Taxonomy & naming
Cyphocharax pinnilepis was described by Richard P. Vari, Angela M. Zanata and Jônatas S. Camelier in 2010, in Copeia 2010(3):382–387, from specimens collected in the Rio Gongogi, a tributary of the Rio de Contas in Bahia state, northeastern Brazil. It belongs to the family Curimatidae — the toothless, detritivorous "curimatas" — within the order Characiformes, and to the large genus Cyphocharax, which the Catalog of Fishes (Eschmeyer, California Academy of Sciences) recognises as governing dozens of small to medium South American species distinguished mainly by fine details of scale counts, fin-ray counts and squamation pattern.
The species epithet pinnilepis references the distinctive patch of scales covering the basal portion of the caudal-fin lobes, a diagnostic feature the original authors used to separate it from congeners. At the time of description it was noted as the third curimatid species known from the Rio de Contas drainage and only the sixth Curimatidae species recorded from Brazil's isolated coastal (as opposed to Amazon or Paraná basin) river systems — a reminder that Brazil's short, independent coastal drainages carry their own endemic fish faunas distinct from the famous interior basins.
Morphology
Cyphocharax pinnilepis is a small, elongate, laterally compressed characin built on the standard curimatid plan: a subterminal, toothless mouth adapted for grazing rather than biting, a silvery body, and no adipose-fin surprises beyond what is typical for the family. The type series recorded a size range of roughly 1–4 in standard length across paratypes, giving a working adult maximum of about 4 in SL — this is a genuinely small fish, nothing like the pacus or true piranhas that share the broader Characiformes order.
As in other Cyphocharax, identification rests on fine anatomical detail rather than obvious external colour pattern — scale counts along the lateral line, the shape and squamation of the caudal-fin base (the feature behind the species name), and proportional measurements distinguish it from the various other Cyphocharax species recorded from Brazilian coastal rivers. No sexually dimorphic colour pattern has been documented for the species; data on live colouration beyond typical curimatid silver is sparse.
Habitat
The species is known only from the Rio de Contas drainage of Bahia, Brazil, including the Rio Gongogi tributary where the type series was collected — a short, independent coastal river system rather than part of the Amazon, Orinoco or Paraná basins. This places it among a small set of curimatid species endemic to Brazil's isolated northeastern coastal drainages, each of which tends to carry its own distinct, narrowly distributed fish fauna.
Detailed water chemistry data specific to C. pinnilepis has not been published. General conditions reported for the Curimatidae as a family run warm and mildly acidic to neutral — roughly pH 6–7.5, moderate hardness, and temperatures in the low-to-high 20s °C — consistent with lowland to mid-elevation Brazilian coastal streams, but these figures describe the family broadly rather than measurements taken at the type locality itself.
Feeding
Cyphocharax pinnilepis has not been the subject of a dedicated diet study, but its family membership is informative: curimatids are toothless detritivores and aufwuchs grazers, feeding on fine organic sediment, algae and biofilm scraped from submerged surfaces rather than on other fish, insects or plant matter in the way many characins do. The genus Cyphocharax as a whole is consistently described as omnivorous in this grazing sense — closer to a small, algae-eating catfish in ecological role than to a predatory tetra.
No aquarium feeding regime has been documented for this species specifically. Related, better-known Cyphocharax kept in the hobby (such as C. multilineatus) are fed a mixed diet of algae wafers, sinking pellets and finely chopped vegetable matter, and that general pattern is a reasonable inference for the genus rather than a confirmed fact for C. pinnilepis.
Mating
No courtship or pairing behaviour has been documented for Cyphocharax pinnilepis. Data is sparse to the point of absence — the species is known almost entirely from its original taxonomic description and a handful of subsequent database records, none of which touch on reproductive behaviour.
Breeding
Breeding has not been documented for Cyphocharax pinnilepis in the wild or in captivity, and the species has no known aquarium-keeping history to draw on. The broader Curimatidae family is generally described as seasonal, flood-triggered spawners that scatter eggs rather than guard a nest or brood — related Cyphocharax such as C. abramoides are reported to mature at roughly 1–1.5 years with a lifespan around 3.5 years — but no breeding mode, clutch size or parental-care pattern has been confirmed for this species specifically, and none should be assumed. This is a case where honesty about the gap in the record matters more than filling it with a plausible guess.
In the aquarium
Cyphocharax pinnilepis has no documented aquarium-keeping history; it does not appear to be established in the ornamental trade, and no common or trade name for it is in use. Everything below is therefore inference from its genus and family rather than direct experience with the species.
Curimatids and Cyphocharax in general are peaceful, actively grazing shoaling fish best kept in a group in a well-established tank with algae growth or biofilm to forage on, supplemented with sinking algae wafers and vegetable-based foods. Given a maximum recorded size under 4 in SL, a modest to mid-sized aquarium would suffice by curimatid standards, but because this species has essentially no hobby track record, a prospective keeper should treat any tank recommendation as provisional and prioritise sourcing information and confirmed identification over assumptions carried from more familiar relatives.
Conservation
Cyphocharax pinnilepis has not been evaluated by the IUCN Red List and carries a status of Not Evaluated. This is unsurprising for a small, recently described (2010) species known from a single, narrowly distributed coastal river drainage in Bahia, Brazil — such species are frequently overlooked by global conservation assessment even when their restricted range would, in principle, warrant scrutiny.
No population trend, threat assessment or habitat-pressure data specific to this species has been published. In general terms, Brazil's isolated coastal drainages face pressure from agricultural runoff, deforestation and water extraction, and a single-drainage endemic like C. pinnilepis would have no refuge elsewhere in the country if its home river system degraded — but this is a general concern about the kind of range it holds, not a documented finding about the species itself.