Lizard and salamanders: hear with ... lungs

Two species of lizards and salamanders have no outer ear. Scientist Thomas Hetherington and colleagues from Ohio State University (USA) said the two species can be heard by . lungs.

The group of experts studied the reaction to the sounds of four species of lizards and three species of salamanders in North America. They found that the animal always tended to head towards the source of the emitting sound and their chests were always heaving.

According to Prof. Thomas Hetherington, it is the thin, elastic skin in the neck and chest, which allows lizards and salamanders to " catch " sound waves as sensitive as the eardrum in the human ear. The neck and chest membranes vibrate according to the frequency of the sound waves, and these impulses are carried through the air from the lungs to the inner ear, making them easier to hear.

According to Prof. Thomas Hetherington, this ' underground listening ' mechanism can only be seen in small lung animals, the body walls in the neck and chest are thin. Previously, it was discovered that frogs often listen to this way.

Eurycea guttolineata salamanders (Photo: fw.vt.edu)

NGUYEN SINH