Do Alligators and Crocodiles Have Gills or Lungs?

Crocodiles and alligators have lungs; they do not have gills. Both of these animals are reptiles, not fish. Some people think that they have gills because they can stay underwater for a long time, but this is a myth.

Alligators and crocodiles cannot breathe underwater. However, they have a specialized type of biology that allows them to conserve oxygen when they dive.

Do Alligators and Crocodiles Have Gills

How many lungs do crocodiles and alligators have?

Crocodiles and alligators have two lungs. They use the lungs to breathe as other land animals do. Both crocs and gators breathe through the nostril.

The air passes through the nose, then to the trachea and then eventually to the lungs. After this, the air goes to the primary bronchi.

Like humans, the lungs of alligators and crocodiles contract and deflate during the inhalation and expiration processes.

Crocodiles, however, have lungs that are much more similar to birds. Unlike humans, crocodiles do not breathe with a tidal pattern. Instead, they breathe with what iscalled unidirectional flow.

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Do crocodiles and alligators breathe through lungs only?

Yes, crocodiles and alligators breathe through the lungs only. Both of these animals are not amphibians. They cannot breathe through their skin.

Underwater, the crocodiles and alligators hold their breath. They do not inhale oxygen from the water as amphibians do.

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Can crocodiles and alligators breathe underwater?

No, alligators and crocodiles cannot breathe underwater. Instead, they hold their breath and conserve both energy and oxygen.

Both crocodiles and alligators have respiratory systems similar to other land creatures. However, these crocodilians have a way to ration oxygen supply only to vital parts of their bodies.

The alligator’s heart can slow down to two or three beats per minute. Because of this, it is possibly the only muscle that receives oxygen when the animal is underwater.

When underwater, the croc or gator will consume about half of its oxygen supply in the first 20 minutes. Then, the alligator will stay active and conscious for the remainder of the dive.

Once the oxygen is almost depleted, it will go back to the surface to breathe. Crocodiles also breathe water while on the surface, and they breathe through their nostrils.

Researchers also found out that crocodilians have some organs and tissues that are not critically dependent on a supply of oxygen. As such, the gator and croc do not have to consistently pump oxygen to these muscles and tissues.

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Do crocodiles and alligators breathe through the skin?

No, crocodiles and alligators do not breathe through their skin. Only amphibians can breathe through their skin, and one of the best examples is the frog.

The frog has three respiratory surfaces. It uses these surfaces to exchange gas with its environment. The frog uses its skin, lungs, and mouth lining to breathe.

When underwater, the frog breathes through its skin. Its skin has special tissue membranes so thin that water can pass through them. This skin also has an extensive network of blood vessels. The gas exchange happens in these blood vessels.

Crocodiles and alligators do not have this type of skin. Instead, they have scutes, or bony armor. Although crocodiles and alligators have sensitive skin, they do not have what it takes to process oxygen through the skin.  

When the frog is not underwater, its predominant way to breathe is through its mouth lining. The gas exchange takes place in this mouth lining, and they fill their lungs occasionally. The lungs of frogs are poorly developed.

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How long can crocodiles and alligators stay underwater?

The average is 10 t 15 minutes. Some say that crocodiles and alligators can stay underwater for two hours, but this is not verified.

Most voluntary dives only last 15 minutes. According to some experts, if the croc is hiding, it can stay underwater for 30 minutes.

Although some experiments showed that crocs and gators could stay underwater for two hours, this is not normal, and the experiments forced these animals to stay submerged.

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How do crocodiles and alligators stay underwater too long?

Researchers found out that these animals have the ability to stay underwater because of a special protein. They have a special type of protein in the haemoglobin, that carries oxygen from the lungs to the rest of the body.

In addition to this, crocodilians use a waste product of metabolism that other animals would have discarded. They use bicarbonate ions, which only form when carbon dioxide dissolves in water.

As the animal burns more energy and produces more carbon dioxide, they get more action from the bicarbonate trigger. As such, they can ensure that they can carry large quantities of oxygen to their muscles and tissues.

Crocodiles also have an efficient system to allocate oxygen only where it is needed. In addition to this, both crocs and gators can significantly reduce metabolism when underwater. With these abilities combined, the croc or gator can stay underwater for a long time without breathing.

The croc and gator use their air supply from the lungs only as a reserve. In many cases, when the animal dives, it pretty much uses a lot of the oxygen that it has before the dive.

From here, the heart’s valve closes. And when this happens, the circulatory system redirects blood flow to critical areas only.In addition to this, crocodilian blood has an amazing ability where it releases oxygen quickly to the areas where it is needed the most.

Overall, crocodiles and alligators cannot breathe underwater. They are not amphibians nor fish. The secret to their longevity underwater is their ability to slow down metabolism and distribute oxygen where it is needed.


Crocodiles and alligators breathe with lungs, not gills. They do not breathe through the skin, and they certainly do not breathe underwater.

Both crocs and gators have a special ability to control their oxygen supply. When underwater, they can reduce their heart rate by three beats per minute. They use the power from their muscles, but they do not necessarily supply oxygen to these muscles when they dive.

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