Cichlid Atlas — the world's cichlid waters, in depth

Taxonomy & naming

Cyprichromis microlepidotus was described by the Belgian ichthyologist Max Poll in 1956 from material collected along the northern shores of Lake Tanganyika. The genus name fuses the Latin cyprinus (carp) with the Greek chromis, an old catch-all for perch-like fishes, while the species epithet microlepidotus means "small-scaled" — a direct nod to the diagnostic feature that separates it from its relatives. Where most Tanganyikan cichlids carry coarse, countable scales, this fish has very fine ones, with roughly 59 to 70 scales in the longitudinal line; that high count is exactly what distinguishes it from the more recently described Cyprichromis coloratus, which has only 41 to 44.

The species belongs to the tribe Cyprichromini, a tight little radiation of open-water cichlids unique to Lake Tanganyika that also includes the familiar Cyprichromis leptosoma and the genus Paracyprichromis. Molecular work on the group (Takahashi and colleagues; Duftner et al. 2005) reads the Cyprichromini as a single lineage that progressively abandoned the substrate for a pelagic life, and it validated Paracyprichromis as a genus distinct from Cyprichromis. In the aquarium trade the fish goes by "smallscale Cyprichromis" or simply "micros," usually sold under a collection-locality tag — Kiriza, Kigoma, Kilila, Kitumba, Bulu Point and others — because the wild populations differ strikingly in male color.

Appearance

This is a small, elongate, almost cigar-shaped fish. Poll's material and FishBase put the maximum at about 4.3 in (11 cm) total length, and aquarium specimens commonly top out a little under that; experienced keepers describe two-year-old males around 3.5 in (9 cm). The body is fusiform and built for cruising open water rather than wedging into rock, with the fine scaling that gives the species its name and a notably small mouth suited to picking tiny prey from the water column.

Color is where C. microlepidotus earns its following — and where it gets complicated. Males are far more colorful than the plain, silvery females, and the species is markedly polychromatic: within a single population, different males can carry different color schemes, and an individual male shifts his colors with mood, flipping between a patterned yellow-and-blue or yellow-and-black livery and a solid, smoldering black when challenged or courting. Geographic variants compound this, with both yellow-tailed and blue-tailed forms recognized across localities. Keepers consistently note that the most saturated coloration arrives slowly: a young male may stay drab for well over a year, and sometimes two, before he comes into full color, which is one reason the fish has a reputation for testing patience. It closely resembles C. leptosoma, and the two are not reliably separated on color alone — scale count and locality data do the real work.

Range & habitat

Cyprichromis microlepidotus is a Lake Tanganyika endemic, restricted to the northern — and into the north-central — reaches of this ancient rift lake. Documented records run along the northwestern (Democratic Republic of the Congo) and northeastern (Burundi and Tanzania) shores, with more sporadic collections trailing down the eastern coastline. It is a fish of the intermediate zone: open water lying just off rocky and sloping shores, over scattered boulders and patches of sand, rather than the wave-washed rock face itself.

Unlike the shoreline cichlids that live their whole lives within a body length of cover, micros hang in the water column above the rubble, often well off the bottom and sometimes over genuinely deep water. They are gregarious, forming loose shoals that in the wild mingle with other Cyprichromis and the similar Paracyprichromis. In-situ conditions are the hard, alkaline, thermally stable water typical of Tanganyika: FishBase records a pH around 7.5–8.5, hardness near 10–18 dH, and temperatures of roughly 73–77°F (23–25°C). That stability is not incidental to the fish — it is a deep, strongly stratified lake whose surface chemistry barely moves, and a species adapted to it has little tolerance for the swings a tank can throw at it.

Ecology & diet

Ecologically, C. microlepidotus is a zooplanktivore — a drifting-plankton feeder that grazes the open water for small invertebrates. Stomach contents have included copepods, and the fish is reported to take small crustaceans and other planktonic prey, with FishBase placing it at a trophic level of about 3.5. The small mouth and slim body are the tools of that trade: this is an animal built to pick scattered, tiny food items continuously through the day rather than to ambush or scrape.

That feeding mode is the whole point of the Cyprichromini story. Lake Tanganyika's littoral is one of the most intensely partitioned habitats in freshwater, every crevice and sand patch claimed by a specialist; the cyprichromines sidestepped that competition by moving up into the water column and exploiting the lake's plankton instead. In doing so, dense shoals of Cyprichromis become a food source themselves, an abundant mid-water prey base for the lake's open-water predators. The species sits, in other words, as a link between the planktonic base of the food web and the larger piscivores above it — a small fish doing outsized ecological work.

