No, most lizards cannot breathe in water directly like fish do with gills. However, some remarkable semi-aquatic lizard species have developed unique and fascinating adaptations that allow them to spend significant time and even "breathe" underwater using clever methods.
The General Rule for Lizards and Water Breathing
The vast majority of lizards are terrestrial or arboreal, meaning they live on land or in trees. Like humans and most other reptiles, they are air-breathing vertebrates that rely on lungs to extract oxygen from the atmosphere. Their respiratory systems are not designed to process oxygen dissolved in water. If submerged for too long, they would drown.
- Lung-based Respiration: Lizards possess lungs, which are specialized organs for gas exchange with air.
- No Gills: Unlike fish, lizards lack gills, the specialized respiratory organs that allow aquatic animals to absorb oxygen from water.
- Risk of Drowning: Prolonged submersion in water will lead to suffocation for most lizard species.
Unique Adaptations: Lizards That 'Scuba Dive'
While typical lizards cannot breathe underwater, the animal kingdom is full of surprises. New research has unveiled extraordinary adaptations in certain semi-aquatic lizards, particularly a species of Anolis lizard found in Costa Rica. These lizards have found a way to essentially become "scuba divers."
How the Underwater Bubble Works
This particular species of semi-aquatic lizard employs a fascinating technique: it produces a special bubble of air over its nostrils and mouth.
- Re-breathing Mechanism: When submerged, the lizard exhales air, which forms a bubble that clings to its water-repellent skin around its head. It then re-inhales this exhaled air.
- Oxygen Exchange: The bubble acts like a temporary "rebreather," allowing the lizard to extract oxygen from the bubble and also potentially replenish its oxygen supply by exchanging gases with the surrounding water. This allows them to stay submerged for extended periods, sometimes up to 16 minutes, to avoid predators or forage for food.
- Water-Repellent Skin: Their specialized skin texture helps the air bubble adhere to their head rather than floating away, making this underwater breathing possible.
Examples of Water-Dwelling Lizards
Beyond the Anolis species with its unique bubble trick, other lizards also exhibit impressive aquatic abilities:
- Marine Iguanas: Found only in the Galápagos Islands, these are the only lizards in the world that forage for food in the ocean. While they can hold their breath for up to an hour, they still breathe air and must surface regularly. They dive to eat algae from rocks. Learn more about marine iguanas.
- Water Monitors: Large, powerful lizards like the Asian Water Monitor are excellent swimmers and divers. They can stay submerged for considerable periods to hunt fish, frogs, or escape threats, but they rely on holding their breath and must return to the surface for air.
- Basilisk Lizards: Known as "Jesus Christ lizards," these reptiles can run across the surface of water for short distances. While impressive, this is an escape mechanism, and they breathe air, not water.
Why Lizards Can't Use Gills
The fundamental difference lies in their evolutionary path and physiological structure. Gills are complex organs featuring a large surface area with numerous blood vessels, designed to efficiently extract the relatively low concentration of oxygen dissolved in water. Lungs, on the other hand, are designed for the much higher concentration of oxygen in air. Lizards simply do not possess the necessary biological machinery to breathe water.
| Feature | Typical Terrestrial Lizards | Semi-Aquatic Lizards (e.g., some Anolis species) |
|---|---|---|
| Primary Respiration | Air (using lungs) | Air (using lungs) |
| Underwater Breathing | Cannot breathe underwater; must hold breath or drown | Can "re-breathe" from a self-made air bubble over nostrils |
| Aquatic Adaptation | Limited to none; may swim for short periods | Specialized; includes water-repellent skin and bubble formation |
| Survival Strategy | Avoids water; escapes on land | Uses water as refuge from predators; can forage underwater |
| Submersion Duration | Very limited; depends on breath-holding capacity | Significantly extended (e.g., 10-16 minutes) |
While most lizards are strictly air-breathers, the astonishing adaptations of certain semi-aquatic species demonstrate the incredible diversity and ingenuity of life in navigating different environments.
