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5 December 2013 11:26 am ,
Vol. 342 ,
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
Since arriving on the island of Guam in the 1940s, the brown tree snake ( Boiga irregularis ) has extirpated native...
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
- 5 December 2013 11:26 am , Vol. 342 , #6163
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Video: Scales Give Sharks Their Speed
9 February 2012 3:12 pm
Shark skin may be de rigueur poolside at the 2012 Summer Olympics. A new study finds that microscopic scales known as denticles propel the predators through the water at speeds 12% faster than they would otherwise achieve without them. To fish out how this happens, researchers mounted pieces of shortfin maco (Isurus oxyrinchus) and porbeagle shark (Lamna nasus) skin on flexible robotic fins and placed them in a tank. By analyzing water flow over the skin, the team found that denticles determined the proximity of swirls of water, called vortices (visible in the video), to the fin. Intact denticles produced swirls close to the skin, the researchers report in The Journal of Experimental Biology, creating low pressure areas that pulled the fin forward. Fins with their denticles sanded off produced vortices further away from the skin, reducing fin flapping speeds. The scientists note that manufacturers of Olympic-worthy swimwear, designed with dimples to reduce drag, may want to build in little ridges instead.
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