Taxonomy & naming
Mormyrus felixi was described by the French ichthyologist Paul Pellegrin in 1939. It belongs to the family Mormyridae, within the order Osteoglossiformes — the bonytongues, one of the oldest surviving lineages of teleost fish, named for a toothed bone at the back of the tongue that bites against a matching pad on the roof of the mouth. GBIF treats Mormyrus felixi Pellegrin, 1939 as the current valid name.
Osteoglossiformes is a scattered, deep-time radiation found today on four continents — the arowanas and arapaima of South America, the mormyrids and featherback knifefishes of Africa, and the Asian arowana and its relatives in Southeast Asia and Australasia. Mormyridae is African only, and with well over 200 described species it is one of the largest families of freshwater fish on the continent. The genus Mormyrus is one of the largest within it, holding more than twenty species of elephant-snout fishes. The genus name comes from the ancient Greek mormyros, originally the name of an unrelated marine sea bream and later carried over by naturalists to this freshwater group; the species name felixi is a Latinized patronym honouring a person named Felix, though the individual commemorated is not identified in the sources reviewed here.
Morphology
Mormyrus felixi has the elongated, laterally compressed body typical of its genus: a long-based anal fin, a small dorsal fin set well back toward the tail, a deeply forked caudal fin, and a downturned snout used to probe soft substrate for food. FishBase records a maximum length of about 5.6 in, given on the species page as standard length — a modest size that makes it one of the smaller members of a genus that elsewhere produces river giants such as Mormyrus caballus, which reaches around 19.7 in.
As in every mormyrid, an electric organ near the base of the tail produces a weak, species-specific, pulse-type electric-organ discharge. Electroreceptors covering the skin read the distortions this field creates around nearby objects, a sense used to navigate and to find prey in dark, low-visibility water, and thought to help fish recognise members of their own species. This electrosensory system is evolutionarily unrelated to the wave-type electric fishes of South America; the two groups arrived at superficially similar solutions independently. Mormyrids as a family are noted for some of the highest brain-to-body mass ratios of any fish, with an enlarged cerebellum devoted to processing electrosensory input; this has not been measured specifically in M. felixi, but it is a defining trait of the family it belongs to.
Habitat
Mormyrus felixi is known from the freshwaters of Cameroon, living on the demersal, bottom-dwelling shelf of the region's rivers and streams. The sources reviewed here do not name a particular river system or drainage in more detail, so its range within Cameroon should be treated as incompletely documented rather than precisely mapped.
Species-specific water chemistry data for M. felixi — temperature, pH, hardness — is not documented in the available sources. Cameroon's river systems are warm and tropical, and often soft and tannin-stained where they drain forested lowlands, the kind of dim, low-visibility water in which the mormyrid electric sense is thought to have evolved. That is a generalisation about the region's rivers, though, not a confirmed reading of this species' particular habitat.
Feeding
No feeding study specific to Mormyrus felixi appears in the sources reviewed here. Mormyrids as a family are nocturnal predators of small invertebrates — insect larvae, worms and other soft-bodied prey — located in soft sediment by electrolocation after dark, and there is no reason to expect this species departs from that general pattern.
General elephant-snout fish care guidance in the aquarium literature describes a diet of live and frozen foods such as bloodworm and brine shrimp, with prepared flake rarely taken. That guidance covers the family as a whole rather than any account of M. felixi in captivity, so it should be read as a starting point rather than a confirmed diet for this particular species.
Mating
Courtship in mormyrids is understood to run through the electric-organ discharge: subtle differences in the pulse waveform and its timing are thought to let fish recognise species and sex and to figure into courtship and dominance interactions. Species-specific mating behaviour for Mormyrus felixi has not been documented in the sources available here.
Mormyrids in general are seasonal spawners tied to the flood cycle, when rising water opens up floodplain habitat and food. Aquarium literature on the family notes that confinement in a tank is thought to disrupt the electric signalling fish rely on to find and assess potential mates, one proposed reason captive spawning across the family is so rarely observed — though the mechanism is not fully worked out, and no evidence either way exists for this species specifically.
Breeding
Breeding of Mormyrus felixi in captivity is, as far as the available sources indicate, unrecorded, and mormyrid breeding in general is poorly understood and only rarely achieved in home aquaria. The species' small size relative to most Mormyrus, at a recorded maximum of around 5.5 in, would in principle make it more tractable for a home tank than a river giant like M. caballus, but that is a size argument rather than any documented breeding success.
Some mormyrids are thought to guard eggs laid among plants or root tangles in the wild, but this has not been confirmed for M. felixi. Anyone encountering a claimed captive spawning of this species should treat it as a notable, poorly documented event rather than a repeatable method.
In the aquarium
Mormyrus felixi is not established in the aquarium trade, and no dedicated care account for the species appears in the sources reviewed here; the elephant-snout fishes most hobbyists encounter belong to other genera such as Gnathonemus and Campylomormyrus. Should this species turn up, its modest recorded size of about 5.5 in puts it well within reach of a large home aquarium, unlike the 19.7 in-plus congeners that are effectively public-aquarium fish.
General care principles for mormyrids apply until species-specific guidance exists: soft substrate for probing, dim lighting, and secure cover for a fish that is most active after dark. Mormyrids are consistently described as sensitive to water quality — sensitive enough that some species have been used as bioindicators in municipal water testing — and this species should be assumed to share that sensitivity, including caution with medication. A group rather than a lone individual is the usual recommendation for the family, to spread any aggression between conspecifics rather than concentrate it on a single tankmate.
Conservation
The IUCN Red List assesses Mormyrus felixi as Data Deficient, an assessment made in 2020. Data Deficient does not mean the species is thought to be at risk; it means there is not enough information on its population, range or trends to support a formal status of threatened or of least concern.
Its documented range appears limited to Cameroon, and the sources reviewed here do not report population surveys, threats, or trend data for the species. Given how little has been published about this fish, the honest read is that its conservation status is genuinely unknown rather than presumed safe, and any claim beyond Data Deficient would be unsupported by current evidence.