Taxonomy & naming
The banded jewelfish was described by the French zoologist Alphone Guichenot in 1861, in a volume of the Archives du Muséum d'Histoire Naturelle edited by Auguste Duméril, as Chromichthys elongatus. The type material came from Gabon, and a single specimen — the holotype, register MNHN A-1111 in the Paris museum — anchors the name; it was later catalogued by Blanc (1962). The fish has long since been moved into Hemichromis Peters, 1858, the genus erected for the African "jewel" cichlids, where Eschmeyer's Catalog of Fishes and FishBase both list it as the valid Hemichromis elongatus (Guichenot 1861). Older literature carries the synonym Hemichromis auritus.
Hemichromis was always recognized as containing two visually distinct lineages: the small, scarlet "red jewel" cichlids beloved of the hobby (guttatus, bimaculatus, lifalili and kin), and a group of larger, banded, piscivorous fishes — the "five-spotted" jewelfish — to which elongatus and the type species Hemichromis fasciatus belong. Peter Loiselle's 1979 monograph (A revision of the genus Hemichromis Peters 1858) was the first modern attempt to sort the genus, and it framed elongatus as one of the big banded predators. A molecular phylogeny and revision by Lamboj and Koblmüller (2022) confirmed that the two groups are not close kin but separate evolutionary lineages. Because the type species of Hemichromis is the banded Hemichromis fasciatus, the banded jewelfish keep the historic genus name, while the red jewels were split off into a new genus, Rubricatochromis Lamboj & Koblmüller, 2022 ("red-coloured perch"). After that revision Hemichromis contains just four species — angolensis, camerounensis, elongatus, and fasciatus — and elongatus remains firmly in Hemichromis. It is told from the closely similar Hemichromis fasciatus by lacking the small black dots between the first three flank bars seen in adult fasciatus, and from Hemichromis camerounensis by carrying a single red opercular spot (or a mix of red and yellow spots) above the large black gill-cover blotch rather than the two flanking red spots of camerounensis. Authorities note that the populations attributed to elongatus across the Congo and southern-African basins may yet prove to be more than one species.
Morphology
Hemichromis elongatus is a comparatively large, deep-bodied jewel cichlid with a fusiform, laterally compressed build and a predator's broad mouth. FishBase gives a maximum standard length of about 7.5 in (roughly 7.5 in total, per Skelton 1993), a far heavier fish than the 3–4 in red jewels. The fin counts run to 13–16 dorsal spines and 11–13 soft dorsal rays, with three anal spines and 7–10 anal soft rays, and the upper jaw normally bears two rows of teeth.
The defining mark is the row of dark blotches that gives the fish its common names: four to five distinct black ovoid bars or spots run along the lateral mid-line, from the operculum back to the caudal peduncle — the "five stars" of the "five-star general." The ground colour is an olive to yellow base over brassy, gold-to-bronze flanks, frequently picked out by series of fine red dots that line up into horizontal rows along the mid-flank, and by a magenta or red spot on the gill cover above the large black opercular blotch. The fins are translucent with gold and bronze iridescence, often red-edged. Coloration is highly mood-dependent: large, dominant or spawning males darken dramatically, sometimes to an almost uniform black in which the bands are swallowed up. Sexual dimorphism is modest and behavioural as much as structural — males grow larger and heavier-headed, while ripe females are rounder-bellied; both sexes intensify and redden when in breeding condition, so reliable sexing usually waits for a pair to form and spawn.
Habitat
The banded jewelfish is a lowland freshwater fish of warm, often slow-moving West and Central African waters. FishBase describes its core range as the coastal rivers of Lower Guinea — from the Ntem in Cameroon south to the Kouilou basin in the Republic of the Congo, including the Woleu, Ogowé and Nyanga — plus the Dja, an affluent of the middle Congo. Populations from the broader Congo River basin and from the southern-African Okavango, upper Zambezi and Cuanza systems are also treated as conspecific (Skelton 1993; Marshall 2011), though these may represent one or more distinct species. Records from far West Africa (Guinea, Sierra Leone, Liberia, Togo, Benin, Nigeria) appear in the literature but are flagged as needing confirmation, partly because of past confusion with Hemichromis fasciatus.
Within these drainages the species occupies shallow lakes, streams, river margins, and floodplain habitats — the kind of vegetated, structure-rich shallows where a sit-and-wait piscivore can ambush prey. It is a benthopelagic fish of the upper few metres rather than a deep-water specialist; published habitat notes place adults in shallow lakes and streams. In-situ chemistry is not extensively tabulated for elongatus specifically, but the genus and basin point to warm, soft-to-moderately-hard, near-neutral water: FishBase lists a pH up to about 7.0, hardness to roughly 15 dH, and a tropical temperature band around 73–77 °F, with the species tolerating the warmer floodplain conditions typical of equatorial Africa. Its hardiness and broad tolerances have helped it establish as an aquarium-release exotic on Oahu, Hawaii (recorded since 1990) and more recently on Bangka Island, Indonesia.
