Taxonomy & naming
Chromidotilapia schoutedeni was described in 1967 by the Belgian ichthyologists Max Poll and Dirk F. E. Thys van den Audenaerde, working at the Royal Museum for Central Africa in Tervuren, as Pelmatochromis schoutedeni. The description appeared in the Revue de Zoologie et de Botanique Africaines on material from Shabunda, in the eastern Congo River basin of the Democratic Republic of the Congo, which stands as the type locality; the holotype (MRAC 56430) and a long series of paratypes are housed in the Tervuren collection. The genus Chromidotilapia had been erected by George Albert Boulenger in 1898, and the species was transferred into it in the modern arrangement — Daget's 1991 CLOFFA treatment and Anton Lamboj's revisionary work on the genus (2002, 2003) both list it as Chromidotilapia schoutedeni, the combination accepted today by the Catalog of Fishes, FishBase and ITIS. Chromidotilapia is a small genus of roughly a dozen species spread across the rainforest waters of West and Central Africa, from Liberia to the Congo basin; schoutedeni is one of its eastern, Congo-basin members and is among the least-studied species in the group. Pelmatochromis, the genus in which it was first placed, has since been restricted to a handful of West-African species, and the historical shuffling of these fishes between Pelmatochromis, Thysochromis and Chromidotilapia is part of why their literature can be confusing.
Morphology
This is a small cichlid. The largest measured specimen is about 2.5 in in standard length, with a maximum total length of roughly 3.5 in — so an adult is a fish of around 3–3.5 in including the tail, modest even by the standards of dwarf West-African cichlids. The body follows the typical Chromidotilapia plan: moderately elongate and laterally compressed, with a fairly straight dorsal profile, a pointed snout and the continuous, many-spined dorsal fin of the genus. Detailed life coloration is poorly documented because the species is so rarely seen alive; preserved and museum material shows the muted brownish to olive ground colour and faint longitudinal banding usual for the genus, over which living congeners typically carry iridescent flank spangling and a coloured band along the dorsal fin. As in other Chromidotilapia, the sexes are expected to differ — males of the genus generally grow somewhat larger with more produced, pointed unpaired fins, while ripe females show a brighter, often reddish or violet belly patch used in courtship — but the specific dimorphism of schoutedeni has not been described in detail from living fish, and any account of its breeding dress is inferred from its better-known relatives rather than observed.
Habitat
Chromidotilapia schoutedeni is a Congo-basin endemic, known only from the Democratic Republic of the Congo. FishBase records it from small tributaries of the middle Congo River near Yangambi, from the Wagenia (Boyoma) Falls area at Kisangani, and from the Lualaba — the upper Congo River — while the type series came from Shabunda further east in the basin; the Catalog of Fishes summarises its range simply as the Congo River basin of the DR Congo. Together these localities place it across the equatorial rainforest reach of the great river and its eastern headwaters, an estimated latitudinal span of about 1°N to 8°S. The little ecological information that exists points to flowing water: the species has been collected in clear, running water rather than in still pools or floodplain lakes, consistent with a fish of shaded forest streams and the margins of larger rivers. In keeping with Congo-basin rainforest drainages it can be expected to live in warm, soft, mildly acidic to near-neutral water, but no detailed in-situ chemistry has been published specifically for this species. As a small, current-loving stream fish it occupies the shallow benthic and near-bank zones rather than deep open water; FishBase classifies it as benthopelagic and gives no specific depth band, so its vertical range is best read as the shallow, well-oxygenated water column of its streams.
Feeding
No direct dietary study has been published for Chromidotilapia schoutedeni, but its feeding can be placed with confidence from its anatomy, its genus and its habitat. FishBase estimates a trophic level of about 3.3, the figure typical of a small omnivore that leans toward animal prey. Members of Chromidotilapia are bottom-oriented foragers — sometimes loosely called African eartheaters — that take mouthfuls of sand and leaf litter and sort small invertebrates, insect larvae, crustaceans, worms, seeds and organic detritus from the substrate before expelling the inedible material. A clear-water stream fish of this size in the Congo forest would feed mainly on aquatic insect larvae, micro-crustaceans and other small benthic invertebrates worked from the gravel and litter of the streambed, supplemented by plant and detrital matter. In its community it functions as a small benthic invertivore-omnivore rather than a specialist predator or a dedicated algae-grazer.
