Taxonomy & naming
Chiloglanis carnosus was described by Tyson R. Roberts and Donald J. Stewart in 1976, part of their landmark survey of the fishes of the lower Congo (then Zaïre) River rapids. It belongs to the family Mochokidae, the African squeakers and upside-down catfishes, within the large genus Chiloglanis — the suckermouth squeakers, a group of small rheophilic (current-loving) catfish found across tropical Africa.
The genus name Chiloglanis combines Greek cheilos ("lip") and glanis (an old name for a catfish), referring to the fleshy, sucker-like modified lower lip these fish use to grip rock in fast water. The species epithet carnosus is Latin for "fleshy", likely describing the well-developed oral disc that gives the genus its name. Chiloglanis is a large genus with many narrow-range endemics across African rivers, and C. carnosus is one of several species described from the lower Congo rapids by Roberts and Stewart's survey work in the 1970s.
Morphology
Chiloglanis carnosus is a small catfish, reaching only about 2.5 in total length, typical for the genus. The body is slender and somewhat flattened, built for clinging to rock in strong current rather than for open swimming. Like all Chiloglanis, its most distinctive feature is the sucker-mouth: the lower lip is expanded into a fleshy, disc-like pad fringed with papillae, used to grip smooth or algae-covered rock surfaces against the force of rapids water.
The skin is naked and scaleless, as in other mochokid catfish, which matters directly for aquarium medication (see "In the aquarium"). Chiloglanis species carry the family's typical barbels and a small, low dorsal fin, and most bear stiff pectoral spines, though these are modest compared to the larger, more heavily armed Synodontis. As with related suckermouth catfishes, C. carnosus is unremarkable in colour — cryptic mottled browns and greys that blend with wet rock.
Habitat
This species is endemic to the lower Congo River, known from the rapids near Inga village in the Democratic Republic of the Congo. The lower Congo rapids are one of the most extreme freshwater habitats on the planet: an enormous volume of water is forced through a narrow, canyon-like stretch of river, creating whitewater conditions, deep scour holes and turbulence unlike almost anywhere else in the world's rivers, and supporting a remarkable radiation of narrow-range endemic fishes found nowhere else.
Chiloglanis carnosus lives clamped to rock surfaces within this high-flow environment, relying on its oral sucker disc to hold position against the current. Specific water chemistry data for this species has not been captured in this cache; broadly, lower Congo rapids fishes experience warm, well-oxygenated, fast-flowing water. Data on the exact temperature and pH range is sparse for this narrow-range species.
Feeding
Chiloglanis species are nocturnal benthic grazers, foraging mostly after dark on the algae, biofilm, detritus and small invertebrates that coat the rock surfaces of their rapids habitat — the same rock they cling to with their sucker mouth. This close tie between feeding and substrate grazing is a defining trait of the genus.
Detailed dietary study of C. carnosus specifically has not surfaced in this cache, but in line with the genus it should be treated as a nocturnal micro-grazer/omnivore rather than a mid-water predator. In captivity, related Chiloglanis species are fed on sinking algae wafers, blanched vegetables and small sinking invertebrate foods offered after lights-out, so any established fish would need mature, algae-rich surfaces to graze in addition to prepared foods.
Mating
No courtship or spawning behaviour has been documented for Chiloglanis carnosus in the sources available here. Data is sparse for this narrow-range rapids endemic, and nothing should be inferred from other, better-studied catfish families.
Breeding
Breeding of Chiloglanis carnosus has not been documented or achieved in the aquarium as far as the available sources record. As a rheophilic specialist tied to the extreme turbulence of the lower Congo rapids, it is not established in the hobby, and no aquarium spawning reports exist in the cache used for this profile. This should not be assumed to follow any generic catfish breeding mode — say plainly that breeding biology is unknown rather than guessing at egg-scattering or cave-spawning behaviour.
In the aquarium
Chiloglanis carnosus is not an established aquarium fish, and reliable husbandry information is sparse. What can be said with confidence follows from its biology and its family. At a maximum size of about 2.5 in it stays genuinely small, but that does not make it an easy community fish: it is a rheophilic rock-clinging specialist that needs strong, well-oxygenated current and clean, algae-mature rock surfaces to graze, conditions few home aquaria replicate well.
As with all mochokid catfish it is scaleless, so it is medication-sensitive — dose copper-based treatments and other medications conservatively, as with loaches, puffers and eels. It should be handled and moved in a container rather than netted, since even modest pectoral spines can catch in mesh. Given the lack of established husbandry data and its extreme habitat requirements, this is a species for specialist rapids-biotope keepers rather than general hobbyists.
Conservation
The IUCN Red List assesses Chiloglanis carnosus as Near Threatened (2022 assessment). As a narrow-range endemic restricted to the lower Congo River rapids near Inga, its entire known population sits within a small, specific stretch of river that has also drawn attention as a hydropower site (the Inga dam complex), making habitat alteration and disruption of the rapids' flow regime the central long-term concern for a fish that depends entirely on fast, turbulent water to survive.
The species is not part of the aquarium trade in any meaningful way, so collection pressure is not a relevant threat; the risk profile is tied to the fate of the lower Congo rapids ecosystem itself.