Taxonomy & naming
Devario manipurensis was described by R.P. Barman in 1987, originally published as Danio manipurensis in the Journal of the Bombay Natural History Society (84(1): 173). The type locality is given as hill streams of Manipur, northeastern India. The Catalog of Fishes (Eschmeyer, the authority for valid names) records the valid combination as Devario manipurensis (Barman, 1987), with the parenthetical authority marking the transfer from Barman's original genus Danio into Devario.
Devario is a genus of medium to large danionine cyprinids distributed across South and Southeast Asia, distinguished from the true small danios (Danio) chiefly by size, fin proportions and the characteristic high number of lateral-line scales in many members. Several species historically placed in Danio have been transferred to Devario as the taxonomy of the danionins has been refined; the reassignment of manipurensis follows that broader reorganisation. No synonyms or misidentified references are known for this species in the literature accessible via present records.
ITIS records the taxon under the valid name Devario manipurensis (TSN 688998). No subspecies or geographic variants have been described.
Morphology
Devario manipurensis is a small species for its genus, reaching a maximum recorded standard length of 1.5 in according to FishBase — considerably smaller than the widespread giant danio Devario aequipinnatus, which approaches 4–6 in, and toward the low end of the size range for Devario as a whole. Specific morphological details — scale counts, fin-ray formulae, colouration pattern — are not well documented in the secondary literature available for this species, reflecting the limited collecting effort in Manipur's hill streams.
The genus Devario is generally characterised by an elongate, laterally compressed body, a large mouth angled upward, prominent barbels, and in many members a pattern of horizontal blue or silver stripes on the flanks, though the precise arrangement varies considerably among species. Sexual dimorphism across the genus typically follows the danionine pattern: females are deeper-bellied when ripe, males slimmer and more vibrantly coloured, though specific notes on dimorphism in this species are not recorded in available sources.
Habitat
The species inhabits clear hill streams in Manipur, northeastern India. FishBase characterises its environment as freshwater and assigns it to the hill-stream ecology typical of Devario species in the region: fast-flowing, well-oxygenated, clear-water streams running over rock, gravel and coarse sand substrates, often shaded by riparian forest and cooler than the lowland rivers of the plains.
Manipur's freshwater drainages lie in a geologically active zone within the Indo-Burma biodiversity hotspot, draining into the Chindwin and ultimately into the Irrawaddy system. The state's hill streams share faunal affinities with Myanmar's western slopes as well as with other northeastern Indian states, and support a diverse and regionally endemic fish fauna that remains incompletely surveyed. The specific river system or sub-basin within Manipur from which the type material was collected is recorded simply as "Manipur hill streams" in the original description, and no detailed habitat data beyond the general hill-stream characterisation are documented in the available literature.
Feeding
No specific dietary studies of Devario manipurensis are documented in the available literature. The feeding ecology of the species can be inferred from its morphology and from what is known of congeners: Devario species in hill streams are typically surface-oriented omnivores and micropredators, taking terrestrial and aquatic invertebrates — insects, their larvae, and small crustaceans — from the surface and water column, supplemented by algae, diatoms and fine organic matter.
The upturned mouth characteristic of Devario suits a fish that intercepts prey at or near the surface, and in clear fast-flowing streams where allochthonous input (insects falling from overhanging vegetation) is often the dominant energy subsidy, surface feeding is likely an important component of the diet. In an aquarium context, Devario species generalise readily to prepared and frozen foods, though this species is not established in the hobby.
Mating
No courtship or mating observations of Devario manipurensis are recorded in the available literature. The species is expected to reproduce according to the pattern universal in Devario and the danionines generally: egg-scattering with no parental care. In the wild, spawning in hill-stream Devario species is typically associated with the monsoon season, when rising water temperatures and increased flow stimulate reproductive behaviour.
Male Devario pursue gravid females actively through the water column and among aquatic vegetation or substrate. Eggs and milt are released together during brief, close-contact bursts, with the adhesive or weakly adhesive eggs settling among plants, moss, gravel or root tangles. No pair bond is formed and neither parent guards or attends the eggs after spawning.
Breeding
Devario manipurensis has not been bred in the aquarium, and no captive-breeding records are documented for the species. Its reproductive biology is inferred from the genus: Devario are egg-scatterers that scatter adhesive eggs over plants, moss, gravel and other fine substrate, with no nest, no bubble-nest, no mouthbrooding, and no parental care of any kind. Adults of many Devario species will eat their own eggs if given opportunity, so separation of spawners from eggs would be necessary in any captive attempt.
In wild hill-stream populations, breeding is presumably seasonal, tied to the monsoon onset as is typical for northeastern Indian cyprinids. Larvae would be expected to feed initially on zooplankton and fine invertebrate matter. The species' small maximum size suggests relatively modest fecundity compared with larger Devario, though no data on egg counts or developmental rates are available.
In the aquarium
Devario manipurensis is not established in the aquarium hobby and is absent from the trade. No keeping records, husbandry notes, or captive-care literature are documented for this species. It is known only from wild-collected scientific specimens from Manipur, and its restricted endemic range in a geographically remote and politically sensitive part of northeastern India means that collection for export has not occurred.
Based on its congeners, it would be expected to thrive in a hill-stream biotope setup: a long, well-filtered tank with good flow, high oxygenation, cooler temperatures, and a substrate of gravel and smooth stone. Like other Devario, it would presumably be an active, surface-oriented shoaling fish best kept in groups of six or more with robust, similarly-sized companions. Its small size makes it suitable for a smaller system than the large-bodied giant danios, though these are inferences from genus-level biology rather than direct observation.
Conservation
Devario manipurensis is assessed as Data Deficient (DD) on the IUCN Red List (2022). The DD listing reflects an absence of sufficient information to make a formal assessment of extinction risk rather than confirmed stability: the species has a narrow endemic range confined to the hill streams of Manipur, and the limited survey effort in the region means that its population size, trend and precise distribution are unknown.
Manipur's freshwater ecosystems face pressures characteristic of the northeastern Indian hill states: deforestation and associated sedimentation of clear streams, agricultural encroachment on riparian zones, small-scale damming and water extraction, and collection pressure for regional food fish markets. The state lies within the Indo-Burma biodiversity hotspot, one of the world's most threatened, and many narrow-range endemics from the region are likely at greater risk than their formal IUCN status suggests. Targeted surveys to establish the species' current distribution, habitat condition and population size are needed before a meaningful threat assessment can be made.