A new study indicates that the overall temperature increases worldwide caused by global warming will have a devastating effect on spider populations – effects that scientists never saw coming.
A recent study published in The Journal of Experimental Biology says that increased temps will have an effect on spiders the same way they would have on robotics. The study says that most robotics rely on hydraulic pumps to move their limbs or ‘parts.’ Thos pumps in robotics, are, in fact, not that different from how spiders move their own limbs, where, in the place of muscles, they have joints that inflate with something called haemolymph to straighten.
Scientists have long known that fluid viscosity can increase dramatically as temperature falls, which can in-turn affect the effectiveness of hydraulics. Lead researcher, Anna Ahn, from Harvey Mudd College to posed the question, if robotics were drastically influenced by temperatures, would spiders be as well?
“I’ve always wanted to study spiders because they use hydraulics. This is a fascinating question.”
Ahn and three other researchers from California colleges decided to test the running abilities of Texas brown tarantulas – Aphonopelma hentzi – in various temperatures. The researchers wanted to make sure that their data was relevant to natural circumstances, so they limited the temperatures the spiders ran in to those they would naturally see – anywhere between 59 to 104 degrees Fahrenheit. Then, by marking the spider’s legs and recording their progression down a runway at set speeds, the researchers were able to assess the spider’s performance under these conditions.
When their data was compiled, the researchers knew that the spiders were indeed affected by heat, actually heavily speeding up from a slow 20 centimeters per second to a surprising 53 centimeters per second when exposed to the harshest heat. However, while the tarantulas were faster, the researchers found that they were also much more clumsy, with the strides of all eight of their legs no longer perfectly synched for maximum efficiency. Ahn suspects this is because there just isn’t enough time for the haemolymph mechanism to fill and drain at the arachnid’s top speed.
“Hydraulic extension may allow spiders to save space and mass in their limb, but it may come at the expense of control.”
Even tarantulas can be a little unsteady on their (eight) feet: http://t.co/0TbFg1r9Wt
— Nat Geo WILD (@natgeowild) April 4, 2015
— Malcolm M. Campbell (@m_m_campbell) April 4, 2015
Ahn guesses that the effects that temperatures have on tarantulas is the reason why the spiders tend to feed most often right around dusk, when temperatures are at an optimum level.
[Photo by Hulton Archive/Getty Images.]