Sailfin Tetras

The Crenuchidae, or crenuchids, are a family of freshwater fish of the order Characiformes. The 11 genera include about 115 species, though several species are undescribed. These fish are relatively small (usually under 10 cm (4 in) in standard length) and originate from eastern Panama and South America. Both subfamilies were previously included in the family Characidae, and were placed in a separate family by Buckup, 1998. Buckup, 1993, revised all genera, except Characidium.

They are the only members of the superfamily Crenuchoidea. They are sister to all other members of the suborder Characoidei, and diverged during the Early Cretaceous, prior to the split between the African characins (Alestoidea) and the other South American characins (Erythrinoidea and Characoidea). This suggests that their divergence likely predates the breakup of Gondwana, when the divergence between those groups likely occurred.