Taxonomy & naming
Micralestes comoensis was described by Max Poll and Jean Roman in 1967, in a paper published in the Revue de Zoologie et de Botanique Africaines (volume 75, numbers 1–2). The type locality is the Comoé River approximately 42 mi south of Bobo-Dioulasso in what was then Upper Volta and is now Burkina Faso; the holotype is lodged at the Musée Royal de l'Afrique Centrale, Tervuren, under catalogue number MRAC 141924. Eschmeyer's Catalog of Fishes (CAS) is the authority for the valid name, which remains Micralestes comoensis Poll & Roman, 1967.
The genus Micralestes belongs to the family Alestidae — the African tetras — a predominantly West and Central African radiation of characiform fishes. Alestidae is separated from the South American characid assemblages and has long been treated as its own family; molecular work has reinforced its distinctness. Within Micralestes, the comoensis species is notable for its restriction to a single drainage system, an unusual degree of endemism for a genus whose other members tend to be more broadly distributed across the western savanna river systems.
Morphology
Micralestes comoensis is a slender, laterally compressed tetra reaching a maximum total length of approximately 2.5 in. Like other members of the genus it has the typical alestid body plan: a moderate arc to the dorsal profile, a rounded snout, and the adipose fin characteristic of all characiforms.
The most striking feature of the species is its fin colouration. FishBase records the fins as red to carmine-red, a vivid pigmentation that stands out against the silvery body typical of small African tetras. The extent and intensity of the red is particularly pronounced in males in good condition, and is likely involved in intraspecific signalling during courtship and male competition. Detailed meristic data from the original description are not widely reproduced in accessible literature, and the species remains comparatively little studied compared with more commercially prominent alestids.
Habitat
The species is endemic to the upper Comoé River system in southern Burkina Faso, West Africa. The Comoé drains a Sudanian savanna landscape characterised by marked seasonality: a distinct wet season from roughly June to October brings spates, rising river levels, and temporary floodplain inundation, while the dry season from November to May sees water levels fall dramatically and many smaller tributaries cease to flow entirely.
Small characiform tetras in this region typically exploit a range of microhabitats — shallow margins with submerged vegetation, pools below riffles, and slower backwaters — and feed in the open water column. The Comoé and its upper tributaries support gallery forest along their banks in places, providing shaded, leaf-litter-rich microhabitats. Water chemistry in Sudanian river systems tends toward soft, slightly acidic to near-neutral conditions during the wet season, with conductivity and temperatures rising markedly in isolated pools during the dry season.
Feeding
FishBase assigns Micralestes comoensis a trophic level of 3.1 (±0.4), consistent with an omnivorous to lightly carnivorous diet — the range typical of small insectivorous-omnivore tetras in African river systems. The natural diet likely includes small aquatic invertebrates such as insect larvae and microcrustaceans, terrestrial insects fallen onto the water surface, zooplankton, and some plant or algal material.
The genus Micralestes as a whole is not well documented in the feeding literature, but alestid tetras of similar size in West African savanna rivers are opportunistic foragers that shift their diet with seasonal availability: taking more terrestrial insects during the wet season when these fall into flooded margins, and subsisting on aquatic prey and detritus during the dry season when food resources contract.
Mating
No published behavioural observations specifically documenting the mating of Micralestes comoensis are available in the accessible literature. Based on the reproductive biology of closely related alestid tetras, the species is expected to be an egg-scattering open spawner without parental care. Males of Micralestes species display vibrant fin and body colouration during courtship; the pronounced red fins of M. comoensis are consistent with a visual signalling role in mate choice and male–male competition.
Spawning in alestid tetras typically peaks during or just after the onset of the wet season, when rising water levels, increasing food availability, and moderating temperatures serve as environmental cues. In closely related species, early-morning spawning activity is common, with males chasing and displaying to females among fine-leaved aquatic vegetation or in open water near the margins.
Breeding
Micralestes comoensis has not been documented as a captive-bred species in the available hobby or scientific literature, and detailed breeding observations are absent from accessible sources. By analogy with other alestid tetras, the mode is almost certainly egg-scattering with adhesive or semi-adhesive eggs deposited among fine-leaved plants or over substrate, followed by no parental investment — a pattern universal within the family.
Females of comparable alestid species produce several hundred eggs per spawning event. The adhesive eggs hatch within a few days at tropical temperatures, and the tiny fry require very fine first foods — infusoria or commercial liquid fry diet — before graduating to newly hatched brine shrimp nauplii. Given the species' Endangered status and extremely restricted natural range, any successful captive propagation would have conservation value, though the fish is essentially absent from the ornamental trade.
In the aquarium
Micralestes comoensis is essentially unknown in the aquarium hobby. It is not commercially available and has not been established as an aquarium fish. Information on its captive husbandry is therefore largely inferential, drawn from what is known of comparable small alestid tetras from the West African savanna zone.
Were it available, a group-housed setup in a well-planted aquarium with soft to moderately hard, near-neutral water and a temperature range of roughly 75–82 °F would likely suit the species. Alestid tetras of similar size are generally active, schooling fishes that benefit from open swimming space and dim lighting accented by patches of fine-leaved vegetation. A varied diet of small live and frozen invertebrates alongside good-quality dried foods would replicate the broad omnivore diet inferred for the species in the wild. Its rarity and Endangered status make wild collection inadvisable; any aquarium interest would depend on captive propagation from legally sourced stock.
Conservation
Micralestes comoensis is assessed as Endangered (EN) on the IUCN Red List under criteria B2ab(ii,iii), with the assessment dating to May 2019. The EN listing reflects the species' extremely small known range — confined to the upper Comoé River system in Burkina Faso — and continuing decline in the extent and quality of its freshwater habitat. Threats to small endemic fishes in the Sudanian zone include agricultural expansion and associated pesticide runoff, increased water abstraction for irrigation, sedimentation from catchment degradation, and climate-driven reductions in dry-season base flow.
The Comoé catchment spans Burkina Faso and Côte d'Ivoire; the Comoé National Park in the latter country protects substantial stretches of the river in its lower and middle reaches, but the upper drainage in Burkina Faso — where M. comoensis occurs — lies outside protected areas. A species endemic to a single river system with a restricted area of occupancy has no geographic buffer against local catastrophe, making habitat protection in the upper Comoé critical to the species' survival.