Just like humans, fish also have five ways of interacting with their surroundings. They can taste, see, hear, touch, and smell.
They use these senses to find food, talk to each other, find partners, and stay away from bigger, scarier fish.
Interestingly, if a fish gets hurt or is born with a defect that affects one of these senses, they can adapt and learn to live without it.
Okay! Let’s now talk about these 5 fish senses in more detail.
1. Vision
The eyes of most fish are located on the sides of their heads, and some fish can even spin their eyes all the way around.
Fish often have big eyes because they live under water where there’s not a lot of light.
There are some types of fish that live in really dark places where they don’t need eyes, so they’ve lost them over time as they have evolved.
Fish can see some colors, but they have a hard time adjusting to quick changes in light because their eyes work slowly.
That’s why they might get scared if you suddenly turn the light on or off in their aquarium when the room is dark.
So, if you notice your fish swimming up to the top of the tank when you turn on the light first thing in the morning, it’s probably because you startled them.
In humans, the shape of our eye lens keeps changing to help us focus, but fish’s eye lenses stay the same shape. They focus by using special ocular ligaments of their eyes that move the whole eye forward and backward.
Scientists have found out that fish in aquariums can learn to recognize human faces over time.
Here are some more interesting things about fish eyes:
- Fish can see in two different directions at the same time, which is called monocular vision. But they can’t focus both their eyes on one thing at the same time.
- Most fish can’t see very far, only about a foot, so they won’t be able to see you across the room. If you want to interact with them, you should wiggle your fingers close to the glass.
- Fish don’t have eyelids, so they sleep with their eyes open in a sort of trance.
How Fish Use Their Lateral Line for Vision
Fish have a special feature called the lateral line. Think of it like a sixth sense that helps them figure out where objects are around them.
This is super helpful because fish don’t see very well. However, not all fish have a complete lateral line.
There’s a type of fish called the blind cave fish which uses its lateral line to move around. Even killifish uses it to find insects above the water surface.
2. Taste
Fish have the ability to taste with their mouths, lips, and sometimes even their fins. However, their sense of taste is not as varied or wide as ours, so they need to keep exploring their surroundings to find their food.
Here’s an interesting fact…
Like humans, catfish also have taste buds but they have it on their barbels. This helps them find food in water that is murky or dark.
However, catfish have more than 27000 of these taste buds, which is a lot more than humans, who only have around 9000.
3. Hearing
Fish ears are pretty simple and are made up of an inner chamber. This chamber picks up vibrations, or movements, from their surroundings which then get turned into sound.
Fish don’t need complex ears like humans do because sound moves faster in water than in air. So, over time, nature didn’t see the need for them to have complex ears.
Fish also use their lateral line to detect sounds. Some types of fish, like carp, even use their swim bladder for hearing. Swim bladder is a part of their body that helps them control their buoyancy, or ability to float.
Many fish experts think that in some species of fish, the swim bladder and the parts of the inner ear work together to help the fish pick out specific sounds.
4. Touch
People have been debating for a long time about whether fish can feel pain or not. It’s not easy to find this out because to do so you would have to hurt the fish.
And it’s not what you want to do. It would be upsetting to find that actions we take could cause pain to our fish.
So to be on the safe side, it’s best to always assume that your fish can feel pain. Therefore, we should handle them gently and take good care of them just as we would do for any other pet.
5. Smell
Smell is very important for fish. They use it to find food, prey, and even a good partner. Fish sniff out smells through their nostrils, which are also known as nares.
Unlike us humans, where our nostrils are connected to our throat, fish nostrils are connected to their olfactory system, which is the part of their body that handles smell.
This olfactory system in fish isn’t completely connected to the part of their body that helps them breathe, it works separately.
