Taxonomy & naming
Ctenopoma petherici was described by Albert Günther in 1864 in a brief account of a labyrinthine fish obtained from the Nile, published in the Annals and Magazine of Natural History. Günther placed it in what was then the broad genus Ctenopoma, and the name has remained there; Eschmeyer's Catalog of Fishes treats Ctenopoma petherici Günther, 1864 as the valid combination. The type locality is the Nile, although subsequent distributional work has shown the species to range far more widely across West African drainages than that origin might suggest — a pattern not unusual in anabantoids described from early colonial-era collections.
Ctenopoma (family Anabantidae) is the largest African genus of labyrinth fishes, comprising roughly two dozen species of freshwater climbing perch spread across sub-Saharan Africa. All are air-breathers equipped with the suprabranchial labyrinth organ, and all are secretive, largely crepuscular predators of invertebrates or small fish. C. petherici sits in the larger-bodied cohort of the genus alongside species such as C. kingsleyae and C. murei, and is sometimes loosely called a 'leopard' or climbing perch in the hobby due to the patterning common to several Ctenopoma species, though that name attaches more reliably to C. acutirostre in trade. The name Ctenopoma riggenbachi is treated as a synonym of this species in Eschmeyer's Catalog of Fishes. The name Ctenopoma togoensis is treated as a synonym of this species in Eschmeyer's Catalog of Fishes.
Morphology
Ctenopoma petherici is a large, moderately robust anabantoid. FishBase records males to 7 in total length and females to 5.5 in standard length, making it one of the biggest species in the genus. The body is laterally compressed and oval in outline, deepening somewhat with age. The dorsal and anal fins are long-based and posteriorly pointed, giving the fish a somewhat elongate silhouette when the fins are fanned; a characteristic serrated or ctenoid scaling along portions of the operculum and posterior body gives the genus its name (Greek ktenos, comb; poma, cover).
The colour pattern is typically cryptic: a base of brownish to olive or tan, overlaid with darker spots, blotches, or mottling that varies individually and with mood. Like most Ctenopoma the species can lighten or darken markedly — a fish at rest in cover may show a very different pattern from one alarmed in open water. Juveniles tend to be more distinctly marked. The labyrinth organ, housed in an expanded suprabranchial chamber above the gills, is visible as a slight swelling behind the head in larger specimens.
Habitat
Ctenopoma petherici occupies a wide arc of West and Central African freshwater: the Senegal River, the Gambia River, the entire Niger drainage except its lower reaches, the Lake Chad drainage, and coastal river systems in Côte d'Ivoire and Ghana. Within those drainages it is a benthopelagic species of marginal and standing waters — slow-moving floodplain backwaters, vegetated swamps, flooded forest margins, and seasonal pools — rather than a fish of fast main-channel flow.
As an obligate air-breather, C. petherici is well adapted to habitats with chronically low dissolved oxygen, including stagnant or heavily vegetated pools. The species is potamodromous, meaning it undertakes freshwater migrations, likely linked to seasonal flooding and recession cycles. Water conditions across its range vary considerably, from the soft acid pools of West African coastal drainages to harder savanna rivers; it appears to tolerate a broad range of temperature and chemistry, which accounts for its success as a generalist across such disparate systems.
Feeding
In the wild, Ctenopoma petherici has been recorded consuming a varied diet that includes plant tissues, ostracods, dipteran larvae, and beetles — a mixed animal and plant intake consistent with an opportunistic predator of the margins. Like other large Ctenopoma it is capable of ambush predation on invertebrates and small fish, using the dense marginal vegetation of its preferred habitat as cover from which to lunge at prey.
In aquaria the species accepts a wide range of meaty foods. Earthworms, pieces of fish or prawn, and large live or frozen foods such as bloodworms or small crickets are taken readily. Juveniles can be started on smaller live and frozen invertebrates. Prepared pellets are accepted by some individuals, particularly those raised in captivity from young. Because of its size, it should be considered a predator: small tankmates that fit in its mouth are likely to be eaten.
Mating
Ctenopoma petherici belongs to the open-water egg-scattering guild of Ctenopoma — a group that releases buoyant, non-adhesive eggs into open water rather than constructing bubble nests or practising mouthbrooding. In this mode the male courts the female and the pair engage in a spawning embrace typical of anabantoids, releasing eggs and sperm together; the fertilised eggs float freely at or near the surface rather than being collected or tended.
Seasonal timing in the wild is linked to precipitation and water-level cycles. Academic work on reproduction in tropical environments suggests that flooding events trigger spawning in many West African anabantoids, with rising water levels and the expansion of marginal habitat providing both the physical space and the food base needed for larvae to grow. Males of open-water spawning Ctenopoma do not build or maintain a nest, and parental care after the initial embrace is absent.
Breeding
Captive breeding of Ctenopoma petherici is rarely documented in the hobby literature, in part because the species is uncommon in trade and in part because large anabantoids with predatory habits present practical challenges. In principle the approach should follow that used for other open-water spawning Ctenopoma: condition a pair or small group on meaty live and frozen foods, provide warm water (75–82 °F) and a large, well-planted tank with subdued lighting, and allow the natural seasonal or water-change cues to trigger spawning.
The buoyant eggs should float at the surface after release; because parental care is absent in this reproductive mode, adults should be removed from the spawning container promptly or the eggs separated, as they will be eaten. Larvae are initially small and require very fine live foods at first feeding. Data on incubation times and larval development specific to this species are sparse in the published literature, and hobbyist records are the most practical source of guidance.
In the aquarium
Ctenopoma petherici is rarely encountered in the ornamental trade but does appear occasionally, usually as wild-caught West African imports. Its large adult size — approaching 6.5 in — means it requires a genuinely spacious aquarium: a minimum of 59 in length is advisable for an adult, with plenty of shelter in the form of caves, driftwood, and dense planting. Being an obligate air-breather, the tank must be covered and a gap left at the water surface; the air in that gap should be warm and humid, as cold dry air reaching the labyrinth organ can injure it.
As a large, predatory anabantoid it cannot safely be kept with fish small enough to swallow. Tankmates of similar or larger size and non-aggressive disposition are appropriate — robust West African cichlids, large characins, or other anabantoids of comparable bulk are sometimes kept alongside it. The species is primarily crepuscular and secretive, spending much of the day in cover; a dimly lit or densely planted tank with evening feeding times produces a more visible and settled fish. Hobby sources suggest it tolerates a moderately broad range of temperature (75–82 °F) and is not exacting in its water chemistry, which makes it more forgiving than many specialist anabantoids. Its relative rarity in the hobby means experienced fishkeepers rather than beginners are the appropriate audience.
Conservation
Ctenopoma petherici has not been assessed by the IUCN Red List; FishBase records its status as Not Evaluated as of December 2019. Its broad distribution — spanning multiple major drainages across West Africa and the Lake Chad basin — suggests it is not immediately threatened at the species level in the way that narrow-range endemics are. However, the individual drainages it inhabits face ongoing pressures: floodplain modification, swamp drainage for agriculture, increasing aridity in the Sahel margins of the Lake Chad basin, and pollution associated with expanding human populations.
As a species that depends on marginal, vegetated, and seasonally flooded habitats, C. petherici is particularly sensitive to the loss of riverine floodplain and wetland. The Lake Chad system has contracted dramatically over recent decades due to water withdrawal and reduced rainfall, eliminating habitat for fishes throughout the drainage. Formal assessment of the species' status would clarify whether the aggregate of these pressures warrants a conservation designation.