Taxonomy & naming
Citharinus macrolepis was described by the Belgian-based ichthyologist George Albert Boulenger in 1899, in his survey of Congo basin fishes published as "Matériaux pour la faune du Congo." It belongs to the family Citharinidae — the citharinids or "African lutefish/moonfish" — within the order Characiformes, a small family confined to Africa and quite distinct from the much larger, superficially similar Distichodontidae that share many of the same rivers.
The genus name Citharinus derives from the Greek kithara, a stringed instrument, an old allusion to the fish's flattened, lyre-like body outline; the species epithet macrolepis combines the Greek makrós (large) and lepís (scale), describing the conspicuously large scales that distinguish it from congeners such as C. citharus and C. congicus. As with much of the older Congo basin ichthyofauna, identification within Citharinus is not straightforward and relies on scale counts, body depth ratios and head proportions rather than colour pattern, so field identification of this species outside expert hands should be treated with some caution.
Morphology
Citharinus macrolepis has the classic citharinid body plan: strongly laterally compressed and deep-bodied, with Boulenger's original description giving a body depth of roughly 2 to 2⅓ times in the total length and a head length of about 3 to 4 times in the total length — proportions that give the fish a rounded, almost disc-like silhouette in side profile, not unlike an oversized silver dollar. The scales are notably large for the genus, which is the character the species is named for.
Maximum recorded size is 29.5 in standard length, making this one of the larger citharinids and a genuinely big fish by any home aquarium standard. Colouration in citharinids generally runs silvery overall, often with a faint yellowish or olive cast dorsally, and the fins are typically translucent to pale; detailed live colouration data specific to C. macrolepis is sparse and not reported in the sources used here.
Habitat
The species is native to the Congo River basin in tropical Africa, where it is described as widespread across the drainage. Congo basin waters occupied by the genus are generally warm, and a closely related species, C. congicus, is documented from the same basin at roughly 72–79 °F and pH 6.2–7.5 — soft to moderately hard, slightly acidic to neutral water, which gives a reasonable working picture of the conditions C. macrolepis experiences, though it is not a direct measurement of this species.
Citharinids in general are schooling, open-water to mid-water fish of river channels and floodplain habitats rather than dense-cover specialists, consistent with a grazing lifestyle that depends on covering ground over soft substrates and vegetation rather than hiding in structure.
Feeding
Citharinus macrolepis is an omnivorous grazer. The genus as a whole feeds on detritus, algae, and plant matter along with some small invertebrates picked up while working over the substrate, and this species is expected to follow the same pattern documented for its relatives. This diet — heavy on vegetable matter and detritus rather than live prey — is very different from the fish-and-invertebrate diet of true piranhas, despite both being grouped loosely as "characins."
In any setting where the species is kept, a diet weighted toward vegetable foods (blanched greens, spirulina-based foods, algae wafers) supplemented with modest protein would follow directly from its documented grazing habits, though specific aquarium feeding accounts for C. macrolepis itself were not found in the sources consulted here.
Mating
No courtship or pairing behaviour specific to Citharinus macrolepis was found in the sources consulted. Citharinids are schooling fish, and spawning in the genus is associated with seasonal cues tied to the Congo basin's flood cycle, as is typical for many African riverine characins, but detailed pair-formation or courtship description for this species is not available and should not be assumed from other families.
Breeding
Citharinus macrolepis and its relatives are egg-scattering seasonal spawners, releasing eggs into open water or over vegetation in response to the rains rather than building or guarding a nest. Breeding of this species has not been established in home aquaria — related Citharinus species kept in aquaria are documented as seasonal spawners in the wild with no home-aquarium breeding record, and the same honest gap applies here. Given the species' 29.5 in adult size, that is unsurprising: few if any hobbyist setups could house a mature breeding-condition pair, let alone a school.
Anyone encountering claims of home-bred C. macrolepis should treat them with real skepticism until backed by a documented, verifiable source; the current record for this species is simply that captive breeding has not been achieved.
In the aquarium
The single fact that matters most for this species is size: a documented maximum of 29.5 in standard length puts Citharinus macrolepis firmly outside the range of any reasonable home aquarium, and it is not a fish that should be purchased as a juvenile without a concrete, large-scale, long-term housing plan — a public aquarium, a very large pond, or a specialist setup, not a standard fish tank. As a schooling species in the wild, a solitary specimen in captivity is also unlikely to reflect its natural behaviour.
Where citharinids are kept at all, their grazing, plant-and-detritus diet means they are unsuited to heavily planted aquascapes, and their scale and bioload demand very large, well-filtered systems. This is a species better appreciated in its native Congo drainage — or as a food fish, its more established role in parts of Central Africa — than as an aquarium subject, and this article does not recommend it for typical hobbyist keeping.
Conservation
The IUCN Red List assesses Citharinus macrolepis as Least Concern, consistent with a species described as widespread across the Congo River basin. This reflects both the size of the Congo drainage and the fact that citharinids in general are not narrow-range basin endemics under acute localised pressure, unlike many smaller Congo basin characins and cichlids.
As with much of the wider Congo basin ichthyofauna, broader long-term pressures — fishing pressure (citharinids are used as food fish in parts of the basin), water quality, and any future hydrological changes from dam development — are relevant watch items even though the species itself does not currently carry an elevated threat status.