Cheirodon is a genus of small characins, the type genus of the subfamily Cheirodontinae, found across a broad swath of South America, with atlas records from Brazil, Chile, Argentina, Peru, Uruguay, Bolivia, and Colombia. The 11 species covered here are small, typically 1–2.5 in, silvery, laterally compressed fish that generally shoal in open water. Unusually for a characin genus, several Cheirodon species live at higher latitudes and cooler temperatures than most tetras, reaching well south into temperate Chile and Argentina rather than staying confined to the tropics.
Cheirodon pisciculus, the Chilean tetra, and Cheirodon interruptus, the Uruguay tetra, are the best known in the hobby, kept by some enthusiasts specifically because they tolerate cooler, unheated water better than most tetras. The southern, range-restricted species face real conservation concern: 2 of the 11 atlas species are Endangered and one is Vulnerable, likely reflecting pressure on the smaller river systems some of them are confined to, while the remaining species split between Least Concern, Data Deficient, and one Not Evaluated.