Bichir
| Bichirs Temporal range: Cretaceous–Recent [1] |
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| Polypterus bichir | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Polypteriformes |
| Family: | Polypteridae |
| Genera | |
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Erpetoichthys |
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The bichirs are a family, Polypteridae, of archaic-looking ray-finned fishes, the sole family in the order Polypteriformes.
All species occur in freshwater habitats in tropical Africa and the Nile River system, mainly swampy, shallow floodplains and estuaries.
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[edit] Anatomy and appearance
Bichirs are elongated fish with a unique, subdivided series of dorsal finlets which varies in number from seven to eighteen, instead of a single dorsal fin. Each of the dorsal finlets have bifid (doubleedged) tips, and are the only fins with spines, the rest of the fins being composed of soft rays. The body is covered in thick, bonelike and trapezoidal ganoid scales. Their jaw structure more closely resembles that of the tetrapods than that of the teleost fishes. Bichirs have a number of other primitive characteristics, including fleshy pectoral fins superficially similar to those of lobe-finned fishes.[1] They also have a pair of slit-like spiracles used to exhale air, two gular plates and double ventral lungs (the left lung smaller than the right),[2] which allow them to obtain oxygen from the air when in poorly oxygenated waters,[3] by swimming quickly to the surface and back to the bottom. They are nocturnal, and feed on small vertebrates, crustaceans, and insects.[1] Four pairs of gill arches are present.[4]
Bichirs have a maximum body length of 97 centimetres (3.18 ft).[5]
[edit] Bichirs as aquarium specimens
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 tank-mates with other species that are large enough not to be prey. Some aquarists[who?] note that Loricariid catfish and common Plecostomus may attack bichirs and suck on their skin.
[edit] Species
There are twelve extant species in two genera:[5]
Order Polypteriformes
- Family Polypteridae
- Genus Erpetoichthys J. A. Smith, 1865
- Erpetoichthys calabaricus J. A. Smith, 1865 (Reedfish)
- Genus Polypterus Lacépède, 1803
- Retropinnis Group
- Polypterus retropinnis Vaillant, 1899 (West African bichir)
- Bichir Group
- Polypterus ansorgii Boulenger, 1910 (Guinean bichir)
- Polypterus bichir Lacépède, 1803 (Nile bichir)
- Polypterus bichir bichir Lacepède, 1803
- Polypterus bichir katangae Poll, 1941 (Most likely variant of Polypterus congicus)
- Polypterus bichir lapradei Steindachner, 1869
- Polypterus congicus Boulenger, 1898 (Congo bichir)
- Polypterus endlicheri Heckel, 1847 (Saddled bichir)
- Weeksii Group
- Polypterus mokelembembe Schliewen & Schäfer, 2006 (Mokèlé-mbèmbé bichir)
- Polypterus ornatipinnis Boulenger, 1902 (Ornate bichir)
- Polypterus weeksii Boulenger, 1898 (Mottled bichir)
- Senegalus Group
- Polypterus delhezi Boulenger, 1899 (Barred bichir)
- Polypterus palmas Ayres, 1850 (Shortfin bichir)
- Polypterus palmas buettikoferi Steindachner, 1891
- Polypterus palmas palmas Ayres, 1850
- Polypterus palmas polli J. P. Gosse, 1988
- Polypterus senegalus Cuvier, 1829 (Gray bichir)
- Polypterus senegalus meridionalis Poll, 1941 (Most likely variant of Polypterus senegalus senegalus)
- Polypterus senegalus senegalus Cuvier, 1829
- Polypterus teugelsi Britz, 2004 (Cross River bichir)
- Retropinnis Group
- Genus Erpetoichthys J. A. Smith, 1865
Extinct species include:
- Polypterus faraou Otero et al., 2006 — late Miocene.[6]
[edit] References
- ^ a b c Wiley, Edward G. (1998). Paxton, J.R. & Eschmeyer, W.N.. ed. Encyclopedia of Fishes. San Diego: Academic Press. pp. 75–76. ISBN 0-12-547665-5.
- ^ UF Vert Zoo Lab 3
- ^ Berra, Tim M. (2001). Freshwater Fish Distribution. San Diego: Academic Press. ISBN 0-12-093156-7
- ^ AccessScience | Encyclopedia Article | Polypteriformes
- ^ a b Froese, Rainer, and Daniel Pauly, eds. (2011). "Polypteridae" in FishBase. June 2011 version.
- ^ Otero, Likius, Vignaud & Brunet (2006). "A new polypterid fish: Polypterus faraou sp. nov. (Cladistia, Polypteridae) from the Late Miocene, Toros-Menalla, Chad". Zoological Journal of the Linnean Society 146 (2): 227. doi:10.1111/j.1096-3642.2006.00201.x.
[edit] External links
