Phylogenomics of African Labeo (Cypriniformes: Cyprinidae) emphasizing central African species

Labeo constitutes the largest genus within the cyprinid tribe Labeonini with over 110 recognized species in Africa and Asia. The clade comprises a major component of the herbivore/detritivore guild with considerable socio-economic importance to artisanal and commercial fisheries. A pan-African distribution and wide variety of habitat occupancy make the group a model to investigate diversification patterns, eco-phenotypic variation, and biogeographical events underpinning their radiation at a continental scale. However, previous attempts to elucidate Labeo systematics using either molecular or morphological data have failed to produce congruent and robust results, and much taxonomic and nomenclatural confusion remains. Here we present the first phylogenomic analysis of the genus using 2,187 ultraconserved elements from 85 taxa, including 56 recognized species, 27 cryptic (candidate) species, and outgroups from the Asian Labeonini. Both concatenated and coalescence-based phylogenetic analyses strongly support monophyly of African Labeo and recover three major clades comprising at least nine species groups. Two main clades are pan-African, while the third is restricted to four ichthyofaunal provinces. With the single exception of the L. umbratus group, none of the previously proposed morphological groupings are resolved as monophyletic, suggesting rampant morphological convergence across the radiation. In this study, interspecific relationships are well resolved and time calibration results corroborate the key role of the Miocene in the radiation of African freshwater fishes. We identify numerous previously unrecognized taxa, and our study provides a much-needed framework for the taxonomic revision of Labeo, a task critical for the development of sound management of these important food fishes.