Characidae

Characidae, the characids, is a family of freshwater subtropical and tropical fish belonging to the order Characiformes. They are found throughout much of Central and South America, including such major waterways as the Amazon and Orinoco Rivers. These fish vary in length; many are less than 3 cm (1.2 in).

The name "characins" is a historical one, but scientists today tend to prefer "characids" to reflect their status as a, by and large, monophyletic group (at family rank). This family includes some of the first characiforms to be described to science, such as Charax and Tetragonopterus, and thus lend their name to the order, as well as to common names such as "characin" and "tetra".

Past taxonomic treatments had a much more expansive definition of the family, including numerous South American fish families such as the piranhas and dorados, as well as the African alestids. Following multiple taxonomic revisions, this was eventually restricted to just the American "tetra" type characins by the 2010s. However, even this definition of Characidae was found to obscure much of the evolutionary diversity within the group, and in 2024 the "tetra" families Acestrorhamphidae and Stevardiidae were split out of the Characidae, leaving it with just five subfamilies.