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Credit: Lindsey Swierk
Semi-aquatic anoles live along neotropical streams and frequently dive for refuge, remaining underwater for up to 16 minutes. Lindsey Swierk, assistant research professor of biological sciences at Binghamton University, documented this behavior in a Costa Rican anole species in 2019. She had been shocked to see an anole submerge itself for such long periods and used a GoPro underwater to document the behavior. It s easy to imagine the advantage that these small, slow anoles gain by hiding from their predators underwater - they re really hard to spot! says Swierk. But the real question is how they re managing to stay underwater for so long.
Some anole lizards can stay underwater for as long as 16 minutes a trick they pull off by rebreathing exhaled air which they store in a bubble attached to their snouts.
Researchers first documented this behaviour among anoles living in Coto Brus, Costa Rica in 2019, filming one of the submerged lizards using a GoPro camera.
Further analysis has now suggested that different species of semi-aquatic anole evolved the rebreathing ability separately to make the most of air while diving.
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Anole lizards can stay underwater for as long as 16 minutes a trick they pull off by rebreathing exhaled air which they store in a bubble attached to their snouts (as pictured)
A team of evolutionary biologists including faculty at Binghamton University, State University of New York have shown that some Anolis lizards, or anoles,
The researchers measured the oxygen content of the air in the bubbles and found that it decreased over time, confirming that rebreathed air is involved in respiration. Rebreathing likely evolved because the ability to stay submerged longer increases the lizard’s chances of eluding predators, the authors say.
The authors studied six species of semi-aquatic anoles and found that all possessed the rebreathing trait, despite most species being distantly related. While rebreathing has been studied extensively in aquatic arthropods like water beetles, it was not expected in lizards because of physiological differences between arthropods and vertebrates.
“Rebreathing had never been considered as a potential natural mechanism for underwater respiration in vertebrates,” says
University of Toronto
A team of evolutionary biologists from the University of Toronto has shown that Anolis lizards, or anoles, are able to breathe underwater with the aid of a bubble clinging to their snouts.
Anoles are a diverse group of lizards found throughout the tropical Americas. Some anoles are stream specialists, and these semi-aquatic species frequently dive underwater to avoid predators, where they can remain submerged for as long as 18 minutes.
“We found that semi-aquatic anoles exhale air into a bubble that clings to their skin,” says Chris Boccia, a recent Master of Science graduate from the Faculty of Arts & Science’s Department of Ecology & Evolutionary Biology (EEB). Boccia is lead author of a paper describing the finding published this week in Current Biology.