Taxonomy & naming
Wallaceochromis rubrolabiatus was described in 2004 by the Austrian ichthyologist Anton Lamboj as Pelvicachromis rubrolabiatus, based on specimens collected from the Badi River, Kolente basin, Guinea in November 2002. The holotype (NMW 94835, male, 2.5 in SL) is deposited at the Naturhistorisches Museum Wien. At the time of description, the species was assigned to Pelvicachromis alongside the better-known kribensis and its allies, but morphological and molecular evidence had long suggested that the west-most members of that genus formed a distinct lineage.
In 2016, Lamboj, Trummer, and Metscher formally described the new genus Wallaceochromis for the 'Pelvicachromis humilis group' — the chromidotilapiine cichlids of Guinea, Sierra Leone, and western Liberia. The new genus is distinguished from Pelvicachromis sensu stricto by a different number and arrangement of tubular infraorbital ossicles, a straighter and more sloping dorsal head profile with a lower supraoccipital crest, and a higher abdominal vertebral count (14–15 versus 13–14). The genus accommodates three species: Wallaceochromis humilis (the yellow krib), Wallaceochromis rubrolabiatus, and Wallaceochromis signatus. Molecular dating published alongside the genus description indicates that Wallaceochromis species diverged from their sister lineage roughly 3.9–14.8 million years ago — considerably more recently than the Pelvicachromis sensu stricto radiation, which is estimated at 12.8–29.5 mya.
The correct authority for the current combination is (Lamboj, 2004): parentheses are required because the species was described in a different genus. The Catalog of Fishes (Eschmeyer/CAS) is followed here as the nomenclatural authority. In the aquarium hobby and older literature the species appears under the original combination Pelvicachromis rubrolabiatus, which FishBase retains as the searched name.
Morphology
Wallaceochromis rubrolabiatus is a small cichlid: FishBase records a maximum of 2.5 in standard length for males, and aquarium literature suggests similar figures, making it one of the most diminutive members of the krib alliance. The body is laterally compressed and moderately deep, typical of the chromidotilapiine cichlids, with a rounded head and a relatively low dorsal profile compared to Pelvicachromis pulcher.
The most immediately recognisable feature is the vivid red or red-orange colouration of the lips in males — the character that gave the species its name. Body ground colour is a reddish-brown in males, more yellowish-brown in females. Both sexes display seven dark vertical bars on the flanks, a genus-level trait that appears in various behavioural contexts; unlike some related cichlids, this barring rarely disappears entirely. A notable field mark distinguishing male Wallaceochromis rubrolabiatus from other Wallaceochromis males is the absence of any prominent coloration or patterning on the unpaired fins — the dorsal, caudal, and anal fins remain relatively plain, in contrast to the spotted or edged fin patterns of some congeners.
Female body shape follows the rounded profile typical of the krib group, and ripe females are rounder in the belly. Detailed published meristic counts for this species specifically are sparse; the genus-level characters from Lamboj et al. (2016) provide the most reliable framework.
Habitat
The type locality is the Badi River within the Kolente (Great Scarcies) basin — a river system that drains the flanks of the Fouta Djallon highlands of Guinea before flowing west and north into Sierra Leone and eventually the Atlantic. The broader genus occupies a restricted area in Guinea, Sierra Leone, and the western fringe of Liberia, all within the Upper Guinean forest zone.
This region is characterised by small, shaded forest streams running over sand, leaf litter, and exposed root systems. The water in these highland-draining tributaries is typically soft and moderately to slightly acidic, reflecting the granitic and lateritic geology of the Fouta Djallon and the heavy leaching of organic matter from the forest canopy. Aquarium literature for the closely related Wallaceochromis humilis, which occupies overlapping terrain, cites pH values of 5.0–7.0 and hardness of 5–12°dH as representative of the wild habitat; Wallaceochromis rubrolabiatus likely encounters similar conditions in the Badi River. Aquarium sources give a maintained range of roughly 73–79 °F, GH 5–8, pH 6.5–7.0 for this species, which is consistent with the Upper Guinean forest stream template.
Field observations of Wallaceochromis rubrolabiatus in the wild are essentially absent in the published literature beyond the original collection event; the Badi River is a remote system and the species has not attracted sustained ichthyological fieldwork.
