The bichirs are a family, Polypteridae, of archaic-looking ray-finned fishes, the sole family in the order Polypteriformes.

Anatomy and appearance

They have thick bonelike ganoid scales and a series of 8-15 dorsal finlets instead of a single dorsal fin. Each of these finlets have a sharp spine. Their jaw structure more closely resembles that of the tetrapods than that of the teleost fishes. Bichirs have a number of other primitive characteristics. One of these such characteristics are fleshy pectoral fins similar to lobe-finned fishes. They also have spiracles. All species occur in freshwater habitats in Africa, mainly swampy, shallow floodplains and estuaries. They have rudimentary lungs, which allow them to obtain oxygen from the air when in poorly oxygenated waters, by swimming quickly to the surface and back to the bottom.

The maximum length among these species is about 90 cm, although most will not exceed much more than 30 cm.

Relationship to humans

Bichirs are popular subjects of public and large hobby aquaria. Though predatory, they are otherwise peaceful and relatively nonactive, preferring to lie on the bottom, and make good tankmates with other species that are large enough not to be prey. Some aquarists note that Loricariid catfish may attack bichirs and suck on their skin.

Species

There are eighteen extant species and subspecies in two genera:

• Genus Erpetoichthys
• Reedfish, Erpetoichthys calabaricus Smith, 1865.
• Genus Polypterus
• Guinean bichir, Polypterus ansorgii Boulenger, 1910.
• Nile bichir, Polypterus bichir bichir Lacépède, 1803.
• Polypterus bichir katangae Poll, 1941.
• Bichir, Polypterus bichir lapradei Steindachner, 1869.
• Barred bichir, Polypterus delhezi Boulenger, 1899.
• Polypterus endlicheri congicus Boulenger, 1898.
• Saddled bichir, Polypterus endlicheri endlicheri Heckel, 1847.
• Polypterus mokelembembe Schliewen & Schafer, 2006.
• Ornate bichir, Polypterus ornatipinnis Boulenger, 1902.
• Polypterus palmas buettikoferi Steindachner, 1891.
• Shortfin bichir, Polypterus palmas palmas Ayres, 1850.
• Polypterus palmas polli Gosse, 1988.
• West African bichir, Polypterus retropinnis Vaillant, 1899.
• Polypterus senegalus meridionalis Poll, 1941.
• Gray bichir, Polypterus senegalus senegalus Cuvier, 1829.
• Polypterus teugelsi Britz, 2004.
• Mottled bichir, Polypterus weeksii Boulenger, 1898.

Extinct species include:

• Polypterus faraou Otero et al., 2006 — late Miocene.

References

External links

• FishBase entry for Polypteridae