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Mormyridae
Pollimyrus marianne Kramer, van der Bank, Flint, Sauer-Gürth and Wink 2003
EOL Text
This taxon is one of a number of benthopelagic species in the Zambezi River system of southern Africa. Benthopelagic river fish are found near the bottom of the water column, feeding on benthos and zooplankton
Nutrient levels in the Zambezi River are relatively low, especially in the upper Zambezi; in that reach, above Victoria Falls, most of the catchment drains Kalahari sands, whose nutrient levels are inherently low due to their aeolian formation; moreover, agricultural fertilizer addition throughout the Zambezi watershed is low, due to the shortage of capital available to farmers of this region.
Nitrate levels (as nitrogen) in the upper Zambezi are typically in the range of .01 to .03 milligrams per liter. Correspondingly electrical conductivity of the upper Zambezi is on the order of 75 micro-S per centimeter, due to the paucity of ion content. From the Luangwa River downstream nitrate levels elevate to .10 to .18 milligrams per liter, and electrical conductivity rises to a range of two to four times the upper Zambezi levels. Not surprisingly, pH, calcium ion concentration, bicarbonate and electrical conductivity are all higher in portions of the catchment where limestone soils predominate compared to granite.
There are a total of 190 known fish species present in the Zambezi River, including eel and shark taxa. The largest native benthopelagic fish in the Zambezi are the 170 cm North African catfish (Clarias gariepinus), the 146 cm common carp (Cyprinus carpio carpio), the 150 cm Indo-Pacific tarpon (Megalops cyprinoides) and the introduced 120 cm rainbow trout (Oncorhynchus mykiss).
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Rights holder/Author | For non-commercial re-use with attribution |
Source | http://www.eoearth.org/article/Zambezi_River?topic=78166 |
Red List Criteria
Year Assessed
Assessor/s
Reviewer/s
Contributor/s
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Rights holder/Author | © International Union for Conservation of Nature and Natural Resources |
Source | http://www.iucnredlist.org/apps/redlist/details/63329 |
Population
Population Trend
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Rights holder/Author | © International Union for Conservation of Nature and Natural Resources |
Source | http://www.iucnredlist.org/apps/redlist/details/63329 |
Major Threats
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Rights holder/Author | © International Union for Conservation of Nature and Natural Resources |
Source | http://www.iucnredlist.org/apps/redlist/details/63329 |
Least Concern (LC)
License | http://creativecommons.org/licenses/by-nc/3.0/ |
Rights holder/Author | Armi G. Torres, FishBase |
Source | http://www.fishbase.org/summary/SpeciesSummary.php?id=62293 |
Conservation Actions
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Rights holder/Author | © International Union for Conservation of Nature and Natural Resources |
Source | http://www.iucnredlist.org/apps/redlist/details/63329 |
Found in fast-flowing areas of river with rapids and rocky bottom where there is little cover, except for crevices and rock holes, and also from dense reed beds on sandy bottoms and weak current (50438).
License | http://creativecommons.org/licenses/by-nc/3.0/ |
Rights holder/Author | Armi G. Torres, FishBase |
Source | http://www.fishbase.org/summary/SpeciesSummary.php?id=62293 |
Upper Zambezi River system. Described from the lower part of the Upper Zambezi River, its overall range is uncertain. Photographs in Kramer et al. (2003) show a more slender species than P. castelnaui (Boulenger 1911), and Tweddle et al. (2004) recognised both deep-bodied and slender Pollimyrus species throughout the Upper Zambezi system. Taxonomic study of their collection may help to clarify the distribution.
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | © International Union for Conservation of Nature and Natural Resources |
Source | http://www.iucnredlist.org/apps/redlist/details/63329 |
Upper Zambezi River, eastern Caprivi, Africa.
Africa: Upper Zambezi River.
License | http://creativecommons.org/licenses/by-nc/3.0/ |
Rights holder/Author | Armi G. Torres, FishBase |
Source | http://www.fishbase.org/summary/SpeciesSummary.php?id=62293 |