Surrounded by Great Lakes: Assessing the ichthyological diversity of Northern Zambian drainage systems

In contrast to the fish diversity of the African Great Lakes, in particular cichlid fishes, the ichthyofauna of most river systems in Africa is poorly documented and remains critically understudied. Here we focus on the fish fauna of Northern Zambia, a region that is located between two African Great Lakes and covers the contact zones between three major drainage systems: the Zambezi drainage system, the Congo drainage system, including the Lake Tanganyika catchment and the Lake Rukwa drainage system. Our study contributes to the taxonomic knowledge of this region by providing DNA barcodes (COI) of 315 newly acquired museum voucher specimens representing approximately 125 species, together with distribution details of these species as well as those for which no barcodes have been obtained during this study. The barcoding efforts focused mainly on the fish fauna of the Luangwa River and its tributaries, the Lufubu River, the Upper Chambeshi, the Saisi River and included some Lake Malawi affluents as well. In total, 147 fish species, distributed over 16 families and 46 genera, were recorded from 38 sampling locations. A large proportion of these species appear to be undescribed. This is best exemplified by the fish fauna of the Lufubu River, where from the 37 species recorded, 25 represent candidate species putatively endemic to the system. This first step to establish a DNA barcode library for the freshwater fish diversity of Northern Zambia will serve as valuable tool for the taxonomic inventory of this region as well as for future conservation actions.