HOW SCUBA DIVING LIZARDS CREATES AIR BUBBLES TO SURVIVE UNDERWATER

One lizard from the tropical rainforests of southwest Costa Rica and Panama is a prime example of how nature is constantly changing in amazing ways. The water anole, or Anolis aquaticus, is a semi-aquatic lizard that has an amazing survival tactic. They are frequently referred to as "scuba-diving lizards" because they have mastered the ability to form an air bubble over their heads that lets them breathe underwater.

These little lizards, which measure between 6 and 8 inches in length, are a favourite food of many predators, such as snakes and birds. In times of danger, they frequently submerge themselves and use their skin to create a bubble over their nostrils, which allows them to breathe. In contrast to lizards without a bubble, Lindsey Swierk, an assistant research professor of biological sciences at Binghamton University, was curious to find out if this bubble helped water anoles stay underwater for longer.

In an experiment, she put something on the lizards' skin to prevent them from developing bubbles. Swierk says, "Lizard skin is hydrophobic."

"Typically, that allows air to stick very tightly to the skin and permits this bubble to form. But when you cover the skin with an emollient, air no longer sticks to the skin surface, so the bubbles can’t form.” 

According to the study, lizards in the control group—those who weren't given the emollient—were able to stay underwater for 32% longer than lizards in the other group. According to Swierk, this is the first experiment that demonstrates the adaptive significance of bubbles, which makes it extremely significant. Repairing bubbles enables lizards to submerge for extended periods. Although we had previously noticed a pattern and suspected it, we had not tested it to see if it had a functional purpose.

Water anoles can stay underwater for up to 20 minutes at a time, thanks to their life-saving bubble. This feature enables them to avoid predators and remain safely hidden until the threat has passed.
Other scientists are now investigating the water anole and its ingenious survival strategy as a result of Swierk's intriguing discoveries. Some speculate that the bubble is a gill, while others want to know if other lizard species share this adaptation for breathing bubbles. In any case, a closer examination of lizards may help us understand how this incredible survival tactic evolved and may even point to additional adaptations.

You can further read about the Swierk's research here