Feeding
No published dietary study exists for Wallaceochromis rubrolabiatus in the wild. FishBase estimates a trophic level of 3.3 (±0.4), which places it at a similar feeding position to other small omnivorous cichlids — suggesting a diet that includes invertebrates, small organisms, and some plant or detrital material, consistent with benthic foraging in forest stream environments.
The closely related Wallaceochromis humilis and the krib group generally feed opportunistically on insect larvae, small crustaceans, worms, algae, and organic detritus picked from the substrate and leaf litter. In the aquarium, Wallaceochromis rubrolabiatus accepts a mixed diet of live and frozen invertebrates (Artemia, daphnia, bloodworm), dry prepared foods, and vegetable matter — the omnivore feeding regime common to its relatives. A diet varied across these categories is considered important for colour and reproductive condition.
Mating
Wallaceochromis rubrolabiatus is a pair-bonding species, following the monogamous, secretive mating system characteristic of the krib alliance. In the aquarium the pair forms and maintains a territory centred on a chosen cave or concealed crevice; courtship intensifies as a spawning site is selected and cleaned.
The species is reportedly somewhat less aggressively territorial than Pelvicachromis pulcher during the breeding period — a useful trait when keeping it in a mixed community — though the pair will defend their immediate spawning territory with considerable determination. No published field observations of mating behaviour exist for wild Wallaceochromis rubrolabiatus; the account here reflects aquarium observations and the broader biology of the Wallaceochromis and Pelvicachromis lineages.
Breeding
Wallaceochromis rubrolabiatus is a cave spawner. In the aquarium, the pair selects a concealed site — a hollow, clay pot, crevice, or buried cave — and the female deposits eggs on the wall or ceiling inside. Lamboj (2004) notes cave-breeding in the aquarium; no field data on spawning exists.
In the krib-alliance pattern typical of this genus, the female takes primary responsibility for tending the clutch, fanning and cleaning the eggs, while the male guards the perimeter of the territory. After hatching, the fry progress through a wriggler stage and then become free-swimming; at this point both parents shepherd and guard them, with the fry often forming a tight, closely-herded school. Aquarium hobbyists report that newly free-swimming fry can be started on Artemia nauplii and later transitioned to finely crushed dry food. The brooding female may excavate shallow pits in the sand substrate during the breeding period, into which the wrigglers may be moved. Details specific to clutch size or incubation time for Wallaceochromis rubrolabiatus are not available in the published literature.
In the aquarium
Wallaceochromis rubrolabiatus is encountered occasionally in specialist cichlid circles but is rarely seen in the general trade — its narrow range, retiring habits, and limited collection from a single river basin in Guinea mean captive stocks are thinly distributed. When available it commands interest among enthusiasts of West African dwarf cichlids and the krib group.
Aquarium requirements follow the Upper Guinean forest-stream template: soft, slightly acidic water (pH 6.5–7.0, GH 5–8, temperature 73–79 °F), fine sand substrate, subdued lighting, and generous provision of caves, roots, and driftwood. Replicating the low-conductivity, tannin-stained character of its native streams — with leaf litter and peat filtration — is encouraged by those who have bred the species. Any plants used should be well-anchored, as the pair excavates during spawning.
A single pair or a species-only tank works well given the size (39.5 in tank minimum is recommended in aquarium literature for a pair). The species is reported as fairly peaceful outside the breeding period; during spawning the pair becomes vigorously territorial. Tankmates, if any, should be non-cichlid and robust. Water quality is important: as a soft-water forest species it is not tolerant of high nitrates or mineral accumulation. Very few captive-breeding accounts have been published in English-language hobbyist literature.
Conservation
Wallaceochromis rubrolabiatus has not been assessed by the IUCN Red List — FishBase records its status as Not Evaluated. This is unsurprising for a species known only from a single river basin (the Badi River, Kolente system, Guinea), described as recently as 2004 and never the subject of a dedicated population or range survey.
The Upper Guinean forest zone is one of the world's recognised biodiversity hotspots, and the small forest streams that characterise Wallaceochromis rubrolabiatus habitat face pressure from deforestation, agriculture, artisanal mining, and changing rainfall patterns linked to upland degradation. Guinea's Fouta Djallon highlands — the 'water tower of West Africa' — are subject to ongoing land-use change that affects stream hydrology and water quality. For a species with an apparently very restricted range, confined to a single drainage, even localised habitat change could have disproportionate effects on the population. A formal IUCN assessment would require field surveys to establish the actual range limits, population density, and habitat condition.