Have you ever encountered a shy yet majestic turtle during one of your swimming trips? If you haven’t, you’ll probably think that these reptiles live in the water for most of their lives.
While it’s true that they can stay underwater, it isn’t their forever home. How then do they breathe while staying beneath the water?
Well, if you’re genuinely interested in solving this mystery, make sure to stay tuned to the article below.
Can turtles breathe underwater?
Despite staying most of their time in the water, turtles cannot breathe underwater. Their respiratory systems aren’t designed to make them remain beneath the water for eternity. However, turtles can stay under the water for prolonged periods by holding their breath. Whenever they feel their oxygen levels drop, turtles swim towards the surface to breathe through their external nares. This occasional visit unfortunately gives us the false impression that turtles breathe underwater.
Why can’t turtles breathe underwater like fish?
Turtles, like fish, are aquatic animals. But, despite their great affinity for the underwater world, these shelled animals primarily live on land.
And, since they live on land, it’s expected that they need to breathe air to live. Thus, a turtle’s respiratory system works like how a land animal’s respiratory system works.
As mentioned earlier, turtles have external nares above their mouths to breathe whenever they resurface. The air immediately passes through their glottis before entering the trachea.
From there, their cartilaginous trachea then splits into two bronchi towards their lungs.
However, as turtles have armor-like shells, their lungs can’t expand fully as a person’s ribcage. Thus, the inside of their shells have muscles that expand and contract to move the air through their bodies.
Since turtles constantly move their limbs to navigate, this behavior also helps move the air through their bodies.
This limb movement of turtles helps alter their lungs’ pressure, ultimately assisting the air to go where it should.
But, if turtles can’t stay beneath the water for long periods, how do they breathe during hibernation? Continue reading the article to find out.
How then do turtles survive underwater?
Most animals, including humans, have nostrils to help them siphon the oxygen in the air. Fish and other aquatic animals breathe by processing the water to get oxygen.
But, for turtles, do they have a choice for their breathing method. How is this possible?
To start, turtles are part of the reptile community. Though reptiles have lungs, they also have other means to respirate when they go into hibernation.
Since reptiles are cold-blooded (ectotherms) animals, their temperature depends on their environment’s temperature. And, with variable body temperatures, their metabolic rate adjusts accordingly as well.
Thus, whenever the wintry months arrive, cold-blooded animals (turtles included) hibernate. It’s like their bodies tell them to take things slowly and sleep instead.
So, when turtles enter the state of brumation (similar to hibernation), their metabolic rate slows down to conserve energy. The only problem is they do this underwater.
Since they enter into a sleep-like state, turtles can’t frequently resurface to take in oxygen. As they’re not moving as often as before, their oxygen needs also go down.
But, to still allow them to breathe while brumating, turtles adapted to the need and breathe through their butts instead.
How is this possible?
Technically, a turtle’s butt called the cloaca contains lots of blood vessels. Since the cloaca’s covered in blood vessels, it can absorb the oxygen from the water directly through the skin.
And, since turtles aren’t moving much, the oxygen they get through cloacal respiration’s enough to last them until spring.
But, while cloacal breathing is the norm for most turtles, some species like the musk turtle can take in oxygen through their throats.
It works similarly to cloacal breathing, only that the oxygen passes through the throat instead of the butt.
How long can turtles stay underwater?
Now that we know that turtles hold their breaths whenever they swim, how long can they do this without resurfacing?
Depending on the turtle’s species, they can hold their breath for an average of 45 minutes to an hour.
But, even if they’re capable of holding their breaths this long, turtles usually dive in five-minute increments.
During these short dives, turtles make sure to revisit the surface to breathe. But, if there’s a need to stay long underwater (like if they’re searching for food), they typically can stay beneath it for an hour.
Even if the water’s murky, certain species of turtles like the Matamata can manage to stay beneath it for an hour or more.
Since constant movement alerts the prey of their presence, Matamata need to stay still for prolonged periods for higher success.
Also, turtles sleep underwater during the night. Since they need to recover their energy stores, it’s such a hassle for them to continually resurface to breathe.
Hence, turtles hold their breath for as long as they can during sleep. They merely come out of the water occasionally to take in the air before resuming with their slumber.
But, one turtle species holds the record for holding their breath the longest.
Though they need to take in air like other members of the family, sea turtles can hold their breath for as long as 4-7 hours when they’re asleep.
Can turtles drown?
Despite the incredible adaptations turtles have to survive underwater, they can still experience drowning.
Though it’s rare, a turtle can drown if they become stuck underwater. This usually happens if the situation they’re in is too stressful that they use up all the oxygen in their bodies.
Since they’re under duress, turtles tend to move a lot, increasing the rate with which they use the oxygen. Once the oxygen levels start to go down, anaerobic respiration sets in.
Anaerobic respiration causes lactic acid build-up, which is highly toxic. Thus, if the struggling turtle fails to reach the surface, they’ll die in a matter of minutes.
Now that we’ve uncovered the truth, we can now appreciate how incredible turtles are.
Though they can’t breathe underwater, turtles can appreciate the beauty of both worlds, all thanks to their “superpower.