Taxonomy & naming
Jupiaba citrina was formally described by Angela M. Zanata and Willian M. Ohara in 2009 in the journal Neotropical Ichthyology (volume 7, issue 4). The holotype, catalogued as INPA 32026, measures 2.5 in standard length and was collected from an igarapé on the left margin of the Rio Guariba, within the Rio Aripuanã drainage, Rio Madeira basin. The specific epithet citrina derives from the Latin citrus (lemon or citrus-orange), referring to the species' distinctive yellowish-orange body colour.
The genus Jupiaba belongs to the subfamily Stevardiinae within the large family Characidae, and is a primarily Amazonian lineage of small, laterally compressed tetras. Within Jupiaba the valid name is recorded as Jupiaba citrina Zanata & Ohara, 2009 in Eschmeyer's Catalog of Fishes, and no subsequent synonymy has moved the species from the genus.
Morphology
Jupiaba citrina is a small tetra reaching a maximum recorded standard length of 2.5 in, though most individuals are smaller. The body is laterally compressed and moderately deep, consistent with the general Jupiaba body plan.
The species is distinguished from its congeners by a combination of characters: two vertically elongated humeral blotches behind the gill cover, and a dark longitudinal stripe extending from approximately the humeral region along the flank to the caudal peduncle. The overall body colouration is yellowish to pale orange — the citrus hue that the species name records — overlaid by the dark lateral markings. Like other members of the genus it possesses the adipose fin characteristic of characids.
Habitat
The known range of Jupiaba citrina is the Rio Aripuanã drainage in Amazonas and Mato Grosso states, Brazil, roughly between 8°S–9°S and 60°W–61°W. The Rio Aripuanã is a clear-water tributary of the Rio Madeira and runs through forested terrain in Mato Grosso before entering Amazonas. Field collections in the Aripuanã system have recorded this species from both blackwater and whitewater stream environments with sandy bottoms, consistent with the heterogeneous microhabitats of Amazonian headwater drainages. The species has also been reported from extensive rapids environments in the Aripuanã basin, where it formed a notable component of the local fish community.
Water parameters for Rio Aripuanã streams are typical of Amazonian tributaries: warm tropical temperatures, soft to moderately soft water, and a pH ranging from slightly acidic blackwater conditions to near-neutral in whitewater reaches.
Feeding
Jupiaba citrina is reported to feed on invertebrates and plant matter, the generalist omnivorous diet typical of small Amazonian characids. In its natural streams it presumably takes small aquatic and terrestrial invertebrates — chironomid larvae, microcrustaceans, fallen insects — along with algae and vegetable detritus.
In the aquarium, congeners and ecologically similar small characids accept a broad range of standard aquarium foods: good-quality flake and micro-pellets as a staple, supplemented with frozen or live foods such as Daphnia, Artemia nauplii, and micro-worms to maintain condition and colour.
Mating
No published observations of courtship behaviour in Jupiaba citrina are available in the sources consulted. Based on the biology of closely related small Amazonian characids, the species is expected to be an egg-scattering open spawner, releasing adhesive or semi-adhesive eggs among fine-leaved aquatic vegetation or over the substrate, with no pair bond formed and no parental care offered.
Males of small Jupiaba species can typically be distinguished from females at maturity by a slimmer abdominal profile, with females appearing deeper-bodied and more rounded when in spawning condition.
Breeding
Captive breeding records for Jupiaba citrina are not documented in the sources consulted; the species remains uncommon in the aquarium hobby. By analogy with similar small Amazonian characids, breeding would likely involve egg-scattering spawning over fine-leaved plants or a spawning mop, with adhesive eggs deposited in small numbers, no parental care, and a requirement to remove adults after spawning to prevent egg predation.
Incubation and larval development times have not been reported for this species; hobbyists breeding related Jupiaba species typically work at soft, slightly acidic water and temperatures in the mid-to-upper 20s Celsius.
In the aquarium
Jupiaba citrina remains a rarely encountered species in the aquarium trade, and detailed husbandry notes are sparse. Based on habitat data and the biology of the genus, it is best treated as a soft-water, warm-water species from Amazonian streams. An aquarium replicating a shaded tributary environment — subdued lighting, dark substrate, tannin-stained water, fine-leaved plants or spawning mops, and gentle filtration — would suit it well.
As a small, likely peaceful schooling fish, it should do best kept in groups of six or more. Tankmates should be similarly small and peaceful: other small Amazonian characins, dwarf cichlids, and small catfish are suitable choices. Water should be soft and slightly acidic to neutral, with temperatures in the range of 73–82 °F. The species' rarity in trade means most hobbyists will encounter it only through specialist importers or breeders focusing on wild Amazonian tetras.
Conservation
Jupiaba citrina has not received a formal IUCN Red List assessment; it does not appear on the IUCN Red List as an individually assessed species, and its status is listed as Least Concern on FishBase based on current trade and collection data rather than a dedicated IUCN evaluation.
The species is endemic to the Rio Aripuanã drainage in Mato Grosso and Amazonas, Brazil. While the Rio Aripuanã basin retains substantial forest cover, Amazonian headwater drainages face ongoing pressure from deforestation, agricultural expansion, and hydroelectric development. Field collections record the species as a regular component of the local fish community in the Aripuanã system, suggesting it is not immediately imperilled, but the absence of a formal assessment means its population trajectory is unmonitored.