Taxonomy & naming
Lufubuchromis relictus was formally described in 2020 by Frederic D. B. Schedel, Viviane M. S. Kupriyanov, Cyprian Katongo and Ulrich K. Schliewen, in a paper in Zootaxa (vol. 4718, no. 2) that erected two new monotypic cichlid genera from northern Zambia at once — Lufubuchromis and Palaeoplex. Eschmeyer's Catalog of Fishes lists Lufubuchromis relictus Schedel, Kupriyanov, Katongo & Schliewen 2020 as the valid name, and it stands as the only species in its genus. The holotype (ZSM 47494, a 3 in SL male) is held at the Bavarian State Collection of Zoology in Munich.
The fish was no stranger to science before it had a name. It moved through the literature for over a decade under a string of provisional labels — "Haplochromine sp. nov." (Koblmüller et al. 2008), "Pseudocrenilabrus sp. 'Lufubu A'" (Koblmüller et al. 2012; Egger et al. 2014), the "New Lufubu Cichlid" (Schedel et al. 2019) and "Orthochromis sp. 'New Lufubu'" (Meier et al. 2019). That tangle of placeholders reflects how hard it was to pin down: molecular work kept recovering it in a deep, basal position that did not sit comfortably inside any existing genus, which is ultimately why a new one was created for it.
The genus name combines the Lufubu River — the species' only home — with the familiar cichlid suffix -chromis. The species epithet relictus is Latin for "left behind" or "relict," chosen by the authors to capture the fish's restricted distribution in the isolated upper region of an ancient plateau. The name is, in effect, a one-word summary of the animal's whole story.
Morphology
This is a small cichlid. The describing authors record a maximum standard length of 3.5 in (about 3.5 in) for a wild-caught male, with the largest female at 3 in SL; males run noticeably larger than females. By the looser total-length measure used in the hobby this is a fish of roughly 4 in or under — squarely in the small-to-medium haplochromine range.
It is comparatively deep-bodied for a stream haplochromine, with body depth running 29.9-34.7% of standard length and the deepest point falling just ahead of the pelvic-fin origin, tapering gently back toward the tail. The head makes up about a third of the standard length, and the caudal fin is subtruncate to slightly emarginate. Diagnostically the genus is set apart from its relatives by a suite of technical characters — among them ctenoid (rather than cycloid) flank scales, the absence of true ocelli (egg-spots) on the anal fin that define some other haplochromine groups, and a higher total gill-raker count than Greenwood's Astatotilapia. Because the genus is monotypic, the species diagnosis is simply the genus diagnosis.
Colour in life is sexually dimorphic and striking in males: breeding males show deep crimson-red areas across the anterior ventral flank, chest, belly and lower head, while the rest of the flank and the caudal peduncle take on a bluish cast. Females are far plainer, in beige-to-grey tones. The red-and-blue male pattern is the species' most memorable field mark.
Habitat
Lufubuchromis relictus is known only from the upper reaches of the Lufubu River and its tributaries — small streams and creeks draining the northeastern Zambian High Plateaux. The Lufubu ultimately feeds the Lake Tanganyika basin (part of the wider Congo drainage), but this fish lives well above the lake, in the river's headwaters, and the type material was collected some 23 mi southwest of Mpulungu at the lake's southern tip.
The key to its entire existence is isolation. The ichthyofauna of the lower Lufubu is clearly different from that of the upper river, a split attributed to a series of cascades and waterfalls that physically seal the headwaters off from the fish communities downstream and from the lake (Koblmüller et al. 2012; Schedel et al. 2018). That barrier is what has let an ancient lineage persist in place while the lake basin below filled with the more familiar Tanganyikan radiations.
The water itself is a clear, rocky stream. At the type locality the Mululwe River is about 49 ft wide with an estimated average depth of around 19.5 in, with a rocky bed broken by patches of sand and gravel and only sparse submerged vegetation (including water-lilies, Nymphaea). This is a shallow, flowing, upland-stream environment rather than a lake habitat — a distinction that matters for understanding the fish and for anyone who might try to keep it. Detailed in-situ water chemistry for the type localities is not reported in the accessible description.
The whole known world range of this species is a small cluster of headwater sites on the upper Lufubu system in Zambia's Northern Province — among them the Mululwe River near Mululwe village (the type locality) and Luwle Creek, on tributaries running off the plateau. It is a narrow-range endemic by any standard.
What makes it more than just another local fish is its evolutionary position. Molecular phylogenies have repeatedly recovered Lufubuchromis (together with Orthochromis kalungwishiensis) in a deep, basal position as the ancient mitochondrial sister group of all other members of the Pseudocrenilabrus lineage (Koblmüller et al. 2008, 2012). In other words, this small stream fish sits near the very root of a major haplochromine group — a living branch off a very old fork. That is the literal meaning of "relict": a lineage that has been left behind, persisting in a refuge while its relatives diversified elsewhere. The waterfalls of the upper Lufubu are the refuge, and the plateau headwaters are the ark.
