Certain chameleons give new meaning to the expression “small but awful”, as a study on their tongues suggests that these smaller species can launch their tongues with incredible force. He found that these chameleons could project their tongues distances 1.5 times their body lengths, on average, and up to 2.5 times the body lengths of some species. The smaller the chameleon, the higher the peak acceleration, relative power, and distance of tongue extension relative to body size. Elastic tissue and muscle surrounding the hyoid (a tongue-anchoring bone also present in mammals and birds) help to spring-load the tongue at the back of the mouth. They preload most of the motion’s total energy into elastic tissues in their tongue.
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Such ability is often an indication of a “power amplification mechanism” in animals that allows their movement to exceed what their muscles are known to produce. 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. When energy is released, the recoil of those tissues increases tongue performance. They have tongues that can literally go from 0 to 60 miles per hour 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. Some smaller chameleons had a performance similar to that of bigger ones, but many of them had tongues even faster and stronger.
A team of experts led by Christopher Anderson, postdoctoral research associate at Brown University’s Department of Ecology and Evolutionary Biology, carried out an appraisal involving a group of 55 chameleons, pertaining to 20 distinct species.
“I show peak accelerations as high as 2,590m/s2, or 264g, and peak muscle mass-specific power values up to 14,040W/kg in a 47mm long individual of Rhampholeon spinosus”, Dr Anderson wrote in the paper.
“By looking at larger individuals and larger species, we really underestimated the capability of chameleons as a group, as a family”, Anderson says. He looked at 20 different species of chameleon.
What became evident was that the smaller the chameleon, the more impressive the performance.
As it turns out, small chameleons severely outmatch their larger cousins in terms of tongue strength, speed, and acceleration. Each one got their turn in front of a camera that shoots 3,000 frames per second.
Several other small chameleons had tongue speeds approaching this level.
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The smallest invertebrate creatures – for instance a jumping flea or a biting ant – manage much higher acceleration. For comparison, the peak power seen in vertebrate muscle comes from the beating wings of quails taking off vertically, at a mere 1,100 watts per kilogram.
