Taxonomy & naming
Barbonymus strigatus was described by the Belgian-British ichthyologist George Albert Boulenger in 1894, with the parenthetical authority in the modern combination reflecting the move out of his original placement. The Catalog of Fishes (Eschmeyer, CAS), the governing authority for valid names, places the species in the genus Barbodes.
Barbodes is one of several genera carved from the sprawling old catch-all Puntius during a major revision of Asian barbs beginning in the early 2010s. The genus contains large-bodied, often deep-bodied Asian barbs, and B. strigatus fits that general mould. Older literature may refer to this species under a different generic combination; the current valid binomial is Barbonymus strigatus (Boulenger, 1894). The species epithet strigatus is from the Latin strigatus, meaning streaked or striped, likely referring to a colour or scale pattern feature.
This fish was long listed as Barbodes strigatus; Eschmeyer's Catalog of Fishes places the species in Barbonymus, and the current combination Barbonymus strigatus is followed here.
Morphology
Barbonymus strigatus is a moderately large barb, reaching up to 6.6 in in total length according to FishBase — substantial for a Sundaland cyprinid and placing it among the larger members of the genus. The body is compressed and deep in the manner of many Barbodes species, with the robust build suited to negotiating riverine currents.
Detailed colour descriptions are sparse in the literature, and no aquarium photographs circulate widely. The species epithet ("streaked") suggests longitudinal markings on the flanks, consistent with the pattern of several related Bornean Barbodes. The fin complement and general anatomy follow the cyprinid ground plan: a single dorsal fin, forked caudal, and the barbels typical of the subfamily Smiliogastrinae.
Habitat
Barbonymus strigatus is native to the Kapuas River system of western Borneo and to waters in Sabah, the Malaysian state occupying north-eastern Borneo. The Kapuas is the longest river in Indonesia, draining a vast lowland forest interior through Kalimantan (Indonesian Borneo), and its tributary network includes a mosaic of clearwater rivers, blackwater peat-swamp streams and riparian forest channels.
The water chemistry of Sundaland's lowland river systems tends toward the soft and acidic: dissolved mineral content is low, pH is typically between 4.5 and 6.5 in peat-influenced reaches and somewhat higher in clearwater rivers, and temperatures are warm throughout the year, broadly in the range of 73–81 °F. Barbonymus strigatus is listed as a benthopelagic species by FishBase, suggesting it inhabits the lower water column and substrate zone in these rivers rather than the open surface.
Feeding
No published dietary analysis specific to Barbonymus strigatus is available. By analogy with closely related and ecologically similar Barbodes species from Borneo and Sundaland generally, the species is expected to be an omnivore — taking a mix of small invertebrates (aquatic insect larvae, small crustaceans, worms), plant material, algae and organic detritus from the substrate and lower water column.
The benthopelagic habit recorded for the species is consistent with foraging at and near the riverbed, picking through leaf litter, sand, gravel and submerged wood for food items. In the aquarium, related species of similar size accept a wide range of prepared and live foods.
Mating
Barbonymus strigatus, like all barbs, is an egg-scattering, non-guarding spawner. No specific courtship or mating observations exist in the literature for this species, but the pattern across the genus is consistent: when a female comes into breeding condition, one or more males drive her through vegetation, over gravel or along the substrate, pressing alongside as eggs and milt are released in brief bursts.
No pair bond is formed and no territory is held beyond the transient space of active courtship. Males compete among themselves for access to gravid females, and spawning activity typically increases after a period of good feeding, rising temperatures or increased water flow — conditions that simulate the seasonal cues of tropical river systems.
Breeding
Barbonymus strigatus has not been bred in captivity in any documented account available to this author. The standard barb reproductive pattern applies: adhesive eggs scattered over fine-leaved plants, roots, gravel or leaf litter, with no parental care of any kind. Adults do not guard, fan, or attend the eggs, and will consume them if not removed.
For any aquarist attempting to breed this species, the approach used for similarly sized river barbs would apply — a spacious, well-planted tank with soft, slightly acidic water in the mid-twenties Celsius, live or frozen foods to condition the adults, and removal of the parents after spawning. The relatively large adult size suggests a corresponding egg capacity, but fecundity figures are not published.
In the aquarium
Barbonymus strigatus is rarely encountered in the ornamental fish trade and does not appear in mainstream hobby literature. Its large adult size — approaching 6.7 in — means it requires a spacious aquarium if it is kept: a tank of at least 59.1–78.7 in in length would be appropriate for a shoal of adults, with good filtration and water movement reflecting its riverine origins.
Water chemistry should replicate Sundaland conditions: soft to moderately soft water, a slightly acidic to neutral pH (5.5–7.0), and a temperature of 73–81 °F. As an active, mid-to-lower-water species, it would benefit from open swimming space alongside areas of structure — submerged wood, root tangles, and leaf litter — that replicate the Kapuas riverine environment. Any aquarium specimens should be assumed wild-caught; captive breeding has not been documented.
Conservation
Barbonymus strigatus has not been assessed by the IUCN Red List. Its known range is limited to the Kapuas River system of western Borneo (Kalimantan, Indonesia) and Sabah, Malaysia, making it an endemic species of the island with presumably restricted natural distribution.
Borneo's freshwater fauna faces severe and ongoing pressure from large-scale deforestation, the conversion of peat swamps to oil palm plantations, gold mining operations along river systems (particularly in Kalimantan), and the resulting siltation, acidification and chemical pollution of river channels. The Kapuas catchment has experienced significant land-use change. For a narrowly endemic, data-sparse species like B. strigatus, these pressures are cause for concern even in the absence of a formal assessment. A targeted survey of its distribution and population status within the Kapuas basin would be a valuable conservation priority.