Feeding
The original description reports that Lufubuchromis relictus feeds on insect larvae and detritus. That is a generalist, opportunistic diet typical of a small stream-dwelling haplochromine — gleaning invertebrate prey and organic material from a rocky, sandy streambed rather than specializing on algae, plankton or other fish.
Beyond that single line, quantitative dietary work — gut-content analysis, seasonal variation, trophic-level estimates — has not been published for this species. What can be said is consistent with its habitat: a shallow, clear upland stream with patchy vegetation supplies aquatic insect larvae and detritus in abundance, and this fish appears to make its living on exactly those resources.
Mating
Lufubuchromis relictus is a maternal mouthbrooder, the near-universal reproductive mode among haplochromine cichlids, and the marked colour difference between the sexes — crimson-and-blue males versus plain females — points to the kind of male display-and-courtship system that mode usually implies. By the general haplochromine template, a male in breeding colour would court passing females, and the female would take the fertilized eggs into her mouth to brood them.
A genuinely unusual field observation breaks the standard script, though: in the wild, at Luwle Creek, mouth-brooding females were seen forming groups (a personal observation by F. Schedel reported in the description). Communal or aggregated brooding is not what one expects from a typical solitary-territorial haplochromine, and it hints that this relict lineage may have its own behavioural quirks. But the observation is preliminary, and the detailed mechanics of courtship, male territoriality and spawning have not been formally studied. This is one of several places where the honest answer is that the fish's behaviour remains largely undocumented.
Breeding
What breeding data exist come mostly from captivity. As a maternal mouthbrooder, the female incubates the eggs and developing young in her mouth. In aquarium observations reported through the description (Indermaur 2014), clutch size varied between roughly 20 and 30 eggs, with an incubation time of about 18 to 20 days — a modest brood and a fairly standard mouthbrooding duration for a haplochromine of this size.
Those are essentially the only quantitative breeding figures available. Fry size at release, growth rate, age at maturity and the details of parental behaviour after release have not been documented in the accessible literature. The wild observation of females brooding in groups (above) raises the intriguing possibility that the species' reproductive biology differs from the haplochromine norm in ways no one has yet worked out. Anyone breeding it would be charting genuinely new ground rather than following an established protocol.
In the aquarium
This is not an aquarium-trade fish in any normal sense. Lufubuchromis relictus is a recently described, narrow-range endemic known to science from a handful of expeditions; it does not circulate in the ornamental trade, and there is no body of hobbyist husbandry experience to draw on. Almost everything below is inference from its natural history rather than tested practice, and it should be read that way.
If it were ever maintained, the target would be its real habitat: a clear, well-oxygenated, flowing upland stream over a rocky bottom with patches of sand and gravel. That argues for strong water movement and high oxygen, a rocky aquascape with open sand, and pristine water quality — the conditions of a shallow, fast headwater creek rather than a still lake tank. Detailed wild water chemistry (pH, hardness, temperature) for the type localities is not published, so specific numbers cannot be given with confidence; matching the general profile of a clear African upland stream is the safest guide.
The captive breeding records that exist — broods of about 20-30 eggs incubated for 18-20 days — show the fish can spawn in an aquarium as a maternal mouthbrooder. But sourcing is the real obstacle: this species is essentially unavailable, and its conservation status is unassessed and its range tiny, which is reason for restraint rather than collection pressure. For nearly all aquarists it belongs in the category of fishes to read about and watch for in the scientific literature, not to expect on a shop list.
Conservation
Lufubuchromis relictus has not been assessed on the IUCN Red List — unsurprising for a species described only in 2020. That absence is not a clean bill of health; it simply means no formal evaluation of its extinction risk has yet been made.
On first principles, the profile is one that would normally draw conservation concern. The species is a single-river endemic with a tiny known range, restricted to the headwaters of one plateau system and confined there by the very waterfalls that protect it. Narrow-range, single-basin endemics are inherently vulnerable: a localized disturbance — changes in land use on the plateau, sedimentation, water abstraction, or the introduction of non-native fishes above the falls — could affect a large fraction of the global population at once, because the global population is so geographically concentrated. Its evolutionary distinctiveness as an ancient, basal lineage near the root of the Pseudocrenilabrus group would make any loss disproportionately significant.
The responsible framing, though, is to state what is and isn't known. No quantitative data on population size, trend, or specific active threats to this species have been published, and no Red List category has been assigned. It is best described as a recently discovered, range-restricted relict whose conservation status remains formally unevaluated and whose small, isolated range warrants attention rather than as a species with a documented level of risk.