Do fish feel thirsty? What do experts say?

Today I have a rather curious question for you: have you ever stopped to think whether fish feel thirsty?

This may seem like a bit of a childish question, but the answer may be surprising! 

With this in mind, we have created this special content! In it, you will learn a little more about how thirst works in these aquatic animals, discover the answer to this question and, in addition, you will understand other aspects about this topic. 

What is considered 'feeling thirsty'?

Everyone already knows that thirst is the desire to drink water. 

According to the definition given by experts, thirst is the sensation that we – human beings and land animals in general – feel and that leads us to seek a source of water. 

Why do we feel thirsty?

The need to drink water arises after our body loses a lot of water. When we sweat a lot or when we go a long time without drinking liquids in general, 

For this situation, there is a little place in our brain called the hypothalamus. When our body needs to replace the water that has been lost, the function of this area of the brain is to signal this need that we are facing. And that is how we feel thirst. 

In addition to this situation, another very common moment when we feel thirsty is right after eating something very salty. Do you know why this happens?

Salt contains a substance that, when present in large quantities in our bloodstream, can be very harmful to our health.

At this point, the hypothalamus feels the need to 'dilute' the blood by drinking water. This way, the substance present in the salt consumed dissolves more quickly, avoiding possible damage to our cells. And the way the hypothalamus finds to perform this task is by sending a thirst signal. 

Now that you know a little more about the exact concept of thirst and why we feel it, it's time to talk a little more about this sensation in fish.

Do fish feel thirsty?

Finally, we come to the question that gave rise to this content. After all, do fish feel thirsty or not?

Of course, it is something quite difficult to know, but according to biologists and experts in animal and marine life, they believe, in a certain way, yes.

But it is important to emphasize that the type of thirst that fish feel is different from thirst as we know it.

Since fish that live in the sea are in a place that has a much higher concentration of salt compared to their own bodies, these animals do need to drink water. And it is through a process called osmoregulation that they avoid the process of dehydration. 

This process consists of consuming water and then eliminating the salt present in it through the action of cells present in the fish's gills.

Therefore, the correct thing to say would be that, despite not feeling thirst as intensely as we do and the vast majority of land animals, fish feel the need to drink water to avoid the dehydration process, but they do so almost 'automatically'.

Difference between freshwater and saltwater fish

Due to the environment in which they live, there are some differences between fish that live in freshwater and those that live in saltwater. 

In the case of freshwater fish, experts suggest that they do not feel water. Since these animals live in a type of water that has a low concentration of salts – an amount lower than the concentration in the animal's cells – fresh water tends to penetrate the animal's body completely involuntarily. This means that these animals do not feel thirsty.

Curiosities that go beyond thirst

Taking advantage of the theme involving marine life and fish, we decided to list some more curiosities that are common involving fish!

Do fish sleep?

The answer is: more or less. Unlike sleeping as we know it, fish vary between two states: wakefulness and rest. If we compare it to our human routine, it would be as if they took very short naps, but they don't have that super sleep that leaves anyone well rested.

Can fish drown?

This is another one of those questions that may seem obvious, but it isn’t. Fish can indeed drown. There are some species – like betta fish – that need to come up to the surface regularly to get air. Otherwise, if they stay underwater for many hours without this “breathing” opportunity, they can drown.

Do fish blink?

Let he who has never had a pet fish and spent a long time staring at it, waiting to see if it blinks or not, cast the first stone.

I’m sorry if this answer disappoints you – and your inner child – but the only fish that blink are the ones depicted in cartoons. Fish don’t close their eyes. That’s because, unlike us humans and animals that live on land, fish don’t have eyelids. 

This makes it impossible for them to blink.

Do fish feel cold?

Yes. Just like us, fish also need some form of heat to live well. When they are subjected to low temperatures, they also get cold.

Except, of course, for animals that actually live in deeper waters. With them, the system works the other way around: when exposed to shallower waters – with more sunlight and, consequently, warmer waters – the health of these types of fish can also be compromised.

Conclusion

What did you think of this brief tour of marine life and the routines of fish? I bet you're almost an expert on marine life now, huh!

Jokes aside, in addition to acquiring new knowledge, learning more about the routine of these marine beings is a great way to learn more about the routine and mysteries surrounding the sea and these fascinating marine creatures.

Did you like this content? Then take the opportunity to read it too Acupuncture for pets: what is it for and how much does it cost?