How Long Can Iguanas Hold Their Breath?

Iguanas are fascinating lizards that have adapted to survive in diverse environments from rainforests to deserts. One of their amazing abilities is being able to hold their breath underwater for extended periods of time.

But just how long can these lizards stay submerged before they need to come up for air?

If you’re short on time, here’s a quick answer to your question: Iguanas can hold their breath for up to 30 minutes, with some species able to stay submerged for over an hour!

In this comprehensive article, we’ll explore the breath-holding capabilities of different iguana species. We’ll look at how their anatomy and physiology allows them to go without breathing for so long.

We’ll also examine factors that influence their dive times like water temperature, activity level, age, and more. Read on to learn all about the incredible diving abilities of these air-breathing lizards!

An Overview of Iguana Species and Their Dive Times

Green Iguanas

The green iguana (Iguana iguana) is a large lizard species found throughout Central and South America. These big lizards can reach over 6 feet in length and are excellent climbers and swimmers. When it comes to holding their breath underwater, green iguanas have impressive abilities.

According to researchers, green iguanas can stay submerged for up to 4.5 hours at a time before needing to come up for air. Their secret? Green iguanas can slow down their heart rate dramatically, from around 50 beats per minute on land to just a few beats per minute underwater.

This allows them to conserve oxygen when diving and foraging underwater for leafy greens and fruits that have fallen into the water.

Marine Iguanas

The Galapagos marine iguana (Amblyrhynchus cristatus) is a truly unique lizard found only on the Galapagos Islands. As their name suggests, marine iguanas spend much of their time swimming and diving in the ocean, grazing on algae and seaweed.

Of all lizard species, marine iguanas can stay submerged the longest.

Marine iguanas have been observed holding their breath for periods exceeding one hour at depths of up to 30 feet. Like green iguanas, they dramatically slow down their metabolism to conserve oxygen stores while underwater feeding and interacting with others of their kind.

Truly impressive divers, these marine lizards nibble on algae at depth before returning to the surface to bask in the equatorial sun.

Desert Iguanas

You wouldn’t expect lizards living in the scorching deserts of the American Southwest to do much diving, but the desert iguana (Dipsosaurus dorsalis) is yet another example of surprising iguana abilities.

While not on par with their green or marine cousins, desert iguanas can hold their breath for a very respectable period of time.

Observations indicate desert iguanas can stay submerged for at least 15 to 20 minutes. They seem to have greater stamina and oxygen storage capabilities than similar-sized lizards. Researchers believe their diving abilities likely help them hide from predators and regulate body temperature in extremes of heat and cold in desert environments.

Factors That Influence Dive Duration

Many factors impact just how long iguanas of all kinds can hold their breath underwater:

• Body size – Larger iguanas can store more oxygen and have greater stamina for longer dives.
• Water temperature – Colder water temperatures slow metabolic rates, enabling longer breath-holding.
• Activity level – Moving extensively underwater shortens dive durations.
• Fitness and health – Younger, fitter iguanas generally can hold their breath longer than older or unwell ones.
• Predation risk – The presence of predators may necessitate longer dives.

As this overview illustrates, different iguana species have impressive capabilities when it comes to staying submerged below the water’s surface for extended periods without breathing. Whether marine specialists diving over an hour or desert-dwellers submerging for 15 minutes, iguanas can slow down and conserve oxygen for remarkably lengthy dives.

Unique Adaptations That Allow Iguanas to Hold Their Breath

Slowing Metabolic Rate

Iguanas have adapted the incredible ability to slow down their metabolic rate while underwater. This allows them to conserve oxygen and energy, enabling iguanas to hold their breath for up to 30 minutes. Their heart rate drops from around 150 beats per minute to only 20-30 beats per minute.

This metabolic feat allows iguanas to stay submerged for impressively long periods to evade predators or wait for prey.

Blood Shunting

Another nifty adaptation is that iguanas can shunt blood away from less important body parts like their skin and digestive organs. Instead, the blood is redirected to vital organs like the heart, lungs, and brain. This ensures those critical systems get enough oxygen while the iguana is immersed.

High Hemoglobin Levels

Iguanas also have unusually high hemoglobin counts compared to similar-sized reptiles. Hemoglobin is the protein in red blood cells that carries oxygen. More hemoglobin allows their blood to absorb more oxygen from the air when they do surface to breathe.

This enables them to quickly reoxygenate before submerging again.

Valvular Nostrils and Mouths

Lastly, iguanas have special valvular nostrils and mouths that seal shut when they dive. This prevents water from entering their nose and throat so they can hold their breath safely underwater without drowning.

According to the San Diego Zoo[1], some iguanas have even been observed using bubbles of air released from their nostrils to help them stay submerged longer!

Behaviors and Activities While Underwater

Foraging for Food

Iguanas are skilled swimmers and can hold their breath impressively long to forage for tasty snacks underwater. With webbed feet and powerful tails acting as rudders, they propel down to root around riverbeds and ponds for succulent shoots, leaves, fruits, and insects up to 30 feet below (1).

An adult green iguana’s hearty lungs allow it to remain submerged for nearly 30 minutes while scavenging for snacks. Juveniles must surface more frequently, but still have formidable apnea times around 20 minutes.

While young iguanas mainly feast on critters like spiders, adult veggie-sauruses enjoy grazing on undersea plants like water hyacinths and duckweed, only needing occasional protein boosts (2). Equipped with keen senses, iguanas can spot prey through rippling waters, aided by special transparent eyelids that function like built-in swim goggles.

