Bowfin

From Wikipedia:
The bowfin, Amia calva, is the last surviving member of the order Amiiformes (which includes three additional, now-extinct families dating from the Jurassic, to the Eocene), and of the family Amiidae (which contains numerous species in about four subfamilies, only one of which, Amiinae, is extant). The bowfin is a freshwater piscivore, preying on fish and larger aquatic invertebrates by ambush or stalking. Native to southeastern Canada and eastern United States, they prefer shallow, weedy waters of lakes or protected back waters of rivers. The bowfin is able to breathe air, using its swim bladder, which is connected to its gastrointestinal tract and allows it to regulate buoyancy in the water, as a primitive lung. The fish can be seen coming to the surface and gulping air. This limits it to a specific depth range in which the surface is accessible. They tend to use shoreline habitats that are not accessible to other predatory fish.