Scales
The gills of a fish.
there r gills
gills and brain
Gills are the things that help fish breath under water.
all fish have gills. they have gills instead of lungs, so they can breathe under water. Whales and dolphins do not have gills because they are mammals.
they have gills
Gills and fins.
In most fish the respiration takes place through gills since there under water there under water there gills are like are lungs .
Fish gills are not suitable for air ventilation because, gills cannot function without water flowing through them. Gills are especially evolved and are an adaption of fish to breath under water.
Gills
opercular gills are found in the class osteichye "bonny fish" who have a operculum. Septal gills are found in chondritchthyes "cartilagenous fish"
They use their gills to breathe under water.