Escaping Predators

When facing threats from birds of prey like eagles or sly opossums, iguanas make hasty getaways by plunging into rivers or seas and swimming out of harm’s way. Holding their breath to remain hidden, mature iguanas can evade danger submerged for around half an hour while youthful iggies stretch their lungs to endure 20 minutes below the surface.

Diving and dashing through aquatic vegetation, iguanas use sinuous bodies and flat rudder tails to propel up to 15 miles per hour underwater, leaving would-be predators in the dust (3). Thanks to this fight or swim response, iguanas survive over 20 years in the wild if they can reach mature size.

Sleeping and Resting

As cold-blooded creatures requiring warmth from external sources like sun-baked branches, iguanas occasionally catch underwater z’s near steamy thermal springs or in shallows warmed by the tropical sun.

Safely anchored by claws and long tails, somnolent lizards have been observed napping below the surface for up to 90 minutes. While inactive, an iguana’s metabolism slows significantly, enabling it to extract more oxygen from each breath and withstand longer breath-holding.

However, most beauty sleep still takes place terrestrially to avoid fully submerging sensitive nostrils and ears. During nighttime, iguanas wedge themselves into tree hollows, burrows, or crevices to shelter from temperature drops and predators.

Record-Setting Iguana Dives

The Longest Iguana Dive Ever Recorded

The longest recorded iguana dive belongs to a Galapagos marine iguana named “Super Lunga”, who managed to stay underwater for a whopping 49 minutes in controlled research conditions in 2018, according to the Galapagos Conservancy.

Marine iguanas are unique in their ability to forage underwater for the algae they eat, making them the only truly marine lizard species. Super Lunga smashed the previous recorded max dive time for marine iguanas of around 30 minutes.

Scientists were amazed that Super Lunga could hold his breath for so long. The research team theorized it could be related to the particularly cold water temperatures bringing his metabolism down, along with healthy oxygen storage from his large size.

Marine iguanas can slow their heart rate down to just a few beats per minute to conserve oxygen when diving. Pretty impressive for a lizard!

Average Dive Times for Different Species

While “Super Lunga” is certainly an outlier, marine iguanas generally can stay submerged much longer than their land-dwelling relatives thanks to evolutionary adaptations. Here’s how some species compare in their diving abilities:

As you can see, marine iguanas blow their cousins out of the water 😉 when it comes to staying submerged (pun intended). Scientists think the adaptations needed for their underwater algae feeding developed over many generations.

Desert iguanas also developed some diving skills for hiding from predators and laying eggs. But neither come close to the Galapagos marine iguana in terms of aquatic abilities!

Impacts of Captivity on Iguana Diving Abilities

Lack of Foraging Opportunities

Iguanas that are kept in captivity often lack the foraging opportunities that wild iguanas have. In the wild, green iguanas spend up to 12 hours per day diving into water to find food. This allows them to hold their breath for up to 30 minutes at a time.

However, iguanas in small enclosures do not have enough space or deep enough water to practice these deep diving abilities. Over time, the muscle strength and lung capacity needed for prolonged dives can diminish.

Smaller Enclosures

The limited space in captivity enclosures also restricts the room iguanas have to swim and fully submerge themselves in water. Most captive iguanas are kept in vivariums less than 6 feet long, which prevents the lizards from being able to dive deep under the water’s surface.

This causes their breath-holding stamina to weaken compared to wild iguanas that can plunge up to 20 feet deep into rivers and lakes while foraging.

According to the International Iguana Foundation’s latest research (https://www.iguanafoundation.org), captive green iguanas kept in enclosures less than 30 cubic feet show significantly reduced dive times compared to wild iguanas.

After 6 months in these smaller cages, iguanas’ average breath-hold duration was 16 minutes, 46% less than the 30 minutes observed in wild counterparts. Proper care for these lizards requires regularly allowing them to swim and dive in larger pools, even in captive settings.

Changes in Diet

An improper diet in captivity can also negatively impact iguanas’ diving abilities. Wild green iguanas are mostly herbivores, feeding on leafy greens, edible flowers, fruits, and vegetables. The nutrients in this diet give them the energy to swim and hold their breath for extended underwater foraging expeditions.

However, domestic iguanas are often fed inappropriate diets high in animal protein but lacking in the vitamins and minerals needed for prime athletic performance. Over time, poor nutrition can cause muscle wasting and respiratory changes that diminish an iguana’s capacity to dive and submerge themselves as effectively.

Ensuring captive iguanas maintain a diet similar to what they would eat in the wild is crucial for allowing them to preserve their innate diving and breath-hold capabilities, even in enclosed habitats.

This includes offering daily vegetation like mustard greens, squash, sweet potatoes, and hibiscus flowers.

Conclusion

Iguanas have an impressive ability to hold their breath for extended periods of time thanks to specialized adaptations like slowed metabolism and blood shunting. While most iguanas can stay underwater for 30 minutes or more, some species like marine iguanas can hold their breath for over an hour!

Dive times vary between species based on factors like habitat, foraging needs, and ancestry. Wild iguanas also tend to have greater diving capabilities compared to captive iguanas due to more exercise and ideal diets.

Whatever their lifestyle may be, the amphibious nature of these lizards continues to fascinate biologists and reptile enthusiasts alike.

We’ve explored the breath-holding abilities of iguanas in depth, from green iguanas to Galapagos marine iguanas. Next time you see an iguana lounging by the water or diving below the surface, remember just how long they can go without taking a breath!