This is the first detailed study on the biology of S. nigromaculatus in the section studied of the Okavango River that forms the international border between Namibia and Angola. It was found to be abundant especially in the floodplain habitats in the eastern section of the river. The minimum length at which this species matures in the Okavango River correlates with the population from the Okavango Delta. Furthermore, the annual flood was found to be the main stimulant for reproduction. The status of S. nigromaculatus in the Okavango River is not threatened, but future monitoring is essential. Changes in the annual flood and degradation of the floodplains may prove to be detrimental to this species. Keywords: Growth, mortality, reproduction, habitat.