The African Lungfish (Protopterus aethiopicus) and the Australian Lungfish (Neoceratodus forsteri) are both ancient eel-like fish, with an elongated body and a paddle tail.
The African Lungfish has a pair of lungs, whereas the Australian Lungfish has one single lung.
The African Lungfish loses the function of its gills and uses only its lungs.
The Australian Lungfish retains the function of its gills and only uses its lungs when there is not enough water to breathe (such as during droughts).
The African Lungfish can live out of water for 3-4 years under the mud in a sleep state called aestivation.
The Australian Lungfish can live out of water only for several days if its body is kept moist. It cannot survive complete water depletion.
The African Lungfish grows to 180 centimetres (72 inches), whereas the Australian Lungfish grows to about 150 centimetres (57 inches) in length.
The African Lungfish is an obligate air breather (restricted to one function – i.e. the use of its two lungs). The adult African Lungfish always breathes with its lungs, and not with its gills.
The Australian Lungfish is a facultative air breather, only breathing air with its one lung when oxygen in the water is not sufficient. It is the only facultative air breathing lungfish in the world. The adult Australian Lungfish can breathe with its gills and with its lung.
Photographer: Martina Nicolls
Martina Nicolls: SIMILAR BUT DIFFERENT IN THE ANIMAL KINGDOM