Spiders have evolved a trick to sail across the water instead of swimming.

[William Gaatjes]

Spiders can use their legs or abdomens as “sails”, helping them to disperse across large bodies of water :

http://www.theguardian.com/science/animal-magic/2015/jul/03/spiders-sail-disperse-water

If, last week, you’d quizzed me about the dispersal strategies of spiders, I would have told you all about “ballooning”, how Charles Darwin, at sea on the Beagle in 1832, was stunned to see thousands of tiny, dusky red spiders come floating on board, borne on silky parachutes that trapped them in the rigging. This and other observations led him to conclude that “the habit of sailing through the air” was probably “characteristic of this tribe”.

I would not, however, have told you that ballooning spiders can sail on water too, because I didn’t know they did until I read a paper out today in BMC Evolutionary Biology. These sailing skills, documented by Japanese research fellow Morito Hayashi and colleagues, make a lot of sense. Earth, after all, is largely water, so aerial dispersal is not a great idea unless you can cope with the presumably frequent fate of alighting on water.

Working in the “SpiderLab” at the University of Nottingham, Hayashi put hundreds of spiders from more than 20 different species “in a shallow tray filled with water to 1cm height”. When buffeted by “pump-generated air (i.e. wind)”, “spiders actively adopt postures that allow them to use the wind direction to control their journey on water,” he says. They are competent sailors even in salty and turbulent condition, the researchers find.

The paper describes five different water-related behaviours. Here they are:

1) Sailing

Sailing spiders raise their legs to create a kind of sail. “Sailing spiders smoothly and stealthily slide on the water surface without leaving any turbulence,” note Hayashi and co.

2) Upside-down sailing

This demands a “handstand-like posture”, the spider using its abdomen rather than legs to catch the wind.

3) Anchoring

Silk is released onto the surface of the water. This slows down the spider’s movement and may help tether the spider to the relative safety of a floating object.

4) Walking

It’s just that, the spider rapidly propelling its legs in an effort to walk on the surface. [Re-reading Darwin’s account of the dusky red spiders he encountered off the coast of South America, it looks like he observed them walking on water: “The little aeronaut,” he wrote in his Journal of Researches, “could run with facility on the surface of water.”]



5) Death mimicry

“Death mimicry behaviour is likely to be a predator avoidance strategy, as is common to many animals.” Essentially, the spider touches the water and freezes. But owing to its water-repellent feet (see the dimples on the surface of the water), it still floats.

In a related investigation, the researchers collected data on ballooning. Those individuals and species that showed a readiness to balloon their way off a dry surface were also the ones with the greatest talent for sailing. “The sailing behaviour is almost completely associated with, and possibly a requirement for, the aeronautic behaviour,” they conclude.

“Being able to cope with water effectively ‘joins the dots’ as far as the spider is concerned,” says Sara Goodacre, head of the SpiderLab and a co-author on the paper. “It can move from one land mass to another, and potentially across huge spatial scales through the air,” she says. “If landing on water poses no problem then in a week or two they could be a long way away from where they started.”

Darwin would have loved this, a neat set of observations that helps explain why spiders are amongst the first to colonise new habitats and why many species are found all the way around the globe. They haven’t just been flying. They’ve been sailing too.

Morito Hayashi, Mohammed Bakkali, Alexander Hyde & Sara L. Goodacre (2015) Sail or sink: novel behavioural adaptations on water in aerially dispersing species. BMC Evolutionary Biology 2015 doi 10.1186/s12862-015-0402-5

 

[Murloc]

luckily there are no flying spiders here.

 

[William Gaatjes]

luckily there are no flying spiders here.

Well, there are a lot of spider species where the little baby spiders make a jump into the big world. When it is windy enough, tiny baby spiders spin a long thread while clamping down on the surface. When the silk thread is long enough, they jump up and fly away when a strong gust of wind appears. Also in western countries. The thread is taken along with the wind and the spider holds on. Spiders have been found hundreds of miles above the ground.

 

[lxskllr]

Spiders have been found hundreds of miles above the ground.

Great. so even if I get a gig on the ISS, I'll still have webs in my face :^S


;^)

 

[William Gaatjes]

Great. so even if I get a gig on the ISS, I'll still have webs in my face :^S


;^)

Yep. There were a few tests done in the past where balloons would be released and at the target height, an inlet to a container would be openend to capture what was in those airstreams. A lot. Spiders, fungi spores, plant seeds, insects, man made materials. And of course, bacteria. Iforgot those.

 

[lxskllr]

Yep. There were a few tests done in the past where balloons would be released and at the target height, an inlet to a container would be openend to capture what was in those airstreams. A lot. Spiders, fungi spores, plant seeds, insects, man made materials.

The ISS orbits at ~230 miles. I don't think they have airstreams up there. That was my point. 230 is /barely/ hundreds with conventional phrasing. Spiders "a few" miles up is much more realistic.

