Taxonomy & naming
Microctenopoma intermedium was originally described by Jacques Pellegrin in 1920, hence the parenthetical authority (Pellegrin, 1920) — the parentheses indicating that the species has been moved from the genus in which it was first placed. The Catalog of Fishes (Eschmeyer et al.) records the valid name as Microctenopoma intermedium. The genus Microctenopoma was erected to accommodate a group of smaller African climbing perches previously lumped within the broad genus Ctenopoma; species in Microctenopoma tend to be smaller-bodied, with reduced scalation on the head compared to the larger Ctenopoma sensu stricto.
The specific epithet intermedium is Latin for 'intermediate', likely reflecting Pellegrin's assessment of the species' morphological position relative to its congeners at the time of description. The common name 'Blackspot climbing perch' references a dark spot that appears on the body flanks in this and related species — a character used in identification within the genus Microctenopoma. Like all members of the family Anabantidae (the climbing perches), it belongs to the suborder Anabantoidei and possesses the labyrinth organ that allows it to breathe atmospheric oxygen directly.
Morphology
Microctenopoma intermedium is a small, moderately compressed labyrinth fish reported to reach a maximum of 2.5 in total length. The body form is typical of the genus: somewhat deep and oval in profile, with a rounded head and a relatively large eye. The dorsal and anal fins are long-based, soft-rayed toward the rear, and the caudal fin is rounded — the characteristic silhouette of an anabantoid.
Colouration in Microctenopoma species tends toward cryptic tones of brown, olive, and grey, with variable dark banding or mottling that provides camouflage among marginal vegetation. A dark spot on the flank, referenced in the common name, may be present, though exact markings vary with condition and stress. As in many anabantoids, colour and pattern can shift rapidly depending on mood and social context, intensifying during courtship and territorial encounters.
Habitat
This species occupies a wide range of still and slow-moving freshwater habitats across central and southern Africa, including rivers, lakes, lagoons, swamps, and floodplains. A constant across all these environments is the presence of dense marginal or emergent vegetation, which provides cover for foraging, refuge from predators, and the calm surface conditions required for bubble-nest construction.
The distribution spans several major drainages: the Okavango, upper and lower Zambezi, and Kafue river systems in southern-central Africa; the St. Lucia basin of KwaZulu-Natal in South Africa; and southern Congo tributaries including the Kwango, Kwilu, Lualaba, and Luapula-Mweru. As a facultative air-breather with a functional labyrinth organ, Microctenopoma intermedium tolerates low dissolved-oxygen conditions that exclude many other fishes — an advantage in warm, heavily vegetated, seasonally stagnant waters. FishBase notes a minimum temperature of 75 °F, consistent with its tropical to subtropical range.
Feeding
Microctenopoma intermedium is an insectivore and generalist predator of small invertebrates, consistent with the diet typical of the genus. FishBase records insects and small organisms as the primary dietary items in the wild. It likely hunts among vegetation and at the water surface, taking aquatic insect larvae, small crustaceans, and surface-fallen invertebrates.
In the aquarium the species accepts a variety of foods. Live and frozen invertebrates such as Daphnia, mosquito larvae, brine shrimp, and small worms form the backbone of a good diet; prepared foods are also taken by acclimated individuals. A diet weighted toward invertebrate protein reflects the natural feeding ecology and keeps the fish in best condition.
Mating
Like other members of Microctenopoma, M. intermedium is a bubble-nest builder. The male constructs a raft of mucus-bound bubbles at or near the water surface, typically sheltered among floating or emergent vegetation where surface agitation is minimal. Courtship precedes spawning: the male displays to the female with spread fins and intensified colouration, driving rivals away from the nest site while attempting to entice receptive females.
Spawning follows a pattern common to anabantoid bubble-nesters: the pair circle and embrace beneath the nest, the male wrapping around the female in the anabantoid spawning clasp, and fertilised eggs float upward into the bubble raft. The male is the primary caretaker of the nest; he collects fallen eggs, repairs the foam, and drives off intruders — including, once spawning is complete, the female.
Breeding
Breeding Microctenopoma intermedium follows the bubble-nest pattern shared by its close relatives. The male builds the nest before spawning and guards it through the incubation period. Eggs and newly hatched fry rise into or beneath the foam raft and are retrieved by the male if they fall. The male's nest-guarding behaviour can become aggressive toward the female after spawning, so in aquarium settings it is generally advisable to remove the female once egg deposition is complete, leaving the male to tend the nest alone.
Water conditions for breeding should be warm — in the mid-to-upper 20s Celsius — and calm, so that the nest surface is not disrupted. Densely planted tanks or those with floating plant cover help the male establish and maintain the nest structure. Fry, once free-swimming, require very fine first foods appropriate to their small size. Detailed captive-breeding accounts for this species are sparse in the hobby literature, and most available information is extrapolated from the broader genus.
In the aquarium
Microctenopoma intermedium is reported by hobbyists as a moderately easy species to maintain. It is best kept in a dedicated or species-appropriate aquarium: like other climbing perches it can be predatory toward smaller tankmates and may harass fish kept in cramped conditions. Given its maximum size of around 2.5 in it does not require a large tank, but space and cover are important — dense planting with open mid-water lanes, floating plants for surface structure, and a secure lid (as the genus is capable of jumping) suit it well.
Water quality is maintained with routine partial water changes of around 25–30% weekly, and stable conditions are preferred over fluctuating parameters. Temperature should remain tropical, around 75–82 °F. Access to the water surface is essential, as the labyrinth organ requires the fish to breathe atmospheric air — restricted surface access causes stress and eventual suffocation regardless of dissolved oxygen levels. The species is not commonly seen in the mainstream aquarium trade but turns up among specialists and African fish enthusiasts.
Conservation
Microctenopoma intermedium is assessed as Least Concern (LC) on the IUCN Red List, evaluated in September 2016. The assessment reflects the species' wide distribution across multiple major African drainage systems — the Okavango, Zambezi, Kafue, St. Lucia basin, and several Congo tributaries — which collectively buffer it against the localised threats that put restricted-range species at risk.
No specific population declines or major range contractions are recorded for this species. General pressures affecting freshwater fish in its range include habitat degradation from agriculture and land-use change, water abstraction, sedimentation, and the spread of invasive species. At present none of these appear to have reduced M. intermedium to a level of conservation concern. The southern African component of its range is confirmed by national biodiversity assessments in South Africa and Namibia, and the species is included in regional biodiversity databases for those countries.