Prochilodus


Prochilodus is a genus of freshwater ray-finned fishes belonging to the family Prochilodontidae, the bocachicos or flannel-mouthed characiformes. This family includes two other genera, Ichthyoelephas and Semaprochilodus, which have been included in Prochilodus instead.
The greatest species richness of Prochilodus is in river basins in eastern, southeastern and southern Brazil, but there are also species in the river basins of the Amazon, Guianas, Colombia, Venezuela, Paraguay and northeastern Argentina.
The largest species in the genus reach about in length, but most species barely reach half that size.

Taxonomy

Species of Prochilodus have an irregular marking on the upper half of their opercle, a marking not present in Semaprochilodus or Ichthyoelephas; this mark, which is made by a "field" of brown to black chromatophores, is thought to be a distinguishing trait of the genus. Another trait is their anal fin, which is either hyaline or irregularly marked by dark pigmentation, a trait shared with Ichthyoelephas.
Prochilodus contains the following valid species:
Cladogram of the most parsimonious hypothesis of relationships based on morphological analysis by Castro and Vari :
Some Prochilodus species are striped, having darkened scale margins which form a wavy, horizontal pattern of stripes on their flanks. Nine Prochilodus species display this patterning, a trait shared with species of Semaprochilodus but not with the more basal group containing P. britskii. The clade encompassing P. brevis and P. rubrotaeniatus possess 2 to 8 irregular chevron-like markings on the caudal fin.