The water anole (Anolis aquaticus), native to Central America, exhibits a remarkable adaptation that allows it to remain submerged underwater for extended periods. When threatened or hunting aquatic prey, this semi-aquatic lizard can stay underwater for up to 16 minutes by creating an air bubble on its snout. This bubble acts as a rebreathing apparatus, enabling the anole to recycle oxygen and expel carbon dioxide, thus facilitating prolonged dives .
The mechanism behind this adaptation involves the hydrophobic properties of the anole’s skin, which aid in trapping the air bubble. Studies have shown that the lizard inhales and exhales within this bubble, effectively reusing the oxygen while simultaneously allowing carbon dioxide to diffuse out into the surrounding water. This dual function not only supports the anole’s respiratory needs during submersion but also underscores a sophisticated evolutionary response to predation and foraging challenges in its habitat .
The discovery of this rebreathing behavior in Anolis aquaticus offers valuable insights into the evolutionary innovations that enable certain species to exploit aquatic environments. It highlights the intricate interplay between physiology and behavior in adapting to ecological niches. Further research into such adaptations can deepen our understanding of evolutionary biology and inform conservation strategies for species inhabiting specialized habitats.
