Pristobrycon

Pristobrycon is a genus of piranhas from the Orinoco and Amazon Basins, as well as rivers in the Guianas.

Pristobrycon is not monophyletic. No single morphological feature has been found that completely diagnoses this genus. P. striolatus is very different from other species of this genus.

The genus Pristobrycon was created by Eigenmann to include species which have intermediate characters between "the fierce Rooseveltiella [=Pygocentrus nattereri] without palatine teeth, and the less blood-thirsty Serrasalmus with a series of permanent teeth along the palatine". The author designed P. calmoni as the type species of the genus. Two groups are included in this genus. One group is characterized by presence of the preanal spine (only P. calmoni) and the other group including the rest of the species assigned (P. careospinus, P. maculipinnis and P. striolatus) (Fink & Machado-Allison, 1992; Machado-Allison et al., 1989; Machado-Allison & Fink, 1996). The validity P. aureus is questionable.

Species
There are currently five recognized species in this genus:
 * Pristobrycon aureus (Spix & Agassiz, 1829)
 * Pristobrycon calmoni (Steindachner, 1908)
 * Pristobrycon careospinus W. L. Fink & Machado-Allison, 1992
 * Pristobrycon maculipinnis W. L. Fink & Machado-Allison, 1992
 * Pristobrycon striolatus (Steindachner, 1908)