Fish is like a dark horse in the America’s favorite pet list which secures the third place after CAT statistically. But overall with the total no. of households, fishes are counted to be in the 3rd place. Basic information about Fish: ???? Fish are aquatic animals with gills, but they don’t have limbs with fingers. Fish have a backbone, fins, and scales that cover their bodies. ???? Fish use their fins for swimming, steering, balance, and sensing movement and vibrations. ???? Fish use their gills to breathe. Gills are located on the sides of a fish’s head and extract oxygen from the water. ???? Fish live in various habitats, including freshwater lakes and rivers, saltwater oceans and seas, and even salty water, a mixture of fresh and saltwater.