Evolutionary and biogeographic history of the subfamily Neoplecostominae (Siluriformes: Loricariidae).

Abstract

Freshwater fish evolution has been shaped by changes in the earth's surface involving changes in the courses of rivers and fluctuations in sea level. The main objective of this study is to improve our knowledge of the evolution of loricariids, a numerous and adaptive group of freshwater catfish species, and the role of geological changes in their evolution. We use a number of different phylogenetic methods to test the relationships among 52 representative taxa within the Neoplecostominae using 4676 bps of mitochondrial and nuclear DNA. Our analysis revealed that the subfamily Neoplecostominae is monophyletic, including Pseudotocinclus, with three lineages recognized. The first lineage is composed of part of Pareiorhina rudolphi, P. cf. rudolphi, and Pseudotocinclus; the second is composed of Isbrueckerichthys, Pareiorhaphis, Kronichthys, and the species Neoplecostomus ribeirensis; and the third is composed of Pareiorhina carrancas, P. cf. carrancas, Pareiorhina sp. 1, a new genus, and all the species of the genus Neoplecostomus, except N. ribeirensis. The relaxed molecular clock calibration provides a temporal framework for the evolution of the group, which we use for a likelihood-based historical biogeographic analysis to test relevant hypotheses on the formation of southeast Brazil. We hypothesize that headwater capture events and marine regressions have shaped the patterns of distribution within the subfamily Neoplecostominae throughout the distinct basins of southeast Brazil.