Taxonomy & naming
Enteromius deguidei was described by Matthes in 1964 under the original combination Barbus deguidei, with the type locality given as Ikela, in what is today the Democratic Republic of Congo. The Catalog of Fishes (Eschmeyer, CAS) places the species in the genus Enteromius, where it has been transferred along with the broad paraphyletic assemblage of small African barbs formerly lumped under Barbus. The parenthetical authority — (Matthes, 1964) — marks the subsequent transfer out of the original genus.
The epithet deguidei honours R. Deguide of the Royal Museum for Central Africa (Musée Royal de l'Afrique Centrale, Tervuren), reflecting the museum's long role in documenting the ichthyofauna of the Congo basin. No subspecies or synonyms are currently recognised. The genus Enteromius as currently constituted is large and phylogenetically complex; its internal relationships among Congo basin species remain an active area of taxonomic work.
Morphology
Enteromius deguidei is a small barb, reaching a maximum recorded total length of approximately 1.5 in. Beyond size, detailed morphological data — meristics, colouration, fin formulae — are not available in accessible literature, and the species is known mainly from the original description and the type material held at Tervuren.
As with most small Enteromius, the body plan is presumed to be the typical shallow-bodied, laterally compressed cyprinid form common to the group, with a small subterminal or terminal mouth, a single dorsal fin, and no adipose fin. Data on colouration and distinguishing external characters are sparse.
Habitat
The type locality is the Ikela region of the central Congo basin, in a zone of dense equatorial forest. Rivers and streams draining this area are typically slow-moving, tannin-stained, low-conductivity blackwater or clearwater systems flowing over sand and leaf litter, often shaded by closed-canopy rainforest. Water temperatures in lowland Congo forest streams are warm year-round, broadly in the mid-to-high twenties Celsius.
No water-chemistry data specific to E. deguidei have been published. Given the type locality, the species almost certainly inhabits soft, acidic waters consistent with the chemistry typical of Congo forest streams. Whether it occurs in the main channel of the Congo or only in smaller tributaries and backwaters is not documented.
Feeding
No diet data have been published for Enteromius deguidei. Small Enteromius in comparable equatorial African habitats are generally opportunistic omnivores, consuming small invertebrates — insect larvae, microcrustaceans, worms — along with algae, biofilm, and organic detritus.
Given the species' small size (under 1.5 in) and the forest-stream habitat, a diet dominated by fine invertebrate prey and surface-fallen matter would be consistent with the ecology of similar-sized Congo barbs, though this remains inference rather than documented fact.
Mating
No direct observations of mating behaviour in Enteromius deguidei have been published. Like all barbs, the species is expected to be an egg-scattering, non-guarding spawner — the universal barb reproductive strategy. In typical small Enteromius, a ready male drives a gravid female through fine-leaved vegetation or over the substrate, and the two release eggs and milt together in brief presses.
No territory is held beyond the transient courtship chase, and no pair bond persists after spawning. The eggs, once scattered, receive no further attention from either parent.
Breeding
Breeding in the wild has not been documented for this species. Based on the biology of comparable small African barbs from equatorial forest streams, E. deguidei likely spawns among fine aquatic vegetation, roots, or leaf litter, scattering small adhesive eggs that adhere briefly to the substrate or plants before the parents disperse. There is no parental care: adults give no attention to eggs or larvae after spawning, and may consume eggs opportunistically.
Enteromius deguidei has not been reported in the aquarium hobby or bred in captivity, so no husbandry data on clutch size, incubation time, or larval development are available.
In the aquarium
Enteromius deguidei is not known in the aquarium trade and has not been kept or bred in captivity as far as published records show. It is a data-sparse species known only from its Congo basin type locality, and no husbandry guidance can be offered with confidence.
For aquarists interested in small African barbs from the Congo basin, related Enteromius species with better-documented biology would be more appropriate subjects. Any future acquisition of E. deguidei from scientific collection would require soft, acidic, warm water consistent with lowland Congo forest-stream conditions.
Conservation
Enteromius deguidei is assessed as Data Deficient (DD) on the IUCN Red List under version 3.1, indicating that insufficient information exists to determine its conservation status. The assessment reflects the scarcity of field data rather than a confident conclusion about population trends or threat levels.
The species is known from a single locality in the central DRC, making it potentially vulnerable to any localised habitat degradation — logging, artisanal mining, or changes to the Ikela region's stream hydrology. The broader Congo forest ichthyofauna faces mounting pressure from extractive industries and land-use change, though the extent to which E. deguidei is affected cannot be assessed without further survey work. A targeted field survey in the Ikela region would be needed before a meaningful threat assessment is possible.