Taxonomy & naming
Enteromius brevidorsalis was described by the Belgian-British ichthyologist George Albert Boulenger in 1915. The species was originally placed in the genus Barbus, as was essentially every African small barb of the era, and has also been listed under the combination Puntius brevidorsalis in older literature. The Catalog of Fishes (Eschmeyer) recognises the current valid combination as Enteromius brevidorsalis (Boulenger, 1915), with the parenthetical authority marking Boulenger's original description under a different genus.
Enteromius is a large African genus encompassing hundreds of small to medium barb species previously lumped under the polyphyletic Barbus. Molecular and morphological work over the past two decades has progressively reorganised the African barbines; Enteromius, as presently constituted, gathers a broadly defined set of small-bodied African barbs while other lineages have been split off into separate genera. The species epithet brevidorsalis is Latin — brevis (short) and dorsalis (pertaining to the dorsal fin) — and likely refers to a relatively short or low dorsal fin that distinguished this species in Boulenger's original description.
Morphology
Enteromius brevidorsalis is a small barb; as implied by its common name "dwarf barb" it is among the smaller members of the genus, with an adult standard length that is unlikely to exceed 1.5–2 in. Its precise maximum size is not well-documented in accessible literature, and the epithet dwarf should be taken as indicative rather than precisely quantified from published measurements.
The body form is typical for small African Enteromius — moderately elongate, laterally compressed, with a relatively pointed snout and small barbels at the corners of the mouth as is characteristic of the genus. Colouration in life is not well-described in the open literature for this species; small African barbs in this group are typically silvery to olive-brown with variable dark lateral markings or spots, and scale-edge pigmentation that produces a faint reticulated pattern. Without detailed published morphological accounts, a thorough coloration description cannot be responsibly provided.
Habitat
Like the great majority of small Enteromius, E. brevidorsalis is a freshwater species of sub-Saharan Africa. Small African barbs in this genus typically inhabit a broad range of lotic and lentic environments — shallow, well-vegetated stream margins, seasonal floodplain pools, the quieter backwaters of rivers, and occasionally lake shallows — often over soft substrates of sand, silt, or leaf litter with emergent or submerged vegetation.
The precise type locality and full natural distribution of E. brevidorsalis are not fully documented in sources accessible to this article. Chemistry across the habitats of small African barbs varies widely: many central and west African stream species occupy soft, slightly acidic to neutral water, while those in savanna or seasonally inundated systems may encounter harder, more alkaline conditions during dry periods. Water temperatures across sub-Saharan African lowland streams are broadly tropical, typically 72–82 °F.
Feeding
Enteromius brevidorsalis is an omnivore in the manner of virtually all small African barbs. In the wild, small Enteromius graze opportunistically on a variety of foods: algal films and fine plant matter scraped from substrate surfaces, small aquatic invertebrates including insect larvae, micro-crustaceans and worms, and organic detritus settled on the bottom. The short snout and small terminal to subterminal mouth are suited to picking at substrate surfaces and fine vegetation.
In captivity, individuals accept standard small-fish foods readily — quality micro-pellets and fine flake, supplemented with small live and frozen invertebrates such as daphnia, cyclops, and baby brine shrimp. A proportion of vegetable matter in the diet supports long-term condition in the omnivorous African Enteromius.
Mating
Enteromius brevidorsalis, in common with barbs as a group, is an egg-scattering, non-guarding spawner. There is no pair bond, no territory held beyond brief courtship pursuit, and no parental care of any kind. When fish are in breeding condition — stimulated by warmth, good nutrition, and often a seasonal trigger such as a water change mimicking rainfall — males actively drive gravid females through vegetation or over the substrate.
Courtship consists of a male pressing close alongside a ripe female, the two releasing eggs and milt together in a brief, vigorous embrace among fine-leaved plants or over the substrate. The adhesive eggs scatter and sink among plant stems or onto the bottom. As in the great majority of barbs, adults will consume the eggs immediately if they encounter them, and no guarding or nest-building occurs.
Breeding
No detailed captive breeding account for Enteromius brevidorsalis specifically is available in the accessible literature, but the species is assumed to follow the typical pattern for small African Enteromius. Breeding can be attempted in a separate shallow tank with fine-leaved vegetation or a spawning mop, soft to moderately hard water, and a raised mesh or dense plant layer to protect eggs from the adults. Conditioning the fish with varied live and frozen foods prior to introduction encourages spawning.
After spawning the adults should be removed, as they will eat the eggs and any larvae. Eggs of small African barbs typically hatch within one to two days at tropical temperatures, and the larvae become free-swimming within a further two to three days. First foods are infusoria or commercial first-fry foods, followed by newly hatched brine shrimp nauplii as growth allows. Fecundity is moderate for a small cyprinid.
In the aquarium
Enteromius brevidorsalis is rarely encountered in the aquarium hobby and is largely absent from the mainstream trade; it does not appear to be commercially bred or imported in any volume. Specialist collectors and those focusing on African stream fishes may occasionally encounter it through species-specific importers or ichthyological contacts, but hobbyist literature on its husbandry is essentially absent.
Were it available, husbandry would likely follow the standard template for small peaceful African barbs: a well-planted aquarium of moderate size, kept in a small group of six or more to allow natural social behaviour, with clean, well-oxygenated water in the tropical range. Compatible tankmates would be other small, non-aggressive African fishes of similar size. Its small size and presumed peaceful temperament make it potentially a good subject for a biotope or African stream aquarium.
Conservation
Enteromius brevidorsalis is assessed as Least Concern on the IUCN Red List. Many small African Enteromius carry this listing, reflecting relatively broad distributions or a lack of documented range-wide decline rather than any lack of scrutiny.
The broader threats facing small African freshwater fishes remain well-documented regardless of individual status: agricultural runoff and sedimentation, damming and water extraction from rivers for irrigation, urban and industrial pollution, and the progressive degradation of riparian vegetation that these stream species depend upon. These pressures are still worth monitoring even under a Least Concern listing, and further survey work would help confirm the picture for E. brevidorsalis specifically.