Taxonomy & naming
Microstomatichthyoborus bashforddeani was described in 1917 by the American ornithologist-turned-ichthyologists John Treadwell Nichols and Ludlow Griscom, in their report "Fresh-water Fishes of the Congo Basin Obtained by the American Museum Congo Expedition, 1909–1915," published in the Bulletin of the American Museum of Natural History (v. 37: 653–756). The species epithet honours Bashford Dean (1867–1928), the American ichthyologist and arms-and-armor scholar who was a curator at the American Museum of Natural History during the period of the Congo expedition.
The genus Microstomatichthyoborus is monotypic or near-monotypic and sits within the family Distichodontidae, order Characiformes — the African sister lineage to the South American Serrasalmidae (piranhas, pacus and silver dollars) within the broader characin radiation. The Catalog of Fishes (Eschmeyer, California Academy of Sciences) is the governing authority for the valid name and combination; this account follows that placement and does not alter the genus. Data on this species is sparse relative to the better-known Distichodus and Citharinus genera in the same family, and no revision has substantially changed its status since the original description.
Morphology
The holotype measured 2.5 in standard length, making Microstomatichthyoborus bashforddeani one of the smallest described members of the Distichodontidae — a family that otherwise includes species reaching 31.5 in or more (Distichodus lusosso and relatives). Family-level characters place it among the small-mouthed, non-predatory distichodontids: a compact, elongate-to-moderately-deep body typical of small riverine characins, with the reduced, terminal or subterminal mouth implied by the genus name ("micro-stoma," small mouth) rather than the protrusible, shredding jaws of the larger Distichodus species.
Beyond the holotype measurements and its generic placement, published morphological detail is limited; no dedicated redescription or detailed osteological account beyond the 1917 original has been located in the sources consulted for this article. Colour pattern and fin-ray counts specific to living or freshly collected specimens are not documented in the available literature, so this account does not speculate on markings beyond what the original description and family placement support.
Habitat
Microstomatichthyoborus bashforddeani is endemic to the Congo basin of central Africa. It has been recorded from the Luilaka, Salonga and Yenge Rivers within Salonga National Park (Équateur Province, Democratic Republic of Congo), and separately from the Mambili and Lékoli River tributaries within Odzala National Park in the Republic of Congo — placing its known range across both the central and northwestern portions of the wider Congo basin drainage system.
These records come from lowland rainforest river systems typical of the central Congo basin: slow-to-moderate flowing forest rivers and their tributaries, generally warm, and often tannin-influenced given the forested catchment. Specific water-chemistry data (temperature, pH) for the collection sites was not available in the sources consulted, so this account does not assign numeric ranges beyond noting the general character of Congo basin forest rivers as warm and typically soft to moderately mineralised.
Feeding
Detailed dietary data specific to Microstomatichthyoborus bashforddeani was not found in the sources consulted. At the family level, Distichodontidae are predominantly herbivorous to omnivorous grazers, feeding on periphyton, macrophytes and detritus rather than on other fish; the family's small mouth and grazing dentition in this genus is consistent with that pattern rather than with the predatory habits seen in some other African characins such as Hepsetus.
Given its small adult size and small-mouthed morphology, it is reasonable to infer a diet weighted toward algae, biofilm, fine plant material and detritus, in line with its distichodontid relatives, but this inference is not confirmed by a species-specific stomach-content study in the available literature, and this account flags it as such rather than presenting it as established fact.
Mating
No courtship or spawning behaviour has been documented for Microstomatichthyoborus bashforddeani in the sources consulted for this article. The species is known almost entirely from museum holotype material and regional faunal survey records (Salonga and Odzala National Parks), not from aquarium or field breeding observations, so no reliable account of pairing, courtship displays or sexual dimorphism exists to report.
Breeding
As with the broader Distichodontidae — Distichodus and the related citharinids are egg-scatterers that are rarely, if ever, bred successfully in home aquaria — there is no documented breeding record for Microstomatichthyoborus bashforddeani, in the hobby or in captive research settings. Given its status as a poorly known, rarely (if ever) exported species, this account reports honestly that breeding biology is undescribed rather than assigning a speculative mode; nothing in the available sources supports guessing at clutch size, spawning site, or parental care.
In the aquarium
Microstomatichthyoborus bashforddeani is not an established aquarium fish; no husbandry accounts, care guides or hobbyist reports were found in the sources consulted, and it appears to be effectively absent from the aquarium trade. Its very small adult size (the holotype was just 2.5 in SL) would in principle make it approachable for a modestly sized tank compared with the giants of its family, but in the complete absence of documented water parameters, temperament or dietary requirements in captivity, this account cannot responsibly recommend specific stocking, tankmates or feeding beyond noting the general grazing habits inferred for the family.
Prospective keepers should treat this species as essentially unavailable and undocumented in captivity; anyone encountering it in the trade should assume it needs warm, Congo-basin-typical water and a grazing-friendly, largely vegetable diet based on its family relatives, while recognising that no verified aquarium record currently exists to confirm those assumptions.
Conservation
The IUCN Red List assesses Microstomatichthyoborus bashforddeani as Least Concern. This reflects records across multiple protected areas within its Congo basin range — including Salonga National Park and Odzala National Park — spanning both the Democratic Republic of Congo and the Republic of Congo, without evidence of the localized, single-river endemism that drives Data Deficient or threatened status in many other small Congo basin characins.
As with much of the Congo basin's freshwater fauna, broader long-term pressures on the region — deforestation, artisanal fishing pressure and any future hydrological development — are relevant watch items for the wider distichodontid community even though this species itself is not currently flagged as threatened. It is not a species targeted by the aquarium trade, so collection pressure for the ornamental market is not a relevant conservation factor here.