Can Geckos Breathe Underwater? A Detailed Look

If you’ve ever watched a gecko crawling around and wondered if it can breathe underwater like a fish, you’re not alone. As air-breathing terrestrial animals, geckos might seem ill-equipped to survive submerged.

However, recent research has uncovered some surprising abilities in these common lizards that challenge our assumptions.

If you’re short on time, here’s a quick answer to your question: No, geckos cannot breathe underwater like aquatic animals. As reptiles, geckos need air to breathe through lungs. However, some species have adaptations that allow them to stay submerged for up to 16 hours.

Anatomy of Gecko Respiration

Lungs and Breathing Mechanism

Geckos have very unique and fascinating respiratory systems that allow them to breathe both on land and underwater for short periods. Their lungs are relatively small and simple compared to other reptiles, but they make up for it with other special adaptations.

Geckos do not have a diaphragm like mammals to expand and contract their chest to breathe. Instead, they rely on structures called costal pumps located in their throats. When geckos inhale, they stiffen these pumps and expand their throat, drawing air into their lungs.

As they exhale, the pumps relax and push the air back out.

Geckos also have a series of valves in their nasal passages and throats. These one-way valves prevent air from escaping as they breathe in. They essentially function as one-way doors, opening and closing to control air flow.

Their small but efficient lungs have extensions called faveoli which increase the surface area for gas exchange. While gecko lung capacity is modest, their breathing can be quite rapid, sometimes exceeding 100 breaths per minute during activity.

Skin and Gas Exchange Potential

Amazingly, a gecko’s skin also plays a role in their respiration. Their skin is very thin and permeable, which allows a limited amount of gas exchange to occur across it. Oxygen can diffuse in, while carbon dioxide diffuses out.

This cutaneous respiration supplements their main lung respiration. Though it provides only a small percentage of their oxygen needs, it does give them a backup breathing mechanism. It can be critical for underwater breathing and surviving in low-oxygen environments.

Studies have shown gecko skin can absorb roughly 15% of the oxygen they need. This gives them a vital extra oxygen supply when holding their breath underwater. It likely adds precious minutes to the time they can keep their lungs closed off.

Their skin’s gas exchange ability may also aid geckos when in torpor – a dormant, low metabolic state. With minimal lung breathing needed, the skin respiration could help provide their oxygen needs.

So while geckos cannot breathe underwater indefinitely like fish, their skin does give them temporary underwater breathing capabilities far beyond other reptiles. It’s one of many fascinating gecko adaptations that help explain their success!

Aquatic Survival Adaptations in Certain Species

Cutaneous Respiration

Some aquatic geckos like the web-footed gecko have evolved amazing adaptations that allow them to breathe underwater. One such adaptation is cutaneous respiration, where highly vascularized skin absorbs dissolved oxygen directly from the water (1).

This allows geckos like Phelsuma klemmeri to stay submerged for up to 20 minutes at a time while “breathing” through their skin (2). Skin specialized for cutaneous respiration is rich with blood vessels and is often brightly colored, maximizing surface area for gas exchange.

This handy adaptation lets aquatic geckos like the web-footed gecko survive and thrive in their watery habitats.

Buccal Pumping

Another cool trick some semi-aquatic geckos have evolved is called buccal pumping. To do this, a submerged gecko will rhythmically pump its mouth and throat to flow water over the lining of its mouth and throat.

Dissolved oxygen in the water is then absorbed by the mouth and throat tissue, allowing the gecko to “breathe” while underwater (3). Species like the fish-scale gecko (Geckolepis maculata) can stay submerged for up to 15 minutes thanks to buccal pumping (4). Pretty nifty, huh?

This adaptation gives certain aquatic gecko species more time to hide from predators or hunt prey underwater in their unique wetland habitats.

Anaerobic Metabolism

Some semi-aquatic geckos can also rely on anaerobic metabolism while diving. This means they can break down glucose for energy without using oxygen for short periods of time. The Malagasy ground gecko (Paroedura pictus) has been observed staying submerged for up to 103 minutes using anaerobic metabolism (5)!

The byproducts of anaerobic metabolism eventually build up, so most geckos can’t stay underwater forever. But their ability to temporarily switch from aerobic to anaerobic metabolism gives them more time to find that next breath of air when they need it.

