Sea turtles seem to spend all of their life in the water, but all other turtle species need to breathe air. So I wondered, can sea turtles breathe underwater? Or can they live without air? To find out the answer I decided to do some research. Here is what I found out.
Can sea turtles breathe underwater? No, sea turtles can not breathe underwater. Sea turtles are very good at holding their breath, this is why they can stay 6 to 8 hours underwater. Sea turtles also have a cloaca that helps them gather oxygen while underwater.
While sea turtles aren’t able to breathe underwater they are still able to spend very long periods of time underwater. One of the reasons why they are able to stay so long underwater is because they have a cloaca which allows them to do something very similar to underwater breathing. But before talking about the cloaca we have to talk about how turtles breathe, and how they can stay so long underwater.
How Turtles Breathe
Like most animals, sea turtles breathe through their noses. They inhale air into their two lungs, and they exhale it, just like all animals do. What makes turtles different is that unlike most animals they don’t have flexible torso, so the mechanics of the process are a little different.
When you and I inhale air, our torso will make itself smaller, and when we exhale the torso will expand. This can happen because our torso is made out of independent ribs that are somewhat flexible. The torso of a turtle is covered with a shell, which is also made out of ribs, but those ribs have all fused together to form the shell, and by doing so they’ve lost all their flexibility.
Because turtles don’t have the same flexibility as most animals, the way their lungs and their muscles in that area are set up completely differently. The kind of setup that they have allows them to have better control over how they breathe. Thus allowing them to hold air in their lungs for extended periods of time, without too much effort.
How Turtles Can Spend so Much Time Underwater
But being able to hold the air longer won’t do them any good if they have to use it all up very fast. Here comes into play another thing that is exclusive to reptiles, and that is the fact that they are cold-blooded. This means that they are unable to generate their own body heat, so they rely on the heat of the environment to maintain their body temperature. The fact that they are cold-blooded also means that they have a slower metabolic rate.
The metabolic rate is basically the speed at which a body is functioning. A fast metabolic rate means that that animal will have a lot of energy and it will be very active, but it will also mean that it will need a lot more food, water, and air. A slow metabolic rate means that the animal will be less energetic, it won’t always be very active, but at the same time, it won’t need too much food, water, or air. All those things will allow a turtle to spend a lot more time underwater than most animals can.
All those things contribute to the amount of time that sea turtles are able to spend underwater, but there is one more thing that helps them and is the closest thing that a sea turtle can do to breathe underwater.
How the Cloaca Helps Turtles “Breathe Underwater”
A cloaca is a small orifice that is can usually be found at the back end of an animal, and it has many different roles depending on the species of the animal.
You might have heard at some point something like: turtles are able to breathe through their butts. And as weird as it sounds that is kind of true, the cloaca is positioned at the end of the turtle’s body so it can be considered the butt of the turtle. But the cloaca acts differently than how you would normally expect a “back end” to work, let’s take for example another animal that we all know, the dog. The purpose of a dog’s anus is to execrate, and that is it, it’s not involved in any other biological processes. But the cloaca is used for more than that.
The cloaca has 4 important roles: execration, urination, reproduction, and breathing. Turtles use only one orifice for those things and that is the cloaca.
The cloaca works in a similar way to the lungs, when the turtle is inside the water the cloaca will act like a pump that will suck water inside and after it gathered all the oxygen from it, it will expel the water out, and then it will start over. Due to the way things are arranged on the inside of the turtle this process is less exhausting than normal breathing.
Here is a short video that shows how cloacal breathing works:
The cloaca can be found at other animals as well, they are not exclusive to turtles. Most birds have a cloaca, some fishes, and a few mammals. The cloaca can be a little different for other animals, but those that have it will generally use it for the same purpose, with the exception of breathing, not too many animals that have a cloaca use it for breathing, mainly because they don’t have any reason to do it.
For turtles, the cloaca consists of the Urodeum, the central part of the cloaca that receives urine from the ureter, Proctodeum, the back ectodermal part of an alimentary canal, and the Coprodeum.
Cloacas are also used to lay eggs, when turtles lay their eggs, they expel them through the cloaca.
Here is a video of a turtle laying eggs through its cloaca, in the video you can see clearly that the eggs leave the turtle’s body at the base of the tail. Even if it’s not a sea turtle, the process is exactly the same.
If you own an aquatic turtle and you want to see your turtle using its cloaca to breathe, you can easily do so. Just look at the back end of the turtle when it’s swimming around, if you spend 15 minutes looking you have pretty big chances of seeing it in action.
If you want to see a cloaca, but you don’t own a turtle, here are a couple of links that will show you a cloaca up close. I chose not to post them as pictures because they can be a little gross, but if that is not a problem for you, here are the links:
Related Questions
How long can a turtle stay underwater? It depends on the turtle, most sea turtles will be able to go for at least 5 hours without breathing, most aquatic turtles should be able to stay underwater for at least 20-30 minutes, land turtles on the other hand are not very good at staying underwater so 1 minute is the average you can expect them to be able to stay underwater. Here is a list of average times a turtle can spend underwater:
- Box turtle – 1 – 2 minutes
- Desert tortoise – 1 – 2 minutes
- Snapping turtle – 20 – 30 minutes
- Red-eared slider – 20 – 30 minutes
- Map turtle – 20 – 30 minutes
Can sea turtles sleep underwater? Yes, all sea turtles sleep underwater. But they usually try to stay as close to the surface as possible, in case they want to get some oxygen.
Can sea turtles drown? Yes, if sea turtles stay too long underwater they can drown. But this only happens if they get caught by a net or something similar, otherwise, there is no reason for a sea turtle to drown.
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