Found over rocks in mainstream and in large soft-bottomed floodplain lagoons. Grazes algae and aufwuchs as well as detritus. A shoaling species, breeding in summer, possibly in flooded marginal habitats, as the young fish are caught in large numbers in fish-weirs set across floodwaters receding from floodplains (Ref. 7248).

Africa: Upper Zambezi/Okavango Rivers.

The upper Zambezi and Okavango systems (Skelton 2001).

Southern Africa.

Maximum size: 400 mm SL

40.0 cm SL (male/unsexed; (Ref. 7248)); max. published weight: 2,500 g (Ref. 7248)

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).

benthopelagic; potamodromous (Ref. 51243); freshwater

Habitat and Ecology

Systems

• Freshwater

Potamodromous. Migrating within streams, migratory in rivers, e.g. Saliminus, Moxostoma, Labeo. Migrations should be cyclical and predictable and cover more than 100 km.

Frequency of occurrence in Caprivi: occasionally in sandy streams, rocky streams, shallow swamps, frequently in standing deep water (Ref. 37065). Found over rocks in mainstream and in large soft-bottomed floodplain lagoons. Grazes algae and aufwuchs as well as detritus. A shoaling species, breeding in summer, possibly in flooded marginal habitats, as the young fish are caught in large numbers in fish-weirs set across floodwaters receding from floodplains (Ref. 7248).

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Specimens with Barcodes: 2
Species With Barcodes: 1

Population

Population Trend

Least Concern (LC)

Major Threats

Conservation Actions

fisheries: subsistence fisheries