Taxonomy & naming
Bryconamericus miraensis was described by the American ichthyologist Henry Weed Fowler in 1945, with the type locality given as Ricaurte on the Río Guebo at an elevation of approximately 3,900 feet (roughly 1,656 ft) above sea level. The Río Guebo is a tributary of the Mira River basin, which straddles the Colombia–Ecuador border in the Andean foothills of northwestern South America.
Eschmeyer's Catalog of Fishes (Fricke, Eschmeyer & Fong) confirms the valid name as Bryconamericus miraensis Fowler, 1945, citing subsequent treatments by Román-Valencia (2000) and Silva in Reis et al. (2003). Bryconamericus is a large and taxonomically complex genus of small Neotropical characids; the group has been subject to repeated revisions and the boundaries among species are often defined by subtle meristic and morphological characters including dentition pattern and the presence of fin-ray hooks on males. FishBase currently places the species in Stevardiidae, reflecting a recent reclassification of part of the broader Characidae sensu lato, but the top-level family recorded here follows the usage of Eschmeyer's Catalog and the project's editorial standard.
No widely used common name exists for this species.
Morphology
Bryconamericus miraensis is a small, streamlined characid reaching a maximum recorded total length of approximately 3.5 in. Like other members of the genus it has the typical Bryconamericus body plan: a moderately compressed, fusiform profile suited to flowing water, a single dorsal fin, an adipose fin, and a forked caudal fin.
Taxonomic comparisons with related species in the Bryconamericus peruanus group have examined characters including dentition pattern and the presence or absence of fin-ray hooks — features that distinguish it from close relatives. Detailed morphometric data for the species beyond the type material are sparse in the accessible literature, reflecting the limited number of specimens that have been examined.
Habitat
The species is known from the Guebo River within the Mira River drainage, a system that descends from the Andean highlands of Nariño Department, Colombia, toward the Pacific lowlands. The type locality at roughly 1,656 ft elevation places it in cool Andean foothill streams rather than the tropical lowland waters most aquarists associate with Neotropical characids.
The Mira River basin drains both Colombian and Ecuadorian territory, and the Cambridge volume on threatened vertebrates notes that B. miraensis is considered endemic to the Guebo River drainage and known from restricted localities. Foothill Andean streams in this region are typically clear, oxygen-rich, and fast-flowing over rocky or gravelly substrates, with temperatures considerably cooler than Amazonian tributaries. Precise water-chemistry data for the collection site are not recorded in the available sources.
Feeding
No detailed dietary study of Bryconamericus miraensis has been published in the sources available. FishBase records a trophic level of 2.6, consistent with a primary invertebrate feeder — a figure typical of small characids that consume aquatic invertebrates, insect larvae, and small amounts of plant or detrital material.
Bryconamericus species in general are regarded as opportunistic omnivores in their foothill-stream habitats, taking whatever invertebrate prey is available in the drift and from the substrate. Given the limited number of records for this species, dietary observations from wild specimens have not been documented.
Mating
No specific mating observations for Bryconamericus miraensis have been published. Based on the biology of related Bryconamericus species, the species is presumed to be a typical characid egg-scatterer that broadcasts adhesive or semi-adhesive eggs among fine-leaved aquatic vegetation or over rocky substrate without forming pair bonds or defending spawning sites.
Males of Bryconamericus species are distinguished in part by the presence of fin-ray hooks — a common feature in male characids that is thought to play a role in spawning contact between partners — and fin-ray hook presence in B. miraensis has been noted in the taxonomic literature in comparisons with related taxa.
Breeding
Captive breeding of Bryconamericus miraensis has not been documented in the available literature or hobby sources. The species is essentially unknown in the aquarium trade and has not been deliberately maintained or spawned in captivity as far as the accessible record shows.
By analogy with other small Bryconamericus and related Andean characids, breeding would be expected to involve open egg-scattering over vegetation or substrate, with adhesive eggs receiving no parental care. The cooler temperatures of its Andean foothill habitat suggest that spawning might be triggered by temperature variation associated with rainfall or seasonal changes in stream flow — a pattern seen in several foothill characid species — though this is inference rather than documented observation for this species specifically.
In the aquarium
Bryconamericus miraensis is not established in the aquarium hobby and is not commercially available. Its restricted natural range, small number of known records, and absence from the ornamental fish trade mean that virtually no husbandry information exists for the species.
On the basis of its habitat — cool, well-oxygenated Andean foothill streams at around 1,656 ft elevation — any aquarium keeping would need to account for temperatures considerably lower than typical tropical community tanks, likely in the range of 61–72 °F, high oxygen levels, and good current. These conditions are similar to those required for other cool-water Andean characids. The species is of scientific interest rather than hobbyist relevance at present.
Conservation
Bryconamericus miraensis is assessed as Data Deficient (DD) on the IUCN Red List, with the assessment conducted on 9 October 2014 by Paula Sanchez-Duarte and Francisco Villa-Navarro. The Data Deficient designation reflects the limited information available on the species' range extent, population size, and ecological requirements rather than any determination that it is unthreatened.
The species is known from a restricted area within the Mira River basin — primarily the Guebo River drainage at the Colombia–Ecuador border — and its narrow endemic range makes it inherently vulnerable to any habitat degradation in that system. The Cambridge reference on threatened and recently extinct vertebrates notes that restricted distribution makes the species potentially vulnerable. Andean foothill streams in this region face pressures from agricultural runoff, deforestation of riparian zones, and altered hydrology. A formal population survey and reassessment of status would be needed to determine whether Data Deficient remains appropriate or whether a threatened category is warranted.