The gars is a small group of freshwater fish found in North America. There are 7 species in 1 family. Gars are large, dangerous looking fish with elongate, streamlined bodies, and long mouths lined with lots of sharp teeth. Gars are heavily armored with thick scales. They live in areas of shallow, weedy, and slow-moving water. These habitats often have very low levels of oxygen in the water, but gars have the ability to gulp air into their swim bladders, which act like lungs. Gars are capable of bursts of speed and are voracious predators, eating anything they can catch.
Tanya Dewey (author), Animal Diversity Web.