Taxonomy & naming
Clypeobarbus pleuropholis was originally described by Boulenger in 1899 with a type locality in Sierra Leone. Like many African small barbs, it spent much of the twentieth century housed in the sprawling genus Barbus — a paraphyletic holding group that once contained hundreds of African and Eurasian species. Subsequent revision of African cyprinids has progressively dismantled that arrangement, and the species now sits in Clypeobarbus, a genus erected to accommodate a set of West and Central African barbs with shared morphological characteristics.
The genus Clypeobarbus is not large; it contains a small number of species distributed across West and Central Africa. The Catalog of Fishes (Eschmeyer, CAS) is the governing authority for the valid placement as Clypeobarbus pleuropholis (Boulenger, 1899), the parenthetical authority signalling that the species was originally described in a different genus. No subspecies are recognised. The species epithet pleuropholis refers to the lateral body features — from Greek pleuro (side) and phis/pholis (scale or relating to the flank) — a reference to the distinctive lateral stripe or markings that characterise this fish.
Morphology
Clypeobarbus pleuropholis is a small barb, reaching roughly 1.5–2 in in standard length, with the streamlined, fusiform body plan typical of rheophilic African cyprinids adapted for clear, moderately flowing streams. The body is laterally compressed, the dorsal profile more arched than the ventral, and the mouth small and subterminal, suited to picking invertebrates and organic matter from the substrate and water column.
The common name allusion — "side-striped" or pleuropholis — points to a lateral marking that distinguishes this fish from related species in the genus. Finnage is unremarkable, consistent with a small, active schooling barb. Sexual dimorphism is mild, as in most barbs of comparable size: females tend to be fuller-bodied when gravid, while males may show slightly more intense coloration during spawning condition. Detailed morphometric data for the species are sparse in the accessible literature.
Habitat
The species is endemic to the coastal river systems and upland streams of Sierra Leone and possibly neighbouring Guinea, a region characterised by forested hills draining to the Atlantic through short, fast rivers. The streams it inhabits are typically clear and well-oxygenated, with moderate to brisk current, rocky or gravelly substrates, and riparian vegetation providing shade and structural complexity.
Water chemistry in the upper reaches of West African coastal rivers is generally soft to moderately soft, with pH in the slightly acidic to neutral range — broadly 6.5–7.2 — and temperatures in the warm tropical band, approximately 72–79 °F. The dry-season hydrology of these rivers can concentrate fish into deeper pools; the wet season expands available habitat across seasonally flooded margins. Clypeobarbus pleuropholis appears to occupy the clearer, higher-gradient portions of its river systems rather than lowland turbid reaches.
Feeding
Like the majority of small African barbs, Clypeobarbus pleuropholis is an omnivore, taking whatever combination of small invertebrates, algal films, plant material, and organic detritus is available in its stream habitat. Small insect larvae, microcrustaceans, and worms are likely core prey items in the wild, supplemented by benthic algae scraped from rocks and fine particulate organic matter.
In an aquarium setting the species is undemanding: standard flake and small pellet foods form a practical staple, enriched with live or frozen invertebrates such as bloodworm, daphnia, and brine shrimp to provide nutritional variety and trigger conditioning. Offering some vegetable matter — blanched spinach, algae wafers — reflects the plant component of its natural diet.
Mating
Clypeobarbus pleuropholis follows the egg-scattering, non-guarding reproductive strategy universal among barbs. No pair bond forms; there is no nest, no territory held beyond the brief duration of courtship, and no parental involvement once eggs are shed. During spawning condition, males become more active and display intensified colouration as they pursue gravid females through vegetation or across the substrate.
Courtship consists of a male driving alongside or beneath a ripe female, the two aligning briefly as eggs and milt are released simultaneously. The adhesive eggs fall among plant stems, fine gravel, or leaf litter. Adults — including the spawning pair — take no further interest in the eggs and will consume them given the opportunity.
Breeding
Breeding Clypeobarbus pleuropholis in captivity follows the standard small-barb protocol. A separate shallow spawning tank with soft, slightly acidic water, fine-leaved plants or a spawning mop, and a coarse mesh or layer of marbles over the base allows scattered eggs to fall out of the adults' reach. A well-conditioned pair or small group is introduced and usually spawns within a morning.
Egg clutch sizes are modest, consistent with the small body size. Incubation at tropical temperatures takes roughly 24–36 hours, and larvae become free-swimming a few days after hatching. First foods are infusoria and green water, transitioning to newly hatched brine shrimp nauplii as fry grow. Adults should be removed promptly after spawning to prevent egg predation. The species has not achieved wide popularity in the hobby and detailed captive-breeding records are sparse; the procedure described here follows the well-established pattern shared across barbs of comparable size.
In the aquarium
Clypeobarbus pleuropholis is rarely encountered in the mainstream aquarium trade and is essentially a specialist's fish — occasionally appearing in shipments of West African stream species collected alongside more commonly traded tetras and killifish from the Sierra Leone and Guinea region. When available, it is best kept in a group of at least six to eight individuals, as it is a schooling species that is more active, less skittish, and more likely to display natural behaviour in numbers.
A biotope-style setup reflecting its native habitat — clear water, moderate flow from a powerhead or canister filter, a dark substrate of fine gravel or sand, smooth pebbles, and some hardy aquatic or emergent vegetation — suits the species well. Water parameters should target the soft, neutral to slightly acidic conditions of its Sierra Leone home: pH 6.5–7.2, temperature 72–79 °F, and low hardness. It is peaceful with similarly sized tankmates and poses no threat to plants. The principal challenge is simply obtaining the species; husbandry once established is straightforward.
Conservation
Clypeobarbus pleuropholis has not been assessed by the IUCN Red List and carries a status of Not Evaluated (NE). This reflects the broader pattern for many small-bodied West African cyprinids, which are described in the nineteenth- and early twentieth-century literature but have received little targeted conservation attention since.
Sierra Leone's freshwater fish fauna inhabits a landscape that has experienced extensive deforestation, agricultural expansion, and artisanal mining activity, particularly alluvial diamond and gold extraction in interior river systems. These pressures — sedimentation, chemical contamination, and habitat destruction — represent real threats to the clear-stream specialist fishes of the region, even where formal assessments have not been conducted. The restricted range of Clypeobarbus pleuropholis, largely confined to Sierra Leone's coastal river drainages, means that localised habitat degradation could have outsized effects on the species. A formal IUCN assessment drawing on recent field survey data would help clarify its status.