Taxonomy & naming
Aphyosemion elberti was described by Ernst Ahl in 1924, making the full authority (Ahl, 1924) with the parentheses indicating the name has been moved from its original generic placement. The species was originally placed in Panchax — then a wastebasket genus for Old World egg-laying toothcarps — before being transferred to Aphyosemion. Eschmeyer's Catalog of Fishes (Fricke, Eschmeyer & van der Laan) lists the combination Aphyosemion elberti (Ahl, 1924) as valid, placing it in the subgenus Kathetys according to the IUCN assessment.
The synonymy is substantial. Seriously Fish records Panchax tessmanni, Aphyosemion rubrifascium, and Aphyosemion bualanum kekemense as junior synonyms. The type locality is the Jade Plateau in Cameroon, associated with the Lebo River — almost certainly part of the Mambéré headwater system. The taxonomic boundary with A. bualanum is contentious: the ichthyologist Huber (1996) argued that the name A. bualanum may have nomenclatural priority, but the type material was unavailable for examination, and Seegers' 1988 revision — which the IUCN assessment follows — retains A. elberti as the valid name. Until fresh type material or a molecular revision resolves the matter, A. elberti stands as the accepted name.
Morphology
Aphyosemion elberti is a slender, fusiform killifish reaching a maximum of around 1.5 in total length (FishBase), with Seriously Fish noting a standard length of 1.5 in for adults. Males are the showpiece of the species: the body is predominantly iridescent blue-green, overlaid with vivid red or orange-red horizontal bars or streaks that give rise to the common name Red-Barred Lyretail. The unpaired fins carry extensions — in well-conditioned males the caudal fin develops pointed lobes giving a lyre-like outline — and the dorsal and anal fins show red and blue patterning edged in white or yellow.
Females are considerably more subdued, as is typical for the genus. They are brownish or olive, with much-reduced or absent red barring, and lack fin extensions. The size difference between the sexes is modest, but females appear deeper-bodied when carrying eggs. The lateral line is absent in the species, which is characteristic of Aphyosemion, and the small, upturned mouth reflects the predominantly surface- and midwater-feeding behaviour of the group.
Habitat
Aphyosemion elberti occupies a relatively wide arc of west-central African highlands. Its primary range is central Cameroon — principally the Sanaga River system — with extensions westward into the upper Benue tributaries of eastern Nigeria and southeastward into the upper Mambéré basin of the Central African Republic. The IUCN records additional occurrence in the upper Logone drainage (Chad basin margin), giving the species a footprint that crosses several major West African watershed divides at high-altitude headwater connections.
The preferred habitat is small to medium-sized highland streams and associated swampy forest margins: cool, soft, slightly acidic water shaded by gallery forest canopy and often stained amber with dissolved tannins and humic acids. FishBase records a temperature range of 64–72 °F, reflecting the cooler conditions of the Cameroonian highlands compared with lowland African rainforest killies. Seriously Fish gives pH 6.0–7.0 and hardness up to 90 ppm — a relatively soft and weakly acidic to near-neutral regime. The benthopelagic habit noted by FishBase is consistent with a fish that forages through the water column and over leaf litter in shallow, structurally complex streams.
Feeding
Aphyosemion elberti is an omnivore in the wild, taking small invertebrates — aquatic insect larvae, small crustaceans, zooplankton, and any terrestrial invertebrates that fall to the water surface — supplemented by algal and organic material encountered during foraging. FishBase characterises the diet as omnivorous, consistent with the generalised feeding mode of most small Aphyosemion species.
In the aquarium, live and frozen foods elicit the strongest feeding response and best condition in both sexes. Daphnia, artemia nauplii and adults, bloodworm (Chironomus larvae), and microworm are all accepted readily. Dry foods of appropriate small size can be offered for convenience but should not form the bulk of the diet; killifish keepers routinely report that colour, condition, and breeding vigour are markedly better on a varied live and frozen regimen. The small mouth limits prey size; foods should be appropriately sized for fish of this scale.
