Fish Facts

Fish have gel-slime on their bodies that protects them from parasites.

Fish swimming at depths of 15,000 feet (almost 3 miles down!) can withstand a pressure of 7,000 pounds per square inch. They are able to live in these crushing depths by pumping gas into their swim bladder.

One way to tell the age of a fish is by looking at its scales. They have growth rings just like trees. These are called circuli. Clusters of them are called annuli. Each annuli show one year.

The world's largest mammal, the blue whale, weighs 50 tons at birth. Fully grown, it weighs as much as 150 tons.