Characiformes
Characiformes form part of a series called Otophysi within the superorder Ostariophysi. Otophysi contains four other orders, Cypriniformes,Siluriformes, and Gymnotiformes.[1] Characiformes forms a group known as Characaphysi with Siluriformes and Gymnotiformes.[2] Characiformes is the sister group to the orders Siluriformes and Gymnotiformes, though this has been debated in light of recent molecular evidence.[1]
Originally the characins were all grouped within a single family, the Characidae. Since then 18 different families have been separated out. However, classification varies somewhat, and the most recent (2011) study confirms the circumscribed Characidae as monophyletic