How does the trout breathe?

The trout breathes through its gills. Gills are specialised organs that extract oxygen from water. They are located on either side of the trout's head and are made up of thin, feathery filaments. Each filament is covered in tiny blood vessels, which absorb oxygen from the water. As the trout breathes, it draws water in through its mouth and passes it over its gills. The oxygen in the water is absorbed by the blood vessels in the gills, and the water is then expelled through the trout's gill slits. The trout's gills are very efficient at extracting oxygen from water, and they allow the trout to breathe even in relatively low-oxygen environments.