Taxonomy & naming
Phenagoniates macrolepis was described in 1913 by Seth Eugene Meek and Samuel Hildebrand from freshwater river material collected in Central America. The authority is given in parentheses — (Meek & Hildebrand, 1913) — indicating that the species has been transferred from its original genus since its description. Eschmeyer's Catalog of Fishes (Catalog of Fishes, California Academy of Sciences) is the governing authority for the valid name, which it lists as Phenagoniates macrolepis.
The genus Phenagoniates belongs to the family Characidae, the largest family of freshwater fishes in the Americas. Within that vast assemblage the genus occupies a relatively minor niche, with limited species richness and modest ecological profile. Its systematic placement has been revisited as molecular phylogenetics has reorganised the characid tree, but it remains within the broad family boundary. Literature records for the genus and this species are sparse, reflecting both its limited hobby visibility and the incomplete state of Central American ichthyology.
Morphology
The most immediately striking feature of Phenagoniates macrolepis is the one encoded in its name: the scales are distinctly large relative to body size, producing a bold, reticulated pattern across the flanks and giving the fish a bright, reflective silvery sheen. This scale morphology distinguishes the species from many small Central American characids that bear finer scaling.
The body is slender and streamlined, consistent with a rheophilic or open-water river species, and the fish reaches a reported maximum of approximately 2 in standard length — placing it firmly in the small-tetra size range. Like other characids it bears the family's characteristic adipose fin between the dorsal and caudal fins. Beyond scale size and the general body plan, morphological data in the accessible literature is limited; detailed counts of lateral-line scales, fin rays, and meristics are recorded in the original 1913 description but are not reproduced in the sources available for this account.
Habitat
Phenagoniates macrolepis is a freshwater river species native to Central America. The original description places it in the river systems of that region, and the species has been recorded from lowland to mid-elevation drainages. It inhabits flowing freshwater, consistent with the riverine ecology typical of many small Central American characids.
Specific habitat details — water depth, current preference, substrate type, and associations with particular vegetation or structural cover — are not well documented in the publicly available literature. By analogy with ecologically similar small Characidae from the same region, it likely frequents the margins and mid-column of clear to lightly turbid rivers and streams, often in association with riparian vegetation. Precise water-chemistry data for wild populations have not been captured in the sources available for this account.
Feeding
Detailed dietary information for Phenagoniates macrolepis in the wild is not available in the sources consulted for this account. As a small characid from Central American river systems, it almost certainly feeds opportunistically on small invertebrates, aquatic insect larvae, and fine organic matter — the generalist diet typical of comparably sized members of the family in flowing lowland habitats.
In an aquarium setting, small Characidae of this type generally accept a wide range of standard prepared foods, including fine-grade flake and micro-pellets, and benefit from supplemental live or frozen foods such as newly hatched brine shrimp, Daphnia, and micro-worms to maintain condition and colour. Data sparse for this species specifically.
Mating
No published reproductive-behaviour data specific to Phenagoniates macrolepis are available in the sources consulted. Based on its placement within the family Characidae and the general biology of small New World characids from similar river habitats, the species is expected to be an egg-scattering open spawner. Males of such species typically display to females with fin-spreading and lateral orientation, and spawning occurs among fine-leaved plants, submerged roots, or in open water over vegetation.
Adhesive or semi-adhesive eggs scattered among fine-leaved aquatic vegetation, with no subsequent parental care, represent the reproductive mode most commonly documented in ecologically comparable small Characidae. Whether Phenagoniates macrolepis deviates from this pattern is unknown; the species has not been documented as a captive-bred aquarium subject in any source available for this account.
Breeding
Phenagoniates macrolepis has not been reported as successfully bred in captivity in any source available for this account. The reproductive biology detailed in the scientific literature is minimal. Extrapolating from the family Characidae, eggs would be expected to be small, non-adhesive to lightly adhesive, scattered over vegetation or fine substrates, and to hatch within a few days at tropical water temperatures. Adults would provide no parental care and would likely consume eggs and fry if left in the same vessel.
Any aquarist attempting to spawn this species would be working largely without precedent from published accounts, and observations should be considered potentially novel. Data sparse.
In the aquarium
Phenagoniates macrolepis is not an established aquarium fish and is rarely, if ever, available in the hobby trade. Its small size — approximately 2 in standard length — and general Characidae body plan suggest it would be manageable in a modestly sized aquarium, and as a schooling fish it would benefit from being kept in a group of six or more individuals.
Water conditions appropriate for Central American river characids — temperatures in the range of 72–81 °F, neutral to mildly acidic to neutral pH, moderate hardness — would be a reasonable starting point in the absence of species-specific data. Given its obscurity, any keeper who acquires this species is encouraged to document husbandry and behaviour carefully, as even basic observations would constitute a meaningful addition to the sparse literature. Data sparse for this species specifically.
Conservation
Phenagoniates macrolepis has not been formally assessed by the IUCN Red List as of 2026, and no dedicated conservation evaluation is recorded for it in the sources available for this account. It is therefore listed as Not Evaluated (NE). The absence of an IUCN assessment reflects the species' low research profile rather than confirmed abundance or security.
Central American freshwater fish communities face broad-spectrum pressures including deforestation, agricultural run-off, damming, and water withdrawal. Small, range-restricted river species are particularly vulnerable to localised habitat degradation. Without a formal range map or population estimate, it is not possible to characterise the conservation status of P. macrolepis beyond noting that the riverine habitats it occupies in Central America are subject to ongoing change. A formal assessment would require field surveys to determine current range extent and population status.