Taxonomy & naming
Pseudocurimata boulengeri was described by Carl H. Eigenmann in 1907, honouring the Belgian-British ichthyologist George Albert Boulenger, a towering figure in early twentieth-century fish taxonomy at the British Museum. It sits in the genus Pseudocurimata, within the family Curimatidae — the toothless characins, a large Neotropical group of detritivorous and algivorous fish distinguished from their close relatives the Prochilodontidae and Curimatidae's other genera by details of jaw structure and dentition (or its absence). The Catalog of Fishes (Eschmeyer, California Academy of Sciences) is the reference for the currently valid combination.
Curimatid taxonomy has seen substantial revision over the decades as the family's many superficially similar, silvery, laterally compressed species have been sorted among genera including Curimata, Curimatella, Cyphocharax and Pseudocurimata; P. boulengeri has remained in Pseudocurimata through that process. As with much of this family, the species is far better known from museum and survey material than from the aquarium trade or popular literature, and no common name is in wide use.
Morphology
Pseudocurimata boulengeri is a small, laterally compressed, silvery characin typical of the curimatid body plan — deep-bodied relative to its length, with a short head, small subterminal or inferior mouth, and no functional teeth, an adaptation shared across the family for grazing rather than biting. FishBase records a maximum standard length of 5.5 in, making this a modest-sized fish by any measure, let alone against the giants elsewhere in this group's wider characin relatives.
As with most curimatids, detailed published descriptions of colour pattern and fin morphology are sparse outside the original taxonomic literature; the working assumption, consistent with its relatives, is an unremarkable silver body without bold markings, suited to schooling in open or slow-flowing water over sand or fine substrate.
Habitat
This species is endemic to the Guayas river basin in coastal Ecuador — the network of rivers that drain toward the northern Gulf of Guayaquil — and is not known to occur naturally anywhere else. FishBase classifies it as a freshwater, demersal (bottom-associated) fish, consistent with a species that feeds by working sediment and submerged surfaces for organic material rather than swimming in open midwater.
Specific water chemistry data for this species was not found in the available sources; the Guayas basin is a lowland tropical Pacific-slope drainage, and detailed temperature and pH figures for this particular species should be treated as data sparse rather than assumed.
Feeding
Pseudocurimata boulengeri is a detritivore/omnivore with a trophic level around 2.0, near the base of the food web. FishBase and related aquaculture-oriented sources describe its diet as flocculated organic matter, microdetritus, fine vegetation, filamentous algae and microcrustaceans — the classic curimatid grazing diet, taken by working sediment and submerged surfaces rather than pursuing live prey.
This toothless, detritus-and-biofilm feeding strategy places the species firmly among the grazing characins of this group (alongside the hemiodus and other curimatas), in contrast to the predatory piranhas or the migratory, larger-bodied Prochilodus and Semaprochilodus that dominate popular accounts of Neotropical characins.
Mating
Wild spawning has been documented as occurring between October and March, with FishBase reporting size at first maturity around 7 in total length in females and roughly 8 in total length in males — figures somewhat larger than the species' recorded maximum standard length, a discrepancy likely reflecting the difference between standard-length and total-length measurement or limited sampling, and one more reason to treat this species' biology as incompletely documented rather than fully resolved. No further detail on courtship behaviour, pairing or external sexual dimorphism was found in the available sources.
Breeding
No aquarium or captive-breeding accounts for Pseudocurimata boulengeri were found in the available sources. The only breeding information on record is the wild spawning window (October–March) noted above; there is no documented aquarium spawning mode, egg type or parental-care pattern for this species, and none should be assumed. Data on captive care and breeding for this species is sparse to the point of essentially absent — this is not a fish with an aquarium-trade or hobbyist-breeding history to draw on.
In the aquarium
Pseudocurimata boulengeri is essentially unknown in the aquarium hobby; no aquarium care literature was found for this species, and it should not be assumed to be available in the trade. What can be inferred from its biology is limited but informative: at a modest maximum size of around 5.5 in SL, a detritus-and-algae grazing diet, and a schooling, demersal lifestyle typical of curimatids, this is a fish that — if it were ever kept — would sit closer in spirit to a peaceful, group-living algae-grazer than to any of the predatory or large-bodied characins that dominate this family's popular reputation.
Given the complete absence of documented husbandry data, any prospective keeper should treat this as a data-sparse species rather than guess at tank size, diet or compatibility from first principles; there is no evidence this species is currently established in the hobby.
Conservation
The IUCN Red List assesses Pseudocurimata boulengeri as Near Threatened (2022), reflecting its narrow endemic range restricted to the Guayas basin of coastal Ecuador. A single-basin endemic freshwater fish in a heavily developed agricultural and urban coastal region — the Guayas basin drains toward Ecuador's largest city, Guayaquil — is inherently vulnerable to habitat degradation, water-quality decline and hydrological change, even without species-specific pressure data in hand.
This is a useful counterpoint to the large, widespread, farmed characins that dominate headlines in this group: P. boulengeri's conservation risk comes not from overfishing or the aquarium trade but simply from having nowhere else to go if its one home basin degrades further.