Do fish get thirsty when living in water?

In fact, fish don't actually need to feel thirsty to drink water. Drinking is simply a reflex that occurs without any conscious decision from their bodies. Therefore, it can be said that fish never feel thirsty.

Whether fish get thirsty or not depends on their species. This is because saltwater and freshwater fish have different anatomical structures, leading to different behaviors when drinking water.

Saltwater and freshwater fish have different ways of drinking water.

Do freshwater fish drink water?

The salt concentration in the blood of freshwater fish is much higher than in the surrounding water. Therefore, if freshwater fish drink water, they face a high risk of blood dilution. That is why freshwater fish do not drink water.

Instead, they utilize osmosis. Freshwater fish absorb water through their gills and skin. Additionally, they excrete much more dilute urine to remove excess water from their bodies.

How do saltwater fish drink water?

Compared to their surrounding water environment, saltwater fish have much thinner blood. Therefore, to avoid dehydration, saltwater fish must actively drink water. With their unique gills, saltwater fish can drink seawater, process it, and excrete all the excess salt.

Saltwater fish always actively drink water under any circumstances.

What about fish that live in saltwater and freshwater?

Fish species capable of living in both saltwater and freshwater environments are not numerous. A prime example is the salmon, which is able to migrate from saltwater to freshwater.

Freshwater salmon hatch into fish that undergo three major transformations before leaving their birthplace to return to saltwater. First, they drink a lot of water. Next, their kidneys reduce their urine output. And most importantly, the mechanisms in their gills begin to work in reverse, eliminating instead of absorbing salt from the water.

When salmon reach maturity, they need to return to freshwater to spawn. They will spend a few days in an intermediate environment, also known as intertidal zones (areas of coastal water or where the seabed is exposed at low tide). Here, their bodies will reverse the entire transformation they underwent as juveniles so they can survive in freshwater. Therefore, the answer is that these fish species are capable of living in both freshwater environments and drinking water.

No matter what environment they live in, fish always need to drink water.

Do other aquatic creatures drink water?

Fish actively drink, but not because they are thirsty. There are two reasons for this seemingly involuntary drinking. First, fish essentially live in water, so their bodies don't have an urgent need to drink.

For fish, thirst is a reflex that occurs without any conscious effort or brain control. It simply happens instinctively. They don't necessarily need to feel thirsty to drink water. We all know that these creatures, like all others, need water. The question here is whether they drink water from their surrounding environment.

Tuyet Anh (Source: Compilation)

Beneficial
Emotion
Creative
Unique
Wrath