Identify a fish quiz

Fish out of water Fish, like all animals, need oxygen. They get it through their gills, which extract oxygen that is dissolved in water. We know that salt dissolves in water, but so does oxygen from the air and from the algae and plants that live in the river. It is this dissolved oxygen (DO) that the fish need to survive. Some species need more dissolved oxygen than others. Fish like trout need lots of dissolved oxygen, whereas carp can survive with much less. Gills work great in the water, not so great in the air. Pollution, especially sewage and fertilizer runoff, can lower the oxygen levels in the river and put stress on fish populations.