Taxonomy & naming
Epiplatys josianae was described by H.-O. Berkenkamp and V. Etzel in 1983 in the journal Killi-Contact (volume 11, number 8). The West Africa Killifish (WAK) reference library records the type locality as eleven miles north of Kenema, in the Kenema district of southeastern Sierra Leone, and notes a second known collection point approximately four kilometres from Joru in the direction of Kenema. Eschmeyer's Catalog of Fishes treats the valid name as Epiplatys josianae Berkenkamp & Etzel, 1983.
The species carries a complex synonymic history. It has appeared in the literature as Epiplatys fasciolatus josianae (Radda & Pürzl, 1987) — reflecting an early placement as a subspecies of the banded panchax — and as Aplocheilus josianae (Scheel, 1990), following Scheel's broad reassignment of many West African Epiplatys to Aplocheilus. FishBase and the AKA species list restore the combination to Epiplatys josianae as the valid name. The species falls within the fasciolatus group of the subgenus Epiplatys, a cluster of morphologically similar forest-stream panchax distributed across the Upper Guinea and Niger river drainages of West Africa.
Meristics recorded by the WAK library are: dorsal fin rays D=10–13, anal fin rays A=16–18. The holotype measured 3.5 in total length, which aligns with the FishBase maximum of approximately 3.5 in TL.
Morphology
Epiplatys josianae is a moderately slender, laterally compressed killifish reaching about 3 in standard length (3.5 in total length at maximum, per FishBase). Body form is typical of the fasciolatus group: a pike-like profile with the dorsal fin set well back, a pointed snout adapted for surface-feeding, and a slightly upturned mouth.
Colouration in the fasciolatus group is generally a pattern of vertical dark bars or spots on a yellowish to olive-green ground, sometimes with metallic-blue or golden flecks on the flanks. Males of related fasciolatus-group species display brighter unpaired fin colouration — reds, yellows, and blacks — that becomes most vivid in breeding condition. The WAK library notes that E. josianae closely resembles E. fasciolatus but is distinguished by a set of meristic and colour characters documented in the original description. Females, as is typical for the genus, are more subdued in colour and lack the elaborate fin ornamentation of males.
The meristic data (D=10–13, A=16–18) place this species firmly within the range documented for the broader fasciolatus complex.
Habitat
The two known collection localities both lie within the rainforested interior of Kenema district, southeastern Sierra Leone. FishBase and the EOL record the habitat as small rivers and brooks under forest cover — the shaded, slow to moderately flowing headwater streams that characterise much of the Upper Guinea forest zone. These are typically shallow, often with a substrate of leaf litter and fallen timber, and with canopy cover dense enough to suppress aquatic macrophytes while encouraging overhanging riparian roots and marginal vegetation.
Water conditions recorded by FishBase for this species are: temperature around 73 °F, pH approximately 6.5, and hardness around 8 dGH — moderately soft and mildly acidic, consistent with rainforest streams in the region that are not strongly blackwater but are not hard or alkaline either. These figures should be treated as a baseline; seasonal variation in forest streams can be substantial, with slight temperature drops and pH reduction during heavy rain events.
Sierra Leone's Upper Guinea forests are a global biodiversity hotspot, but the Kenema area has experienced significant deforestation pressure from agricultural expansion and logging. The extent of intact forest-stream habitat available to E. josianae at its two known sites today is undocumented.
Feeding
Like all Epiplatys, E. josianae is a carnivore. The upturned mouth and surface-oriented body posture are adaptations for intercepting small prey at or just below the water surface. In the wild this means terrestrial insects and other invertebrates that fall onto the water, as well as aquatic larvae and small invertebrates in the water column.
FishBase classifies the species as carnivorous, consistent with the feeding ecology documented across the genus. In an aquarium setting, closely related fasciolatus-group species readily accept live and frozen foods — small invertebrates such as Daphnia, bloodworm, and brine shrimp are standard, and some individuals learn to take high-quality dried foods. Because E. josianae is a surface-to-mid-water feeder, food should be offered at the appropriate level and allowed to drift at the surface before sinking.
