Tadpoles form air bubbles in the mouth to breathe

Tadpoles, too weak during the early stages of their life to “break” the surface tension of the water to be able to put part of their head out to breathe, use a rather characteristic and interesting method to obtain the oxygen needed to survive.

The discovery, almost by chance, was made by researcher Kurt Schwenk of the University of Connecticut while studying salamanders in the laboratory that fed on tadpoles.
It was an even more exciting discovery when the researcher realized that this strange behavior had never been described by any previous study.

Basically the story is this: tadpoles, i.e. frog cubs, do not have gills yet developed to obtain the necessary air as adults do.
For this reason they have to get to the surface to obtain the necessary oxygen but in the first days of life they are too weak to perform this action, in particular to “break” the tension of the water surface in order to be able to drive out part of their body.

They have therefore developed a surprising method to obtain the necessary air: they form a partial bubble through a special sucking action under the surface of the water, a bubble naturally filled with air.
The tadpole is therefore able to trap this small air bubble in its mouth and push it, through the muscles in the mouth, directly into the lungs.

And since the bubble formed in the mouth contains a greater quantity of air than their lungs can contain, the tadpoles expel the unnecessary air and form other small bubbles which then float on the surface of the water for some time, which creates many small bubbles on the surface of the ponds.