Freshwater fish that are transferred to saltwater can literally die of dehydration. Unlike saltwater fish, which have evolved ways of retaining water, freshwater fish have evolved ways to expel excess water. When placed in saltwater, a freshwater fish's body can expel more water than it takes in, eventually resulting in dehydration. Does the fish know it's thirsty? Who knows, but it can definitely die of thirst.
Maybe they just call it airst
Freshwater fish that are transferred to saltwater can literally die of dehydration. Unlike saltwater fish, which have evolved ways of retaining water, freshwater fish have evolved ways to expel excess water. When placed in saltwater, a freshwater fish's body can expel more water than it takes in, eventually resulting in dehydration. Does the fish know it's thirsty? Who knows, but it can definitely die of thirst.
They thirst for sparkling water
Electrolytes, it's what fish need
The fish that climb trees knows