Hyphessobrycon Durbin (Characiformes: Characidae) in the upper rio Paraná basin: taxonomy and systematic

Abstract

Brazil, besides being one of the megadiverse contries of the world, presents the most rich freshwater ichthyofauna. Hyphessobrycon Durbin, among brazilian fishes, is one of the most species-rich genus of the largest Characiformes family, the Characidae. The genus was recently restricted to a monophyletic group with 25 species of Characidae, which share the following non-ambiguous synapomorphies: paired projections on the paresphenpoid absent; conspicuous black spot present on the dorsal fin; ventral portion of the third infraorbital contacting preopercle laterosensorial canal; black or silver, longitudinal and medium lateral, stripe absent. So, based on the fact that knowing the diagnostic limits among species is very important, we herein propose the taxonomic analysis of the Hyphessobrycon species of the upper rio Paraná system ('H.' anisitsi, 'H.' balbus, 'H.' bifasciatus, 'H.' coelestinus, 'H.' duragenys, H. eques, 'H.' flammeus, 'H.' reticulatus), two among those threatened ('H.' duragenys and 'H.' flammeus), besides those still not recognized for the system (e.g. 'H.' moniliger), and other possibly new. Furthermore, a phylogenetic analysis including those taxe in a Characidae phylogenetic context will be also pursued.