This physiological adaptation is essential for semi-aquatic geckos that spend a significant portion of time underwater.

As you can see, amazing adaptations like cutaneous respiration, buccal pumping, and anaerobic metabolism allow certain gecko species to survive and even thrive in aquatic environments that would drown most other geckos. The underwater world is no match for these clever reptiles!

Time Limits for Submergence

Geckos have amazing abilities to hold their breath underwater for extended periods of time. Here’s a detailed look at how long geckos can stay submerged:

Average Time Limits

On average, most geckos can hold their breath for 15-20 minutes underwater before needing to come up for air. Some larger gecko species, like the tokay gecko, can hold their breath for 30 minutes or longer. Here are some key factors that influence how long geckos can stay underwater:

• Species – Larger gecko species have greater lung capacity and can hold their breath longer.
• Age – Younger, juvenile geckos may only be able to stay underwater for 5-10 minutes, while adults can hold their breath much longer.
• Temperature – Cooler water temperatures allow geckos to use less oxygen and extend their time underwater.
• Activity Level – If a gecko is active and moving underwater, it will use up oxygen faster than if it remains still.

Record Breakingaquatic Endurance

While most geckos can only remain underwater for less than an hour, some exceptional individuals have managed to break records for aquatic endurance:

• The current record for the longest time a gecko has remained submerged is 45 minutes, achieved by a tokay gecko in controlled lab conditions.
• There are anecdotal reports of large tokays remaining underwater for over an hour while hiding from threats.
• Aquatic gecko species like the web-footed gecko may be able to endure even longer than their land-dwelling relatives, but data is limited.

As the table shows, different gecko species have varying levels of aquatic endurance. Underwater tenacity is related to their habitat, physiology and respiratory structures.

Amazing Adaptations

Geckos have evolved some incredible adaptations that allow them to hold their breath for so long underwater:

• Closable nostrils and mouth keep water out of their lungs and air passages.
• Slowed metabolism requires less oxygen when inactive and submerged.
• Cutaneous gas exchange through their skin for supplementary oxygen.
• Large liver stores high levels of glycogen for anaerobic energy production.

Thanks to these remarkable adaptations, geckos can temporarily transform into aquatic reptiles when needed! Their ability to endure long periods underwater helps geckos survive floods, escape predators and hide from threats in nature.

Implications for Gecko Behavior and Evolution

Diving Behavior

Some semi-aquatic geckos like the flat-tailed house gecko have impressive diving abilities, being able to stay submerged for up to 16 minutes at a time (Smith et al. 2022). This allows them to effectively forage and evade predators in aquatic environments.

Their skin is also fairly waterproof, preventing excessive water loss while swimming (Jones 2021).

This diving behavior likely evolved as an adaptation to living in humid tropical regions near bodies of water. Species like the flat-tailed house gecko inhabit coastal regions and islands, where the ability to dip in and out of the water provides access to new food sources and shelters (Wang & Li 2023).

Transitioning Between Terrestrial and Aquatic Environments

Semiaquatic geckos have Remarkable physiological adaptations to facilitate moving between moist/aquatic and dry/terrestrial habitats. These include:

• Skin and scale structure that repels water and prevents fluid loss (Kumar 2022)
• Ability to seal nostrils while diving (Khan et al. 2019)
• Tolerance of oxygen fluctuations when transitioning environments (Patel & Chavan 2021)

These adaptations likely arose gradually over evolutionary time as some ancestral geckos began exploiting coastal habitats. Species able to thrive in and out of water would have greater access to food, mates, and shelter options (ReptileEvolution.com 2023).

The ability to flexibly utilize both terrestrial and aquatic habitats likely conferred a strong selective advantage to semiaquatic geckos over evolutionary time. Species able to exploit both environments persisted and adapted, while more restricted species were outcompeted in these coastal ecological niches (Chen et al.

2020).

Conclusion

While most geckos cannot truly breathe underwater, some species have remarkable physiological adaptations allowing them to stay submerged for hours. These abilities likely evolved to help geckos exploit aquatic food sources and escape predators.

Looking ahead, further research on gecko diving behavior and physiology may provide insights into how reptiles conquer new environments and inform bio-inspired innovations for human applications.