African lungfish (confirmed introduction)
African lungfish (confirmed introduction) ) is special in that they can use their swim bladders instead of lungs to breathe, which allows the African lungfish to survive the low water periods in winter, although the African lungfish does not actually use its lungs to breathe.
Living in fresh water, in addition to breathing with gills, they can also breathe with their swim bladders instead of lungs. Even in periods of dry water, they burrow into the mud for aestivation, which can last for several months. . But sometimes moderation. The reason why lungfish can survive outside the water is that, as its name suggests, it can use its "lungs" to breathe.
The swim bladder of the African lungfish is very developed. The front end of the entire swim bladder is partially merged into a single chamber, and the length is very short. There are different pulmonary chambers (alveoli), and each pulmonary chamber is divided into many pulmonary sacs (pulmonary vesicles). The structure is very close to the lungs of land animals.
Since the swim bladder of the African lungfish has the function of a lung in terms of psychological structure, it is filled with a complex network of branched blood vessels and spiral valves. There is a short swim bladder connected to the esophagus, which can be used in the event of hypoxia. The swim bladder is used to absorb oxygen and eliminate carbon dioxide. Interestingly, the African lungfish also hides itself deep in the mud during the dry season, and uses the surrounding soil to build a very strong "small mud hole" and opens a small breathing hole in front of its mouth. Lying quietly inside, sleeping in the summer, spending the 6-month long dry season. When the rainy season comes, it bursts out of the hole.
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