 

[bononos]

So do spiders actively balloon/sail across oceans and continents? Didn't think they were smart or patient enough to do that.

 

[lxskllr]

So do spiders actively balloon/sail across oceans and continents? Didn't think they were smart or patient enough to do that.

I don't think it's a question of intelligence or patience. They're compelled by genetics to travel, and they end up where they end up. Some of that ends up being spectacular with regards to distance.

 

[GagHalfrunt]

Shit! My billion dollar anti-spider moat business idea is now shot to hell.

 

[K7SN]

Animals also migrate long distances. The native population of Madagascar evolved from hitching rides on floating debris and journeyed for streams entering the ocean in modern day India and Pakistan. Isn't life clever in how it disperses and finds new homes, sometimes great distances from their land of origin. Thanks for an informative post.

 

[futurefields]

yeah man those spiders did the research, conducted the time trials, and deduced the best way to propogate their species was to ride marine currents

#lifefindsaway

 

[William Gaatjes]

The ISS orbits at ~230 miles. I don't think they have airstreams up there. That was my point. 230 is /barely/ hundreds with conventional phrasing. Spiders "a few" miles up is much more realistic.

Sorry, i did not back check that.

But it has been discovered that life ( including spiders can be found at least a hundred miles up. When they get captured by jet streams, they can travel for a long time and survive the hars conditions for a short while.
I do agree, at altitudes where there is no more air currents, only a electric field charge might do the trick for such small almost weightless creatures.
What is the case, is that the with respect to the earth, spiders silk used for traveling, carries a negative charge, repelling surfaces. While the Earth it self is also negatively charged ( I do not know from which source which is seen as positive. Maybe the sun ?). Perhaps these spiders can travel higher then you know. Although most should not survive. The fluid used for their "hydraulic" movement should freeze and rip them apart... Although spiders bodies can expand and collapse a great deal... But their cells would still be damaged i would think....

 

[Jeff7]

Well, there are a lot of spider species where the little baby spiders make a jump into the big world. When it is windy enough, tiny baby spiders spin a long thread while clamping down on the surface. When the silk thread is long enough, they jump up and fly away when a strong gust of wind appears. Also in western countries. The thread is taken along with the wind and the spider holds on.
...

A spider living somewhere in my kitchen had an egg sac hatch.
One day I found several dozen baby spiders lined up on the back of one of the chairs, each with a silk strand fluttering in the gentle breeze that was bouncing off a wall from a fan.
I got a tissue, snatched up all the strands, and relocated them outside.

 

[William Gaatjes]

A spider living somewhere in my kitchen had an egg sac hatch.
One day I found several dozen baby spiders lined up on the back of one of the chairs, each with a silk strand fluttering in the gentle breeze that was bouncing off a wall from a fan.
I got a tissue, snatched up all the strands, and relocated them outside.

You are so sweet. Love to you man ! :wub:
A lot of people kill spiders which are not poisonous for no reason. Just let them out side. They will find your outside lamp and keep all the mosquitoes at bay.

 

[Jeff7]

You are so sweet. Love to you man ! :wub:
A lot of people kill spiders which are not poisonous for no reason. Just let them out side. They will find your outside lamp and keep all the mosquitoes at bay.

There are limits though. Spiders crawling in my bed at night are likely to face execution.



Also..."venomous." Not poisonous.

 

[William Gaatjes]

There are limits though. Spiders crawling in my bed at night are likely to face execution.



Also..."venomous." Not poisonous.

Well, i can fully understand that. Last week, i had to relocate a spider from my bedroom ceiling outside to my balcony.
I learned that a lot of people devour spiders in their sleep because the spider is looking for a source of water. And a mouth is very moist... Especially, an open one. So, they are save in my house as long as the bedroom is a "no go" area. But since a spider does not understand that or has any perception of that, i just relocate them to my balcony(in a cup).

 

[JMapleton]

OP must work for the major media. What do you mean they "evolved"? Linkbait title? You make it sound like they learned to do it last week.

They've probably been doing it for millions of years.

 

[William Gaatjes]

OP must work for the major media. What do you mean they "evolved"? Linkbait title? You make it sound like they learned to do it last week.

They've probably been doing it for millions of years.

Of course, but spiders that repelled water with their tiny little feet because of i assume the repelling charge, got an advantage and could reproduce more often.

At some time, spiders got the evolutionary advantage of creating legs and silk ( maybe some use of the same gene, i am guessing here) that created that electric repelling force. If my sources about the repelling electric force is correct... Is water negatively charged as well ? H2O seems to favor negative charges. But i am to drunk to think about it. And that is pure water, How about salt water ? I have no idea at the moment...

 

[werepossum]

Spiders do something else cool with water - some of them live down in it. Some fisher spiders live most of their lives under water, coming up periodically for a fresh ball of air. (Not as often as you might think, as oxygen diffuses in and CO2 out.) The first time I looked down to see a half dollar sized spider crawling around under a foot of water eating a minnow, I was not amused.