Taxonomy & naming
Astyanax kennedyi was described by the French ichthyologist Jacques Géry in 1964, in a paper covering upper Amazonian characoid fishes collected by Jack Roberts, published in Tropical Fish Hobbyist (vol. 13, no. 4). The type locality is the upper Amazon River basin of Peru, in the region surrounding Iquitos. Eschmeyer's Catalog of Fishes (CAS) is the governing authority for the valid name Astyanax kennedyi Géry, 1964.
The species sits within Astyanax, one of the most species-rich genera of Neotropical characins, placed in the family Characidae. Some sources have noted ongoing debate about the higher-level placement of certain Astyanax lineages, and FishBase has flagged that the family may be subject to further revision; however, the top-level family assignment used here follows the current literature. The species appears in the annotated checklist of Peruvian freshwater fishes by Ortega et al. (2012), where the common vernacular name used locally is mojara, a broad term applied to various small characins in Peru.
Morphology
Kennedy's tetra is a moderately slender-bodied characin reaching a maximum standard length of roughly 1.5–2 in (about 1.5–2 in), based on data compiled by Seriously Fish. Like most Astyanax, it has the typical characin body plan: a laterally compressed, fusiform form with a complete lateral line, an adipose fin, and the family's characteristic small teeth.
Detailed published meristic or colouration data for this species in the primary literature are sparse. FishBase assigns a trophic level of 2.9, consistent with a predatory dietary strategy that includes invertebrates and small fishes, and notes benthopelagic habits — meaning the species uses both mid-water and near-bottom zones. Sexual dimorphism is subtle; females become noticeably rounder in the abdomen when gravid, which is the most reliable way to distinguish the sexes in live fish.
Habitat
Astyanax kennedyi is endemic to the upper Amazon River basin of Peru, with records centred on the area surrounding Iquitos at an elevation of roughly 312 ft. This lowland Amazonian region is characterised by warm tropical freshwater environments: permanent rivers, streams, and creeks draining through rainforest, often with soft, slightly acidic, tannin-stained water.
Seriously Fish recommends replicating an Amazon-themed aquarium setup with sandy substrate, driftwood, twisted roots, and tannin-stained water — a close approximation of the blackwater or whitewater stream habitats typical of the region. Water temperature in the natural range is warm year-round, consistent with the tropical lowland climate of the Peruvian Amazon. Beyond these broad parameters, detailed field data on microhabitat use, depth preferences, or seasonal movements have not been published.
Feeding
In the wild, Astyanax kennedyi is a generalist predator that preys on aquatic invertebrates and smaller fishes. Its trophic level of 2.9 (FishBase) places it firmly in the carnivore-to-omnivore range. The species shows mild piscivorous tendencies, meaning it may consume very small fish in community aquaria if tankmates are significantly undersized.
In captivity, the diet should reflect this predatory inclination. Seriously Fish recommends a mix of small live and frozen foods — bloodworm, brine shrimp, Daphnia, and similar items — supplemented by quality dried foods such as small pellets or flake. A protein-rich diet maintains condition and may bring fish closer to breeding readiness. Very small fishes should not be kept as tankmates.
Mating
No spawning has been reported for Astyanax kennedyi in the aquarium hobby as of the current literature, according to Seriously Fish. As a member of Astyanax, it is expected to follow the general characid reproductive strategy: egg-scattering broadcast spawning over fine-leaved plants or substrate, with eggs and fry receiving no parental care.
In other Astyanax species, males are typically slimmer and more active during courtship, pursuing females and releasing milt over scattered eggs. Conditioning on high-protein live or frozen foods is standard practice to bring wild-caught or unseasoned adults into spawning condition. Whether A. kennedyi forms temporary pairs or spawns in loose groups, and the details of any courtship display, are undocumented.
Breeding
Captive reproduction of Astyanax kennedyi has not been formally recorded in the hobby literature. Based on the biology of the genus, breeding would be expected to follow the pattern common to open-water Astyanax species: adhesive or semi-adhesive eggs scattered among fine-leaved aquatic plants, driftwood roots, or over a planted substrate, with no parental attention afterward. Adults will eat their own eggs and fry and should be removed after spawning if eggs are to be raised.
Breeders working with related Astyanax species typically use a slightly cooler, soft-water trigger — mimicking the dilution of Amazonian waters during the wet season — along with enhanced feeding on live foods to stimulate spawning. Water temperature in the 79–82 °F range, soft and slightly acidic water (pH around 6.0–6.5), and a tank with fine-leaved plants or spawning mops would represent a reasonable first attempt. Fry, once hatched, would require very fine first foods such as infusoria or commercial liquid fry food, graduating to newly hatched brine shrimp nauplii.
In the aquarium
Kennedy's tetra is an active mid-water schooling fish that does best in a group of six or more. Its mild piscivorous streak means it should not be housed with very small species such as neon tetras, ember tetras, or juvenile fishes that fit in its mouth; similarly-sized or larger peaceful characins, non-aggressive South American cichlids, callichthyid corydoras, and loricariid catfishes are appropriate tankmates, as noted by Seriously Fish.
An Amazonian-themed aquarium suits the species well: sandy substrate, tangles of driftwood and submerged roots, some fine-leaved planting, and water conditioned with botanicals to achieve a slight tannin tint. Recommended parameters are 79–84 °F, pH 5.5–7.0, and moderate hardness in the range of 18–215 ppm total dissolved solids. Good filtration and regular water changes are important; the species is not noted as unusually hardy, and stable, clean water will keep it in best condition and colour. The species is traded internationally as an ornamental fish exported from Peru, though it remains uncommon in the hobby.
Conservation
Astyanax kennedyi is assessed as Data Deficient (DD) on the IUCN Red List, with the assessment completed on 21 April 2014 by Ortega Torres and Correa and published in 2016. Data Deficient does not mean the species is not at risk — it means the information required to make a sound assessment of risk is absent. The assessors noted that the species' distribution is not well defined, no population size or trend data exist, and the threats it faces are unknown.
The species is known to be collected for the international ornamental fish trade, exported from Peru, which introduces at least one potential pressure. No protected area occurrences have been documented within its range. Given that so much basic biology — distribution extent, population density, ecological requirements — remains uncharacterised, targeted surveys from the Iquitos region and surrounding Peruvian Amazon are among the research priorities identified in the IUCN assessment. Aquarists keeping this species should source captive-bred stock where available, though tank-bred specimens are rarely encountered in the trade.