As with all other reptiles, sea turtles sleep. So how do sea turtles sleep?
Sea turtles sleep underwater. Here they hold their breath.
This allows the turtles not to drown when sleeping. The turtle will resurface every few hours to breathe.
These turtles can stay underwater for several hours. Sea turtles have been known to hold their breath for 4 to 7 hours when sleeping. They can sleep underwater for 4 to 7 hours at a time.
While hatchlings sleep by lying on the surface of the water, subadults and adults sleep in deep water. In nearshore waters, they also do sleep on the sea bed wedged under rocks.
While sea turtles can go hours without breathing while they sleep, they need to breathe every 45 to 60 minutes while they go about their normal routine during the waking hours. When stressed these turtles need to quickly resurface to breathe within a few minutes.
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Adaptations that allow sea turtles to sleep underwater
There are seven sea turtle species and these are hawksbill, leatherback, loggerhead, Australian flatback, Kemp’s ridley, olive ridley, and green turtles.
All of these sea turtles spend all their lives in water. The only times they are out of the sea are when they hatch on the beach and rush into the sea and when nesting females come to the beach to lay eggs.
Sea turtles are reptiles and as such have powerful and well-developed lungs. As such they have come to the surface to breathe all the time.
You may be wondering how sea turtles are able to sleep underwater if they need to breathe. Well, here are some adaptations that have made it possible for sea turtles to sleep underwater.
Low metabolic rate – The sea turtle’s metabolic rate slows down while they sleep. This allows their bodies to use less oxygen. As such, they do not have to resurface as often to maintain their bodily functions.
Cloacal respiration – Sea turtles can respire through their cloaca they do this by expanding and contracting the muscles down there to push water in and out of the cloaca. A concentration of blood vessels there allows for gaseous exchange. Of course, the capacity of cloacal respiration is limited and cannot sustain the turtle.
Large lungs – the lungs of sea turtles are large and powerful. This allows them to store air which they can use larger.
High hemoglobin for oxygen storage – this allows for a higher concentration of oxygen in their veins.
All of these adaptations mean that sea turtles can remain underwater for hours.
Sleep Length of Sea Turtles
As aquatic reptiles, sea turtles sleep in the water. So how do these turtles sleep?
Well, hatchlings sleep floating near the surface of the water and adults sleep in deep waters. These turtles can spend as many as 11 hours sleeping in a day.
Turtles can also sleep underwater for 4 to 7 hours before they resurface to breathe.
Sleeping Locations of Sea Turtles
The sleeping location of turtles depends on their age as well as their habitat.
As mentioned in the previous paragraph, juveniles and hatchlings sleep near the surface of the water. Older turtles on the other hand sleep in deep waters.
Sleeping on water’s surfaces can leave the turtle vulnerable to predators, however, hatchlings usually live in the open ocean. Here there are fewer predators.
This allows them to be relatively safe. Also since the seafloor on the open sea is quite far, the hatchlings won’t be able to dive down there to sleep even if they wanted to.
Older turtles sleep between rocks, on the seafloor, or even on a reef.
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Frequently Asked Questions
Do sea turtles sleep underwater?
Yes, sea turtles sleep underwater.
While hatchlings float near the surface, adults and subadults sleep in deep waters. Some even sleep at the bottom of the sea wedged between rocks.
Although they sleep underwater, they still breathe air. As such these reptiles have to resurface every now and then to breathe.
With that being said, these reptiles can stay underwater for as long as 4 to 7 hours when sleeping according to the Sea Turtle Conservancy. This allows them to get their beauty sleep.
Sea turtles also hibernate/brumate underwater when temperatures are low enough. This allows them to save energy.
Can turtles sleep underwater?
Yes, turtles can and do sleep underwater. All sea turtles can sleep underwater.
In fact, no sea turtle can sleep on land. When it comes to freshwater turtles such as red-eared sliders, map turtles, musk turtles, mud turtles, and softshell turtles only sleep underwater.
There are turtle species such as box turtles and forest turtles that sleep on land. They prefer to sleep in burrows and under leaves. Turtles prefer to remain hidden as they sleep.
Tortoises are also turtles and these sleep on land. Tortoises sleep in dark places where they are well hidden from predators.
They sleep in burrows they dig themselves (an example of tortoises that dig burrows is the gopher tortoise). Some, such as the pancake tortoise, prefer to sleep in crevices and under/between rocks.
Do turtles sleep in water?
Yes, most turtles sleep in the water. These include pond turtles, such as sliders, cooters, mud turtles, and several others.
Few turtles don’t sleep in the water. An example of a turtle that doesn’t sleep in water is the box turtle.
Tortoises also do not sleep in the water.
How long do sea turtles sleep?
Sea turtles can sleep for 4 to 7 hours at a time. In all, a sea turtle can sleep for up to 11 hours a day.
How much do sea turtles sleep?
While sea turtles can and do sleep for about 4 to 7 hours at a time, they are known to sleep for about 11 hours a day.
How do sea turtles breathe?
Sea turtles may be marine animals but they breathe air. This means that they have to resurface every few minutes to breathe.
Similar to humans, sea turtles breathe air into their lungs which they extract oxygen through gas exchange. The lungs of sea turtles are powerful and well-developed.
Their lung capacity is also very impressive.
Conclusion
You may be wondering how these turtles sleep. While they sleep the same way most reptiles do. Since they are marine reptiles they sleep underwater.
A sleeping hatchling or juvenile sleep by floating passively on the surface of the water. This allows them to easily breathe when they need to.
Adults and subadults on the other hand have different methods of sleeping. They usually sleep in deep waters.
Here, they can sleep for 4 to 7 hours before they need to resurface for air.
Sea turtles may also hibernate. During hibernation, they also need to resurface now and then to breathe.