How Do Fish See? How Do Fish Sleep? How Do Fish Breathe?

Feb 2, 2018

But Why visits the New England Aquarium in Boston to get answers to those and other questions kids have sent us about fish.


How did the first fish get into the ocean? How do fish breathe under water? If you put a fish's head underwater, but not its tail, would it survive? How do fish get diseases? How do fish see underwater without googles? Why do fish swim when they are asleep? Do fish drink water? Do fish have ears? How are fish born?

They swim in oceans, lakes and streams, and sometimes even in tanks in your living room! We’re talking all about fish this week with Jo Blasi, manager of education and training at the New England Aquarium in Boston.

"How do fish see underwater without goggles?" - Bennett, 4, San Carlos, Ca.

"Animals have eyes that are built in the best way for their environment. Your eyes are designed to see in air and that's the way that they work best. If you swim underwater with no goggles, your eyes can't see really well. When you put on goggles, there's a little teeny tiny bit of air that's trapped in the googles with your eyes and you can still see underwater."

"Fish don't need goggles because their eyes are designed to work underwater. They still have the same parts that you do: there's a cornea, an iris and a pupil, the way the light gets in and bounces around and then transmits a signal to their brain so they can see things. Some fish can actually see really well. But their eyes are designed to work better in a water environment, rather than an air environment."

"And fish don't need to blink because they don't have any eyelids! No blinking necessary."  --Jo Blasi, New England Aquarium

Click listen to hear the entire episode.