Air Breathing
Bichirs possess paired lungs which connect to the esophagus via a glottis. They are obligate air-breathers, requiring access to surface air to breathe in poorly oxygenated water. Their lungs are highly vascularized to facilitate gas exchange. Deoxygenated arterial blood is brought to the lungs by paired pulmonary arteries, which branch from the fourth efferent branchial arteries (artery from the fourth gill arch), and oxygenated blood leaves the lungs in pulmonary veins. Unlike most lungfish and tetrapods, their lungs are smooth sacs instead of alveoated tissue. Bichirs are unique in that they breath using a recoil aspiration.
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Famous quotes containing the words air and/or breathing:
“I date the end of the old republic and the birth of the empire to the invention, in the late thirties, of air conditioning. Before air conditioning, Washington was deserted from mid-June to September.... But after air conditioning and the Second World War arrived, more or less at the same time, Congress sits and sits while the presidents—or at least their staffs—never stop making mischief.”
—Gore Vidal (b. 1925)
“The cayote is a living, breathing allegory of Want. He is always hungry. He is always poor, out of luck and friendless. The meanest creatures despise him, and even the fleas would desert him for a velocipede.”
—Mark Twain [Samuel Langhorne Clemens] (1835–1910)