This diving water anole lizard breathes through a bubble: Shortwave: NPR

This semi-aquatic lizard produces a bubble above its nostrils to help it breathe underwater.

Lindsey Swierk

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Lindsey Swierk

This semi-aquatic lizard produces a bubble above its nostrils to help it breathe underwater.

Lindsey Swierk

What’s scaled, striped, and breathes underwater, just like a diver?

Water anoles, a semi-aquatic lizard found in the tropical forests of southern Costa Rica. These greenish-brown water anoles can dive underwater to escape potential predators — and stay there for more than 15 minutes thanks to an air bubble.

“Water anoles are kind of like the chicken nuggets of the forest. They’re smaller than a pencil. And they’re eaten by so many things in the forest,” says Lindsey Swierk, an assistant research professor at Binghamton University.

In a study published this week by the Royal Society, Swierk and her colleagues describe the mechanism of bubble making and how it helps the lizard “rebreathe.” When anoles dive, they exhale a bubble of air. Certain features of their skin help keep the bubble in place. A bubble appears when an anole exhales and disappears when it inhales.

To prove this aquatic longevity, the research team coated the skin of a group of anoles with a soothing agent to prevent a bubble from forming. Untreated lizards stayed underwater 32% longer than those with the anti-bubble coating on their skin.

“It’s just a fascinating fundamental adaptation,” Swierk said.

Earyn McGee, the herpetologist behind #FindThatLizard on social media, says that studying bubbles over the past few years has made her curious about whether anoles also had underwater predators.

“When the lizards dive to avoid their predators on land, do they at some point become fish food?” McGee wonders.

Swierk hopes to conduct further research into the way anoles perform this breathing trick.

“Fundamental science is so important because that’s often where our really new discoveries come from that can impact people, that can change the way we use materials and the way we develop products,” she says.

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This episode was produced by Rachel Carlson and edited by Rebecca Ramirez. Tyler Jones fact checked. Audio engineer was Kwesi Lee.