As the fish closes its mouth, the flap opens. Oxygen is extracted from the water as it passes over the gills. Other fishes have gill slits. Tails: Fish tails also take many shapes. A crescent ...
As the fish closes its mouth, the flap opens. Oxygen is extracted from the water as it passes over the gills. Other fishes have gill slits. Tails: Fish tails also take many shapes. A crescent ...