The "chicken nuggets of the forest" uses a bubble to dive underwater to escape predators.
(CN) -- It took humans awhile to figure out how to swim underwater for long periods of time with scuba diving suits and other technology, but water anoles, small semi-aquatic lizards from Central America, figured it out first by forming bubbles over their nostrils, according to a new scientific study published on Tuesday.
"Anoles are kind of like the chicken nuggets of the forest. Birds eat them, snakes eat them," wrote Lindsey Swierk, an assistant research professor of biological sciences at Binghamton University, and the author of the study published in Biology Letters, in a press release.
Swierk had previously observed that, when threatened in their native small, rocky streams in lowland wet forests in southwestern Costa Rica and western Panama, the lizards use microscopic spindles on the skin to trap air so they can dive underwater for at least 20 minutes to escape their predators.
Anoles are in fact the only group of vertebrates known to form bubbles of air while underwater.
But whether that bubble was a functional part of their respiration process that allows them to be underwater for longer periods of time, or just a side effect of the makeup of their skin, was a mystery.
In order to find out, Swierk went to Costa Rica, found the lizards, applied a moisturizer to their upper snouts and sides of their heads to prevent them from forming the bubble, and then observed how long they could stay underwater. That group was then compared with the underwater performances of another group of lizards who were allowed to form the bubble normally.
Swierk found that the lizards that formed the bubble could stay underwater for an average of 32% longer than the lizards whose bubble formation was blocked.
"This is really significant because this is the first experiment that truly shows adaptive significance of bubbles. Rebreathing bubbles allow lizards to stay underwater longer. Before, we suspected it -- we saw a pattern -- but we didn't actually test if it served a functional role," Swierk wrote.
Further research on the lizards' bubble has potential to lead the way towards "bio-inspired innovations relating to hydrophobicity and for the development of underwater technologies," Swierk writes in the study.
Swierk also wants to continue her research on the lizards to see if their bubbles act as a "physical gill," which insects use to breathe underwater.
"I've had people talk to me about how much they love scuba diving and freediving, and how they're interested in how animals might do the same thing," Swierk wrote. "So there's a great opportunity to get people excited about science by having this relationship between what they love to do and what's evolved in nature. Even in animals that seem commonplace -- you're always finding new things."