Dolphins are animals that spend their lives underwater. It may come as a surprise that dolphins are not able to breathe underwater, since they don’t have gills. How do dolphins breathe? Find out more in this lesson.
Dolphins: Fish or Mammal?
Of all the animals living in the sea, there is one in particular that attracts attention for its intelligence, clever tricks, and cute face. That’s right, it’s the dolphin! Dolphins spend their lives cruising the depths of the ocean. So they must have gills like fish, correct? Actually, no: dolphins breathe air just like you and I. How does this work for an underwater creature?
We already mentioned the fact that dolphins seem like fish since they live underwater. However, dolphins are actually mammals, just like you and I. This means that they have lungs and breathe air. When dolphins are swimming, they must come to the surface to get air just like you do. But unlike people, dolphins have a special feature that allows them to breathe. This is known as a blowhole.
What is a Blowhole?
A blowhole is just what it sounds like: a hole in the top of a dolphin’s head. Dolphins use their blowholes to take in air and also to blow it out (hence the name). Now, when you are swimming and come up for air, you probably take a big breath through your mouth. This is not the case with dolphins! They do not use their mouths to breathe at all, only their blowholes. How do they work?
Let’s first look at when a dolphin is under the water. While swimming, it has the ability to close its blowhole so that water doesn’t leak in. You may have had the unfortunate experience of getting water up your nose while swimming: no fun! The blowhole of a dolphin comes equipped with a flap of skin that makes a tight seal while underwater so that this doesn’t happen. When a dolphin is ready to breathe, it comes to the surface and removes the flap from its blowhole.
How Does a Blowhole Work?
You might expect that once at the surface of the water, a dolphin gasps air through the blowhole like you do through your mouth. However, dolphins do things a little differently. Like whales, they first blow air out of the hole when surfacing. And this isn’t just a gentle puff: they expel the air with great force! This releases old air and clears away any water from the blowhole. With the water blown clear, a dolphin can take a nice deep breath and then resume its playful swimming under the water.
Dolphins can hold their breath for quite a long time before coming to the surface for air. In fact, they can stay underwater for up to seven minutes before surfacing to breathe. Did you know that dolphins must even breathe while sleeping? They keep part of their brain awake at all times so that they remember to come up for air.
Dolphins are mammals that live underwater; instead of gills, they have lungs, which means that they must come to the surface for air. To breathe, a dolphin uses a hole in the top of its head called a blowhole; it first expels water to clear the hole, then takes a breath. Dolphins can hold their breath for about seven minutes and must breathe when they are asleep.