Taxonomy & naming
Microctenopoma ansorgii was originally described by George Albert Boulenger in 1912, and the parenthetical authority notation reflects that the species has since been moved from the genus in which it was first placed. Eschmeyer's Catalog of Fishes (Fricke, Eschmeyer & van der Laan) records the current valid name as Microctenopoma ansorgii (Boulenger, 1912). The species belongs to the genus Microctenopoma, a group of small African climbing perches within the family Anabantidae — distinct from the larger-bodied genus Ctenopoma, though the two share the characteristic ctenii (rough, comb-like scales) that give the group its name.
The genus Microctenopoma contains roughly a dozen small, forest-stream species distributed across Central and West Africa, all labyrinth fishes sharing the suprabranchial air-breathing organ. M. ansorgii is one of the more colourful representatives of the genus and has attracted periodic hobbyist interest since at least the early twentieth century, though it has never achieved the mainstream availability of more easily bred anabantoids.
Morphology
Microctenopoma ansorgii is a small, fusiform labyrinth fish. FishBase records the maximum standard length at 2 in SL, while hobbyist sources report males reaching approximately 3 in in total length; females remain notably smaller. The body is moderately deep and laterally compressed, typical of the anabantoid body plan, with dorsal spines numbering 16–19 and anal spines 10–12.
The colour pattern is the species' most immediately striking feature and is highly variable with mood and context. The base coloration ranges from reddish-brown to a warmer orange-brown, overlaid with six broad, dark vertical bars that extend through the dorsal and anal fins — giving a banded, almost tiger-striped impression at rest. In breeding dress or when excited, the body washes through to bright orange and greenish tones, the bars deepening. Males develop more intense orange coloration in the vertical fins. The capacity for rapid, visible colour change is considerable and makes the fish a rewarding subject for observation.
Habitat
Microctenopoma ansorgii is distributed across the Chiloango River drainage and the central Congo basin, with a possible extension to the Nyong River system in Cameroon. These are lowland equatorial freshwater systems characterised by slow to still water, dense riparian and aquatic vegetation, and often leaf-litter-covered substrates — the shaded, tannin-rich microhabitats that support much of the region's anabantoid fauna.
FishBase records the species as a freshwater, benthopelagic fish tolerating a fairly wide water-chemistry envelope: pH 6.0–8.0 and total hardness 5–19 dH, with temperatures of 79–82 °F in its natural range. Like all labyrinth fishes, M. ansorgii is a facultative air-breather, accessing atmospheric oxygen at the water surface through its suprabranchial organ; it is therefore tolerant of the low dissolved-oxygen conditions typical of dense tropical vegetation beds and stagnant backwaters.
Feeding
In nature, Microctenopoma ansorgii is a carnivorous predator of the small invertebrates that populate its densely vegetated, still-water habitats — insect larvae, small worms, and similar live prey are the presumed dietary mainstays, consistent with the feeding ecology of the genus.
In captivity the species shows a strong preference for live and frozen foods. Bloodworms (chironomid larvae) and brine shrimp are accepted readily, while flake and other prepared foods are largely ignored. Aquarium Glaser notes a high feeding requirement and recommends frozen or live prey as the staple; Barry Lynch's detailed breeding account corroborates that frozen bloodworms and frozen brine shrimp were the foods that sustained the fish through conditioning and spawning. Offering variety — alternating live and frozen invertebrate prey — appears to support condition and breeding readiness.
Mating
Microctenopoma ansorgii is a bubble-nest builder. The male constructs a raft of mucus-bound air bubbles at or near the water surface, typically anchored beneath floating plants or a leaf in a sheltered part of the aquarium, in a process that takes roughly one day. This nest-building behaviour follows the pattern common to many anabantoids and is analogous to that of the paradise fish and related species.
Courtship involves the male displaying to the female in the vicinity of the completed nest, the vertical bars and orange fin coloration intensifying during display. The species is described in hobbyist accounts as relatively inactive outside of feeding periods — retiring into cover and showing a seclusive temperament — but males become animated and territorial around the nest site when a receptive female is present. Spawning typically follows nest completion within approximately two days of the male beginning construction.
Breeding
Spawning takes place beneath the bubble nest the male has constructed. Eggs are released into the nest structure, where they are tended by the male; incubation lasts approximately three days before hatching. Barry Lynch's breeding account records 36 eggs produced in one spawn, with 35 surviving to adulthood — a tight clutch compared with prolific anabantoids, but the parental care invested by the male compensates for the small number.
The newly hatched fry are initially very small and essentially invisible; infusoria or similarly fine first foods are required before the fry are large enough to take baby brine shrimp nauplii. Growth rates are described as highly variable in the early weeks, with some individuals pulling ahead quickly while others lag. Aquarium Glaser notes that water temperature should be raised by 36–37 °F above the maintenance level to trigger spawning, and that soft, slightly acidic water improves spawning success. A dedicated breeding tank of around 10 US gal, well-planted with Java moss or similar cover, suits a conditioning pair.
In the aquarium
Microctenopoma ansorgii is an atypical anabantoid for the hobbyist who wants something genuinely different — small, colourful, behaviourally interesting, and demanding in a way that rewards rather than punishes careful husbandry. It is not a community fish in the conventional sense: outside of feeding it is inactive and secretive, retreating to cover and rarely displaying unless given reason to. Dither fish — calm, similarly sized, non-aggressive species that occupy open water and signal safety — help draw it out.
The tank should be heavily planted, with floating cover near the surface where the male can build his nest, and broken sight-lines throughout to reduce aggression between individuals. Gentle filtration that avoids strong surface turbulence is important both for nest integrity and for the fish's preference for still or slow-moving water. Temperature in the 75–82 °F range is appropriate for maintenance; pH in the mildly acidic to neutral zone, 6.5–7.0, seems optimal in practice, though the species tolerates a wider range.
As a labyrinth fish, surface access is non-negotiable — the space between the water surface and the tank lid must be warm and humid, as cool or dry air drawn into the suprabranchial organ can cause respiratory distress. The species is not aggressive toward dissimilar fish but may show territorial behaviour toward conspecific males. Its dietary insistence on live or frozen prey is the principal demand the fish places on its keeper.
Conservation
Microctenopoma ansorgii is assessed as Least Concern (LC) on the IUCN Red List, with the assessment dating to 16 February 2009. The species is distributed across a substantial portion of the Congo basin — one of the largest and most intact tropical river systems in the world — and does not face the restricted-range pressures that threaten many narrowly endemic freshwater fishes.
The Congo basin retains large areas of intact tropical forest and relatively lower levels of habitat alteration compared with similarly sized river systems in Southeast Asia. No specific major threats to M. ansorgii are identified, though the broader pressures of deforestation, artisanal mining, and water-quality degradation affect parts of its range. Captive breeding is feasible and hobbyist interest, though modest, helps maintain knowledge of the species' reproductive biology independent of wild collection.