Abstract

RIVERO, ANA BONILLA  and  LOPEZ ROJAS, HÉCTOR. Biogeographic Analysis of the Characiformes Fishes of Venezuela. Acta biol.Colomb. [online]. 2013, vol.18, n.1, pp.69-86. ISSN 0120-548X.

Based on the information available on fishes of the order Characiformes of Venezuela a biogeographical analysis was performed to explore the relative importance of the processes that may have contributed to the establishment of current distribution patterns of the Venezuelan continental ichthyofauna. Geographic and phylogenetic information available for this group of fishes was analyzed by Parsimony Analysis of Endemicity (PAE) and Brooks Parsimony Analysis (BPA). PAE uncovered the western plains and southern Amazonas as areas of endemism. BPA, using the phylogenetic information of seven genera, showed a general pattern with two major clades (Caribbean + Maracaibo) and ((((Rio Negro + Orinoco River) + Paria) + Valencia) + Cuyuní), where the proposed hypothesis highlights a dispersion event from the Rio Negro basin to the Orinoco River. The results indicate that the plains-Amazonas region, where the Amazon biota mixed with that of the incipient Orinoco s biota, contains the largest species richness, areas of endemism, and well as many speciation events with posterior dispersion to other regions of Venezuela. The biota of the northern coastal region in turn seems rather governed by punctual vicariant speciation processes, which may have been conditioned by the historical isolation of the basins draining this region.

Keywords : BPA; dispersal; fishes; PAE; vicariance.

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