Multilocus phylogeny and historical biogeography of <i>Hypostomus</i> shed light on the processes of fish diversification in La Plata Basin

Abstract

Distribution history of the widespread Neotropical genus <i>Hypostomus</i> was studied to shed light on the processes that shaped species diversity. We inferred a calibrated phylogeny, ancestral habitat preference, ancestral areas distribution, and the history of dispersal and vicariance events of this genus. The phylogenetic and distribution analyses indicate that <i>Hypostomus</i> species inhabiting La Plata Basin do not form a monophyletic clade, suggesting that several unrelated ancestral species colonized this basin in the Miocene. Dispersal to other rivers of La Plata Basin started about 8 Mya, followed by habitat shifts and an increased rate of cladogenesis. Amazonian <i>Hypostomus</i> species colonized La Plata Basin several times in the Middle Miocene, probably via the Upper Parana and the Paraguay rivers that acted as dispersal corridors. During the Miocene, La Plata Basin experienced marine incursions, and geomorphological and climatic changes that reconfigured its drainage pattern, driving dispersal and diversification of <i>Hypostomus</i> . The Miocene marine incursion was a strong barrier and its retraction triggered <i>Hypostomus</i> dispersal, increased speciation rate and ecological diversification. The timing of hydrogeological changes in La Plata Basin coincides well with <i>Hypostomus</i> cladogenetic events, indicating that the history of this basin has acted on the diversification of its biota.