Do Turtles Have Gills?

When I first learned that certain species of turtles spent their whole lives underwater, I couldn’t help but wonder whether they had gills or some other adaptation that allowed them to breathe underwater. In light of this, I decided to conduct some investigating on my own.

Gills are absent in turtles, but their cloaca performs a similar function. A gill-like organ called the cloaca may take in oxygen from the water. When on the surface, sea turtles fill their lungs with oxygen, allowing them to dive deeper.

Indeed, they spend most of their existence in the water. There may be some confusion here since, after all, reptiles are air breathers, right? Now, let’s go a bit further and see how these ancient reptiles have adjusted to life in the water.

Do Turtles Breathe Through Their Gills Or Lungs?

In contrast to fish, sea turtles lack gills to breathe through. They are needed to reach the surface in order to take in the air so that they may continue to remain immersed in the water once their lungs have been filled with oxygen.

As a result of having a shell that prevents them from contracting, turtles lack diaphragms. Rather, they possess muscles that are embedded within their shells that assist them to move air in and out of their bodies.

Above their mouths, turtles have breathing holes called nares that function similarly to nostrils. To enhance oxygen exchange, the small air sacs known as alveoli are located in the lungs and may be reached via the turtle’s nares when the animal closes its mouth.

Cloacal respiration is a breathing mechanism utilized by numerous turtle species.

What Is The Cloaca?

Cloacas are tiny orifices often located at the rear of animals. Their functions vary greatly from species to species.

Maybe you’ve heard that turtles have a special breathing system in their bottoms. Yet as strange as it may seem, it is sort of true. 

The cloaca is located towards the tail of the turtle, and it is possible that it might be termed the butt of the turtle.  Yet, the cloaca does not function as one would anticipate a “back end” should.

Exercising, urinating, reproducing, and breathing are the four major functions of the cloaca. The cloaca is the sole opening that turtles use for the aforementioned activities since they only have one.

The Urodeum, which is located in the middle of the cloaca and collects urine from the ureter, the Proctodeum, which is the rear ectodermal section of an alimentary canal, as well as the Coprodeum are the three components that make up the cloaca in turtles.

Several blood veins branch out from this cloacal aperture, allowing turtles to take in oxygen from the surrounding water. While the term “respiration” is often used to describe this process, the lungs are not involved.

How Do Turtles Breathe?

When it comes to breathing, all turtles have two tiny apertures on their faces that operate as any conventional nose would. 

In addition, turtles have two lungs, which are the organs that are responsible for transporting air throughout the body. But, a turtle’s primary method of respiration is via its nose.

Thus far, it has seemed that a turtle’s breathing is indistinguishable from our own.  like us, turtles take in the air via their nostrils and release it through their mouths and noses. Yet, the inner workings of a turtle’s respiratory system are very different.

1. Through Inner Muscle Movement 

As you breathe in, your chest constricts and expands as a result of your ribs being flexible. In contrast, a turtle’s shell is rigid and cannot move in response to its circumstances.

Because of their lack of mobility, turtles have no need for the complex system of lungs and muscles that humans and other animals rely on.

In order to breathe, turtles use muscles that move the body away from the shell’s apertures and squeeze the stomach against the lungs during exhalation.

2. Through Their Cloaca

The cloaca functions similarly to the lungs in that it draws water in, collects oxygen from it, and then expels it. This process is repeated until the turtle has exhausted its supply of oxygen.

The inside structure of the turtle makes this procedure easier than regular breathing. Although the cloaca may be less taxing on a turtle’s energy reserves, in the wild, a turtle cannot rely on it for lengthy periods of time.

The cloaca is crucial for the survival of certain turtle species, including the Olive ridley sea turtle, which may spend up to 10 hours at a time underwater.

Although not all cloacal-breathing turtles can stay submerged for as long as these specimens can, they nevertheless benefit greatly from their adaptation.

