Chameleon's Super-Long Tongue

The chameleon's hunting prowess is legendary, largely due to its extraordinary tongue (Review). This remarkable organ can extend at astonishing speeds, capturing unsuspecting prey in a mere fraction of a second. Even as far back as 300 B.C., the Greek philosopher Aristotle noted the breathtaking speed of its tongue projection, though the exact mechanisms remained a mystery for centuries. Modern science has revealed that this rapid strike is not simply due to muscle power alone, but rather a sophisticated biological catapult system.

The secret lies in an intricate interplay of specialized muscles, bones, and elastic tissues. Before striking, the chameleon "loads" its tongue by contracting an accelerator muscle around a rigid bone-like structure called the entoglossal process. This action stores immense elastic energy within collagenous sheaths that envelop the bone. When the chameleon is ready to strike, this stored energy is unleashed, propelling the tongue forward with incredible force. Smaller chameleons, in particular, exhibit astounding acceleration, reaching up to 2,590 meters per second squared, a force greater than that of a fighter jet. This allows them to project their tongues up to 2.5 times their body length.

Upon impact, the chameleon's tongue tip is not only sticky but also equipped with a textured pad and a small flap that helps it wrap around the prey. The mucus at the tip is exceptionally viscous, about 400 times thicker than human saliva, akin to honey, ensuring a firm grip on insects, some weighing up to a third of the chameleon's own body mass. Additionally, a suction component, generated by specialized muscles pulling the tongue pad inwards, further secures larger or smoother prey. This highly adapted feeding strategy provides a significant evolutionary advantage, enabling chameleons to effectively capture food even when their body temperatures are low, expanding their foraging opportunities.