Taxonomy & naming
The French naturalist Bernard Germain de Lacepède described this fish in 1803 as Mormyrus bane, from a specimen taken at Cairo, Egypt; the holotype is held at the Muséum national d'Histoire naturelle in Paris (MNHN A-0908). It was later moved into Petrocephalus, a genus erected to hold the short, blunt-snouted mormyrids that Lacepède and his contemporaries had originally lumped in with the long-snouted Mormyrus. The Catalog of Fishes treats Petrocephalus bane (Lacepède, 1803) as the valid combination.
The genus name Petrocephalus comes from the Greek petra, "rock", and kephale, "head", a reference to the hard, bony skull typical of these fish. The species epithet bane is not the English word; Lacepède's Nile-basin species from this period were routinely built from vernacular names collected during the Napoleonic-era survey of Egypt, so bane most likely transliterates a local Egyptian or Arabic name for the fish rather than describing any trait of the animal.
Petrocephalus is one of the largest genera in the family Mormyridae, and many of its roughly 30 recognized species look very similar to one another. Because the fish rely on electric-organ discharge for species recognition, ichthyologists increasingly use the discharge waveform, not just body shape and fin-ray or scale counts, to separate species, and cryptic species complexes are common within the genus.
Morphology
Petrocephalus bane has the short, rounded, almost blunt snout that defines the genus, in contrast to the long tubular snout of Mormyrus or the trunk-like chin appendage of Gnathonemus. The body is laterally compressed and covered in fine scales, the mouth is small and set low, and the single dorsal fin sits well back on the body, roughly opposite the anal fin, ahead of a deeply forked caudal fin. Overall coloration is a plain silvery to grey-brown, without the bold patterning seen in some other mormyrids.
FishBase records a maximum size of about 7.9 in standard length, with sexual maturity reached at roughly 4.3 in; in sampled populations, females tend to run larger and are caught more often than males, though the reason for that skew is not established. As in mormyrids generally, the electric organ sits in the caudal peduncle just ahead of the tail, and the brain carries an unusually large, highly folded cerebellum relative to body size, one of the highest brain-to-body ratios recorded in fish, an adaptation linked to processing the constant stream of electrosensory information the fish generates.
Habitat
Petrocephalus bane is widespread across several African river systems rather than confined to one basin. FishBase records it from the Nile basin, including the Bahr el Ghazal, Jebel and White Nile, the Blue Nile, and Lake Nubia, as well as the Comoé, Chad basin, Volta, Cross, and Niger rivers, spanning a broad swath of Sahelian and Sudanian Africa from Egypt and Sudan through the Lake Chad basin to Nigeria, Ghana and Côte d'Ivoire.
It is a demersal freshwater fish, living near the bottom in open water as well as vegetated margins of lakes, lagoons, and even irrigation canals, indicating some tolerance for altered and slow-moving habitats. Species-specific water-chemistry data for this fish has not been published; general mormyrid habitat is warm, soft, and often stained or turbid water in which vision is limited and the electric sense does most of the work, but the precise temperature and pH range Petrocephalus bane experiences across its wide range is not documented and should be treated as data sparse.
Feeding
Like other small mormyrids, Petrocephalus bane is presumed to feed on benthic invertebrates, mainly aquatic insect larvae, worms, and small crustaceans picked from the substrate. Unlike Gnathonemus petersii, it lacks an elongated chin barbel (the schnauzenorgan) for probing sand, so it likely takes prey more directly with its small, low-set mouth while using its electric sense to locate it in low light or turbid water. Detailed dietary studies specific to this species are not available.
In the aquarium, mormyrids of this size generally accept live and frozen invertebrate foods such as bloodworm, brine shrimp, and chopped mysis, and most feed primarily after dark. A nocturnal, electrosensory forager can be slow to find food in a brightly lit tank with fast competitors, so feeding after lights-out and ensuring the fish is actually getting enough is standard practice with this group.
Mating
In mormyrids generally, the pulse-type electric-organ discharge plays a role in courtship and species recognition, letting individuals identify potential mates of the right species amid a mix of related, similar-looking fish. Spawning in the wild is thought to be seasonal and linked to the rains and rising floodwaters that characterize the rivers and floodplains these fish inhabit.
For Petrocephalus bane specifically, FishBase does not document a breeding mode, and no detailed account of courtship or spawning behavior for this species could be found. As with most of the genus, this side of its biology remains essentially unstudied.
Breeding
Petrocephalus bane is not established as a captive-bred aquarium fish, and mormyrids as a family are notoriously difficult to spawn under aquarium conditions; successful captive breeding of this genus is rare to nonexistent in the hobby literature. What little is inferred about the family points to seasonal, flood-triggered spawning in the wild, with the electric discharge involved in pairing, but the mechanics of egg-laying, fertilization, and any parental role are poorly known across Petrocephalus as a whole.
Given that gap, keepers should not expect to breed this species, and any claim to have done so would be unusual enough to warrant real documentation. facts.breeding below reflects that this is a seasonal spawner whose reproduction is both rarely achieved in captivity and poorly described even in the wild.
In the aquarium
Petrocephalus bane is not a fish routinely seen in the aquarium trade, and species-specific husbandry notes are scarce; care for it follows general guidance for small Nile-and-West-African mormyrids. Provide a dimly lit tank with soft substrate, ample hiding places such as driftwood, rockwork, or plant cover, and stable, clean water; mormyrids as a group are sensitive to poor water quality and to some common medications, so changes should be gradual and dosing conservative.
As an electric fish that navigates and communicates by discharge, it does best without other strongly electrogenic species competing for the same electrical "space," and mormyrids can be intolerant of their own kind in a small tank, so a single specimen or a properly sized group in a large, well-furnished aquarium is the safer approach over an ad hoc pair or trio. Being a nocturnal forager, it is easily outcompeted for food by fast diurnal tankmates, so feeding after dark and confirming it is actually eating matters more than with most community fish.
Conservation
The IUCN Red List assesses Petrocephalus bane as Least Concern, based on an assessment from September 2019. Its distribution across multiple large river basins, from the Nile through the Chad basin to the Niger, Volta, Cross, and Comoé systems, means it is not confined to a single vulnerable population, which supports the low-concern rating.
No specific, localized threats to this species are documented in the sources reviewed here. As with many wide-ranging African freshwater fish, the longer-term pressures relevant to it are the general ones facing its river systems, such as damming, irrigation withdrawal, and habitat modification, rather than any threat singled out for this species.