West African lungfish are prehistoric animals. They have survived unchanged for so long (nearly 400 million years) that they are sometimes nicknamed “living fossils.” West African lungfish have remarkable adaptations that have helped them survive: a primitive lung and the ability to survive in a state of estivation, which is similar to hibernation.

A lungfish’s lung is a biological adaptation. A biological adaptation is a physical change in an organism that develops over time. Like all fish, lungfish have organs known as gills to extract oxygen from water. The biological adaptation of the lung allows lungfish to also extract oxygen from the air.

A lungfish’s estivation also involves a number of biological adaptations, including the excretion of a mucus “cocoon” and digestion of the fish’s own muscle tissue to obtain nutrients.

A lungfish’s estivation also includes a behavioral adaptation. A behavioral adaptation describes a way an organism acts. Prior to estivation, lungfish furiously burrow into the muddy ground. The behavioral adaptation of burrowing allows lungfish to create a protected habitat where they can survive during a long period of dormancy.

Watch this video, from the Nat Geo WILD series “Destination Wild,” and use our glossary to help answer questions in the Questions tab. Learn more about these fascinating fish with our Fast Facts.