic bodies. To see the spiders in action, researchers let 325 spiders cross trays of water, placed in artificially created winds. They noted that the spiders balloon when in wind and sail by lifting their legs. They then slow down by dropping silk on water.

"We've now found that spiders actively adopt postures that allow them to use the wind direction to control their journey on water. They even drop silk and stop on the water surface when they want. This ability compensates for the risks of landing on water after the uncontrolled spider flights," lead author Morito Hayashi said in a press release.

Navigating oceans allows greater genetic connectivity between populations that can influence rate of local adaption, researchers wrote in the paper.

"Being able to cope with water effectively 'joins the dots' as far as the spider is concerned. It can move from one land mass to another, and potentially across huge spatial scales through the air. 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 co-author Sara Goodacre.