Taxonomy & naming
Distichodus ingae was formally described by Moelants and Snoeks in 2018, one of several distichodontid species resolved from the taxonomically complex lower Congo River system in recent years. It belongs to the family Distichodontidae within the order Characiformes, the African sister lineage to the South American characins that includes the pacus and piranhas. The Catalog of Fishes (Eschmeyer, California Academy of Sciences) lists it as a valid species in the genus Distichodus.
The species epithet references Inga, the site of the major rapids and hydroelectric complex on the lower Congo River near the type locality, placing D. ingae among a cluster of small-bodied, rapids-adapted fishes described from that stretch of river in the past two decades as ichthyologists have worked through the Congo's exceptional cryptic diversity. As a 2018 description, it has not yet accumulated the layered synonymy or generic reshuffling seen in older, more heavily studied Distichodus species.
Morphology
Distichodus ingae is a small member of a genus whose other species range up to 31.5 in; FishBase records a maximum length of just 2.5 in standard length for D. ingae, making it one of the smallest known Distichodus. Detailed morphological description beyond the type material is sparse in the sources available, and no photographs or aquarium accounts documenting its live colouration were found in this pass — data is sparse enough that speculative colour or fin-shape description is avoided here rather than borrowed from larger congeners.
Habitat
The species is known from the lower Congo River near Inga, Democratic Republic of the Congo — a stretch of river famous among ichthyologists for extreme current, deep bedrock gorges and a remarkable concentration of endemic, rapids-adapted fish species found nowhere else. No temperature or pH data specific to D. ingae was recorded in the sources checked for this article; broadly, the lower Congo rapids run warm and are turbid with strong flow rather than typical still-water blackwater conditions, but precise figures for this species are not documented and are not assumed here.
Feeding
No diet study specific to Distichodus ingae was found. Related Distichodus species studied in the nearby Pool Malebo stretch of the Congo River show a mixed pattern across the genus — some take aquatic insect larvae (dipterans, coleopterans, trichopterans) picked from the substrate, while others graze more heavily on plant material — but this is evidence about congeners, not about D. ingae itself, and should not be read as a confirmed diet for this species. Given the genus's general herbivore-to-omnivore grazing habit, a mixed diet is plausible, but the specific balance for D. ingae is undocumented.
Mating
No courtship or spawning behaviour has been documented for Distichodus ingae. FishBase notes maturity data as unknown for the species, and no external sexual dimorphism has been recorded.
Breeding
Breeding biology for Distichodus ingae is undocumented. As with most Distichodus and other distichodontids, egg-scattering over substrate with no parental care is the pattern typical of the genus, but this has not been specifically confirmed for D. ingae, and — as a rapids-dwelling species described only in 2018 and essentially unknown to the aquarium trade — it has no known breeding history in captivity.
In the aquarium
Distichodus ingae is not an established aquarium fish; no hobby care accounts, import records or captive-husbandry reports were found. Its very small maximum size (2.5 in SL) sets it apart from the large, plant-shredding Distichodus species that dominate the trade, such as D. sexfasciatus and D. lusosso, which regularly outgrow home aquaria and require dedicated large tanks. If it were ever to appear in the hobby, its rapids origin would suggest a preference for strong flow and high dissolved oxygen, but this is an inference from habitat rather than a documented care requirement, and prospective keepers should treat any specimen as essentially unstudied in captivity.
Conservation
Distichodus ingae has not been formally assessed by the IUCN Red List and is classified here as Not Evaluated. As a narrow-range endemic tied to the lower Congo rapids near Inga — a stretch of river already altered by major hydroelectric development and slated for further large-scale dam projects — it belongs to a cluster of recently described, poorly known Congo rapids fishes whose conservation status deserves attention even though no formal assessment yet exists.