Taxonomy & naming
Enteromius macrotaenia was described by Edgar Barton Worthington in 1933, originally placed in the genus Barbus — the broad catch-all under which virtually all African and many Asian barbs were then grouped. The species was long known in the literature under the older combination Barbus macrotaenia (Worthington, 1933); the parenthetical authority in the current name reflects the subsequent transfer out of Barbus.
The genus Enteromius was erected by Cope in 1867 and was revived and expanded to accommodate the large paraphyletic block of small African barbs that could not be placed in the more tightly defined Puntius or its daughter genera following molecular and morphological reappraisals in the early twenty-first century. Enteromius macrotaenia is closely allied to Enteromius eutaenia and several other southern African streamlined barbs distinguished primarily by the width and extent of the lateral stripe and details of the dorsal-fin ray count. The Catalog of Fishes (Eschmeyer, CAS) records Enteromius macrotaenia (Worthington, 1933) as the currently valid name.
Morphology
The broadband barb is a streamlined, moderately compressed cyprinid with the body shape typical of active riverine barbs — elongate relative to its depth, with a pointed snout, a forked tail, and a single dorsal fin set mid-body. Its most prominent feature is the broad, dark lateral band that runs from behind the gill cover to the caudal fin, giving the species both its common and scientific names (Greek makros, large or long; tainia, band). This stripe is notably wider and more diffuse than the narrower lateral line stripe of the closely related E. eutaenia, providing the primary field character separating the two.
The last simple dorsal-fin ray is another diagnostic feature cited in the literature. The flanks are otherwise pale to silvery, and — as in many Enteromius — fin colouration is generally subdued. Precise maximum size data are sparse in the literature for this species; it is a small barb consistent with the range typical for Enteromius, which runs broadly from about 1.5 in to 6 in total length across the genus.
Habitat
Enteromius macrotaenia is native to south-central and southeastern Africa, occurring in the lower Zambezi River system and the coastal river systems that drain into the Mozambique Channel — notably the Pungwe River, the Buzi River, and associated drainages — as well as the southern lake-shore rivers of Lake Malawi. These are predominantly warm savanna and lowland rivers, varying from clear-flowing reaches over sand and gravel to slower, vegetated floodplain channels.
The chemistry of these systems reflects their savanna and lowland character: water tends toward neutral to slightly alkaline pH and moderate hardness, particularly in the Zambezi drainage and the rivers fringing Lake Malawi, contrasting with the softer, more acidic streams typical of rainforest-associated barbs. Seasonal fluctuation in flow is marked across much of the range, and the species is adapted to the variable conditions of a strongly seasonal African river system.
Feeding
Like most small African barbs, Enteromius macrotaenia is an opportunistic omnivore. It feeds on small invertebrates — aquatic insect larvae, worms, and micro-crustaceans — as well as algae, fine plant material, and organic detritus picked from the substrate and mid-water. The streamlined body and forked tail suggest an active forager capable of holding position in moderate current.
In the aquarium the species accepts the broad diet typical of omnivorous barbs: good-quality flake and small pellet foods alongside live and frozen supplements such as bloodworm, daphnia, and brine shrimp, with some vegetable matter to round out the diet.
Mating
Enteromius macrotaenia follows the breeding strategy universal among barbs: it is an egg-scattering, non-guarding spawner with no nest construction and no parental investment beyond fertilisation. A conditioned male pursues a gravid female through vegetation or over the substrate, and the pair releases eggs and milt together in brief, close contact. There is no lasting pair bond, no territory held after spawning, and no care of eggs or fry.
Colour and activity intensify in courting males — as in other Enteromius — with competing males driving females and one another through the water column. Eggs are adhesive and fall among plants or onto the substrate, where adults will eat them if not separated.
Breeding
Enteromius macrotaenia is an egg-scatterer that produces adhesive eggs scattered over fine-leaved plants, submerged root mats, or gravel in its natural riverine habitat. Wild spawning in the Zambezi drainage and its coastal sister rivers likely follows the seasonal flooding cycle, when warmer and more oxygenated water triggers reproductive condition.
In the aquarium, conditioning on live and frozen foods, a separate spawning tank with fine-leaved plants or a spawning mop, and soft to moderately hard, slightly warm water will prompt spawning. Eggs and adults must be separated immediately after spawning. Fry are small on hatching and require fine first foods such as infusoria or commercial fry food before graduating to micro-worms and newly hatched brine shrimp. The species is not commonly bred in the hobby and is considered a minor aquarium fish; reports from artisanal fisheries in the region confirm it is also harvested for local food use.
In the aquarium
The broadband barb is occasionally available in specialist African fish circles but is not a mainstream aquarium fish. It suits a setup that reflects its savanna-river origins: a spacious tank with moderate to good flow, open sandy or fine-gravel substrate, some submerged wood and sparse planting, and neutral to mildly alkaline, moderately hard water at temperatures broadly in the low-to-mid twenties Celsius.
It should be kept in a group, as a shoaling barb, with robust and similarly sized tankmates. The aquarium trade interest in the species overlaps with its exploitation in local Mozambican and Zimbabwean fisheries for human consumption, so wild-caught specimens are conceivable in the trade. Care requirements are consistent with other medium-sized Enteromius: clean, well-oxygenated water, a varied omnivorous diet, and adequate swimming space.
Conservation
Enteromius macrotaenia is assessed as Least Concern (LC) on the IUCN Red List (2020 assessment, IUCN taxon ID 182655). The species has a sufficiently broad distribution across the lower Zambezi system and the Mozambican coastal rivers — and is tolerant enough of the variable conditions in these systems — that it is not considered to face range-wide population decline.
Pressures on the species and its habitat include increasing agricultural water extraction, dam development on the Zambezi and its tributaries (especially Cahora Bassa and downstream engineering), and local exploitation for human consumption. Habitat degradation in the lower Zambezi Delta and the coastal river systems of Mozambique is ongoing, but the species' LC status reflects current assessment that these pressures have not yet driven a decline that would meet threatened thresholds. Continued monitoring of the Zambezi drainage barb fauna is warranted as basin development intensifies.