Mating
Aphyosemion elberti is a non-annual killifish — it inhabits permanent or near-permanent highland streams and does not undergo the desiccation-and-diapause cycle of annual soil-spawning species. Reproduction follows the plant-spawning mode characteristic of many Aphyosemion: pairs or a male with two females deposit adhesive eggs individually on fine-leaved plants, moss, spawning mops, or among fibrous roots over an extended period, rather than releasing a mass clutch in a single event.
Male courtship involves lateral display with fins spread fully, body colour intensified, and slow circling of the female. The mating posture is a brief side-by-side press with the male arching slightly alongside the female as a single egg is deposited and fertilised. This behaviour is repeated multiple times per session across days or weeks, yielding a scattered egg deposition that spreads reproductive risk across time and substrate.
Breeding
Eggs of Aphyosemion elberti are small and adhesive, attaching to the surface or substrate where they were laid. Unlike the diapausing eggs of annual species — which can withstand months of desiccation in moist peat — the eggs of non-annual plant-spawners develop in water continuously and hatch in approximately two to three weeks at appropriate temperatures. At the cooler end of the species' range (around 68–72 °F) development is at the slower end; warmer conditions accelerate hatching but can compromise egg quality.
In the aquarium the standard approach for this group is to maintain a breeding tank with one male and two females, dense Java moss or spawning mops, and soft, acidic, slightly tannin-stained water. Eggs are picked from the mops or vegetation every few days and incubated separately in small containers of shallow water to prevent fungus spread and predation by adults. Fry are free-swimming from hatching and can take microworm and paramecium immediately; they grow quickly and can accept baby artemia within a week or two of hatching. The species' comparatively long lifespan (two to three years in good conditions) relative to annual killies means that breeding groups can be maintained productively for extended periods.
In the aquarium
Aphyosemion elberti is one of the more accessible non-annual African killifish for the beginning killi keeper. Its non-annual status eliminates the peat-spawning protocol and incubation-from-dry-egg steps that can intimidate newcomers, and its modest size (under 1.5 in) means a functional breeding and maintenance set-up can be run in a small species-specific aquarium of 10–15 US gal. The cooler temperature requirement (64–72 °F) is comfortable at typical room temperature in temperate climates without supplemental heating, making it economical to keep multiple tanks.
Water chemistry should be soft and slightly acidic: pH 6.0–7.0, low hardness, and good filtration to keep nitrates in check. Gentle flow — sponge filtration is ideal — maintains clean water without stressing fish adapted to sluggish highland streams. Heavy planting or moss coverage provides the subdued lighting and spawning substrate the species uses, and tannin from Indian almond leaf or peat filtrate reproduces the natural blackwater tinge. Males are territorial with one another and should be kept one per tank with two or three females unless the aquarium is large enough to provide sight-line breaks.
The species is not widely available in general pet trade but circulates reliably within killifish society networks and specialist breeders. Importation from the wild appears limited; most aquarium stock is captive-bred, which has conservation benefits and generally produces well-adapted fish.
Conservation
The IUCN assessed Aphyosemion elberti as Least Concern in 2009 (assessor: Moelants, T.; published 2010). The justification cited the species' widespread presence across Cameroon — a range that spans multiple major river systems and suggests no single drainage-scale event could eliminate the entire population. The population trend is listed as Unknown.
The Least Concern status should not be taken as evidence that the species faces no threats. Deforestation for agriculture and logging across the Cameroonian highlands is ongoing and progressively degrades the shaded, leaf-litter-rich gallery stream habitats that the species and related Aphyosemion depend upon. The introduction of mosquitofish (Gambusia affinis) and other invasive species into highland streams in parts of Africa has devastated local killi populations where it has occurred, and the connectivity of small highland streams is vulnerable to road-building and agricultural water extraction. The taxonomic complexity noted in the IUCN assessment — specifically the uncertain relationship with A. bualanum — means that the 'widespread' range attribution may actually aggregate two or more narrower-range taxa, in which case the individual units' conservation status could be considerably more precarious than the current assessment implies. A modern molecular revision of the A. elberti / A. bualanum complex is overdue.