How does a guppy breathe?

A guppy breathes through specialized respiratory organs called gills. Their gills are located on the sides of their head, behind the eyes. Gills are composed of thin, delicate filaments that are covered in tiny blood vessels. When a guppy takes in water through its mouth, it passes over the gills where oxygen from the water is absorbed into the blood vessels. At the same time, carbon dioxide, a waste product of respiration, is released from the blood and into the water through the gills. The movement of water over the gills is facilitated by the guppy's operculum, which is a bony flap that opens and closes over the gills, creating a pumping action that draws water in and out of the mouth and over the gills.