It breathes oxygen from the water through its gills and moves by swimming. Fish are called cold-blooded because, unlike mammals, their blood temperature fluctuates with the temperature of the surrounding water. This allows them to adapt to seasonal variations.
Fish breathe by taking in water through their mouths and passing it out through the gills.
The oxygen from the water is retained and passes into the fish's bloodstream. There are of course a huge number and variety of fish species in fresh and saltwater habitats across the world but they have, with certain exceptions, the above characteristics in common. The most important point to remember is that they all have the capacity to suffer pain and stress. Angling is the catching of fish by the lips with rod, line and hook and can also be called fishing. It is undertaken primarily for the enjoyment of the angler, who gets pleasure from outwitting a fish into being caught.