Mating
Epiplatys josianae is a non-annual killifish. It inhabits permanent or near-permanent forest streams rather than the seasonal pools that are the habitat of annual species, and its reproductive mode is correspondingly different: pairs or small groups spawn adhesive eggs on fine-leaved plants, floating roots, spawning mops, or other submerged fibrous material near the water surface, releasing a small number of eggs each day over an extended period rather than a single mass-spawning event.
Male courtship in the fasciolatus group is active: males display their brightest colouration to females, erecting dorsal and caudal fins and manoeuvring alongside the female before guiding her to a suitable spawning site. The WAK library notes that breeding behaviour in E. josianae is broadly similar to that of E. fasciolatus, though hobbyists have reported it to be somewhat more challenging to bring into spawning condition.
Breeding
As a non-annual plant-spawner, E. josianae deposits a small number of adhesive eggs (typically one to a few per spawn act) on fine-leaved plants or spawning mops each day. The eggs incubate directly in water without diapause — there is no requirement for a drying or peat-storage phase. Incubation period for fasciolatus-group species is typically 12–16 days at around 75 °F, though data specific to E. josianae are not on record in the sources consulted.
The WAK library describes breeding as similar to E. fasciolatus but reports that hobbyists have found the species more difficult to breed. Possible reasons include sensitivity to water quality or temperature during spawning conditioning, or selectivity in mate acceptance. Adults should be separated from their eggs promptly, as Epiplatys will eat freshly deposited eggs; spawning mops or java moss can be removed and placed in a separate hatching vessel. Fry are relatively large for a killifish of this size and can generally accept Artemia nauplii as a first food, alongside microworm and other fine live foods.
Adults are comparatively long-lived relative to annual killies, with a life expectancy under aquarium conditions measured in years rather than months.
In the aquarium
Epiplatys josianae is a specialist fish kept primarily by killifish hobbyists affiliated with organisations such as the American Killifish Association (AKA), which maintains a species profile and cites relevant JAKA journal articles from 1984, 1989, 1997, 2005, and 2022. The fish is not commonly encountered outside the killifish hobby network and is likely maintained in small numbers by dedicated enthusiasts.
Appropriate aquarium conditions mirror the species' forest-stream habitat: a temperature of 72–77 °F, pH around 6.0–7.0, and soft to moderately soft water (up to around 10 dGH). A well-planted, shaded tank with a dark substrate and surface cover of floating plants closely replicates the dappled canopy-stream environment. Surface access is important since, as a surface feeder, the fish spends much of its time in the upper water column. A tight-fitting lid is mandatory — Epiplatys are accomplished jumpers.
The WAK library notes that hobbyists have found E. josianae somewhat more demanding to breed than E. fasciolatus, so careful attention to conditioning (varied live foods, water-change regimes to simulate seasonal cues) is worthwhile. It is best kept in a species or single-genus aquarium to avoid competition from more assertive fish; males may spar but serious injury is rare in a well-decorated tank with sufficient space.
Conservation
Epiplatys josianae is listed as Not Evaluated (NE) on the IUCN Red List — it has never received a formal assessment. This is not unusual for many West African killifish, particularly those described from small numbers of specimens at a single locality or pair of localities. The known distribution of E. josianae is exceptionally narrow: only two collection points are on record, both within a small radius in the Kenema district of southeastern Sierra Leone.
Sierra Leone's forests have experienced severe deforestation pressure over decades of civil conflict, post-conflict agricultural expansion, and charcoal and timber extraction. The Upper Guinea forest block in which the Kenema area sits is one of the most threatened forest regions in Africa. Species dependent on intact forest-stream microhabitats — the shaded, leaf-littered brooks that constitute E. josianae's habitat — are acutely vulnerable to canopy clearance, which alters water temperature, sedimentation, and flow regime even where streams themselves are not physically destroyed.
No targeted survey work on E. josianae appears to have been carried out since the original collection expeditions documented in the 1983 description. Whether populations persist at the type locality or the Joru site, and whether additional populations exist elsewhere in the Kenema basin or adjacent drainages, is unknown. The narrow endemism, restricted habitat type, and level of deforestation in the region mean that a precautionary assessment would likely place the species in a threatened category — but without survey data, the honest position remains that its current status is entirely undocumented.