Although most people would assume that all aquatic animals can breathe underwater, this is actually not the case for some. In fact, there are many animals that live underwater that don’t get their oxygen from the water.
And did you know that despite the ability to hold their breath underwater for long periods of time, turtles, water snakes, crocodiles, alligators, dolphins, whales, and other water going creatures will drown if kept underwater too long?
This is because these animals have lungs used for breathing air and are what we call air-breathers. They actually can’t breathe underwater and just have the ability to hold their breath for a very long time.
Unlike fishes that have gills which enable them to breathe underwater, aquatic animals like dolphins and whales that can last up to 30 minutes underwater, have blowholes instead, located at the top of their heads which function like how people’s noses function. Manatees or sea cows, on the other hand, come up after 20 minutes or so underwater and exchange up to 90% of air in their lungs (this is quite impressive as humans can only do 10%).
Moreover, when resting, sea turtles hold the record for the animal that can hold its breath the longest underwater which can last for days. Impressive!