Prochilodus is a genus of large characiform fish in the family Prochilodontidae, found across South American river systems in Brazil, Colombia, Venezuela, Guyana, Argentina, Bolivia, Ecuador, and Paraguay. The atlas's 15 species run from around 9.5 in to 31.5 in, and they are built around a distinctive protrusible, sucker-like mouth that lets them scrape algae, detritus, and organic sediment from riverbeds and submerged wood, an unusual feeding mode among characins known as iliophagy. Several species undertake large seasonal spawning migrations upstream, most famously Prochilodus lineatus in the Paraná system, and these mass movements have made the genus important both ecologically, as a major link in river food webs and nutrient cycling, and economically, as a long-standing subsistence and commercial food fish across much of the continent.
Species such as the flagtail prochilodus (P. argenteus and P. mariae), Brazilian bocachico (P. brevis), redfin prochilodus (P. costatus), streaked prochilod (P. lineatus), bocachico (P. magdalenae), black prochilodus (P. nigricans), and netted prochilod (P. reticulatus) show how widely the common name "bocachico" or "prochilodus" travels with the genus. They occasionally appear in very large planted aquaria or ponds as algae-grazing oddballs, but their adult size puts them out of reach of most home tanks, and their real significance is as a migratory, riverine species vulnerable to dam construction that blocks spawning runs, reflected in the Vulnerable status carried by two species here.