In most species they are on either side of the head behind the eyes.
The fishes have gills for breathing
cartilaginous fishes have lamelliform gills. bony fishes have filiform gills.
Fishes having gills are more. Also some fishes have lungs.
No they have gills
yes
Gills
their gills
gills
Correct
In their mouth.
Gills
they allow them to breath underwater