Continental Diversification of an African Catfish Radiation (Mochokidae: Synodontis). Syst. Biol

Abstract.—Despite African rivers containing high species diversity, continental-scale studies investigating the mechanisms generating biological diversity of African riverine faunas are limited compared with lacustrine systems. To investigate the build-up of diversity in a tropical aquatic continental radiation, we test different models of lineage diversification and reconstruct the biogeographic history in a species-rich siluriform genus, Synodontis (∼130 species), with a broad distribution across all major tropical African drainage basins. The resulting robust species-level phylogeny (∼60 % complete, based on a multigene data set) exhibits a near constant rate of lineage accumulation throughout themid-Cenozoic to recent, irrespective of missing species and despite the changing environmental conditions that were prevalent during this time period. This pattern contrasts with the findings for species-level diversification of large clades that commonly show an early burst of cladogenesis followed by declining rates through time. The identification of distinct biogeographic clades demonstrates