Lungfish are a type of freshwater fish known for their unique ability to breathe air. They possess both gills and lungs, allowing them to survive in low-oxygen environments. There are several species of lungfish, primarily found in Africa, South America, and Australia. They can live in stagnant waters and are known for their ability to aestivate, a form of dormancy during dry periods. These fish have elongated bodies and can grow quite large, with some species reaching over four feet in length. Lungfish are considered important for understanding the evolution of vertebrates, as they share characteristics with early land-dwelling animals. Their diet mainly consists of insects, crustaceans, and plant material.