African Lungfish

Marbled_lungfish_1

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The African lungfish is a medium-sized fish living in Africa (duh!). There are other lungfishes besides the African lungfish and these animals live in South America and Australia. The African lungfish is actually a genus containing the following four species: the marbled lungfish, the gilled African or east African lungfish, the spotted African or slender lungfish, and the west African lungfish. The marbled lungfish has three subspecies and the west African lungfish has two subspecies.

These fish have both gills and lungs, and even though they can breathe with their gills while underwater, they still need to take a breath of air every once in a while in order to get enough oxygen. These fish can even drown if they are held underwater for a long time. The organ used to breathe above water scientifically speaking is not actually a lung but an air bladder that was made with the ability to extract oxygen for the fish to use.  Most of the time lungfishes move around like eels, but they can use their long, thin fins to “walk” on land or on the bottom of a body of water. These bodies of water include lakes, streams, rivers, and swamps. Although these animals can grow very large and are predators, they are often kept as pets. Here are three short videos about these fish: one, two, and three

Size

African lungfishes can grow up to 78 inches (2 m) long. This is the same as 6.5 feet, longer than most people are tall! Despite being so long, these fish are skinny and only weigh at most 25 pounds (11 kg). These measurements are the size for the marbled lungfish, the largest species of all lungfish. The gilled African lungfish is the smallest lungfish in the world, reaching only seventeen inches (1.4 feet or 44 cm) long.

Diet

As I mentioned earlier, lungfishes are predators. They eat several small animals including shrimp, frogs, clams, insects, fish, and crustaceans. In zoos, lungfish feed mainly on krill although other invertebrates and fish may be eaten. Typically these animals are not picky eaters and will eat pretty much any fleshy animals that comes their way, if they are hungry that is. In some rare occasions, lungfish have been reported to eat plants.

Hibernation

Unlike many fish, the African lungfish hibernates. This is not during the winter as with most other hibernating animals but during the dry season when the rivers these fish live in dry up. Since other fish cannot breathe air, they die from lack of oxygen, but the lungfish still survives. When all of the water has dried up but there is still mud left, African lungfish will burrow into the mud. They do this by swallowing the mud and pushing it out of their gills. After the fish has reached a certain depth, it will stop digging and secrete a mucous out of its skin. Once the mucous hardens it forms a protective barrier around the lungfish. This barrier lets air in for the fish to breath but keeps water in so it can stay hydrated. While most other animals digest fat while hibernating, the lungfish will digest muscle tissue in its tail. Because of this, lungfish are very weak after hibernating.

Native Africans will sometimes use mud blocks to build their houses. Occasionally a lungfish will be inside one of these blocks. This is not bad news for the lungfish however, for when it eventually rains, the mud will soften, the mucous barrier will liquefy, and the lungfish will wriggle out and find a new body of water to call home. Even if the rains take a while to come again the lungfish is able to survive for up to four years in the mud!

Reproduction

Eggs are normally laid in muddy underwater holes during the rainy season. I could not find how many eggs are laid, but whatever the number is, the male fertilizes them after they are laid and then guards them for the week they remain as eggs. For the fist two or three months after hatching, the young must remain underwater. During this time, their lungs are not fully developed, and their gills are external branches much like with newts. After these few months are up, the lungs are completely developed and the branch-like gills have disappeared in exchange for gill slits that lead to internal gills. These fish can live for up to twenty-five years in the wild and presumably longer in captivity.

 Don’t forget to scroll down and comment your guess about what the next animal is!

Andrias_japonicus_pair

Sources:

Photo credits:

  • Lungfish – OpenCage
  • Mystery animal – V31S70

One Response

  1. Japanese giant salamander
    Japanese giant salamander at |

    […] the world, only smaller than the Chinese giant salamander. Like last week’s animal the African lungfish, Japanese giant salamanders can breathe both above and under water. These animals have small eyes […]

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