How Do Turtles Breathe?

HOW DO TURTLES BREATHE?

An exploration of the process of respiration, the interesting ways that turtle respiration differs from other vertebrates, and the conservation implications of respiration for aquatic turtles.

MAY 2020 WHAT IS RESPIRATION?

Before we get too excited about turtles, let’s talk about respiration.

What is it? Hey look, it’s a Golden Coin Turtle from Hong Kong!

• Cellular respiration is a set of chemical reactions that happen in animal cells that convert oxygen and nutrients into energy and create water and carbon dioxide as byproducts. • Breathing is the method used by some animals to exchange the oxygen used in cellular respiration for the carbon dioxide that is produced. • The whole point is to create energy!

• Humans use lungs to breathe. • We take in air through our mouths, and it goes into the lungs where oxygen is absorbed into the bloodstream and into our cells. • Carbon dioxide is released from the cells into our blood stream, back into our lungs and then out into the environment. • We have a small muscle called a diaphragm that regulates our breathing.

• Fish take in water through their mouths and wash it over their gills. • The gills are filled with capillaries that absorb oxygen and release carbon dioxide.

• Frogs can breathe like many other vertebrates, with their lungs. • But they can also absorb oxygen from water through their skin! Frog skin is covered in a mucus to stay moist, and the capillaries in the skin help absorb oxygen from the surrounding water.

• Turtles have lungs to breathe but they do it a little differently than us. Their shells don’t allow their ribcages to expand and contract. • Instead of a diaphragm, they have muscles lining the inside of their shells to help push air in and out.

• Many aquatic turtles spend long stretches of time underwater. • In addition to being able to breathe with their lungs, they are able to run water through their cloaca, the opening under their tails that is used for excretion, defecation, reproduction, and in this case, absorbing oxygen.

• The cloacal opening (1 in the diagram) allows water into pouches called the cloacal bursae (2) that are lined with tiny, finger-like projections (3) that increase surface area. • The cloacal bursae are loaded with capillaries that absorb oxygen from the water running through, allowing the turtles to avoid having to surface for air for long periods.

• Remember, breathing is just the method for getting oxygen into cells. • From there, the oxygen will react with nutrients to create energy during cellular respiration. • Most living things need a regular supply of food and oxygen to create energy so they can keep living, and eventually reproduce.

HOW IS RESPIRATION IMPORTANT IN TURTLE CONSERVATION?

• All turtles, like all living things, need clean air to breathe. • Aquatic turtles have more specialized needs— the water they live in must have specific qualities in order for them to survive, including an appropriate amount of dissolved oxygen for them to absorb. • If waterways are polluted or disturbed, it can cause turtle populations (along with fish, amphibian and aquatic insects) to die off.

• Get involved! • Learn more about the turtle and tortoise species that live in your area. • What habitat do they live in? • What threats do they face? • Are there any local groups working to help them?

Visit www.turtleconservancy.org to learn more about turtles and how you can help.