Taxonomy & naming
Discherodontus colemani was originally described as Barbus colemani by the American ichthyologist Henry Weed Fowler in 1937, based on material from the Mae Poon River, a tributary of the Mae Nam Yom in Chiang Mai Province, northern Thailand. The Catalog of Fishes (Eschmeyer, California Academy of Sciences) records the original combination as Barbus colemani Fowler, 1937, with the parenthetical authority in the current name marking subsequent genus transfer.
The species has been moved among cyprinid genera in subsequent decades. FishBase currently places it in Discherodontus as D. colemani following Rainboth (1989), who revised the genus; the site here follows the Barbodes combination, which is in use in part of the literature and was the basis for the species' IUCN assessment. The old wastebasket genus Puntius, from which most Southeast Asian barbs have been progressively redistributed, does not apply here — the species was never formally transferred there. The taxonomic placement remains an area where reference sources differ, and the Catalog of Fishes is the final arbiter of the valid name.
The species name honours H. W. Coleman (1847–1907), a physician associated with the specimen collection.
This fish was long listed as Barbodes colemani; Eschmeyer's Catalog of Fishes places the species in Discherodontus, and the current combination Discherodontus colemani is followed here.
Morphology
Detailed morphological data for Discherodontus colemani are sparse in the accessible literature. FishBase records a maximum standard length of approximately 3.15 in (3.1 in SL), placing it among the medium-small Asian barbs. Like other members of this broadly defined group it is presumed to have the moderately compressed, deep-bodied shape typical of Barbodes and allied genera, with a small mouth, pharyngeal teeth and the usual cyprinid scalation.
No detailed colour description or illustration is available in the sources accessed for this article. The scarcity of specimens in collections and the species' absence from the aquarium trade mean that photographic records are essentially non-existent in the hobby literature.
Habitat
Discherodontus colemani is recorded from submontane and lowland freshwater streams and tributaries in the upper Chao Phraya basin, specifically the Mae Nam Yom drainage in Chiang Mai Province, northern Thailand. This region is characterised by hill streams descending from the northern ranges into the broad alluvial lowlands of central Thailand, with water that is generally soft to moderately hard and near-neutral to slightly acidic depending on substrate and season.
The species is described as a tropical freshwater fish; beyond that, precise habitat preferences — water depth, substrate type, velocity, vegetation associations — are not documented in the sources accessed. Its occurrence in tributary streams rather than main channels suggests an association with sheltered, lower-gradient flow, a pattern common in closely related genera from the same region.
Feeding
No detailed dietary study of Discherodontus colemani in the wild has been published in the accessible literature. Based on the feeding ecology of congeners and related Asian barbs of comparable size and habitat, the species is presumed to be an omnivore, taking small invertebrates, algae, plant matter and organic detritus from the substrate and water column.
The species is not established in the aquarium trade and feeding observations in captivity are not available.
Mating
Discherodontus colemani has not been studied in detail with respect to its reproductive behaviour, but as a member of the cyprinid tribe that encompasses the Asian barbs it is a presumed egg-scattering, non-guarding spawner. Barbs of this type do not form lasting pair bonds or hold territories during spawning, and they perform no nest construction.
A driving male pursues a gravid female through vegetation or over the substrate, releasing milt alongside a scatter of adhesive eggs. There is no courtship display beyond this pursuit, and the spawning act is brief. Seasonal reproductive activity likely correlates with water temperature and the onset of the rainy season, as is typical for tropical stream barbs in mainland Southeast Asia.
Breeding
Discherodontus colemani has not been bred in captivity and its detailed reproductive biology — clutch size, egg characteristics, incubation period, larval development — is undocumented in the accessible literature. The species is essentially absent from the ornamental fish trade and has not been the subject of aquaculture or ex-situ breeding programmes.
By analogy with closely related species, eggs are expected to be small, adhesive and scattered among fine-leaved vegetation or over the substrate, with no parental care given after spawning. Adults of most barbs actively predate their own eggs if they remain in contact with them. Larvae would likely be free-swimming within a few days of hatching at tropical stream temperatures.
In the aquarium
Discherodontus colemani is not established in the ornamental fish trade and is essentially unknown in the aquarium hobby. Its rarity, restricted range and Data Deficient IUCN status mean that it has never been imported in meaningful numbers, and no captive-care guidelines exist in the published hobby literature.
For the rare individual held in a specialist collection, it would be reasonable to provide conditions reflecting its northern Thai stream origins — warm tropical temperatures, neutral to mildly acidic, soft to moderately hard water, with good flow and oxygenation. The species has not been assessed for compatibility with other aquarium fish.
Conservation
Discherodontus colemani was assessed as Data Deficient (DD) by Chutapong Vidthayanon for the IUCN Red List in 2012. The Data Deficient designation reflects genuine gaps in knowledge about the species' population size, distribution extent and trends rather than confirmed decline; it is a signal that further survey work is needed before a threat status can be assigned.
The species is confirmed as endemic to Thailand and appears to be restricted to the upper Chao Phraya basin, a drainage that has undergone significant anthropogenic modification. Primary threats to freshwater biodiversity in northern Thailand's hill-stream systems include deforestation of riparian and catchment areas, agricultural expansion and associated runoff of pesticides and fertilisers, and sedimentation resulting from land clearance — all of which are documented as active pressures in the Mae Nam Yom watershed. Discherodontus colemani's restricted range makes it inherently vulnerable to any degradation of its limited habitat, and targeted survey effort in the Mae Poon River and nearby tributaries would be valuable to determine whether the species remains extant and at what density.