Taxonomy & naming
Cyphocharax jagunco was described in 2016 by Dutra, Penido, Guimarães de Mello and Pessali as one of two new Cyphocharax species from headwater streams of the Jequitinhonha and São Francisco river basins in Minas Gerais, Brazil, published in Zootaxa. It sits in the genus Cyphocharax, part of the family Curimatidae within the order Characiformes — the curimatas, a large Neotropical group of small-to-medium, generally toothless, detritus- and aufwuchs-grazing characins that includes dozens of superficially similar species distinguished mainly by fine details of pigmentation, scale counts and mouth structure.
The species epithet references the Rio Jagunco, the small tributary of the Rio Jequitinhonha that is its type locality. In the original description the authors distinguished C. jagunco from its close congeners C. lundi, C. punctatus and C. vanderi chiefly by the number and arrangement of dark pigment patches along the lateral line. The Catalog of Fishes (Eschmeyer, California Academy of Sciences) is the governing authority for the valid name; as a recently described, narrow-range species, C. jagunco has not been subject to any taxonomic revision since 2016.
Morphology
Cyphocharax jagunco is a small curimatid, known from a holotype measuring 2 in standard length (about 2 in) — modest even by the standards of the genus, which itself sits at the small end of Curimatidae. Like other Cyphocharax, it has the family's characteristic compressed, elongate body, a small subterminal or inferior mouth adapted for scraping rather than biting, and no true jaw teeth, relying instead on pharyngeal structures to process algae and organic detritus scraped from surfaces.
The distinguishing features cited in the original description are subtle rather than showy: a distinctive pattern and count of dark pigment patches running along the lateral line, which separates C. jagunco from the other Cyphocharax species sharing its river system. No colour photographs or field-condition colouration notes appear in the available literature, and general body form and fin proportions have not been described beyond the technical diagnosis in the type description.
Habitat
The species is known only from its type locality, the Rio Jagunco, a small headwater tributary of the Rio Jequitinhonha in Minas Gerais, southeastern Brazil, with occurrence records placing it within the broader Jequitinhonha basin. This is a clearwater, upland headwater setting typical of the crystalline highlands of Minas Gerais, quite different from the vast Amazonian floodplains associated with many better-known characins.
No published water chemistry or seasonal habitat data are available for this specific stream reach. Cyphocharax species in general are found grazing algae and detrital film from submerged rock, wood and sediment in flowing, well-oxygenated streams, and there is no reason from the available record to expect C. jagunco to differ, but this is inferred from the genus rather than documented for the species itself — data sparse.
Feeding
As a curimatid, Cyphocharax jagunco is presumed to be an aufwuchs and detritus grazer, consistent with the toothless, downturned mouth typical of the genus and family: these fish scrape algae, biofilm and organic sediment from submerged rock and wood rather than hunting or taking large prey items. This diet inference comes from the well-documented feeding ecology of Cyphocharax and Curimatidae generally, not from a stomach-content study of this particular species, which has not been published.
No aquarium feeding data exist, since the species has not been reported in the trade. A grazing curimatid of this size would be expected to take fine-particle foods, algae wafers and biofilm-based foods in captivity, by analogy with related species, but this has not been tested.
Mating
No courtship or spawning behaviour has been documented for Cyphocharax jagunco. The species is known only from its type series collected for taxonomic description, and nothing has been published on pairing, breeding condition or sexual dimorphism. Data sparse.
Breeding
There is no record of Cyphocharax jagunco being bred, or even maintained, in captivity. Curimatids as a family are rarely kept or bred in the aquarium hobby, and this narrow-range, recently described headwater endemic has no aquaculture or hobbyist breeding history to draw on. Rather than assign a breeding mode by inference from more familiar characins, the honest statement is that breeding biology for this species is entirely unknown.
In the aquarium
Cyphocharax jagunco is not a fish anyone will encounter in the aquarium trade. It has no recorded aquarium history, no FishBase account, and no hobbyist care literature — it exists almost entirely within the taxonomic record of its 2016 description and subsequent GBIF occurrence data from the Jequitinhonha basin. There is nothing to responsibly recommend about stocking, tank size or tankmates because none of that has ever been tested with this species.
What can be said, by analogy with other small Cyphocharax and curimatids that do occasionally reach specialist collections, is that a fish of this size and grazing habit would likely need a well-oxygenated, flowing setup with algae and biofilm-friendly surfaces and the company of a shoal, mirroring its presumed stream-dwelling, grazing lifestyle — but this is speculation, not documented practice, and should be treated as such.
Conservation
Cyphocharax jagunco has not been formally assessed by the IUCN Red List and carries a status of Not Evaluated. It is known only from its type locality and immediate surroundings in the Rio Jagunco, a small tributary of the Rio Jequitinhonha in Minas Gerais, Brazil — a narrow range that would typically warrant conservation attention once assessed, though no formal evaluation has been carried out.
Headwater streams in the Jequitinhonha and neighbouring São Francisco basins face pressure from mining, agriculture and water diversion across Minas Gerais, but no species-specific threat assessment or population data exist for C. jagunco to confirm how these pressures affect it. Given the single-locality nature of its known distribution, it is a reasonable candidate for future IUCN evaluation, but any conservation statement beyond Not Evaluated would be speculation.