We all know just how unique the chameleon is — but perhaps we estimated how truly fascinating this animal is.
Perhaps the most recognizable feature of the chameleon — besides their rotating eyes — is their incredibly long tongue that reaches out and snatches prey from a distance almost instantaneously. But the tongue has always held a riddle for scientists: how does it grab so effectively? Does it use suction, or act like velcro, or is it something else? Now, scientists think they have their answer: it’s very, very sticky, much more so than researchers realized, according to a Univerite Libre De Bruxelles release.
Researchers measured the viscosity of the mucus of the veiling chameleon to figure this out. Even though the chameleon doesn’t have much sticky mucus, it makes use with what it has. In fact, the size of the mouth appears to be the limit to how big its prey can be for it to go after — the spit was strong enough to grab even the largest creatures.
“Despite their nonchalant appearance, chameleons are formidable predators, leaving little chance to their prey. During a capture, their tongue whips out with an acceleration up to 1500 m/s² and extends to reach a length twice that of the chameleon’s body. They are also able to capture preys weighing up to 30% of their own weight. Sufficient adhesion between the prey and the tongue is therefore necessary to catch such preys,” the release reads. “Under the leadership of Fabian Brau from the ULB Faculty of Science’s Nonlinear Physical Chemistry Unit, Pascal Damman from the UMONS Interfaces and Complex Fluids Laboratory, Faculty of Science researchers from the UMONS, ULB, and Vincent Bels from the Muséum national d’Histoire naturelle de Paris have just demonstrated that the mucus secreted at the tip of a chameleon’s tongue has a viscosity 400 times larger than the one of human saliva. The tongue’s deformability during projection, producing a large contact area with the prey, together with this viscous liquid, form a particularly efficient adhesive weapon.”