This is the 965th most frequent Catalan word.
viuen
"Viuen" means "they live."
In this sentence, 'viuen' is used to describe the action of residing in a certain location—a rural setting in this case.
Les persones que viuen al camp sovint tenen animals.
The people who live in the countryside often have animals.
Here, 'viuen' denotes the natural environment or habitat of the subject, the fish.
Els peixos viuen a l'aigua.
The fish live in water.
In this context, 'viuen' illustrates the overall state or lifestyle experience of the subject, which is tranquil living.