Central Africa: It is found in the Lumbumbashi River, Democratic Republic of the Congo (Roberts 2003). However, Skelton P. says that is not in the Congo River basin (pers. comm.). These specimens are probably Leptoglanis brevis.
Eastern Africa: This species has been recorded in the Lake Malawi catchment area as well as tributaries of the Shire but is not found in the main Shire River. Also listed as occuring in the Malgarasi system and Lake Victoria drainage (affluent rivers).
Southern Africa: It occurs in the middle Zambezi, Zambia and Zimbabwe. It has also been found in the Cunene, Okavango, Pungwe, Buzi and Save systems.
Zambezi River Demersal Habitat
This taxon is one of a number of demersal species in the Zambezi River system of southern Africa. Demersal river fish are found at the river bottom, 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 fish species present in the Zambezi River, including eel and shark taxa. The largest native demersal species present are the 117 centimeter (cm) long tiger fish (Hydrocynus vittatus), the 175 cm African mottled eel (Anguilla bengalensis labiata), the 120 cm Indonesian shortfin eel (Anguilla bicolor bicolor), the 200 cm Giant mottled eel (Anguilla marmorata), the 150 cm African longfin eel (Anguilla mossambica), the 183 cm Sampa (Heterobranchus longifilis), the 150 cm Cornish jack (Mormyrops anguilloides) and the 700 cm largetooth sawfish (Pristis microdon).
Kunene River Demersal Habitat
This taxon is one of a number of demersal species in the Kunene River system. Demersal river fish are found at the river bottom, feeding on benthos and zooplankton
The Kunene River rises in the central highlands of Angola, and thence flows southward to form a major element of the border between Namibia and Angola before the final discharge is to the Atlantic Ocean in the vicinity of the Angola-Benguela Front. The geometry of the Kunene riparian zone is distinctly narrow, with rugged arid landscapes persisting on both sides of the river over long distances, and a virtual lack of any extensive floodplains.
There is a relatively high rate of endemism of aquatic biota in the Kunene. Proposed expansion of dams on the Kunene poses a threat to biodiversity in the river, especially regarding proposals at Epupa Falls. However, a greater threat to the Kunene is a plan by Angola to greatly expand withdrawal of water from the river to expand irrigated agriculture by 600,000 hectares; not only will this action significantly diminish downriver flow rates, but also add considerable nitrate, herbicide and pesticide substances to the river.
The catchment area of the Kunene Basin is approximately 106,560 square kilometres (41,143 square miles) in area, of which 14 100 km² (13%) lies within Namibian territory. Its mean annual discharge is 174 cubic meters per second (6145 cubic feet per second) at its mouth on the Atlantic. Water quality of the Kunene River is relatively high, since the human population density and agricultural intensity is relatively low, including a conspicuous absence of overgrazing. However, bacteria and other microbial pathogens pose a material threat to Kunene water quality, due to the fact that only a small fraction of the domestic wastewater in Angola is treated;
Regarding freshwater bivalves, the central reaches of the Kunene manifest particularly high endemism, similar to parts of the Okavango, Chobe, Upper Zambezi and Etosha Pan basins. The bivalve Etheria elliptica, which also occurs in the Upper Zambezi, is a freshwater mussel in the family Etheriidae, known from a limited extent of the central Kunene River in Angola. It is threatened by proposed dam construction on the Kunene.
There are two endemic denmersal fish in the Kunene: the 26 centimeter (cm) long demersal Kunene happy (Sargochromis coulteri) and the demersal fish Hippopotamyrus longilateralis.
Habitat and Ecology
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Zaireichthys rotundiceps, the Spotted sand catlet, is a species of loach catfish that occurs in the countries of Botswana, Kenya, Malawi, Mozambique, Namibia, Tanzania, Zambia and Zimbabwe with uncertain records from Burundi and the Democratic Republic of the Congo. This species may actually consist of several species. It reaches a length of 3.8 cm. The colouration of Z. rotundiceps is highly variable, from abundant dark spots in several rows to a light pale spotting pattern; marks are often present on the head and fins as well as the body. The humeral process of the pectoral girdle is moderately long with poorly developed or fine denticulations. The caudal fin shape is variable, from slightly forked through, emarginate, truncate, or even slightly rounded, but not deeply forked. The dorsal and pectoral fins have strong and stout spines. It inhabits fairly shallow water where it occur over sand, usually buried with just the eyes protruding. Its eggs are few (12–16) and large (3–5 millimetres diameter), which suggests that the parents may care for the eggs and young.
- Froese, Rainer and Pauly, Daniel, eds. (2011). "Zaireichthys rotundiceps" in FishBase. December 2011 version.
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