How Do Turtles Breathe Under Water?

Actually, turtles cannot breathe underwater in the sense that we would call breathing. That is, the taking in of oxygen through inhalation and exhalation. However, there are ways that turtles can "absorb" or take in oxygen through means other than just by their lungs. In fact, there are two other areas of the turtle's body where it gets oxygen besides it lungs. The absorption of oxygen through air by the turtle largely depends on the turtle's state of activity.

  1. Air Via Lungs

    • Like most land animals, the turtle has a set of lungs that it can breathe with. As its activity increases, so does his demand for air. The turtle, depending on the species, can hold its breath for a long time while under water. How long it can hold his breath is in direct proportion to how active it is and if it is able to find pockets of air. These pockets of air can be in small caves or under ice. However, while hibernating, some species do not breathe at all.

    No Breathing?

    • In some studies, turtles were virtually not breathing at all. Instead they would take in air by a different area of the body and therefore by different means than the traditional lungs. It was once thought that turtles indeed did breathe underwater because movement of water was seen around the turtle's mouth. Later studies showed that the air was actually absorbed through gill-like structures in the neck in some turtles and through the skin at the throat on others. Water movement was also found near the turtle's anal area where there was also absorption of air through two sacs. These sacs, like the throat, have tiny capillary blood vessels that can absorb the oxygen needed from the water.

    Hibernation

    • Some turtles hibernate for up to four months without breathing or eating while underwater. In addition to the absorption of air through both ends of its body, the turtle's system slows down. The cold-blooded turtle is comparable to the environment around it. When the temperature drops, the turtle cools down. His heart can slow to as little as five to 10 beats per minute. His need for oxygen and/or food is diminished. Cold water not only lowers the turtle's body temperature, it also will retain more oxygen, which the turtle will absorb.

    Oxygen Deprivation

    • Turtles like other living organisms need oxygen for natural bodily functions. Also like other animals, they can go without air for short periods of time. The lack of air will cause what is called "anaerobic respiration." Anaerobic respiration is when the body uses oxygen as our body uses energy. This causes lactic acid in the body, which can be poisonous, even to the turtle. However, as the turtle is in hibernation, some of its shell is absorbed into its bloodstream in the form of calcium that offsets the presence of lactic acid, allowing the turtle to go longer without air and the body to still function.

    Limitations of the Turtle

    • The turtle is still in need of oxygen while it is hibernating. Two things can still cause a turtle to die: the lack of oxygen due to a stagnant body of water or the body of water freezing solid. The turtle would fare better in a pond or river that has a constant flow of water regardless of the temperature to bring in a fresh supply of oxygen. Obviously, if the water freezes, the turtle will literally freeze to death as with any other animal.