Taxonomy & naming
Epiplatys bifasciatus was described by the Austrian ichthyologist Franz Steindachner in 1881, with the type locality recorded as the Bahr el Seraf and Bahr el Gebel — tributaries and channels of the White Nile system in Sudan. Because Steindachner's original placement has since been superseded, the authority is presented in parentheses, and Eschmeyer's Catalog of Fishes treats the current combination Epiplatys bifasciatus (Steindachner, 1881) as the valid name.
The genus Epiplatys belongs to the family Nothobranchiidae (African rivulines), the large Old World clade of egg-laying Cyprinodontiformes. Epiplatys species are surface-oriented, non-annual panchax-type killies centred on West and Central Africa; they differ from the annual Nothobranchius and Fundulopanchax by inhabiting stable or near-permanent waters and by their plant-spawning reproductive strategy. The specific epithet bifasciatus is Latin for 'two-banded', describing the two longitudinal dark stripes that mark the flanks of living fish.
Morphology
Epiplatys bifasciatus is an elongate, slightly compressed killifish with the upturned mouth typical of surface-feeding panchax genera. FishBase records a maximum length of 2.5 in TL for males and unsexed individuals, with some measurements given as 2 in SL; the British Killifish Association reports males reaching approximately 2 in and females slightly smaller at around 2 in.
The body is pale to golden-olive on the dorsal surface, fading to cream or buff on the belly. The two dark lateral stripes that give the species its name run along the midline and above it, often with a reddish or brownish suffusion between them in males. Fins are hyaline to faintly yellowish; males in good condition may show colour in the unpaired fins. The scales are moderately sized and cycloid. Sexual dimorphism is modest: males are slimmer and more vividly marked than females, which are rounder-bodied and typically paler.
Habitat
The distribution of Epiplatys bifasciatus spans a vast arc of sub-Saharan Africa — Senegal, Gambia, Guinea, Mali, Burkina Faso, Ghana, Togo, Benin, Nigeria, Cameroon, Chad basin, Central African Republic, and reaching east to the Bahr el Jebel and White Nile drainages of Sudan. This range encompasses both the Sahelian savanna zone and wetter Guinea-zone habitats, and the species tolerates correspondingly variable conditions.
Typical habitats are shallow, heavily vegetated sites: marsh margins, seasonally flooded swamp edges, weedy rivulets, and the calm, bank-side zones of larger rivers. The British Killifish Association characterises the biotope as water with surface aquatic vegetation under which the fish shelter and spawn. FishBase records the temperature preference as 73–81 °F; aquarium husbandry recommendations suggest pH 6.6–7.0 and a hardness of 4–7 German degrees (roughly 70–125 ppm) — water that is soft to moderately soft and slightly acid to neutral, consistent with savanna river and swamp conditions across the range.
Feeding
Epiplatys bifasciatus is an opportunistic predator that focuses on surface and near-surface prey. FishBase records the wild diet as including terrestrial and aquatic insects — notably culicid (mosquito) larvae and pupae, and small beetles — along with browsing on algae and higher plant material. The upturned mouth is well adapted to snatching insects from the water surface or just below it.
In captivity the species is reported to be demanding: the British Killifish Association states that it accepts live food only and does not adapt readily to dry or prepared foods. Daphnia, mosquito larvae, small bloodworm, and similar live or frozen invertebrates are the most reliable diet. Good condition and willingness to spawn depend on regular provision of live prey.
Mating
Epiplatys bifasciatus is a non-annual, plant-spawning killifish. Unlike the annual species of open savanna pans, it inhabits permanent or near-permanent water and reproduces continuously across an extended season rather than in a single burst tied to the wet season. Spawning pairs search out the roots of floating vegetation, submerged mosses, or the fibres of artificial spawning mops near the water surface, and deposit eggs individually or in small numbers over many days and weeks.
Males are territorial and aggressive toward one another; the British Killifish Association notes that males become antagonistic when kept in small groups, and that a single male with one or more females is the recommended arrangement. Courtship involves brief lateral displays by the male before the pair align side-by-side and press together as an egg is deposited and fertilised.
Breeding
Eggs are relatively large for the fish's size, transparent, and adhesive. At an incubation temperature of approximately 73 °F (74 °F), hatching occurs after 11–13 days according to British Killifish Association records. There is no diapause and no requirement for a dry peat-storage period — this is a water-incubating plant spawner, and the eggs simply develop in situ or in a separate rearing vessel filled with tank water.
Fry are very small and transparent on hatching. For the first two to three days they require infusoria or equivalent microscopic first foods; from the end of the first week they can take micro-worms or small nematodes, and by the third week newly hatched brine shrimp nauplii are appropriate. Sexual maturity is reached at approximately six to seven months. The maximum lifespan recorded by the British Killifish Association is around 30 months — typical for a non-annual Epiplatys and substantially longer than annual killifish of comparable size.
In the aquarium
Epiplatys bifasciatus is assessed as moderately difficult to keep, reflecting its insistence on live food and some sensitivity to water quality. A small, well-planted species aquarium with a tight-fitting lid — essential for any killifish — is ideal. Water should be soft to moderately soft and slightly acidic to neutral (pH 6.6–7.0, 4–7 °dH, 73–75 °F). Floating plants such as water sprite or riccia, or fine-leaved submerged plants, provide surface cover that the fish requires and doubles as spawning substrate.
Because males are aggressive toward one another, keeping a single male with two or three females reduces fighting. The fish is shy and best observed in a quiet setting with subdued lighting. Regular partial water changes are important; stagnant or degraded water depresses feeding and spawning activity. A dedicated spawning mop of dark wool or synthetic fibre hung near the surface can serve as an egg-collection point, allowing eggs to be removed and hatched separately away from the adults.
The species is not suited to a mixed community tank: it is small enough to be harassed by larger fish, too predatory for small companions, and too timid to compete in a busy aquarium. It appeals primarily to killifish specialists who appreciate its wide natural distribution and the logistical straightforwardness of non-annual plant-spawning breeding compared with annual peat-spawners.
Conservation
The IUCN Red List assessed Epiplatys bifasciatus as Least Concern (LC) in November 2019, a status supported by the species' very wide distribution across multiple river basins and its tolerance of varied savanna water conditions. Its occurrence across more than a dozen countries and several major drainage systems means that localised threats are unlikely to jeopardise the species as a whole.
Nonetheless, the habitats it occupies — seasonal swamps, marsh margins, and weedy river shallows across West and Central Africa — face ongoing degradation through agricultural drainage, grazing pressure, and the conversion of wetland edges to cultivation. The introduction of mosquitofish (Gambusia spp.) to West African waterways for larval mosquito control poses a documented risk to small surface-dwelling killifish in the region, as Gambusia are highly competitive fin-nippers that displace and injure panchax-type species. The broad range of E. bifasciatus provides a buffer that many single-locality Epiplatys endemics lack, but continued monitoring of population status across the more degraded parts of its range remains warranted.