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bichir
bichir , common name for African freshwater fishes as of the family Polypteridae, and particularly for those of the genus Polypterus. Bichirs are among the most primitive of the ray-finned fishes, or Actinopterygii, the dominant group of modern fishes. The long, narrow body of Polypterus is 2 to 3 ft (60–90 cm) long and is covered by thick, rhombic scales made of an enamellike substance called ganoine. Such scales were also present in the earliest ray-finned fishes, now extinct, and are quite different from those of other living fishes. The dorsal fin of the bichir is split into a row of small, saillike finlets that are erected when the animal is agitated. Like the sharks and the rays, it has a pair of spiracles. The bichir seems especially adapted to life in dry environments. Instead of the swim bladder of most ray-finned fishes, it has a pair of lungs, somewhat like those of the lungfishes , which enables it to survive out of water for several hours. It also resembles the lungfishes in having a pair of external gills when newly hatched. The bichir is a bottom-dwelling fish, found in the Nile and in the rivers of W Africa. When these rivers overflow in late summer, it moves out to spawn in the flood marshes. It is sometimes caught as a food fish. In addition to the ten species of Polypterus, the bichir family includes the reedfish, Erpetoichthys calabaricus, similar in character and distribution, but with a longer, more eellike form. Bichirs are classified in the phylum Chordata , subphylum Vertebrata, class Osteichthyes, order Polypteriformes, family Polypteridae. |
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"bichir." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. 31 May. 2012 <http://www.encyclopedia.com>. "bichir." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. (May 31, 2012). http://www.encyclopedia.com/doc/1E1-bichir.html "bichir." The Columbia Encyclopedia, 6th ed.. 2011. Retrieved May 31, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-bichir.html |
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bichir
bichir (Polypterus) See BRACHIOPTERYGII; POLYPTERIDAE.
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Cite this article
MICHAEL ALLABY. "bichir." A Dictionary of Zoology. 1999. Encyclopedia.com. 31 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "bichir." A Dictionary of Zoology. 1999. Encyclopedia.com. (May 31, 2012). http://www.encyclopedia.com/doc/1O8-bichir.html MICHAEL ALLABY. "bichir." A Dictionary of Zoology. 1999. Retrieved May 31, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O8-bichir.html |
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