Taxonomy & naming
Ctenopoma gabonense was described by Albert Günther in 1896 on material from Gabon — the Ogowe River system that drains much of modern Gabon westward to the Atlantic. The valid name as recorded in Eschmeyer's Catalog of Fishes is Ctenopoma gabonense Günther, 1896. The species is a member of the family Anabantidae, the Old World climbing perches and bushfishes, and falls within the large African genus Ctenopoma, which encompasses the majority of African labyrinth fishes outside the true climbing perch Anabas.
The genus name Ctenopoma combines the Greek kteis (kteinos), meaning comb, and poma, meaning cover or lid, a reference to the toothed or serrated preopercular bones that many species in the group display. The specific epithet gabonense simply means 'of Gabon', recording the type locality. FishBase and the main reference for Central African fishes, Norris (2008) in Stiassny, Teugels & Hopkins's comprehensive account of freshwater fishes of Lower Guinea, treat it as a valid species distributed across the Ogowe system and parts of the Congo basin.
Morphology
FishBase records a maximum standard length of 6.5 in for Ctenopoma gabonense, placing it among the larger members of the genus. The body form is typical of the African bushfishes: moderately deep, laterally compressed, with a rounded snout and a large upturned mouth well suited to striking at prey from below or at the water surface. Overall body pigmentation is described as brown — a useful camouflage in the leaf-litter and root-choked margins this group typically inhabits.
The fin formula shows considerable spination: dorsal fin with 19 to 21 spines plus 8 to 11 soft rays, and anal fin with 9 to 11 spines plus 8 to 11 soft rays. This high spine count, shared across the genus, is thought to deter gape-limited predators. The preopercular region bears the comb-like serrations that give the genus its name. As in other Ctenopoma, the suprabranchial chamber housing the labyrinth organ creates a slight dorsal hump behind the head in adults. Sexual dimorphism in colour and size has not been formally characterised for this species specifically; most Ctenopoma show subtle or no differences between sexes, and distinguishing them reliably often requires close inspection of the genital papilla.
Habitat
Ctenopoma gabonense is a freshwater, demersal (bottom-associated), tropical species recorded from the Ogowe River in Gabon and the Congo River basin — two of the major drainage systems of West-Central Africa. Within these basins it likely occupies the slow-moving, vegetated marginal and floodplain habitats favoured by most Ctenopoma: backwaters, flooded forest edges, dense stands of aquatic macrophytes, submerged root tangles, and reed margins where cover is abundant and currents minimal.
Like all anabantids, C. gabonense is an obligate air-breather: it surfaces periodically to gulp atmospheric oxygen directly into the suprabranchial chamber above the gills, allowing it to persist in warm, slow, seasonally oxygen-depleted waters that exclude many other fish families. Specific water-chemistry data for the natural habitat of this species are not available in the published record; broadly, the lowland tropical rivers of the Ogowe and Congo systems tend toward warm temperatures and circumneutral to mildly acidic conditions, though the Congo basin is notably heterogeneous in chemistry across its vast extent.
Feeding
Ctenopoma gabonense is a predator. The broader genus is well established as taking small fish, crustaceans, aquatic insects, insect larvae, amphibians, and fish eggs — opportunistic ambush hunters that rely on camouflage and patience rather than open-water pursuit. The brown coloration of C. gabonense is consistent with this lifestyle.
In captivity, related species such as the leopard bushfish (C. acutirostre) accept meaty foods including live and frozen fish, earthworms, prawns, bloodworm, and similar fare; adult specimens may refuse prepared dry foods initially, though many adapt with time. Given the broadly similar ecology across the genus, C. gabonense would be expected to respond similarly, though specific captive-husbandry data for this species are sparse in the hobby literature.
Mating
Ctenopoma are open-water egg-scatterers. Spawning follows a body-contact embrace: a male curves around the female and the pair release eggs and sperm simultaneously into the open water. The eggs are buoyant, rising to the surface where they may adhere loosely to floating vegetation or surface film. There is no pair bond and no preparation of a nest site — spawning is a brief, repeatable act rather than an extended courtship sequence.
Sexual readiness in the genus can be difficult to assess externally; most Ctenopoma show little obvious dimorphism. In well-conditioned pairs, males may become more actively aggressive or territorial in the lead-up to spawning. A female in breeding condition may appear slightly fuller in the abdomen with developing eggs.
Breeding
Following the embrace, eggs float to the surface and the adults take no further role: there is no guarding, fanning, or parental care of any kind. Eggs of Ctenopoma typically hatch within roughly 48 hours at tropical temperatures; fry are tiny and pelagic at first, hanging near the surface film. Fry survival in nature is likely low — females of the genus may release thousands of eggs, with fry dependent on plankton and microinvertebrates in the first days of life.
Breeding this species in private aquariums is considered difficult; analogous accounts from experienced keepers of C. acutirostre note that even willing pairs may not produce viable spawns without well-matched conditioning, appropriate temperatures, and soft acidic water in some cases. Removing eggs or transferring spawning-medium material to a separate rearing vessel is advisable given the adults' likely predatory response to their own offspring. Detailed breeding reports specific to C. gabonense are not established in the hobby literature.
In the aquarium
Ctenopoma gabonense is not a common aquarium fish and rarely appears in the commercial trade; it is essentially a species of interest to specialist anabantid keepers rather than the general hobby. Its size — up to 6.5 in SL — and predatory nature dictate the principal keeping requirements: a sufficiently large aquarium (at minimum 47 in in length for an adult), no tankmates small enough to be swallowed, and a décor scheme that provides overhead and lateral cover in the form of driftwood, broad-leaved plants, or floating vegetation.
As an obligate air-breather, surface access is non-negotiable: the tank must not be sealed in a way that prevents the fish from reaching the air above the water. Surface turbulence should be gentle. Water should be kept warm — 75–82 °F is a reasonable target based on the tropical lowland origin — and filtration should maintain water quality without generating strong current. Like all anabantids, the labyrinth organ needs to breathe air at approximately the same temperature as the water to avoid gill inflammation; avoid cold draughts over the tank surface. The species can live 10 years or more in captivity when well kept, as recorded for related species.
Conservation
Ctenopoma gabonense has not been assessed by the IUCN Red List and carries a status of Not Evaluated (NE). Its basin-level distribution across the Ogowe in Gabon and the broader Congo drainage suggests it is not a restricted-range endemic of immediate concern, but the absence of a formal assessment means threats are unquantified.
The Congo basin and associated West-Central African river systems face ongoing pressures from artisanal and industrial fishing, deforestation and sedimentation, and extractive industries; downstream effects on labyrinth fish communities are poorly documented. Because C. gabonense is seldom collected for the ornamental trade and attracts limited research attention, robust population data are lacking. An IUCN assessment, even a rapid one, would be a useful baseline given the pace of land-use change in the Ogowe corridor.