Taxonomy & naming
Enteromius anniae was described by Christian Lévêque in 1983. Lévêque was a prolific French ichthyologist who described numerous West and Central African cyprinids over several decades, and the species was originally placed in the broadly defined genus Barbus — then the catch-all for virtually all Old World small barbs. Subsequent molecular and morphological work revealed the old Barbus to be a highly polyphyletic assemblage, and the African species were progressively reassigned to Enteromius.
The Catalog of Fishes (Eschmeyer, CAS) records the current valid combination as Enteromius anniae (Lévêque, 1983), the parenthetical authority indicating the original combination was under a different genus. Enteromius is now one of the largest cyprinid genera in Africa, encompassing hundreds of small to medium barbs distributed across sub-Saharan river systems. The specific epithet anniae is a personal name in the feminine, presumably honoring a person named Annie, but the original dedication was not traceable from available sources at the time of writing.
Morphology
As with the majority of small Enteromius species, E. anniae is expected to be a slender to moderately deep-bodied cyprinid with a fusiform profile, a terminal mouth bearing one or two pairs of barbels, and a moderately forked tail. Precise measurements and distinctive markings are not reliably documented in secondary sources accessible at the time of writing; data for this species are sparse.
African Enteromius in the same size class as described by Lévêque during this period typically reach 1.5–3.5 in standard length, are silvery to olive-bronze in ground colour, and may carry one or more lateral spots or blotches, a dark caudal spot, or faint banding — but without confirmed data these details cannot be stated for E. anniae specifically. Researchers or hobbyists with access to the original 1983 description or fresh specimens are the authoritative source.
Habitat
Specific habitat data for Enteromius anniae are not available from the sources consulted. The genus Enteromius spans an enormous ecological range across sub-Saharan Africa, from humid lowland forest streams with soft, acidic water to open savanna rivers with harder, more alkaline chemistry and pronounced seasonal fluctuation. Without confirmed locality data it is not possible to specify which of these environments E. anniae occupies.
General features common to small African barbs include preference for flowing or slowly moving water with a substrate of sand, gravel, or leaf litter, and association with marginal vegetation, submerged roots, or rocky areas depending on the river type. Water temperatures across sub-Saharan African lowlands typically fall in the range of roughly 72–82 °F. Aquarists or researchers with access to collecting data or the type locality description should consult the primary literature directly.
Feeding
Enteromius anniae, like the broader genus, is presumed to be an opportunistic omnivore. Small Enteromius across Africa typically graze on algae, diatoms, fine detritus, and plant matter, while also taking invertebrates such as insect larvae, small crustaceans, and worms encountered at or near the substrate. This broad, generalist diet is characteristic of small barbs in dynamic tropical river systems where food availability shifts seasonally.
No specific gut-content studies for this species were located. In an aquarium context, small Enteromius barbs are generally undemanding and accept quality flake and micro-pellet foods supplemented with live or frozen invertebrates such as daphnia and brine shrimp, along with vegetable matter to satisfy herbivorous grazing behaviour.
Mating
Enteromius anniae is an egg-scattering, non-guarding spawner, consistent with the universal reproductive strategy of barbs. There is no nest construction, no bubble-nest, and no mouthbrooding or egg-guarding in any Enteromius. When ripe, a driving male pursues a gravid female through vegetation, roots, or over the substrate; at the peak of the chase the pair press together briefly and release eggs and milt simultaneously.
Spawning is typically triggered by seasonal cues in the wild — rising water temperatures, increased rainfall, and improved food availability — and in captivity by similar conditioning through generous feeding on live foods and gradual temperature increase. No pair bond persists after spawning, and both sexes will eat scattered eggs if given access to them.
Breeding
No captive-breeding records for Enteromius anniae are documented in the hobbyist literature available at the time of writing. By analogy with the many small Enteromius that have been spawned in aquaria, the approach would follow standard small-barb protocol: a shallow spawning tank with fine-leaved plants or a spawning mop, a mesh floor to protect eggs from the adults, soft to moderately hard water at an appropriate tropical temperature, and a well-conditioned pair or small group introduced in the evening.
Eggs are adhesive and would settle among plants or on the substrate. The adults should be removed promptly after spawning is observed. Larvae typically hatch within one to two days at tropical temperatures and become free-swimming a few days later, when they are fed infusoria or commercial fry foods, progressing to newly hatched brine shrimp as they grow. Specifics for this species may differ from the general pattern; the primary description is the appropriate starting reference.
In the aquarium
Enteromius anniae is not established in the mainstream aquarium trade and is essentially unavailable commercially. It is unlikely to appear outside specialist cichlid and cyprinid collections or research contexts. Detailed husbandry guidelines therefore cannot be drawn from hobbyist experience with this specific species.
Aquarists who obtain specimens — whether as wild-caught individuals from West or Central African collecting expeditions or from specialist breeders — should treat the species as a standard small African barb: a shoaling fish best kept in groups of at least six in a roomy, well-filtered aquarium with subdued lighting, fine sandy substrate, some cover from driftwood and vegetation, and stable tropical water conditions. Diet should be varied and include both animal protein and vegetable matter. Any observations made in captivity would be a valuable contribution to the knowledge of this poorly documented species.
Conservation
Enteromius anniae has not been evaluated by the IUCN Red List; its conservation status is Not Evaluated (NE). Without a formal assessment or reliable range data in widely accessible sources, it is not possible to characterise current population trends or the threats this species faces.
Many small, range-restricted African barbs described in the mid-twentieth century from limited material face pressure from habitat degradation — including dam construction, water extraction for agriculture, sedimentation from deforestation, and pollution from human settlements — without formal documentation of their status. Until a proper assessment is conducted and distributional data are gathered, the conservation situation of E. anniae remains unknown. Researchers with access to the original type locality are best placed to determine whether the species persists and in what numbers.