Chameleons and salamanders snap out their tongues in the blink of an eye to snatch insects. Their tongues shoot out at speeds of up to 5 meters per second. Scientists have uncovered how the tongue fires so quickly, opening the door to developing devices from medical instruments to disaster rescue tools and space exploration equipment.
A University of South Florida (USF) research team said on the 9th that it had "confirmed the potential to apply the ballistic tongue-launch system of salamanders and chameleons to a medical device to remove blood clots in blood vessels." The findings were published the same day as the cover paper of the international journal Current Biology.
Chameleons are reptiles that breathe with lungs and live on land, while salamanders, which are amphibians, breathe not only with lungs but also through their skin and live both in water and on land. An analysis of videos collected by the team over more than 10 years found that, although different species, both salamanders and chameleons extended their tongues at speeds of up to 16 feet (about 4.9 meters) per second. It moves in an instant even to the human eye.
The secret to such rapid tongue firing lies in a structure that makes muscles and bones operate separately. Because the muscles do not pull the tongue directly but transmit force by pressing on a bony structure, animals of various body sizes, from small to large, can stably fire their tongues. Efficient energy transfer that surpasses the force–velocity limits of vertebrate muscle is also possible.
What is unusual is that although the two animals live in different environments, they fire their tongues in similar ways. Chameleons live on warm trees, while salamanders live in humid places such as rivers, ponds, leaf litter, and caves. Yet the two animals evolved the same principle for shooting out the tongue at extreme speed.
The team described this as a case of "convergent evolution (收斂進化)." Convergent evolution refers to different species, like whales and fish or bats and birds, acquiring similar forms and lifestyles as they adapt to similar environments.
The researchers believe that applying the tongue-launch principle of salamanders and chameleons could lead to medical devices that remove thrombi (clots). A thrombus is a mass formed by coagulated blood, and when it blocks a blood vessel, it can cause dangerous conditions such as myocardial infarction, stroke, or pulmonary embolism. The team assessed that the tongue-launch principle could provide a technical clue to developing medical devices that insert a tool into a blocked vessel to directly extract or dissolve a thrombus and restore blood flow.
Yu Zeng, a USF researcher who led the study, said, "It is not special materials but the modular structure of muscle and bone that enables this high-speed launch function," and added, "Using this principle, we can develop devices that move quickly by combining flexible and rigid materials."
The team said it is already in discussions with engineers about biomedical applications, such as clot-removal devices. Stephen Deban, a USF biology professor, said, "By mimicking the tongue-launch principle of chameleons and salamanders, the technology could also be extended to tools that retrieve hard-to-reach objects inside collapsed buildings or in space."
Going forward, the researchers plan to expand their work by analyzing the process by which the tongue rapidly and precisely retracts, applying designs learned from nature to human technology.
References
Current Biology (2025), DOI: www.doi.org/10.1016/j.cub.2025.07.085