Taxonomy & naming
Nannocharax schoutedeni was described by the Belgian ichthyologist Max Poll in 1939, as part of his extensive work cataloguing the fish fauna collected during Belgian expeditions to the Congo Basin. It is placed in the genus Nannocharax within the family Distichodontidae, the African family that also holds the much larger and more heavily traded Distichodus species; Nannocharax itself is a large genus of small, slender, bottom-associated characins often called "spiny characins" for the short, stiffened rays at the front of the dorsal and anal fins.
FishBase's nomenclature record lists Nannocharax schoutedeni Poll, 1939 as an accepted name in its original combination — the genus placement has not shifted since description. As with many small, geographically restricted African characins, published taxonomic and biological work on this species is sparse, and this account follows the available record rather than filling gaps with assumption.
Morphology
Nannocharax schoutedeni is a genuinely small fish: FishBase gives a maximum size of 2 in total length, placing it among the smallest members of its genus and family. Like other Nannocharax, it has an elongated, slightly compressed body and a flattened underside suited to resting and perching on submerged wood, leaf litter and fine sediment rather than holding position in open water.
Detailed morphological description — fin ray counts, precise colour pattern and pigmentation — is not covered in the sources available for this account, and specific data on sexual dimorphism has not been documented; this is noted honestly under Mating rather than guessed at.
Habitat
The species is native to the middle Congo River system in the Republic of the Congo and the Democratic Republic of the Congo, with records from Pool Malebo (Stanley Pool) and the Ubangi and Ruki river drainages. FishBase classifies it as a freshwater, pelagic-associated species in tropical Congo Basin waters.
Detailed water chemistry data — temperature range, pH and hardness — is not reported in the sources available here. Given its range in the warm, often soft and tannin-influenced tributaries of the central Congo Basin, it is reasonable to expect warm, soft-to-moderate water typical of the region, but specific figures are not confirmed in the record and are left out rather than invented.
Feeding
No detailed dietary study is available for Nannocharax schoutedeni in the sources consulted for this account. Its small size and bottom-oriented body plan are consistent with the genus's general habit of picking at biofilm, small invertebrates and organic matter on wood and substrate, similar to other small Nannocharax, but this is a reasonable inference from genus-level habit rather than a confirmed record for this species, and it is flagged as such.
Mating
No courtship or spawning behaviour has been documented for Nannocharax schoutedeni in the available literature. Sexual dimorphism is not described in the sources consulted, and this account does not speculate on colour or fin differences between the sexes.
Breeding
There is no established aquarium breeding record for Nannocharax schoutedeni. Like most small African characins in Distichodontidae, it is essentially unbred in the hobby, and the wider genus is not known for being reliably spawned at home. Prospective keepers should not expect to breed this species and should treat any offer of captive-bred stock with caution given the absence of a documented protocol.
In the aquarium
Nannocharax schoutedeni is rarely, if ever, seen in the aquarium trade, and detailed care information specific to this species is not available in the sources consulted here. Given its tiny adult size of around 2 in and its bottom-hugging habit, any tank offered would need to be modest but heavily furnished with driftwood, leaf litter and fine sediment to give it the structure it naturally rests on, alongside gentle, well-oxygenated water typical of Congo Basin biotopes; this is a reasonable extrapolation from its natural habitat rather than a tested care regimen.
As with any small, poorly known wild-collected characin, a keeper should assume any specimen offered in the trade is wild-caught rather than farmed, and should be prepared for very limited husbandry information to draw on.
Conservation
The IUCN Red List assesses Nannocharax schoutedeni as Least Concern, an assessment dated 16 February 2009. This reflects the absence of known major threats specific to the species within its Congo Basin range rather than active monitoring or abundance data at the population level.
As with much of the middle Congo Basin's small-fish fauna, the species is not the subject of a dedicated trade or fishery, and broader regional pressures on Congo Basin waters — such as deforestation-linked sedimentation and localised habitat disturbance — are the general long-term watch items rather than any threat documented specifically for this species.