The mechanics of prey prehension in chameleons

Iguanian lizards generally use their tongue to capture prey. Because lingua l prehension is based on surface phenomena (wet adhesion, interlocking), th e maximal prey size that can be captured is small. However, published recor ds show that prey items eaten by chameleons include small vertebrates such as lizards and birds, indicating that these lizards are using a different p rey prehension mechanism. Using high-speed video recordings, cineradiograph y, electromyography, nerve transection and stimulation experiments, we inve stigated the function of the tongue during prey capture. The results of the se experiments indicate that chameleons have modified the primitive iguania n system by including a suction component in their prehension mechanism. Su ction is generated by the activity of two modified intrinsic tongue muscles that pull the tongue pad inwards. Moreover, we demonstrate that the mechan ism described here is a prerequisite for successful feeding.