Mating
The mating biology of schoutedeni has not been observed directly, so it must be read through the well-studied social system of its genus. Chromidotilapia are famous among aquarists as monogamous, pair-bonding cichlids: a male and a female form a lasting bond, jointly hold and defend a territory, and cooperate through courtship and parental care to a degree unusual among African cichlids. Courtship in the genus centres on mutual displays in which the ripe female, with her flank or belly flushed a bright colour, solicits the male; pairs are typically formed from a group, where fish can choose partners, rather than by forcing two strangers together. This combination of firm pair bonds and shared territory defence is the behavioural signature of Chromidotilapia, and there is no reason to think schoutedeni departs from it, though the fine detail of its courtship, the strength of its territoriality and any colour signals it uses remain undocumented for this particular species.
Breeding
Chromidotilapia is one of the comparatively few cichlid genera in which mouthbrooding is combined with strong biparental care, and schoutedeni shares this reproductive mode. FishBase, following Lamboj, records it as a mouthbrooding species and lists it among the female (maternal) mouthbrooders — eggs are laid on a surface, then taken up and incubated in the mouth, with the female carrying the developing clutch while the pair jointly guards the territory. In the genus more broadly the pattern is biparental: eggs are deposited on a cleaned surface or in a pit, picked up into the mouth, and after the larvae are released both parents continue to shepherd and shelter the free-swimming fry, taking them back into the mouth when danger threatens. The specific clutch size of schoutedeni has not been published; as a guide to scale, the closely studied congener Chromidotilapia guntheri produces clutches that have been measured at roughly 70 to 470 eggs, the modest fecundity expected of a mouthbrooder that invests heavily in each egg. Because mouthbrooded young are protected inside a parent and then guarded after release, survival per egg is high and clutches are correspondingly small compared with open-water spawners. No captive spawning of schoutedeni has been documented, so the timing of release, the duration of mouthbrooding and the length of post-release guarding are inferred from its relatives rather than recorded for the species itself.
In the aquarium
Chromidotilapia schoutedeni is effectively absent from the aquarium hobby. Unlike its celebrated relatives — Chromidotilapia guntheri, Chromidotilapia linkei, Chromidotilapia kingsleyae and the dwarf species described by Lamboj, all of which are kept and bred by West-African cichlid specialists — schoutedeni is a small, obscure Congo-basin endemic that has rarely if ever been collected for the trade, and no body of first-hand keeping or breeding experience exists for it. What follows is therefore a careful extrapolation from the genus rather than a record of established practice. Were the fish to become available, it would be treated as a small, soft-water, current-loving stream cichlid. A pair would suit a modest, well-filtered tank in the region of 35.5–47 in with gentle to moderate flow, a fine sand bottom over which it could sift, and plenty of structure — driftwood, roots, leaf litter and rockwork — to break sightlines and provide spawning sites and refuges. Water should mirror the warm, soft, slightly acidic to neutral conditions of Congo rainforest streams: roughly 75–81 °F, soft and low in carbonate hardness, and a pH from the low 6s to around neutral, with the strongly alkaline, hard water suited to Rift Lake cichlids being entirely wrong for this fish. Diet would be the easy part — a varied menu of small live and frozen foods (bloodworm, brine shrimp, Daphnia, small crustaceans) alongside quality sinking prepared foods. As a monogamous pair-bonder it is best acquired as a group of juveniles and allowed to pair naturally, after which the pair will hold a territory; tankmates should be small, peaceful, soft-water species that will not bully the pair or harass brooding fish. All of this is genus-typical husbandry applied to a species no one is actually keeping, and it should be read as informed guidance, not proven protocol.
Conservation
The IUCN Red List assesses Chromidotilapia schoutedeni as Least Concern, in an assessment dated 16 February 2009 by T. Moelants under the Central Africa freshwater biodiversity review. The rationale notes that the species is widespread, or at least without identified major threats, across the Central-African assessment region; its current population trend is recorded as unknown, and no specific threats to it are documented. It carries no CITES listing. That comparatively reassuring status should be read against the wider state of Congo-basin freshwaters, which remain among the most biodiverse and least-studied in the world: deforestation, expanding mining (including artisanal gold mining and its mercury pollution), unregulated fishing, sedimentation and proposed hydropower development are recognised pressures on the basin's rivers, and the eastern Congo in particular — including the Shabunda region from which schoutedeni was first described — has seen severe disruption. None of these is documented as a present danger to this specific cichlid, but the species' true status is uncertain simply because so little fieldwork has targeted it; its Least Concern listing reflects an apparently broad range as much as any positive evidence of abundance.