Taxonomy & naming
Chiloglanis macropterus was described by Max Poll and Donald J. Stewart in 1975. It belongs to the family Mochokidae — the African squeakers and upside-down catfishes — placing it in the same family as the far more familiar Synodontis, though the two genera look and behave quite differently. Chiloglanis is a large genus of small, sucker-mouthed rheophilic catfishes distributed across tropical Africa, with dozens of species distinguished mainly by fine details of the oral disc and fin structure.
The genus name Chiloglanis derives from the Greek cheilos (lip) and glanis (an old name for a catfish), a direct reference to the enlarged, sucker-like lower lip that defines the genus. The species epithet macropterus combines the Greek makros (large) and pteron (fin/wing), describing its comparatively large fins. As with much of Siluriformes, the group has seen taxonomic revision over the decades, but Chiloglanis macropterus is the currently recognized valid combination and there is no older genus placement to flag here.
Morphology
Adult Chiloglanis macropterus reach only about 4 in total length, making this one of the smallest catfishes an aquarist is likely to encounter — but, as with any wild-collected species, that small headline size should not invite complacency about its specialised needs. The body is the classic Chiloglanis shape: a flattened, shovel-like head tapering to a robust trunk, with the mouth modified into a ventral suckerdisc rimed with papillae that let the fish grip smooth rock in strong current, much as a hillstream loach does by convergent evolution.
Like other members of Mochokidae, the skin is naked and scaleless, which has direct consequences for medicating the fish (see "In the aquarium"). The pectoral and dorsal fins carry stiff, serrated spines that lock erect — a defence against predators, and a hazard to keepers if the fish is netted rather than moved in a container. The relatively large fins referenced in the species name are most obvious in the dorsal and pectoral rays, which are believed to aid station-holding against current.
Habitat
This species is known only from the Luongo River, a tributary of the Luapula River in the upper Congo River basin, within Zambia — a genuinely narrow, single-river endemic. Like other Chiloglanis, it is a benthic, rheophilic fish, meaning it lives clinging to rock and cobble substrate in flowing water rather than drifting in open water or resting on soft sediment.
The cache does not report specific temperature or pH figures for the Luongo River, and none should be invented; the safest working assumption for an upper Congo basin tributary is a well-oxygenated, flowing tropical stream, but keepers should treat exact water chemistry as data sparse rather than assume a soft-acidic blackwater profile without confirmation. What is well documented is the habitat type: fast-flowing, rocky, oxygen-rich water, the opposite of a still, sediment-bottomed aquarium setup.
Feeding
Chiloglanis macropterus is a nocturnal benthic grazer/micro-predator in the mould of its genus: it uses its sucker mouth to rasp biofilm — algae, diatoms and associated microinvertebrates — from rock surfaces, foraging mostly after dark. This aufwuchs-grazing habit is consistent across small Chiloglanis species and follows directly from the specialised oral disc.
In the aquarium, this means offering sinking algae wafers and biofilm-based foods alongside small invertebrate foods (frozen bloodworm, daphnia, brine shrimp), rather than relying on a single pellet type. Because it feeds mainly at night, food is best offered after lights-out so a small, quiet fish like this is not out-competed by more active tankmates at the more usual daytime feeding time.
Mating
The cache does not document courtship behaviour specific to Chiloglanis macropterus, and none should be invented. FishBase records the species as oviparous with distinct pairing during breeding, which places it with the many small rheophilic mochokids that form discrete male–female pairs at spawning rather than mixed group-spawning aggregations — but the fine detail of that pairing (site selection, courtship display) is not documented in the cache and should be treated as data sparse.
Breeding
Confirmed breeding mode for this species in the cache is limited to "oviparous with distinct pairing" — egg-laying with paired spawning, rather than the open-water egg-scattering sometimes wrongly assumed for catfish generally, and rather than the bubble-nest or brood-parasite strategies seen elsewhere in African catfish. Beyond that, there is no documented account of Chiloglanis macropterus being bred in the aquarium, and none should be claimed.
As a narrow-range, wild-collected rheophilic species with specialised current and substrate requirements, it should be assumed to be effectively unbred in captivity unless credible evidence says otherwise. Aquarists interested in breeding small Chiloglanis should expect to need to replicate flowing, highly oxygenated, rocky conditions with a distinct paired spawning event — a considerably harder proposition than a community tank.
In the aquarium
At under 4 in, Chiloglanis macropterus is genuinely one of the smaller catfishes suited to a modest aquarium — but its needs are specialised, not simple. It requires strong water flow (powerheads or a high-turnover filter outlet aimed across rockwork), excellent oxygenation, and a rocky, cobble-strewn scape that lets it exercise its sucker-mouth grip and graze biofilm, rather than a soft-sediment or heavily planted setup. A mature tank with an established biofilm layer on hardscape will suit it far better than a sterile new setup.
Two care points follow directly from its biology. First, like other mochokids it is scaleless, so it is more sensitive than scaled fish to copper-based medications and should be dosed conservatively. Second, it carries locking, serrated pectoral and dorsal spines that can snag in a net and jab the handler, so it should be moved in a container rather than netted. It is a nocturnal fish and appreciates rock crevices for daytime cover, emerging to graze once the lights go down. Given its very restricted wild range, any specimens in the trade should be assumed wild-collected, and stocking decisions should reflect that conservation context.
Conservation
The IUCN Red List assesses Chiloglanis macropterus as Vulnerable (VU), an assessment made under the D2 criterion — meaning a very restricted area of occupancy or number of locations that leaves the species vulnerable to a single future threatening event, even without evidence of an ongoing population decline. This status maps directly onto the species' known biology: it is documented from only the Luongo River, a single tributary of the Luapula within the upper Congo basin in Zambia.
A fish restricted to one river is inherently exposed to localised pressures — pollution, damming, sedimentation from land-use change, or any other disturbance affecting that single watercourse — that would pose little risk to a widespread species but could jeopardise the entire population of a Luongo River endemic. There is no indication in available sources of a large aquarium trade in this species; any conservation-minded aquarist encountering it should treat it as a narrow-range fish whose long-term prospects are tied to the ecological integrity of one small river system.