Protocheirodon, a new genus of Characidae (Teleostei: Characiformes) with the redescription of the poorly known Protocheirodon pi

Protocheirodon, a new genus of the Characidae, is proposed to include a species previously assigned to Leptagoniates. This action is supported by molecular and morphological phylogenetic hypotheses that place Protocheirodon pi as the sister group of the remaining tribes in the Cheirodontinae versus the traditional assignment of the species to the Aphyocharacinae. The phylogenetic position of Protocheirodon is recognized as a new tribe, the Protocheirodontini. Protocheirodon pi, originally described based on a small number of specimens from a single location in the rio Mamore basin in the southwestern Amazon, is redescribed on the basis of larger series of specimens from the western and central portions of the Amazon basin.