The Australian lungfish has a single lung that can be used to breathe during dry periods. It belongs to a lineage of air-breathing fishes that appeared in the fossil record around 380 million years ago. These ancient aquatic animals were related to the ancestors of modern-day birds, amphibians, reptiles and mammals. | National Aquarium

The West African lungfish is an ancient species that has survived on Earth for more than four hundred million years. Known for its remarkable resilience, it can endure extreme droughts by burrowing into the mud and forming a hardened mucus cocoon around itself. During this state, called aestivation, the lungfish slows its metabolism to a near standstill and can survive for up to three years without food or water, breathing through a tiny air hole until the rains return. When the rivers fill agai