In a fascinating development, scientists have discovered that a semiaquatic lizard called the diving anole can stay submerged underwater for extended periods. This incredible ability is achieved by utilising a small air bubble atop its head as a reservoir of oxygen.
In the Costa Rican rainforest, a unique behaviour of the diving anole has been documented. These lizards have been observed to use an air bubble as a ‘scuba tank’, allowing them to breathe underwater. This technique is crucial for evading predators and has piqued the interest of researchers.
Dr. Lindsey Swierk, a research professor at Binghamton University, captured footage showing this bubble-breathing behaviour. The bubbles form on the reptiles’ heads, expanding and contracting, allowing them to stay submerged longer.
Swierk’s research, published in Biology Letters, suggests this method helps diving anoles avoid predators. By staying underwater, they can hide effectively from threats on land.
Trapping air in bubbles is not unique to anoles. Some insects and arachnids, like water beetles and diving bell spiders, also utilise this technique.
For vertebrates, however, this behaviour is exceptional. Anoles are the only known back-boned animals to breathe underwater using bubbles, making them a subject of considerable interest among scientists.
Swierk’s team conducted experiments to analyse this behaviour. They found that Anolis aquaticus, native to Costa Rica and Panama, could stay submerged for 3.5 minutes on average when using bubbles.
Anoles that were hindered from forming bubbles surfaced sooner, proving the significance of these bubbles in extending their underwater time.
The researchers conducted their experiments at Costa Rica’s Las Cruces Biological Station. Here, they observed anoles in clear plastic tanks mimicking their natural stream environments.
Using emollients to prevent bubble formation, the team could compare the different behaviours and survival times of the lizards, leading to significant insights.
The mechanism behind bubble breathing involves gular pumping, a throat-pumping action aiding in oxygen circulation. This method supports the anole’s ability to stay underwater longer.
However, there are costs. Cold water from mountain streams can reduce an anole’s ability to run, defend territories, or court mates due to the temperature drop experienced during diving.
Understanding this behaviour in anoles could reveal much about evolutionary adaptations. Researchers are keen to explore whether head shapes or scale structures influence bubble formation and oxygen storage.
The oxygen might be taken underwater in various body parts or adhere to their skin, contributing to their ability to remain submerged.
This discovery of bubble-breathing anoles opens up new avenues for research into evolutionary biology. By understanding how these lizards have adapted to their environments, scientists can gain deeper insights into survival strategies in the animal kingdom. The diving anole’s unique respiratory method showcases nature’s ingenuity and highlights the importance of continued scientific exploration.
