Do Fish Drink Water? Do Fish Ever Feel Thirsty? All Details

One thing that primary school taught you is that every organism needs water to live. It’s a fact that no one can live without water. So the question is comes to mind “Do Fish Drink Water?”

However, if water surrounds a living being, it would be ridiculous for it to drink, right? Think about the fish, they live in the water yet they need it for living.

Yes, fish require water, despite literally having water all around them. So, how do fishes replenish their water needs? Let’s dive in to find out.

Do fish drink water?

First, let’s answer the question at hand. Some, not every fish, “drink” water. Whether they drink water or not depends on their environment. Based on the environment, there are different types of fishes.

  • Freshwater fishes: They are present in lakes, ponds, rivers, and streams. Here, the salt concentration outside the fish is very low. So, what does that have to do with drinking? We’ll get to that later.
  • Marine fishes: These fishes are present in salty waters, like that of seas and oceans. In such environments, the outside has more salt than the inside of the fish.

Fish and Osmosis

Fish do not drink water as we do. However, they absorb water. The process by which they do that is Osmosis, which is the movement of water from an area of low concentration to a higher one.

Now, think about the environment. In freshwater, the body has more salt concentration than the water. Therefore, naturally, the water will move towards the body, right? Similarly, the flow will be opposite in the seas and oceans. It all makes sense, right?

Hopefully, now you are familiar with Osmosis?

Great! Let’s move on.

How do fishes get water?

Fish Drinking Water

Fishes absorb water through their skin and gills. Also, they pee the water out from the gills.

Naturally, in rivers, ponds, lakes, and streams, the water goes towards the fish. However, in seas and oceans, it’s the other way.

However, to make things work, fish need a certain amount of water and salts in their bodies. They can’t afford to keep a lot of water or let it run out from their bodies excessively.

So, saltwater fish deliberately get more water into their bodies. It makes sense because they’ll end up removing the water due to concentration.

Contrarily, the freshwater ones have to frequently remove the water. There’s a limit to the water that they can take. Therefore, they remove the water directly from their gills as soon as it gets in their bodies.

Moreover, the gills have an additional function: to take in or take out the salt. They do it to maintain the balance of salts and water to keep the fish alive.


If you are going to get a fish, make sure you set the right environment for it.


1. Can you use tap water for fish?

Tap water is fine for the fish. However, you have to clean it and set the right environment for the fish you are going to keep.

2. How much water do fish have in their bodies?

The quantity of water in a fish varies. Nonetheless, the average is 70%, and the total water content can be between 30% to 90%.

Hopefully, Now you know about “Do Fish Drink Water.” If you need more details related to fishes please visit PetsHood.