One of the largest components of the freshwater fish fauna world-wide is the order Characiformes with nearly 2,000 species now recognized from myriad drainages of the New World and Africa . Over 300 characiform species have been described in the last decade, primarily from the Neotropics and the pace of descriptions of new species gives no sign of abating. The characiform faunas on the two sides of the Atlantic Ocean demonstrate pronounced asymmetry in terms of numbers of both species and supraspecific taxa. The African components of the order include circa 220 recognized species. These range south from the Nile River basin in the deserts of North Africa through much of the rest of the continent, with maximum diversity in the wetter areas such as the Congo River Basin, West Africa and Lower Guinea. On the other side of the Atlantic Ocean, over 1,700 species are now recognized extending from the southwestern portions of the United States south through Mexico and Central and South America to central Chile and Argentina. Major drainage basins in South America are all home to large and taxonomically overlapping assemblages of characiform species. Characiforms inhabit a range of ecosystems extending from the swiftly flowing rivers and streams of the Andean piedmont and cordilleras of the Neotropics through to the lentic backwaters of lowland flood plains in the Americas and Africa. Within these habitats, characiforms range from dozens of miniature and diminutive species (sensu Weitzman and Vari ) through to hundreds of midsized to giant species. Among the larger forms, many are economically and ecologically important, with some dominant in various drainages in terms of the total fish biomass. These and other characiform species play key roles for intra-ecosystem energy flux and material cycling in lowland river systems and as ecosystem engineers (e.g. Prochilodontidae - [3, 4])."
Phylogenetic relationships within the speciose family Characidae (Teleostei: Ostariophysi: Characiformes) based on multilocus analysis and extensive ingroup sampling