Taxonomy & naming
Prochilodus binotatus was described by the Scottish naturalist William Jardine in 1841 and placed in the genus Prochilodus, part of the family Prochilodontidae within the order Characiformes. The family sits close to the curimatas (Curimatidae) and the headstanders in the broader characin radiation, united by a distinctive, highly protrusible, disc-like mouth adapted for scraping biofilm, algae and organic detritus from submerged substrate rather than for grabbing prey.
No record of this species could be located in the Catalog of Fishes search used to prepare this profile, and no FishBase page could be confirmed for it, which means its current taxonomic standing, synonymy history and any recent revisions are not verifiable here — data sparse. The genus itself has a long history of taxonomic revision, with species boundaries across the widely distributed "curimbatá" and "bocachico" forms periodically reassessed; readers researching this species further should treat older literature with some caution and check the Catalog of Fishes directly for the current accepted name.
Morphology
Detailed morphological data specific to Prochilodus binotatus was not found in the sources consulted, so this account describes the genus-level body plan that the species shares. Prochilodus species are moderately deep-bodied, laterally compressed characins with a small, protrusible, sucker-like mouth set low and slightly forward on a blunt head — an adaptation for grazing detritus and biofilm off submerged surfaces rather than for hunting prey. The scales are typically silvery, sometimes with dark cross-bars or a dusky sheen, and the fins are unremarkable in shape, without the elongated rays or bright ornamentation seen in some other characins.
No confirmed maximum length figure for P. binotatus specifically could be traced. Other members of the genus reach up to roughly 31.5 in in exceptional cases, though most Prochilodus species top out well short of that extreme, commonly in the 12–19.5 in range as full-grown adults. Prospective keepers should assume this species will grow to a substantial adult size consistent with its genus rather than expect a small or aquarium-scaled fish.
Habitat
Prochilodus binotatus is confirmed from the Amazon basin and the Guiana region, spanning parts of Brazil and neighbouring Guiana. The broader genus Prochilodus is distributed widely across South America on both sides of the Andes, with species recorded from Colombia, Venezuela, Ecuador, Peru, Bolivia, Paraguay and Brazil, occupying lowland river channels, floodplain systems and tributary streams typical of Neotropical freshwater drainages.
Specific water chemistry data — temperature range, pH and hardness — for this species was not found in the sources consulted. Prochilodus species in general inhabit warm, seasonally fluctuating South American rivers and floodplains, and as migratory fish they are closely tied to the flood pulse of their home drainage; beyond that generalisation, this account does not assert specific numbers it cannot source.
Feeding
Prochilodus species are detritivore-herbivores, and the available sources for this genus describe a diet built around biofilm, algae and decomposing organic matter scraped from submerged surfaces and sediment using the fish's distinctive protrusible mouth. This puts P. binotatus in the same feeding guild as its relatives the curimatas and the hemiodontids — quiet, continuous grazers rather than active predators — and there is no indication in the sources consulted that this species deviates from that pattern.
In captivity, fish of this feeding type require a vegetable-forward diet: spirulina-based flakes or pellets, blanched vegetables, algae wafers and other herbivore-oriented foods, supplemented lightly with protein. A tank kept without adequate grazing surface or greenery-heavy diet is likely to leave a Prochilodus undernourished regardless of how much conventional flake or pellet food is offered.
Mating
No species-specific courtship or spawning behaviour for Prochilodus binotatus was found in the sources consulted. What is documented for the genus is that Prochilodus fishes are migratory spawners: mature adults undertake seasonal, often long-distance migrations upriver or into floodplain systems timed to the wet-season flood pulse, gathering in large schools before spawning. This is a population-level, river-scale event rather than a pair-bonding or territorial courtship behaviour of the kind seen in substrate-spawning cichlids or true piranhas, and it does not translate into anything a home aquarist can trigger or observe.
Breeding
Prochilodus binotatus should be understood as a migratory food-fish rather than an aquarium-breedable species. Across the genus, Prochilodus and its close relatives Semaprochilodus are classic long-distance spawning migrators: mature fish move in large schools along river corridors on a seasonal cue tied to the flood pulse, releasing pelagic eggs in open water far from any fixed nest site. Commercially, genus members are propagated at scale using hormone-induced spawning (hypophysation) in aquaculture and stock-enhancement programmes, not through natural pairing in captivity.
This reproductive strategy is fundamentally incompatible with home aquarium conditions — there is no nest to provide, no pair to condition, and the fish itself grows far too large for a typical tank long before it would reach reproductive maturity. P. binotatus is essentially never bred by hobbyists, and this account makes no claim to the contrary; any fish in the trade will be wild-collected or sourced from commercial hormone-induced hatchery stock rather than home-bred.
In the aquarium
Prochilodus binotatus is not a beginner community fish, and its biggest hazard is size: as a member of a genus that produces substantial adults, it will outgrow the vast majority of home aquaria within a couple of years and needs a plan for a very large, long-term setup — several hundred litres at minimum — from the outset, or it should not be purchased at all. It is best regarded as a public-aquarium or large-pond subject rather than a standard hobby tank fish, and prospective keepers should never assume it will "stay small."
Because it is a detritivore-grazer, tank furnishing matters as much as tank size: driftwood, smooth rockwork and other surfaces that develop a biofilm layer give it something natural to graze between feedings, and a vegetable-heavy diet (spirulina foods, blanched greens, algae wafers) should form the bulk of its rations. As a schooling river fish in nature, it is likely to do best in the company of its own kind or other robust, similarly sized tankmates rather than housed as a singleton, though specific compatibility data for this species was not found and this should be treated as a general precaution rather than a documented recommendation.
Conservation
Prochilodus binotatus has not been evaluated by the IUCN Red List — its current status is Not Evaluated (NE) — and no assessment year or supporting document could be located for this species. This is a common situation for less commercially prominent members of a large, widely distributed genus: better-known relatives that support major regional fisheries have been assessed, while this species appears to have fallen outside recent assessment cycles.
No species-specific threat information was found in the sources consulted. Generic pressures facing Amazonian and Guiana-region river fish — damming that blocks migratory spawning runs, deforestation-linked sedimentation and overfishing of migratory schools at bottleneck points — are relevant to migratory Prochilodontidae as a family, but this account does not attribute any specific documented threat to P. binotatus itself without a source to support it.