Myleinae

Acnodon is a genus of freshwater ray-finned fish belonging to the family Serrasalmidae, which includes the pacus and piranhas. The fishes in this genus are found in South America

Myloplus is a genus of freshwater fish in the family Serrasalmidae found in tropical and subtropical South America, where they inhabit rivers and streams (both slow and fast-flowing). They are primarily herbivores, but also take some animal matter. Depending on the exact species, they reach up to in standard length. Adult males have a double-lobed anal fin and filamentous extensions on the dorsal fin, and both sexes (but especially males) can be brightly colored when breeding.

Myleus is a genus of serrasalmids from South America, where found in the Amazon, Orinoco and São Francisco basins, as well as the river basin of the Guiana Shield. They are found in rivers with moderately or fast-flowing water, including rapids. They are primarily herbivores, but also take some animal matter. Depending on the exact species, they reach up to in standard length, and the adult males have a double-lobed anal fin and filamentous extensions on the dorsal fin. Their strong teeth means that larger individuals can inflict severe bites on humans.

Utiaritichthys is a genus of serrasalmid fish found in the Amazon and Orinoco basins in tropical South America. The adults are typically found in rapidly flowing water where they feed on aquatic plants in the family Podostemaceae and filamentous algae. They reach up to in standard length.

Mylesinus is a genus of serrasalmids from South America, where found in the eastern Amazon, Essequibo and Orinoco basins. They are rheophilic, typically found at rapids and mainly feed on Podostemaceae plants. Because of their habitat preference, they are threatened by the building of dams. They reach up to in standard length, and the adult males have a double-lobed anal fin and several filamentous extensions on the dorsal fin.

Tometes is a genus of fish in the family Serrasalmidae found in fast-flowing rivers in northern South America. Adults of all seven species in this genus are phytophagous, feeding primarily on aquatic plants in the family Podostemaceae.

thumb | right | alt=Adults of Ossubtus xinguense: GEA 1973, (a) male, 202.7 mm SL; (b) female, 168.5 mm SL. Brazil, Rio Xingu, Volta Grande. | Adults of Ossubtus xinguense: GEA 1973, (a) male, 202.7 mm SL; (b) female, 168.5 mm SL. Brazil, Rio Xingu, Volta Grande. Ossubtus is a genus of fish in the family Serrasalmidae. It contains a single species, Ossubtus xinguense, the parrot pacu or eaglebeak pacu, The species is endemic to rapids in the Xingu River basin in the Brazilian Amazon. This vulnerable species is primarily a herbivore.

Prosomyleus is a monospecific genus of freshwater ray-finned fish belonging to the family Serrasalmidae, the pacus, piranhas and related species. The only species in this genus is Prosomyleus rhomboidalis, which is a medium to large omnivorous fish from South America, where it is found in the Amazon River basin, as well as the north and the eastern Guiana Shield rivers. It can grow to a length of .