Taxonomy & naming
Enteromius multilineatus was first described by the British limnologist Edgar Barton Worthington in 1933 under the combination Barbus multilineatus, from material collected in the Lake Bangweulu basin and the upper Congo drainage in what was then Northern Rhodesia (present-day Zambia). The epithet multilineatus — "many-lined" — refers directly to the parallel lateral stripes that define the species.
The genus Barbus long served as a near-universal catch-all for small African barbs, but systematic work over the late twentieth and early twenty-first centuries broke it into a series of more coherent genera. The Catalog of Fishes (Eschmeyer, CAS) now records the valid combination as Enteromius multilineatus (Worthington, 1933), with the parenthetical authority marking the transfer out of Barbus. Enteromius accommodates a large number of small to medium African barbs previously assigned to Barbus, and the species' placement within it reflects current consensus on African cyprinid classification. No subspecies are recognised.
Morphology
The Copperstripe barb is a slender, fusiform fish that reaches approximately 2 in in standard length (about 2 in total length), typical of the small-bodied African Enteromius. The body is moderately compressed and elongate, with the typical small barb profile: a blunt snout, subterminal mouth, and a single pair of barbels.
The most striking feature is the colour pattern: a broad coppery or brassy stripe runs along the mid-lateral line from the head to the caudal peduncle, bordered above and below by narrower dark brown to blackish bands that give the fish its multi-striped appearance. The flanks above these stripes are pale silvery-olive, and the belly is pale. Fins are generally hyaline or faintly pigmented. Females are likely deeper-bodied when gravid, though detailed dimorphism data are sparse.
Habitat
Enteromius multilineatus occurs across a broad swath of south-central Africa, spanning the Cunene, Okavango and Zambezi river systems and extending north into the upper Congo basin — principally the Lufira and Luapula drainages — and the Lake Bangweulu flats. This range encompasses some of the most biodiverse freshwater habitats on the continent, from the shallow papyrus-fringed floodplains of the Okavango and Zambezi to the clear streams draining the Congo highlands.
Within these systems the species favours shallow, well-vegetated backwaters, river margins and floodplain pools where the current is still or slow-moving. Aquatic vegetation provides both cover and foraging surfaces. Water chemistry across this broad range can vary from soft and mildly acidic in forested headwaters to harder and more neutral in open savanna channels, but the species' wide distribution suggests reasonable tolerance of mid-range conditions.
Feeding
The Copperstripe barb is an omnivore typical of small African riverine barbs, taking a mixed diet of small aquatic and terrestrial insects, algae, plant fragments and organic detritus. Its small terminal-to-subterminal mouth is suited to picking food items from the water column and from surfaces of vegetation and substrate rather than digging or active pursuit of large prey.
In the aquarium the species accepts standard small-particle foods readily — quality flake, micro-pellets and granules form a good staple base, supplemented with small live and frozen invertebrates such as daphnia, cyclops and finely chopped bloodworm. Algae and blanched vegetable matter are also taken. Regular variety supports condition and colour.
Mating
Like all barbs, Enteromius multilineatus is an egg-scattering, non-guarding spawner. There is no pair bond, no nest construction and no parental involvement beyond the act of spawning itself. When fish are in condition, a driving male pursues a gravid female through vegetation or along the substrate, repeatedly pressing close alongside her as both fish quiver and release eggs and milt in brief, energetic bursts.
Spawning readiness is promoted by good feeding, slight rises in temperature and — in seasonal environments — by the onset of floodplain conditions that simulate the rainy season. No territory is defended and multiple males may pursue a single female in a group. Adults do not distinguish their own eggs from food, and eggs left among the parents are quickly consumed.
Breeding
In the aquarium, breeding Enteromius multilineatus follows the standard approach for small egg-scattering barbs. A separate spawning vessel with shallow water, fine-leaved plants or a spawning mop, and a mesh or loose gravel base that allows eggs to fall beyond the adults' reach gives the best results. Well-conditioned fish introduced in the evening typically spawn by morning.
The adhesive eggs are small and numerous; a healthy female may deposit several hundred in a session. Adults must be removed promptly once spawning activity ceases to prevent egg predation. At tropical temperatures eggs hatch within one to two days, and the larvae become free-swimming within a further few days, at which point they can be fed infusoria or commercial fry foods followed by newly hatched brine shrimp nauplii as they grow. No parental care is provided at any stage.
In the aquarium
The Copperstripe barb is a peaceful, active schooling fish that suits a planted community aquarium with other small, non-aggressive species of similar size. Like most small barbs it is best kept in groups of six or more, which allows the natural shoaling behaviour to express itself and reduces the low-level chasing that isolated individuals may direct at tankmates.
A tank with open mid-water swimming space, dense marginal planting and a dark substrate brings out the coppery lateral band well. Water conditions reflecting the species' broad natural range — temperatures in the mid-twenties Celsius, neutral to mildly acidic pH and low-to-moderate hardness — suit it well. The species is hardy relative to many specialist African barbs and undemanding in feeding. It remains a somewhat specialist find in the hobby, more commonly encountered among enthusiasts of African riverine fishes than in general trade.
Conservation
Enteromius multilineatus is assessed as Least Concern (LC) on the IUCN Red List. The species has a wide native distribution across multiple large river systems — Cunene, Okavango, Zambezi and upper Congo — and there is no evidence of significant population decline across this range.
The principal pressures on its habitat are those common to south-central African freshwater systems: water extraction for agriculture, floodplain modification and drainage, pollution from small-scale agriculture and mining, and, in the Okavango and Zambezi lowlands, seasonal hydrological changes associated with land-use shifts upstream. None of these is yet assessed as driving range-wide decline for this species, but monitoring of floodplain and backwater habitats that the species depends on remains relevant as development pressures in the Zambezi basin intensify.