Behavior & breeding

C. microlepidotus is a maternal mouthbrooder and a lek breeder — a combination that makes its courtship unusually theatrical for a fish that owns no real estate. Males establish three-dimensional territories in open water, defended volumes rather than patches of substrate. Females and other species are allowed to drift through; rival males are driven off. When a ripe female enters, the resident male displays, and if she follows him to the center of his column, spawning happens in mid-water, the female taking up each egg almost as it is laid. The male's pelvic fins carry pale, egg-shaped marks; as the female snaps at these "dummy eggs" near his vent, he releases milt and the clutch is fertilized inside her mouth.

Broods are small — most accounts give roughly 5 to 25 eggs — and the female carries them for around three to four weeks, not feeding, her swollen throat and gentle chewing motion giving her away. In the wild she eventually releases the fry into rocky crevices, and there is a striking twist: released fry sometimes mix into the broods of other cichlids, such as the predatory Lepidiolamprologus profundicola, and are guarded by that foster mother as if her own. In captivity the species is described as placid and a poor competitor against boisterous tankmates, but it is not meek among its own kind: dominant males will dive-bomb rivals and displaying tankmates, and keepers rank its aggression as mild — roughly a step above the gentle Paracyprichromis and far below mbuna. Breeding it is reliably described as harder than breeding the common leptosoma and jumbo cyps, with stressed females prone to spitting or eating a clutch.

In the aquarium

Micros are a connoisseur's fish: sought after, periodically scarce, and not a beginner's project. Because they live in open water and swim constantly, footprint and swimming room matter more than rockwork — a tank around 48 in (120 cm) long is a sensible minimum, and keepers favor deeper tanks where the upper water column can simply be left open. They are committed shoalers; the standard advice is to start with no fewer than 8 to 10 and ideally a dozen or more, with several females per male, so that subordinate males eventually color up and the colony settles into a stable pecking order. A tight-fitting lid is essential — excited fish jump.

Water must be hard, alkaline and, above all, clean and stable: a pH in the high 7s to mid 8s and warmth around 75–81°F (24–27°C), with the steady, well-filtered conditions the species enjoys in the lake. Keepers repeatedly stress that micros are more sensitive to water quality than the hardier leptosoma, and many run them in bare-bottom tanks with strong filtration and flow to keep things pristine. Feed small foods often rather than in one large meal — frozen and live daphnia, brine shrimp and the like, sized for a small mouth, alongside good dry foods. For tankmates, pick peaceful Tanganyikans that occupy other zones: shell-dwellers such as Neolamprologus ocellatus, the milder Julidochromis and Altolamprologus, or Paracyprichromis are repeatedly cited as good companions, while mbuna and other rowdy fish are not. The two mistakes keepers own up to most are expecting quick color — males can take one to two years to come into their own — and underestimating how unforgiving the species is about water quality. Different geographic variants should never be mixed, as they interbreed freely and produce worthless hybrids.

Conservation

The IUCN Red List assessed Cyprichromis microlepidotus as Least Concern on 13 March 2025 (version 2025-2), an upgrade from its earlier Data Deficient listing. The species is endemic to Lake Tanganyika but is described as widespread within its northern-to-central range, and no major lake-wide threats specific to it have been identified, which is why it carries the lowest concern category; its population trend, however, is recorded as Unknown. The assessment does flag localized pressures — the aquarium trade (the fish is collected commercially for export), pollution near large lakeside cities, and sedimentation driven by deforestation in the northern and central basin — that it judges may have local rather than range-wide impact.

That species-level reassurance sits inside a lake under real strain. Lake Tanganyika has been warming and stratifying more strongly, and O'Reilly et al. (2003, Nature, doi:10.1038/nature01833) tied that warming and reduced vertical mixing to roughly a 20% decline in primary productivity, with an estimated knock-on loss on the order of 30% in fish yields — a direct concern for a zooplankton-feeding shoaler whose food supply is the lake's own production. Cohen et al. (2016, PNAS, doi:10.1073/pnas.1603237113) documented a roughly 38% loss of oxygenated benthic habitat as the oxygenated layer thins, and sedimentation from shoreline deforestation continues to degrade the rocky littoral (Cohen et al. 1993) that micros release their fry into. Meanwhile the lake's open-water clupeid fishery (Stolothrissa and Limnothrissa) and its Lates predators feed four nations, with governance shared through the Lake Tanganyika Authority. C. microlepidotus is not itself fished commercially and is genuinely Least Concern; the honest framing is that the species is, for now, secure, but the open-water, plankton-dependent guild it belongs to is exactly the one most exposed to a warming, less-productive lake.

Cyprichromis microlepidotus

About this species