Taxonomy & naming
Jupiaba poekotero was described by Angela M. Zanata and Flávio C. T. Lima and published in Copeia in 2005. The type locality is the beaches in a pool below Cachoeira do Caruru, on the Rio Tiquié, in the state of Amazonas, Brazil (approximately 00°16'28.9"N, 69°54'53.6"W), and the holotype is deposited as MZUSP 83460 at the Museu de Zoologia da Universidade de São Paulo. Eschmeyer's Catalog of Fishes (CAS) confirms Jupiaba poekotero Zanata & Lima, 2005 as the valid name.
The genus Jupiaba belongs to the subfamily Jupiabinae within what has been treated as Acestrorhamphidae by some authors, though the species-level data from FishBase and CAS position the group within the broader Characidae. A 2009 phylogenetic review by Birindelli and colleagues that included J. poekotero confirmed its placement within Jupiaba and noted that the species was part of the broader Rio Negro fauna. No synonyms are recorded.
Morphology
Jupiaba poekotero reaches a recorded maximum of 2.5 in standard length for males and unsexed individuals — a small, slender characid with the typical Jupiaba body plan: moderately compressed laterally, with a subterminal mouth suited to grazing low-lying substrates and vegetation. Like other members of the genus it carries the family's adipose fin, a forked caudal, and the modest but characteristic silvery-flanked colouration of a blackwater stream fish.
Detailed meristic and morphometric data appear in the original 2005 description. Externally, the species is a fairly plain small characin — the kind of fish easily overlooked in a diverse tropical community — without the bold lateral stripes or vivid colour patches that mark many of its relatives. Sexual dimorphism has not been described in detail in the available literature.
Habitat
Jupiaba poekotero is known from the upper Rio Tiquié, a blackwater tributary of the upper Rio Negro basin in Amazonas state, Brazil. The type series was collected specifically from sandy beaches forming in pools at the base of waterfalls and rapids — notably below Cachoeira do Caruru — rather than from the quieter reaches or small forest streams of the same drainage. FishBase records the species as benthopelagic in freshwater tropical habitat.
The ecological notes from the original collection indicate that J. poekotero avoids small forest streams, being instead associated with the exposed, higher-energy beach and pool environments that develop where cascades slow and broaden. These microhabitats are characterised by coarser substrate, high oxygenation, good light penetration relative to closed-canopy forest streams, and an abundance of Podostemaceae — the rheophytic flowering plants that anchor themselves to wet rock faces in moving tropical water and form a significant component of this fish's diet.
Feeding
The diet of Jupiaba poekotero is unusually well characterised for a small Amazonian characid. Gut-content analysis documented in the FishBase species account records filamentous algae, fragments of Podostemaceae (the rheophytic river-weed plants common on cascade rocks), and both terrestrial and aquatic Hemipterans (true bugs), as well as Trichopteran (caddisfly) and odonate (dragonfly/damselfly) nymphs. This is a mixed algal-invertebrate diet consistent with a fish foraging on and around submerged rocky and sandy substrates in well-lit, fast-adjacent habitats.
The inclusion of Podostemaceae is notable — these plants are only found in the kind of high-gradient, waterfall-associated environments from which the species was collected, reinforcing the link between its microhabitat specialisation and its feeding ecology. The arthropod component (aquatic insects and surface-fallen terrestrial bugs) is broadly typical of Jupiaba and related genera, which tend to be opportunistic foragers supplementing plant material with available invertebrate prey.
Mating
No specific courtship or mating observations have been published for Jupiaba poekotero. Based on what is known of the genus Jupiaba and the broader subfamily, the species is expected to be an egg-scattering open spawner without parental care — the ancestral and most widespread reproductive mode among characids. Males and females likely congregate over fine substrates or among aquatic vegetation during spawning events, with adhesive or semi-adhesive eggs scattered and left to develop without adult attendance.
Any seasonal component to spawning in the Rio Tiquié would probably track the regional hydrological cycle, with higher water and flooding potentially cueing reproductive activity, as is commonly observed in Amazonian small characins. No captive breeding records or courtship descriptions have been traced for this species in the available literature.
Breeding
Jupiaba poekotero has not been documented in captive breeding in the available sources, and the species is not established in the ornamental trade. Based on genus-level expectations for Jupiaba and related characids, breeding in captivity would likely follow the standard egg-scattering pattern: a conditioned pair or small group introduced to a well-planted or mop-equipped tank, with spawning triggered by slightly cooler, softer water mimicking onset-of-wet-season conditions.
Eggs would be expected to be small, adhesive, and deposited among fine-leaved vegetation or on substrate. Incubation times and fry rearing requirements are not recorded for this species. Given its microhabitat preferences — pool and beach environments below waterfalls — a degree of water movement and good oxygenation may be beneficial in any breeding setup.
In the aquarium
Jupiaba poekotero is not an established aquarium fish and is not recorded in the ornamental trade. It is a scientific collection species known from a narrow range in the upper Rio Negro basin, and its ecological specialisation to waterfall-associated beach pools would make it a demanding fish to maintain even if available. Water quality requirements consistent with Rio Negro blackwater — warm, soft, and acidic — would apply, with the addition of good water movement and high oxygenation reflecting its natural cascade-edge habitat.
For the specialist keeping Rio Negro blackwater characins, a dimly lit, tannin-stained aquarium with fine sandy substrate, current from a powerhead or spray-bar, and a diet of varied frozen and live invertebrate foods would be the logical approach. In the absence of specific husbandry data, care guidelines for related Jupiaba species from similar Rio Negro tributaries offer the most relevant analogy. The species is not recommended for general community tanks and is unlikely to appear in the trade without targeted collection for scientific or specialist purposes.
Conservation
Jupiaba poekotero is considered Least Concern by the IUCN, reflecting a judgement that — despite its restricted known range in the upper Rio Tiquié — the species does not currently meet thresholds for a threatened category. The upper Rio Negro basin, while remote, remains one of the better-preserved large river systems in Amazonia; deforestation and human settlement pressure are lower here than in many other parts of the Amazon watershed.
Nonetheless, the species' apparent microhabitat specialisation to waterfall-pool beach environments is a potential vulnerability. Any alteration to flow regime, riparian vegetation, or substrate in the vicinity of key cascade sites such as Cachoeira do Caruru could degrade or eliminate the specific conditions this fish depends on. The narrow collection record means population size and the full extent of the range are poorly known, and further survey work in the upper Tiquié and adjacent Rio Negro tributaries would refine the conservation picture considerably.