It is to be anticipated that various turtle species would be able to breathe more deeply via their cloaca depending on the conditions of their native environment.

Considering that certain species of sea turtles never leave the water, they rely on it constantly. Yet, aquatic turtles also spend considerable time on land.

However, the cloaca serves no practical use for terrestrial turtles who never go underwater.

Most turtles wouldn’t make it through the winter without their cloaca, thus it serves a far more important purpose than just supplying them with breathing air as they swim.

Do Sea Turtles Have Gills?

Gills are not present in sea turtles. Turtles are reptiles, not fish, thus they need to emerge for air even if they spend the vast majority of their lives submerged.

In addition to increasing their cloacal surface area, the papillae’s abundant blood supply also makes them very resilient. Turtles are able to extract oxygen from the water via structures called papillae, which appear similar to gills in other animals.

How Can Sea Turtles Breathe When Submerged?

Their bodies have evolved to the watery environment in a way that ours have not. To keep their body temperatures stable, sea turtles must constantly adjust to their surroundings, making them cold-blooded. 

Everything about a turtle’s anatomy changes as it descends below the surface, allowing it to save and distribute oxygen as effectively as possible. 

Their breathing rate decreases to a mere ten breaths per minute, and their heartbeats might drop to once every nine minutes. 

By this method, they can spend extended amounts of time submerged without running out of oxygen.

Compared to terrestrial reptiles, sea turtles’ lungs are enormous. With each breath, they may trade anywhere from 27% to 80% of their lung capacity.

As a result, they may take a second, deep breath, then dive back down relatively rapidly after exchanging all the gasses in their lungs.

This, however, can only be effective if the turtle is relaxed and not anxious. Panic causes a rise in heart rate and effectively undoes everything that helps a turtle to remain underwater. 

Therefore turtles who are trapped in nets or being hunted are unable to hold their breath for much longer. Turtles who are trapped in nets or other forms of confinement typically drown because their oxygen levels drop so low so rapidly when they are stressed.

How Long Can Sea Turtles Hold Their Breathe?

How long a sea turtle can go without breathing depends on several factors, including the kind of turtle and how active it is.

A sea turtle can hold its breath for up to two hours when swimming but may do so for five or more while resting.

Several species of sea turtles are able to hold their breath for more than 7 hours because they enter a hibernation condition and use so little oxygen during dormancy.

The cloaca is the only means of oxygenation for a turtle when it is hibernating since the animal spends most of its time underwater.

Nevertheless, land turtles are not particularly proficient at surviving underwater, and their average time spent under is just one minute. The typical amount of time a turtle may spend submerged is as follows:

Box turtle:  1 – 2 minutes

Snapping turtle, Red-eared slider, Map turtle: 20 – 30 minutes

Green sea turtle, Leatherback sea turtle,  Kemp’s ridley, Olive ridley:  7 – 10 hours

Could a turtle ever drown?

Turtles are susceptible to drowning if they become stuck underwater and are unable to make it to the top to breathe. 

If a turtle emerges from hibernation in a pond that has a layer that has not completely melted over, the turtle might drown. 

After a turtle’s metabolism begins to function normally again, the quantity of oxygen she requires much exceeds what can be supplied by cloacal respiration alone. Thus she is forced to take in oxygen from the surrounding air. 

Even marine turtles have the potential to perish if they get entangled in a fishing line or trap and are unable to free themselves. 

A turtle that is unable to free itself from its confinement may flail its flippers in an attempt to free itself. However, this behavior causes the turtle’s oxygen levels to drop more rapidly, which can lead to the turtle’s death.

Before You Go

So, do turtles have gills to breathe through? Not at all, no. Nonetheless, turtles do have lungs and a cloaca, which functions in a manner similar to that of a lung in that it permits the animal to absorb oxygen from its surrounding water.

If you found this article interesting, you may also be interested in  How Do Softshell Turtles Breathe Underwater?