Taxonomy & naming
Danio choprae was described by Sunder Lal Hora in 1928 from specimens collected in the Mogaung Chaung river system, Myitkyina District, Kachin State, northern Myanmar. The species has also circulated in the literature under the spelling Danio choprai — both forms appear, though choprae is the authority's original orthography and the one followed here.
When this fish entered the aquarium trade in the early 2000s it was briefly placed in a monotypic genus, Celestichthys, as Celestichthys choprae. Subsequent molecular and morphological work determined that Celestichthys is a heterotypic synonym of Danio, and the species is now treated as Danio choprae, a placement followed by the Catalog of Fishes (Eschmeyer, the authority for valid names). The Catalog of Fishes governs the valid combination here; hobbyist sources still occasionally use the Celestichthys name, and the Seriously Fish profile is filed under that former combination. Danio choprae sits within the core true-danio radiation alongside D. rerio, D. kyathit and other horizontally striped cyprinids of the eastern Himalayan foothills and Indochina.
Morphology
Danio choprae is among the smallest members of the genus, reaching a maximum of roughly 1 in SL (approximately 1 in for males or unsexed individuals) and remaining slender even when fully grown. The body is typical of the true danios — elongate, slightly laterally compressed, with a subterminal to slightly upturned mouth equipped with small barbels, and a forked caudal fin.
Coloration is the species' defining feature. The flanks carry alternating dark and brilliant lines running horizontally from behind the operculum to the caudal fin, with a vivid orange-gold stripe that can appear to glow under good lighting — the glowlight effect for which it is named. Depending on lighting angle and condition, iridescent blue-green or greenish elements appear in the dark bands. The fins are largely hyaline with faint yellow or orange tints. Females are visibly deeper-bodied than males when gravid, and males tend toward more intense and contrasting coloration.
Habitat
The type locality of Danio choprae is a small, rocky stream system within the Mogaung Chaung drainage, itself a tributary of the Irrawaddy (Ayeyarwaddy) in Myitkyina District, Kachin State, far northern Myanmar. Field notes describe streams approximately 98 ft wide and 12–19.5 in deep with clear water and gravel or muddy substrate; aquatic vegetation is largely absent. The water is typical of upland Burmese hill streams — clear, moderately soft to moderately hard, and spanning a notably wide temperature range from cool montane conditions to warmer lowland figures.
Seriously Fish gives water parameters at the type locality as 61–79 °F, pH 6.0–8.0, and hardness 18–215 ppm — a broad envelope reflecting the seasonal variation of a highland river system. The species appears to require clean, well-oxygenated water with some current, as would be expected of a fast-water rocky-stream cyprinid, rather than the still, tannin-stained blackwater of lowland tropical forests.
Feeding
In its natural habitat Danio choprae feeds on insects and their aquatic larvae as well as other small invertebrates — the opportunistic micropredator diet typical of the true danios. FishBase characterises the diet as insects, aquatic insect larvae, and small animals; the upturned mouth and mid-to-surface position in the water column suit a fish that takes prey at or near the surface film as well as drifting in the current.
In the aquarium the species accepts most standard small foods without difficulty. Seriously Fish notes that while dried foods are taken readily, live and frozen items — bloodworm, Daphnia, Artemia nauplii — bring out best condition and peak coloration. Given the fish's small size, finely ground foods or micro-sized pellets are preferable to larger granules. Regular variety in the diet is beneficial for long-term health and reproductive readiness.
Mating
Danio choprae is an egg-scattering, non-guarding spawner. There is no pair bond, no nest, and no parental investment beyond the act of spawning itself. In a conditioned group, ripe males pursue gravid females actively through the tank, the chasing intensifying as a female approaches peak readiness. When the pair aligns among fine-leaved plants, moss, or over the substrate, eggs and milt are released simultaneously.
The eggs are weakly adhesive and may settle among plant strands or on the substrate. Adults will consume eggs given the opportunity, so the absence of parental care is total — eggs that fall beyond reach of the spawning fish have the best survival prospects. Spawning is typically triggered in the morning, especially after a partial water change or a mild drop and rebound in temperature that mimics the thermal signals of seasonal stream conditions.
Breeding
To breed Danio choprae, a small, shallow conditioning tank with a layer of fine-leaved plants (Java moss is widely used) or a mesh over the base works well; the goal is for eggs to fall out of reach of the adults. A group with multiple males and females produces the highest egg yields through competition and mutual stimulation. A partial water change with slightly cooler water often stimulates spawning the following morning.
Eggs hatch in two to three days at around 72–75 °F, and the larvae become free-swimming a few days after that, at which point infusoria or commercially prepared fry foods are needed before transitioning to Artemia nauplii. Growth is modest and the fish remain small; separating fry by size helps prevent predation among fast and slow growers. Because the species is captive-bred in the hobby in reasonable numbers, obtaining domestically raised fish is preferable to wild-caught individuals.
In the aquarium
Danio choprae is an excellent aquarium subject for a small, well-planted tank with good filtration and gentle current. Its diminutive size — barely 1 in — means it is better suited to tanks where it will not be outcompeted or threatened by larger, more boisterous fish. It is an active, shoaling species and should be kept in groups of at least eight; a larger group of twelve or more brings out its natural schooling behaviour and reduces individual stress. In a species tank or alongside similarly sized, peaceable companions such as small rasboras, pygmy corydoras or small tetras it thrives.
Water quality should reflect the clear rocky-stream habitat: well-filtered with moderate current, temperature in the 64–75 °F range (the cooler end of its tolerance is well within reach without a heater in many climates), pH 6.0–7.5, and soft to moderately hard water. The fish's vivid orange stripe reads best in good light against dark substrate and dense planting. Aquarium specimens are reliably captive-bred and captive-raised fish are recommended over wild imports.
Conservation
Danio choprae is assessed as Least Concern (LC) on the IUCN Red List (Vishwanath 2010). The assessment notes that the species is found in a remote part of Myanmar with no major threats identified at the time of assessment; it is believed to be fairly common within its known range, though the full extent of that range requires further research. It is noted as an ornamental fish used in the aquarium hobby.
The species is endemic to the Mogaung Chaung tributary system of the Ayeyarwaddy drainage in Kachin State — a geographically restricted range that, while currently remote, makes it inherently vulnerable to any future habitat change in that watershed. Broader pressures facing Myanmar's freshwater fauna include deforestation, sedimentation and agricultural runoff in highland catchments. The popularity of this fish in the aquarium hobby has been served mainly by captive-bred stock rather than large-scale wild collection, which reduces direct harvest pressure on wild populations.