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Nitin Dimri
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Chameleon Catapult

Chameleons are among the slowest moving reptiles. But their protruding eyes swivel independently for a 360 degree range, so they can look for prey in different directions at the same time. When a hapless insect victim is detected, both eyes focus on it to judge range and distance with superb accuracy. 

Ballistic Brilliance! The chameleon then launches its tongue, which is 1.5 times its body length, at speeds of 26 body lengths per second. That works out to 13.4 miles per hour or 6 meters per second . The initial acceleration is enormous: 500 m s−2 or 51g. For comparison, the space shuttle launches at 3g and humans pass out at accelerations approaching 10g. It takes less than a tenth of a second for the chameleon to snag its prey!

Corkscrew Collagen: This impressive performance exceeds the capability of any muscle in biology by an order of magnitude. So what’s the secret behind the ballistics? The chameleon’s tongue has energy stored in concentric layers of a springy fiber, called collagen, wrapped around a stiff cartilage core. The powerful tongue muscle initially primes the spring by compressing it, to the same effect as a bow being pulled taut. When the tongue is launched, the spring uncoils explosively, slipping off the cartilage core. Once the sticky end snares the prey, the muscles work more slowly to reel it back in. This gives chameleons a competitive edge over lizards and other reptiles. Watch ▶ http://goo.gl/EBFty

Breakfast at Dawn: Another advantage to this strategy is that the chameleon can catch its prey even at chilly temperatures when its muscles slow down drastically: unlike birds and mammals, reptiles are cold blooded and at the mercy of their ambient temperature. Watch how only the retraction of the tongue is slowed at low temperatures ▶ http://goo.gl/gT2hd

REF ▶ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1691657/

Slo Mo ▶ http://vimeo.com/12068409

H/T to +Panah Rad for the gif ▶ http://i.imgur.com/XCytc.gif

#ScienceSunday  
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4 • 8 BRAIN • GAMES • (  One of Right Answers )
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One Gif to Rule Them All: From Amphipod to Diatom to Bacterium. Captured in this amazing image is an electron microscope scan that zooms in on a tiny bacterium perched upon a diatom, lodged near the leg of an amphipod (a type of crustacean). Watch the scale at bottom right, go all the way from a millimeter, through the range of micrometers, down to 500 nanometers!

I was reminded of the verse by Jonathan Swift (1733):
"So nat'ralists observe, a flea
Hath smaller fleas that on him prey,
And these have smaller fleas that bite 'em,
And so proceed ad infinitum ."

Image Credit: "Fractal Cosmos" by James Tyrwhitt-Drake at the University of Victoria.
Stunning images of Diatoms: http://goo.gl/smk3w

#scienceeveryday +ScienceSunday 
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