The Cynodontidae (order Characiformes), or dogteeth tetras, are a family of freshwater fishes found in the Neotropics. This group is not very diverse, and includes only five genera and 14 species. Most of what is known about this family is from the members of the subfamily Cynodontinae, which includes the largest species of this family, up to 117 cm (46 in). The members of subfamily Roestinae are less known, though they only reach up to 20 cm (7.9 in).