Lungfish can survive in poorly aerated waters since they have lungs which make its possible for them to obtain oxygen directly from the air. The lungs are related to those in primitive amphibian animals. Today, there are six known Lungfish species in world, but they used to be much more common. Lungfish have been around since the Lower Devonian era and during earlier stages of the planets history there existed much more than six lungfish species. Those species that have survived have changed little since the Lower Devonian age. The Australian lungfish have for instance looked pretty much the same during the last 100 million years.

Today, you will find wild Lungfish in Africa, South America and Australia. The African and South American Lungfish species all belong to the family Lepidosirenidae, while the Australian Lungfish has its own family the Ceratodidae. As mentioned earlier, all Lungfish species are capable of breathing oxygen from the air. Other shared features are their large, elongated and snakelike bodies. They are also predators and will eat pretty much anything that they manage to catch. Fish is their staple food, but they will happily also gulp down crustaceans, larger insects and other aquatic creatures. They are very robust and can survive in waters shunned by most other fish species. If you want to keep Lungfish in your aquarium you should however avoid the highest pH-values. Before you buy a Lungfish for your aquarium should consider their size. The largest Lungfish is one of the African lungfish species, a fish which can reach a maximal size of 2 metres / 6 feet which makes it unsuitable for hobbyist aquariums. Even the smaller Lungfish species grow very large and should only be housed in huge tanks.

In Africa, you will find four different Lungfish species. Protopterus annectens is the most popular species among aquarists. The three other ones are Protopterus aethiopicus, Protopterus amphibious and Protopterus dolloi. You should never get an African lungfish unless your aquarium is very large, since they grow rapidly. As long as you can provide them with enough space, they are however though fishes that will tolerate a wide range of water conditions. They will eat all sorts of food. Even though they are predatory fish, it is not very hard to make them accept dry and frozen foods. When kept on a diet of prepared food they will still appreciate occasional live treats. This means that your African lungfish should ideally be housed alone since it will happily devour any tank mates. If the other fish is too large to swallow, the African lungfish will simply bite chunks out of it until it is fully consumed.

On the South American continent you will only find one Lungfish, Lepidosiren paradoxa. This Lungfish can also be kept in aquariums and its requirements are very similar to the African lungfish species. Just like its African cousins, it must be given plenty of room. Lepidosiren paradoxa can reach a maximal size of 1.2 meters / 4 feet.

The Australian Lungfish, Neoceratodus forsteri, can also be kept in aquariums but you should be aware of the fact that they are CITES listed. You are only allowed to by Australian Lungfish from licensed breeders and if you live anywhere outside Australia it can be hard to get exportation and importation licenses. The Australian Lungfish is also known as Queensland Lungfish.