their size, tiny chameleons have the quickest tongues, and can catch their prey in the blink of an eye. They have tongues that can literally go from 0 to 60 mph in just one hundredth of a second, according to a study published on January 4 in Scientific Reports, outperforming the fastest cars ever built, and outperforming their bigger relatives.
According to an article in Live Science, the speedy tongues of tiny chameleons are able to accelerate and snag a cricket or other insect at up to 264 times the force of gravity. According to the study’s author, Christopher Anderson, a postdoctoral researcher at Brown University, they have to be able to catch their prey at superfast rates of speed, because of their high metabolisms. Compared to larger chameleons, the tiny ones need to eat more food per ounce of their body weight, so their incredibly quick tongues are designed to enable them to catch more prey, faster. The evolution of the tiny chameleons was “driven by metabolic constraints,” Anderson said.
Tiny Chameleons Have the Quickest Tongues
The tongues of chameleons are basically like elastic bands between a tubular sheath of muscle. The chameleons do not rely on the muscle power of their tongues alone to catch stationary or flying insects. With a rubber band-like tongue anchored by a hyoid bone, when the chameleon contracts its tongue, the elastic tissues contained between the muscle surrounding the chameleon’s tongue is stretched taut. Then, when the chameleon snaps its tongue out, the stored energy is released, and viola, dinner is served.
In general, most previous studies had been conducted using larger chameleons. But, with chameleons, like the predatory mantis shrimp, the tinier the animal is, the quicker and harder their strikes are. For instance, research published in June 2012 in the journal Science indicates that the claw of a mantis shrimp can accelerate as rapidly as a 0.22-caliber bullet exiting a gun.
In conducting his research on chameleons, Anderson captured 55 individual chameleons on high-speed video, from 20 different species, as they shot out their tongues to catch insects. The chameleons he recorded were from 1.6 inches to 7.8 inches long, and they could snap out their tongues 1.5 times the length of their bodies. Some chameleons could shoot out their tongues up to 2.5 times their entire body lengths. He recorded them at 3,000 frames per second.
The study that Anderson conducted was in Nature, which publishes the latest articles in Scientific Reports. In the Introduction, Anderson wrote, “Rapid recoil of elastic tissues enables organisms to achieve power outputs that exceed the maximum power capacities of muscle.” That is, the elastic tissues in the tongues of the chameleons caused the power output of their tongues to be greater than the muscles alone could have achieved.
The smallest chameleon that he used in his study was from the species, Rhampholeon spinosus, according to The Washington Post. It is not the smallest chameleon in the world, but it is the smallest one Anderson used in his study. Its tongue is the one that Anderson studied that could shoot out up to 2.5 times the length of its body.
Anderson was impressed by exactly how much power and force the tiny chameleons possessed in their tongues. He stated, “Power output — we’re talking 14,000 watts per kilogram.” To put that into perspective, when quails take off vertically, the rate of energy they release is just “1,100 watts per kilogram.” The amount of energy that the tongues of chameleons release is “almost three times” as much.
While Anderson acknowledged that the tongues of salamanders can accelerate at faster rates of speed than even the tongues of chameleons, salamanders are amphibians. Chameleons have tongues that accelerate quicker compared to the muscles of any other reptile, mammal, or bird.
It is all a matter of physics. As Anderson put it, “As body size increases, acceleration capacity decreases. So, small organisms, based on physics alone, are expected to have high accelerations.”
Bigger chameleons, with body metabolisms that are not quite as fast, do not need to have tongues that shoot out as quickly or as powerfully as the tongues of their smaller relatives. For example, the acceleration rate of the tongue of a two-foot-long chameleon in his study, from the species Furcifer oustaleti, had a tongue that accelerated out at a rate that was 18 percent less than Rhampholeon spinosus.
Size matters, when it comes to chameleons and their tongues, with the tiny chameleons having the quickest tongues in comparison to their larger relatives. The study that Brown University’s Christopher Anderson published on Monday, January 4, 2016, offers video proof that the smaller a chameleon is, the greater the rate of speed is that they are able to accelerate their tongues out to catch insects. They have to be faster and more efficient, to feed their energy requirements, because they have higher metabolisms than chameleons that are larger.
By John Samuels
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