Can they breathe underwater?
No they don’t breathe underwater. Penguins have lungs like humans so they need to take a deep breath and hold their breath while underwater and come up for air. When swimming near the surface penguins will use a technique called porpoising to leap out of the water in order to take a breath of air. They can maintain a speed of up to 6 miles per hour while porpoising. Penguins have several special physiological characteristics that allow them to stay underwater for extended periods of time. A penguin’s hemoglobin, the iron-containing oxygen-transport metalloprotein in the red blood cells of vertebrates, is adapted to utilize every last bit of oxygen while diving. They can also store additional oxygen in their muscle tissue and have the ability to use their muscles underwater for extended periods of time without experiencing lactic acid buildup. And to conserve on oxygen consumption a penguin can lower its heart rate to 5 beats per minute.
