Taxonomy & naming
Enteromius lineomaculatus was described by George Albert Boulenger in 1903, with the type locality recorded as the Lumi River, on the border region between what is now Tanzania and Kenya. The species was originally placed in the old, broadly circumscribed genus Barbus, and for much of the twentieth century it appeared in literature and aquarium references under Barbus lineomaculatus or the related catch-all Puntius. Under modern phylogenetic revisions the species is placed in Enteromius, a genus used for a large assemblage of small African barbs that were separated from the European-Asian Barbus complex.
The Catalog of Fishes (Eschmeyer, CAS) is the governing authority for the valid name; the current accepted combination is Enteromius lineomaculatus (Boulenger, 1903). GBIF records the species under this combination with the GBIF species key 9582714. The parenthetical authority indicates the species was moved from Boulenger's original genus placement into Enteromius by subsequent revisers.
Morphology
Enteromius lineomaculatus is a small, moderately deep-bodied barb reaching a maximum of 3.5 in in standard length (SL) per FishBase. The common name "line-spotted barb" refers to the patterning of spots or spot-rows along the flank, a characteristic that distinguishes it from plain-flanked African barbs in the same river systems.
As with many Enteromius, the species is sexually dimorphic in a modest way: females tend to be fuller-bodied, particularly when gravid, while males show brighter coloration and a slimmer profile. Precise meristic details (scale counts, fin-ray formulae) from the original Boulenger description are not reproduced here as the primary description has not been independently verified from a copy in cache.
Habitat
The line-spotted barb inhabits a broad range of freshwater environments across southern and central Africa, including the Cunene, Okavango, Zambezi, and Limpopo river systems, as well as coastal Indian Ocean drainages. A biotope record from the Mtamvuna River (Eastern Cape, South Africa) describes the species in the middle course of a clear-water river with slow-moving flow, characteristic of savanna and transitional plateau streams rather than dense forest blackwater.
FishBase records it as a benthopelagic and potamodromous species, indicating it moves within freshwater systems rather than undertaking marine or estuarine migrations. Temperature range is 72–77 °F per FishBase, consistent with the warm subtropical and tropical drainages it occupies. Water chemistry across this broad range varies from the soft, slightly acidic headwaters of montane streams to harder, more productive lowland rivers and floodplain systems.
Feeding
Enteromius lineomaculatus is an omnivore, consistent with the feeding strategy of the broader Enteromius assemblage. Like other small African barbs it forages near the bottom and in mid-water, picking at small invertebrates — insect larvae, worms, microcrustaceans — as well as algae, plant matter, and organic detritus.
In the aquarium the species is undemanding and accepts good-quality flake and small pellet foods, supplemented with live or frozen items such as bloodworm and brine shrimp. Its active foraging behaviour and generalist diet make feeding straightforward for beginner hobbyists.
Mating
Like all barbs, Enteromius lineomaculatus is an egg-scattering, non-guarding spawner. There is no nest construction, no pair bond, and no parental territory maintained beyond the brief act of spawning. Courtship consists of a male driving a gravid female through vegetation or over the substrate; the two press together momentarily as eggs and milt are released simultaneously into the water column or among fine-leaved plants and gravel.
Spawning in small African riverine barbs is typically triggered by seasonal cues — rising water temperature, changes in rainfall and flow regime — that characterise the onset of the rainy season across their range. In aquaria, conditioning on live and frozen foods and a modest temperature rise encourages spawning behaviour.
Breeding
Enteromius lineomaculatus spawns as an egg-scatterer with no parental care whatsoever; adults will consume their own eggs if given the opportunity. In aquarium breeding, a shallow tank furnished with fine-leaved plants or a spawning mop and a mesh or gravel layer over the base — so that eggs fall beyond reach of the adults — is a standard approach. A well-conditioned group or pair is introduced, and spawning usually follows within a day or two.
Eggs are adhesive and small, hatching within one to two days at tropical temperatures. The larvae become free-swimming after a further two to three days and can be raised initially on infusoria or commercial fry foods, graduating to newly hatched brine shrimp as they grow. Growth is steady, and the species is considered straightforward to breed.
In the aquarium
The line-spotted barb is described as peaceful, diurnal, and beginner-friendly by hobbyists who have kept it in biotope setups. It is best maintained in a shoal of six or more individuals, which brings out natural schooling behaviour and reduces any skittishness. A tank with open mid-water swimming space, some fine-leaved planting, and a sand or fine-gravel substrate reflects its riverine natural habitat.
Water temperature of 72–77 °F and broadly neutral to slightly acidic pH suit the species well. It is compatible with other peaceful community fishes of similar size. The biotope record from the Mtamvuna River notes slow-moving, clear freshwater conditions, suggesting it does not require strong current but benefits from good filtration and moderate oxygenation. Availability in the hobby outside of South Africa is limited; it is more likely encountered through specialist African biotope aquarists than in mainstream trade.
Conservation
Globally, Enteromius lineomaculatus is considered Least Concern (LC) per FishBase, reflecting its wide distribution across multiple major southern African drainage systems. The global population is regarded as stable and without major range-wide threats.
However, the SANBI (South African National Biodiversity Institute) regional Red List assessment of December 2017 rates the species as Near Threatened (NT) within South Africa, where it occurs in the Limpopo River system. Regional threats identified include habitat degradation from erosion and agricultural runoff, mining activity in the Olifants River catchment, water pollution, and dam construction — pressures that are widespread across southern African river systems and affect many rheophilic and small riverine cyprinids. Conservation attention in South Africa focuses on improved land-use practices and catchment management to reduce sedimentation and pollution in affected river systems.