Have you ever been fishing and tiptoed to the edge of the brook in order not to scare the fish away? If a fish hears you, then chances are he might decide it is safer elsewhere because fish do have ears and can hear. But the ears of a fish are located internally, not externally as are the ears of so many other familiar.
Many people imagine that fish somehow get along without performing some of the functions we know are necessary to live. This may be because fish are cold-blooded. And it may also be because we like to catch fish and prefer to think they do not know what is happening to them. But fish have a nervous system like other animals. When we make them uncomfortable, they feel it, and when we hurt them, they suffer pain.
Fish have a very keen sense of touch, and they taste, as well as feel, with their skin. They also have two small organs of smell which are located in the nostrils on the head. And just because a fish is cold-blooded does not mean it can go without “fuel” to keep the body going. This “fuel”, of course, is food. It is burned in all the living tissue of the fish and provides the power of life, growth, and motion.
The bloodstream carries not only this food to every organ of the body but also oXygen to keep the “fires” going. So the fish has the heart to pump this blood, just as we have. Fish, of course, live in so many different kinds of environments that they differ from each other in many ways. For example, lungfish actually have both gills and “lungs” for breathing in the air! Some fish that live in caves are blind, and so they have developed feeders on their heads. Some live in saltwater and come in fresh. And some fish live only on the bottom of the ocean.
What Frequency Can Fish Hear?
Most fish, both in freshwater and salt, detect sound from 40 Hz up to 500 or 1,000 Hz (though some, like salmon, only hear to about 400 Hz, while others, such as herrings, can hear to over 3,000 Hz).