Taxonomy & naming
Cyphocharax notatus was described by the Austrian ichthyologist Franz Steindachner in 1908. It belongs to the genus Cyphocharax within the family Curimatidae — the curimatas, a large group of small-to-medium South American characiforms distinguished from their more famous relatives, the piranhas and pacus of Serrasalmidae, by a toothless or near-toothless mouth adapted for grazing detritus and biofilm rather than biting flesh or plant matter.
The Catalog of Fishes (Eschmeyer, California Academy of Sciences) is the governing authority for the valid combination Cyphocharax notatus, and no alternate genus placement is used here. Curimatidae as a whole has seen substantial revision over the decades as taxonomists worked out relationships among the many superficially similar silver curimata species, but C. notatus is a stable, recognised member of the genus. It has no established common or trade name in the aquarium hobby, reflecting its status as a species known primarily from ichthyological survey and museum material rather than the ornamental trade.
Morphology
Cyphocharax notatus is a modestly sized, laterally compressed characin with the generalised silver-flanked, forked-tail body plan typical of Curimatidae — an unremarkable-looking fish built for steady schooling and bottom-oriented feeding rather than speed or display. FishBase records a maximum standard length of 6 in for males and unsexed individuals, making this a small-to-medium characin, well short of the large food-fish curimatas and nowhere near the size of a pacu.
Detailed morphological description beyond the size record is not covered in the available sources; like most curimatids it can be expected to show the small, subterminal or ventrally placed mouth associated with substrate grazing, but this account does not assert fin-count or colour-pattern specifics that are not documented in the cache.
Habitat
Cyphocharax notatus is native to South America, recorded from the Tocantins, Amazon and Capim river basins. FishBase classifies it as a benthopelagic species inhabiting tropical freshwater, consistent with a fish that forages near the bottom while still moving through the water column in schools.
Specific water-chemistry data — temperature range, pH, hardness — is not reported in the available sources for this species. Given its Amazonian and Tocantins-basin range, warm tropical freshwater conditions are a reasonable general expectation, but this account does not assign precise figures that the cache does not support.
Feeding
Detailed dietary data specific to Cyphocharax notatus was not found in the available sources — FishBase's summary for this species does not include diet notes. What is known comes from the wider genus: related Cyphocharax species, such as C. multilineatus, are documented as feeding in schools with detrital feeding noted across the genus, consistent with the toothless, grazing mouth typical of Curimatidae.
On that basis, C. notatus can reasonably be expected to graze detritus, biofilm, algae and associated microfauna from sediment and submerged surfaces as a schooling forager, in the same general mode as its curimatid relatives — but this is an inference from genus-level information, not a confirmed record for this species, and should be treated accordingly.
Mating
No courtship or pairing behaviour specific to Cyphocharax notatus is documented in the available sources. Related Cyphocharax species, including C. multilineatus, are recorded as oviparous open-water spawners, which is the typical reproductive pattern across Curimatidae, but no confirmed account of courtship behaviour in C. notatus itself was located. Sexual dimorphism is likewise undocumented for this species in the sources reviewed.
Breeding
Breeding in Cyphocharax notatus specifically is not confirmed in the sources reviewed. The genus-level pattern — seen in C. multilineatus — is oviparous, open-water egg-scattering typical of many small Curimatidae, with no parental care after spawning. It would be a mistake to assert this mode as established fact for C. notatus itself, since the cached sources explicitly note that the species' specific breeding mode is not confirmed in aquarium literature.
There is no evidence that Cyphocharax notatus is bred or kept in home aquaria at any scale; it appears to be known almost entirely from ichthyological survey and museum records rather than the hobby, and no aquarium-breeding accounts were found.
In the aquarium
Cyphocharax notatus is not an established aquarium species, and no hobby care literature was found for it in the available sources. Its modest adult size of roughly 6 in SL and its schooling, bottom-grazing habits suggest it would, in principle, suit a large, well-planted or driftwood-furnished tank with sediment for foraging and the company of a proper school, in keeping with the general needs of Curimatidae — but this is inference from its biology and relatives, not documented aquarium experience.
Prospective keepers should treat this as a data-sparse species: there is no confirmed record of it being routinely traded, kept or bred in the hobby, and anyone encountering it would likely be working from survey collections or specialist importers rather than typical retail supply.
Conservation
Cyphocharax notatus is assessed by the IUCN Red List as Least Concern, with an assessment dated 19 October 2020. This reflects a species with a range spanning multiple substantial river basins — the Tocantins, Amazon and Capim — without evidence of significant population decline or concentrated threat.
As with many small, non-commercial characins across the Amazon basin, the longer-term watch items are the general pressures facing South American freshwater systems — damming, deforestation-linked sedimentation and water-quality change — rather than any specific documented threat to this species. There is no indication in the available sources that C. notatus is targeted by the aquarium trade or subsistence fisheries.