Aim The formation history of Africa’s current river basins remains largely unknown. In order to date changes in landscape and climate, we studied the biogeography of the African freshwater fish with the largest natural distribution. We also validated biogeographic units. Location Continental Africa. Taxon Clarias gariepinus sl. Methods We investigated mitochondrial cytb sequences of 443 individuals from 97 localities, using a haplotype network and a genetic landscape analysis. We inferred a dated phylogeny using maximum...