Taxonomy & naming
Campylomormyrus curvirostris was described by the Belgian-British ichthyologist George Albert Boulenger in 1898. It belongs to the family Mormyridae — the elephantfishes or mormyrids — within the order Osteoglossiformes, the bonytongues, one of the most ancient lineages of living ray-finned fish and a group that split into separate radiations on four continents deep in geological time. The family's diagnostic feature, and the one that gives the whole order its name, is a bony, toothed structure on the floor of the mouth (the "tongue") that bites against a matching toothed plate on the roof — a jaw-within-a-jaw unrelated to the true tongue of other vertebrates.
The genus name Campylomormyrus combines the Greek kampylos, "curved, bent", with mormyros, an old Greek name applied to this group of electric fishes, referencing the down-curved, trunk-like snout shared by most species in the genus. The specific epithet curvirostris is Latin for "curved-snout", from curvus (curved) and rostrum (snout, beak) — a doubly descriptive name for a fish whose face is its most obvious feature. Campylomormyrus is a modest Congo-basin genus of a dozen-plus species that are notoriously difficult to tell apart by eye; in mormyrids generally, the electric organ discharge (EOD) is often the most reliable way to confirm identity, and museum and field work on the genus continues to refine which populations are distinct species.
Morphology
Campylomormyrus curvirostris has the classic elephantnose build: an elongated, laterally compressed body, small cycloid scales, a forked tail, and dorsal and anal fins set well back toward the tail. Its defining feature is the snout, drawn out and distinctly curved downward into a slender, trunk-like probe with the small, toothless mouth at its tip — an adaptation for reaching into crevices and probing soft substrate rather than a true elephant's-trunk equivalent of the elephantnose Gnathonemus petersii's fleshy schnauzenorgan. FishBase records a maximum size of about 15.9 in total length, making it a mid-to-large mormyrid rather than a nano species.
Like other mormyrids, it carries an electric organ in the caudal peduncle, just ahead of the tail, built from modified muscle cells (electrocytes) that fire a weak, species-specific pulse used for electrolocation and communication. To process the resulting electric field it has an unusually large, elaborately folded cerebellum relative to its body size — mormyrids are famous among fish for having one of the highest brain-to-body mass ratios of any vertebrate group, earning them a reputation in the literature as "thinking fish". Coloration is a fairly plain grey-brown to olive over the body, without bold markings, and — as in many Campylomormyrus — reliable field identification between similar species in the genus often comes down to snout shape and EOD signature rather than colour pattern alone.
Habitat
This species is native to the lower and middle Congo River basin, recorded from Cameroon, the Democratic Republic of the Congo, and Angola. It is a freshwater, demersal fish — a bottom-dweller of the river channel rather than the open water column — living in the same dark, sediment-laden, tannin-stained water that characterises so much of the Congo system.
Water in this part of the basin is warm and tropical, typically in the region of 75–82 °F, and generally soft and slightly acidic to neutral, though exact pH figures for this species' native reaches are not recorded in the available literature. Visibility in Congo River water is often poor, and it is exactly this dim, murky environment that the electric sense of mormyrids like C. curvirostris evolved to read — locating food, obstacles, and other fish by the shape their bodies distort in its self-generated electric field rather than by sight.
Feeding
In common with other elephantnose-type mormyrids, C. curvirostris feeds by probing the substrate with its curved snout, picking small invertebrates — insect larvae, worms and other benthic prey — out of sand, mud and leaf litter, largely under cover of darkness or dim light. The electric sense doubles as a foraging tool here, letting the fish detect buried or hidden prey that it cannot see.
In the aquarium it should be fed a varied diet of sinking, meaty foods: frozen or live bloodworm, mysis shrimp and tubifex worms are all reported as accepted foods for mormyrids of this kind. It is not a fish that competes well for food in a boisterous community — offering food after the lights go down, when it is naturally most active, gives it a better chance to feed undisturbed.
Mating
Very little is documented about courtship in Campylomormyrus curvirostris specifically, and the same is true across most of the Mormyridae. What is understood, largely from work on related mormyrids, is that the electric organ discharge plays a role beyond navigation: its precise waveform is species-specific and is thought to function in courtship and mate recognition, letting individuals identify a suitable partner of the right species in water too dark or turbid for visual cues to work.
Beyond that role for the EOD, details of pairing, courtship displays, and any territorial or seasonal behaviour around spawning in this species remain essentially unrecorded. This is a broader gap in mormyrid biology rather than a peculiarity of this one species — the family is electrically sophisticated but reproductively obscure.
Breeding
Campylomormyrus curvirostris is, as far as the literature shows, a seasonal spawner in the wild, with reproduction thought to be triggered by the Congo basin's flood cycle — a pattern reported broadly across mormyrids, whose spawning tends to track rising water and the associated flush of food and flooded vegetation. Beyond that generality, the details of nest site, egg-laying, and fry development for this species are poorly known.
Captive breeding of C. curvirostris has essentially not been achieved and is not something the hobby should expect to reproduce. This mirrors the family as a whole: mormyrids are among the least commonly bred aquarium fish groups, and aquarium stock is overwhelmingly wild-collected rather than captive-raised. Any account describing a captive spawning of this species should be treated with caution rather than taken as an established, repeatable protocol.
In the aquarium
This is not a beginner's fish. Mormyrids as a group are notoriously sensitive to poor or fluctuating water quality, and C. curvirostris should be kept in a mature, well-filtered tank with pristine water rather than introduced to a newly cycled setup. A soft, fine sand or smooth gravel substrate lets it forage naturally by sifting and probing with its curved snout without abrading the sensitive skin around its mouth. Dim lighting, driftwood, pipes and caves for daytime cover suit its naturally crepuscular-to-nocturnal habits, and strong, steady filtration matters more for this fish than for most community species.
Two further care points follow directly from mormyrid biology. It is markedly sensitive to copper-based and some other medications, so any treatment needs to be dosed conservatively and copper-free formulations avoided where possible. And it is generally intolerant of its own kind — aquarium reports for mormyrids of this type describe conspecific aggression rather than peaceful shoaling, so this is usually best kept singly or in a large enough system to let individuals establish separate territories, rather than assumed to be a group fish by default. At a reported maximum of roughly 15.9 in TL it also needs a genuinely large, long-term tank, not the small setup its "elephantnose" relatives are sometimes wrongly assumed to tolerate.
Conservation
The IUCN Red List assesses Campylomormyrus curvirostris as Least Concern, an assessment dating to 2009. The species is not considered globally threatened, and its Congo basin population is regarded as stable.
As with many Congo basin fish, C. curvirostris is restricted to a specific stretch of one of the world's great river systems rather than being truly widespread, so long-term pressures on the lower and middle Congo — including habitat disturbance, sedimentation, and any future hydrological development on the river — remain the relevant watch points even for a species currently rated of least concern.