Yes fish need some oxegen because every living organism needs air.:D
Floran fish need oxygen other wise it will death . so always need oxygen
All fish need oxygen....
All fish, whether baby or older, need oxygen.
Of course all fish need oxygen even puffer fish....
Gills carry oxygen fish need directly from the water
it depends on the fish.
Fish extract oxygen from water using gills, but gills cannot extract oxygen from air. A few species of fish (e.g. lungfish, snakehead) have some ability to extract oxygen from air (e.g. lungfish use a modified swim bladder like a lung) and can survive short trips across dry land from one shallow pool to another.
They need water Fish can not process oxygen the same way mammels do. They get their oxygen throu molecules in the water.
Fish are like humans in the way that they need oxygen. Fish breathe in dissolved oxygen and pass out carbon dioxide.
Food water oxygen
Usually fish need high oxygen levels. Sure they live in water, however they often hide near rocks and corals, places were they are able to get alternating levels of oxygen. Some creatures live near underwater volcanoes where the temperature and oxygen levels are altered. Other fish need to surface to the water in order to capture a breath of air before they dive down into the water again. Some fish species who are unable to collect water can drown from suffocation when unable to get enough oxygen.
Fish live in the water, so generally they only need food. But they get their oxygen from the water through their gills, so they will need the water to have dissolved oxygen at a proper level.