Thursday, 16 February 2017

The Lungfish: A Fish Lives Without Water

The lungfish, also known as “salamanderfish”, is a type of freshwater fish actually famous for its ability to live on land, without water, for months on end, and sometimes even years. The lungfish name suggests, the fish have a highly evolved respiratory system that can take oxygen straight from the air, similar of land animals do. However, few species of lungfish are quite used to breathing air that they gradually lose the function of their gills as the fish reach adulthood. Whereas they still live in water, and their requisite to frequently come up to the surface for fresh air. The lungfish can even drown if they are keeping him for underwater for a long time. It has elongated bodies, just like eels, with thread-like pectoral and pelvic fins which they use to swim and crawl along the bottom. The lungfish usually inhabit shallow waters, such as swamps and marshes, but they’re also found in bigger lakes. Lungfish is feeding on fish, insects, crustaceans, worms, molluscs, amphibians and plant matter. They have an intestinal spiral valve rather than a true stomach. Normally, lungfish excrete nitrogenous waste as ammonia directly into the water. The lungfish can be extremely long-lived.

Moreover, when there’s water, the lungfish acts like any other fish, swimming in the waters and eating small fish and crustaceans on the bottoms of ponds and streams. However when the dry season comes, the lungfish burrows itself deep into the mud, digging out a path by taking mud into its mouth and forcing it out its gills. Thus after the fish has touched a comfortable depth, the fish will stop digging and secrete a mucous out of its skin that hardens to form a protective cocoon around it. Though only the mouth is left showing for breathing. Therefore, for its long hibernation, the lungfish will greatly decrease its metabolism and live off the muscle tissues in its tail. Because once the water returns and the mud soften, it will wriggle out of its burrow. Furthermore, some reports claim that the fish can stay underground in dried mud for as long as four years. The lungfishes are found only in Australia, Africa, and South America. In Africa, the people use to eat lung fish that would often dig out the fish from dry soil. The fish is said to have a strong taste, and is not enjoyed by all. 

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