Taxonomy & naming
Cyphocharax spiluropsis was described in 1889 by the American ichthyologists Carl H. Eigenmann and Rosa Smith Eigenmann, originally placed in the genus Curimatus, as Curimatus spiluropsis. The type locality is given as Ica — the Iça River, in the Brazilian–Colombian border region of the western Amazon basin. Like many curimatid species from that era, it has since been reassigned to Cyphocharax, one of the largest genera in the family Curimatidae, within the order Characiformes.
Curatidae — sometimes called the toothless characins — sit within the broader characin radiation alongside the pacus, silver dollars and piranhas of Serrasalmidae, but occupy a very different ecological niche: small-mouthed, algae- and detritus-grazing shoalers rather than predators, seed-eaters or plant-shredders. The genus name Cyphocharax combines Greek kyphos ("bent, humped") with charax, a name applied broadly to characin-like fishes, alluding to the somewhat arched dorsal profile typical of the genus. No taxonomic synonymy issues beyond the original Curimatus placement are documented in the sources consulted for this article.
Morphology
Cyphocharax spiluropsis is a small, compact characin, reaching a documented maximum of 3.5 in standard length. Like other curimatids, it has a subterminal, small, essentially toothless mouth adapted for grazing rather than biting — a jaw architecture built for scraping biofilm, algae and fine organic detritus off submerged surfaces and substrate rather than for capturing prey. Beyond the size record and general family-level body plan, the sources consulted here do not document fine details of colouration, fin shape or the humeral markings implied by the species epithet spiluropsis (from the Greek for "spot-like"), so this article does not speculate further.
Habitat
The species is documented from the central and western Amazon basin, with its type locality on the Iça River near the Brazilian–Colombian border. FishBase characterises it as benthopelagic in tropical freshwater, consistent with the grazing, riverbed-associated lifestyle typical of Curimatidae. Specific water chemistry data — temperature range, pH and hardness — are not reported in the sources available for this account, so no numeric range is given here; broadly, Amazon-basin curimatids of this kind are associated with warm, tropical lowland river and floodplain habitats typical of the region.
Feeding
As a member of Curimatidae, the toothless characins, Cyphocharax spiluropsis is presumed on family-level grounds to be a detritivore/grazer, feeding on organic sediment, algae and biofilm rather than on other fish, insects or plant matter in the manner of predatory or herbivorous characins elsewhere in the order. No species-specific diet study is available in the sources consulted, so this account describes the family-typical feeding mode rather than asserting a confirmed diet for this particular species.
Mating
No courtship or pairing behaviour has been documented for Cyphocharax spiluropsis in the sources consulted for this account. Sexual dimorphism is likewise undocumented for the species; data is sparse.
Breeding
Breeding biology for Cyphocharax spiluropsis is not documented in the sources available for this account, and this article does not assign a breeding mode on the basis of guesswork. There is no record of the species being kept or bred in the aquarium hobby; as with many small, obscure Curimatidae, it appears to remain essentially a wild, riverine species outside of scientific collection.
In the aquarium
Cyphocharax spiluropsis is not established in the aquarium trade, and no husbandry record for the species was found in the sources consulted. At a modest 3.5 in maximum size it would, on general curimatid biology, be expected to need a planted or driftwood-furnished tank with a sandy substrate suited to a grazing shoaler, kept in a group rather than alone — but this is an inference from family-level natural history, not a documented care record, and prospective keepers are unlikely to encounter this species outside targeted biotope or scientific collecting.
Conservation
The IUCN Red List assesses Cyphocharax spiluropsis as Least Concern, in an assessment dated 19 October 2020. FishBase likewise notes a low vulnerability to fishing pressure. As an Amazon-basin endemic without any documented aquarium trade or targeted fishery, the species does not face the collection or exploitation pressures that affect some more commercially important characins; broader Amazonian habitat pressures such as damming, deforestation-linked sedimentation and water-quality change are the relevant long-term watch items for the basin generally, though none are documented as specific threats to this species.