How do sea turtles breathe underwater?

Sea turtles are fascinating creatures that have adapted to life in the ocean. They are air-breathing reptiles and need to surface regularly to breathe. When sea turtles dive underwater, they rely on a variety of adaptations to help them hold their breath and extract oxygen from the water.

Sea turtles have powerful lungs that are specially adapted to allow them to stay underwater for long periods. They can hold their breath for up to several hours depending on the species, activity level, and water temperature. Before diving, sea turtles take a deep breath and then use their powerful flippers to push themselves down into the water.

While underwater, sea turtles slow down their heart rate, which allows them to conserve oxygen. They also have a unique system of blood vessels that allows them to extract oxygen directly from the water through the lining of their mouth and throat. This process is called buccal pumping and helps them extract up to 80% of the available oxygen from the water.

Sea turtles also have a specialized gland near their eyes called the salt gland that helps them excrete excess salt from their bodies. This adaptation allows them to drink saltwater and extract freshwater from it, which helps them stay hydrated and prolong their time underwater.