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(West African lungfish breathing air)
Lungfish are a species of rhipidistian freshwater fish found in Australia, Africa, and South America. Although Lungfish may look like any other lobe-finned fish at first glance, they hide a huge secret. They can do what no other species of fish can– breathe air.
Fossil records reveal that Lungfish have existed since the Triassic era, and the many unique abilities they have (such as the ability to breathe air), are the primitive characteristics of the Osteichthyes (bony fish) group and the Sarcopterygii (lobe-finned fish) group that they retained.
The reason lungfish can breathe air unlike other fish is that, well like their name suggests, they have lungs. Lungfish actually possess a highly specialized respiratory system, where they have a lung that is connected to the pharynx and the larynx without a trachea. While many species of fish are capable of breathing air through modified gas bladders, lungfish are the only ones that can do so using complex lungs with small air sacs. All species of lungfish except the Australian lungfish possess 2 lungs that are homologous to that of tetrapod lungs. But hey don’t feel bad for the Australian lungfish. Although they might not be as efficient as the other species of lungfish when breathing air, they are actually the only species of lungfish that have gills. You win some, you lose some.
Wow. Lungfish are cool aren’t they. Well here comes the bad news. Many species of lungfish are currently endangered due to the man-caused destruction of many of their breeding and nursing sites. Dams are the biggest contributors to this, as the constructions of dams deplete the availability of shallow water habitats lungfish need to mate. In order to make sure that these cool lungfishes don’t go extinct like many of their prehistoric cousins, we need to help them against habitat loss– use less water, reduce your carbon footprint, and spread awareness!
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Photo credit: https://animals.sandiegozoo.org/animals/west-african-lungfish