South American lungfish

Lungfish (subclass Dipnoi) are a group of six living species of air-breathing fish, along with extinct relatives. They are characterized by possessing one or two lungs and first appeared in the Early Devonian Epoch. Today, lungfish inhabit rivers and lakes in Africa, South America, and Australia.

The South American lungfish, Lepidosiren paradoxa, can reach lengths of about 1.25 meters (4 feet). These fish are notable for their peculiar lifestyles and disjunct distribution across Earth's tropical regions. While their economic importance is generally slight, they are consumed as food in some parts of Africa and locally in South America. Lungfish are particularly interesting to scientists due to their ability to breathe atmospheric air, a trait that allows them to survive in oxygen-poor waters.1