Feeding
Hemichromis elongatus is a committed carnivore and one of the more formidable predators among the African cichlids of its size class — FishBase places it at a trophic level near 3.7. Field accounts describe it as highly predaceous, feeding on fish, shrimp, and aquatic insects, and note that in some regions it has been used deliberately as a biological control on overcrowding tilapia by cropping their young. Its deep, muscular body, large mouth, and ambush-and-lunge habit suit a fish that takes substantial live prey rather than grazing or sifting. In the river-margin and floodplain shallows it inhabits, it functions as a top-tier small-bodied predator, exerting real pressure on juvenile fishes and crustaceans and helping to structure the prey community. This same appetite is exactly what makes the species both useful in tilapia ponds and notorious in community aquaria.
Mating
Like the other jewelfishes, Hemichromis elongatus is a monogamous, pair-bonding cichlid, and its reproductive biology is inseparable from its aggression. Outside of breeding the fish is already territorial and intolerant; once a male and female pair and claim a spawning site, both become ferociously defensive, driving every other animal — conspecific or not — out of a wide perimeter around the nest. Pair formation is the delicate stage: because the sexes look so similar and the fish are so quick to attack, an unready or mismatched pairing can end with one fish killing the other. Aquarists who breed jewelfishes typically grow a group of juveniles together and let a pair sort itself out naturally, then watch for the cooperative, parallel "following" and site-cleaning behaviour that signals a genuine bond rather than simple hostility. A committed pair will work a chosen flat surface together, both intensifying in colour, the female swelling with eggs, in the prelude to a substrate spawning.
Breeding
The banded jewelfish is an oviparous, biparental substrate (open) brooder — a classic cichlid spawning that the species performs reliably once a stable pair exists. The pair cleans a flat hard surface — a rock, a broad leaf, a piece of bogwood — and the female deposits her adhesive eggs on it in neat rows while the male follows to fertilize. Reported clutches are large: hobby accounts of elongatus cite on the order of several hundred eggs (around 600 in one captive description), consistent with a fecund congener group in which even small red jewels lay 400–500 eggs per spawn. The eggs typically hatch in about two days, after which the parents move the wriggling larvae to pre-dug pits in the substrate, shuttling them between pits and guarding them closely; the fry become free-swimming within several more days. Both parents guard the nest and the resulting school of fry, and brood care may continue for up to about four weeks before the parents disengage. Newly free-swimming fry are large enough to take baby brine shrimp and finely powdered foods at once. The pair's combined vigilance — and the wide no-go zone they enforce around the brood — is the same intense parental defence seen across Hemichromis, scaled up to a much larger and more dangerous fish.
In the aquarium
Hemichromis elongatus reaches the trade under the evocative names "five-star general" and "banded jewelfish," and it has a deserved reputation as one of the most aggressive cichlids a hobbyist can keep. It is not a beginner's fish and emphatically not a community fish. At up to ~7–7.5 in and with a relentless predatory temperament, it needs space: a single fish or a bonded pair should have at least a 4-foot tank (a 200-litre / ~45–55 US-gallon footprint is a realistic minimum, and more is better), because much of the aggression is about controlling territory and sightlines.
Water chemistry is the easy part — this is a hardy, adaptable fish. Aim for warm tropical temperatures (roughly 75–82 °F), a pH around neutral (about 6.5–7.5), and soft-to-moderately-hard water; it tolerates a wider envelope than most of its tankmates ever will. Provide a sand or fine-gravel substrate, plenty of structure (bogwood, rock caves, broad flat stones that double as spawning sites), and expect digging — plants should be tough-rooted or potted, as the fish will rearrange the layout, particularly around breeding. Good filtration and regular water changes keep this big-appetite carnivore healthy.
Feeding is straightforward: a varied carnivore diet of frozen or live bloodworms, blackworms, krill, and shrimp, supplemented with quality sinking cichlid pellets, suits it well; some keepers offer the occasional larger live food, but a steady prepared-and-frozen diet is cleaner and avoids disease and aggression spikes. Feeding small amounts more than once a day is preferable to one large meal.
Tankmate selection is where most keepers come unstuck. The five-star general will hunt anything it can swallow and will fight anything it cannot, and a spawning pair turns murderous toward everything in the tank. If kept in a community at all, it belongs only with robust, similarly aggressive cichlids of comparable size and the muscle to stand their ground — and even then in a large tank with broken sightlines and contingency plans. Many experienced keepers run it as a single specimen or as a dedicated breeding pair in a species tank. The most common mistakes are underestimating both its adult size and its temper, and pairing it carelessly: introduce potential mates as a group of juveniles, keep a divider on hand, and be ready to separate fish if a pairing goes wrong.
Conservation
The IUCN Red List assesses Hemichromis elongatus as Least Concern, in an assessment published in 2020 (assessed 13 January 2020 by Dankwa, Marshall, Moelants and Tweddle), with the population trend listed as Unknown. The rating reflects an enormous and fragmented range spanning the coastal rivers of Lower Guinea, the Congo basin, and the southern-African Okavango and upper-Zambezi systems, across which the species is widespread and locally common, together with the absence of any documented species-wide threat. It carries no CITES or CMS listing and is considered harmless to humans. The fish is harvested for the ornamental aquarium trade and is hardy enough to have established feral populations outside its native range (Hawaii; Bangka Island, Indonesia), where as an aggressive predator it is treated as a potential invasive of concern rather than a conservation worry at home. The main caveat is taxonomic rather than demographic: because the Congo and southern-African populations may represent one or more undescribed species, a future split could leave some narrower-range lineages in need of their own, less reassuring assessments.