Taxonomy & naming
Labeobarbus petitjeani was described by the French ichthyologist Jacques Daget in 1962 under the original combination Barbus petitjeani, from specimens collected in the upper Senegal River basin of Guinea. The species was subsequently transferred to the genus Labeobarbus, which accommodates many of the larger African barbs — the African analogues of the Asian mahseers — that were formerly lumped within the broadly defined genus Barbus. The Catalog of Fishes (Eschmeyer, CAS) records the valid combination as Labeobarbus petitjeani (Daget, 1962), with the parenthetical authority noting the move from the original genus.
GBIF records a chromosome count of 2N = 150 for the species, consistent with hexaploidy. This polyploid condition — six sets of chromosomes rather than the standard two — is characteristic of large African Labeobarbus and is thought to reflect an autopolyploid origin within the lineage. It sets these fishes apart genomically from most other cyprinids and has implications for understanding the evolutionary history of the African large-barb radiation.
Morphology
Labeobarbus petitjeani is a large-bodied barb reaching at least 6.5 in standard length per FishBase. Like other members of Labeobarbus, it is expected to have the robust, fusiform body, well-developed lips, and moderately large scales characteristic of the genus — features that suit a fish moving through flowing river environments. Detailed morphometric data specific to this species are sparse in the accessible literature.
As with other large African barbs, the sexes are likely dimorphic in overall body depth and girth when sexually mature, with gravid females being noticeably deeper-bodied. Coloration in life has not been described in detail in the available sources; related Labeobarbus species in West and Central Africa often display silvery to brassy flanks, sometimes with darker dorsal pigmentation.
Habitat
The species is native to the upper Senegal River basin in Guinea, with confirmed records from the Bafing River and the Ténéa River drainage. The Bafing is a major highland tributary of the Senegal River, originating in the Fouta Djallon massif — a region of elevated guinea savanna that generates cool, relatively fast-flowing headwaters before dropping into broader lowland reaches. The iDigBio specimen record also references the upper Niger in connection with the range.
Water chemistry data specific to Labeobarbus petitjeani are not published; FishBase notes temperatures around 73–75 °F and pH values of 6.3–6.4 for related Labeobarbus in reservoir systems, and habitat notes for the group indicate flowing rivers from highland to lowland. The Fouta Djallon highlands receive high rainfall and supply well-oxygenated, relatively clear water to their drainages, consistent with the ecological preferences of large riverine barbs in the region.
Feeding
No specific dietary studies for Labeobarbus petitjeani have been published in the accessible literature. Large African Labeobarbus are generally omnivorous to opportunistically herbivorous, taking algae, plant matter, benthic invertebrates, detritus, and — in the larger species — small fish and molluscs. The robust lips and subterminal mouth of the genus suit bottom-grazing and manipulation of food items from the substrate or rock surfaces.
In rivers of the upper Senegal basin, food availability varies seasonally with hydrology: high-water periods inundate floodplain areas and expand foraging opportunities, while dry-season low water concentrates fish into river channels. Large barbs in West African rivers are known to make use of seasonal pulses of fallen fruits and flooded terrestrial vegetation where available.
Mating
Like all barbs, Labeobarbus petitjeani is an egg-scattering, non-guarding spawner. No specific mating observations for this species have been recorded in the literature, but the reproductive biology of large Labeobarbus follows the pattern common to the genus: males pursue gravid females through the water column or over the substrate, and eggs and milt are broadcast together with no lasting pair bond and no preparation or defence of a spawning site.
Large river barbs in West Africa are typically seasonal spawners, with reproductive activity tied to the annual flood cycle. Rising water levels and associated changes in temperature, turbidity, and food availability trigger spawning migrations in many species. The Bafing River, fed by the Fouta Djallon rains, has a strongly seasonal hydrology that likely governs the timing of spawning in Labeobarbus petitjeani as it does in other large barbs of the region.
Breeding
Labeobarbus petitjeani is an egg-scatterer with no parental care. Eggs are broadcast over the substrate — gravel, sand, or among roots and vegetation — and abandoned immediately after fertilisation. Adults do not guard eggs or larvae, and in natural conditions the eggs and newly hatched fry are left to develop unassisted, subject to predation including by the spawning fish themselves.
No captive-breeding records for this species appear in the hobby literature. Large West African Labeobarbus are not established in the ornamental trade, and their size, seasonal breeding cues, and the scale of water bodies they inhabit make them impractical for standard aquarium reproduction. Information on incubation time, fecundity, and larval development specific to this species is not available in the sources consulted.
In the aquarium
Labeobarbus petitjeani is not a species found in the ornamental aquarium trade. At 6.5 in standard length it is already at the upper boundary of what most aquarists can house comfortably, and as a large riverine fish from flowing West African systems it would require very substantial aquaria with strong filtration and high dissolved oxygen — conditions challenging to maintain in a domestic setting.
The species is essentially unknown in the hobby, with no published accounts of its maintenance in captivity. For aquarists interested in large African barbs, the practical options are limited to species that have become available through specialist importers; Labeobarbus petitjeani is not among them. Information on temperament, compatibility, or aquarium diet is not available from hobbyist sources.
Conservation
Labeobarbus petitjeani was assessed by the IUCN in January 2020 and listed as Least Concern, reflecting a range that spans the upper Senegal River basin in Guinea without evidence of major population decline at that time. The IUCN range note identifies the upper Senegal basin as the species' core territory.
The Fouta Djallon highlands of Guinea, where the Bafing River originates, face ongoing pressures from agricultural expansion, deforestation, and increasing human water extraction — threats that affect water quality and flow regimes in the tributary systems. Large barbs are additionally sensitive to dam construction, which blocks seasonal migration routes and alters the flood dynamics that trigger spawning. While the current assessment is Least Concern, the restricted range within the upper Senegal system means that significant changes to that basin's hydrology could affect the species more quickly than the broad LC status might suggest.