Taxonomy & naming
Petrocephalus levequei was described in 1990 by Roger Bigorne and Didier Paugy, published within Lévêque, Paugy & Teugels' Faune des poissons d'eaux douces et saumâtres de l'Afrique de l'Ouest (Collection Faune tropicale no. XXVIII) and again the following year in Bigorne & Paugy 1991. It belongs to the family Mormyridae within Osteoglossiformes, the ancient bonytongue lineage of teleosts. The holotype (MNHN 1990-0136) and two paratype lots (MNHN 1990-0949, seven specimens; MNHN 1989-1852, nine specimens) come from the Rokel River at Bumbuna, Sierra Leone, which stands as the species' type locality. The Catalog of Fishes lists the name as valid, with its status confirmed in the molecular and electric-organ-discharge revision work of Kramer et al. (2012).
Petrocephalus — from the Greek petros, rock, and kephale, head — is one of the largest mormyrid genera in Africa, and West African rivers in particular have yielded a steady run of newly described or newly confirmed species over recent decades as researchers separate look-alike populations by their electric signals rather than by eye alone. P. levequei is one member of that West African group, restricted so far to a narrow stretch of coastal drainage rather than a wide continental range.
Morphology
Petrocephalus levequei reaches about 5 in in standard length, according to FishBase, placing it among the mid-sized members of a genus that runs from tiny to moderately built mormyrids. Meristic counts recorded for the species include 27–32 branched dorsal-fin rays and 32–37 branched anal-fin rays, an upper jaw bearing 15–21 teeth and a lower jaw with 24–30, and a head-length-to-eye-diameter ratio of 2.8–3.91 — a comparatively large eye set in the genus' characteristic blunt, rounded head. Pigmentation includes a triangular dark spot below the front of the dorsal-fin base and a V-shaped mark at the base of the caudal fin.
As in every mormyrid, an electric organ near the base of the tail generates a weak, pulse-type discharge that the fish reads through electroreceptors spread across its skin, used for orientation and object-sensing in low-visibility water. No electric-organ-discharge waveform has been published specifically for P. levequei, so the finer diagnostic detail modern Petrocephalus taxonomy increasingly relies on is not yet available for this species — external counts and pigmentation remain the working means of telling it apart from close relatives.
Habitat
Petrocephalus levequei is known from the Atlantic Guinean slope of West Africa, with its type locality on the Rokel River at Bumbuna, Sierra Leone. FishBase notes it may also occur in coastal river basins of Liberia, though that extension of range is unconfirmed rather than a documented record. The species is a freshwater, benthopelagic fish, living and foraging near the riverbed rather than in open water.
Detailed, site-specific habitat data for this species is limited. What is recorded points to slow-flowing, densely vegetated freshwater reaches, consistent with the general pattern for small West African Petrocephalus, which favour quiet, structure-rich stretches of river over fast or open channel water. Beyond that general description, water chemistry and seasonal conditions at its known localities have not been published.
Feeding
No dedicated dietary study has been published for Petrocephalus levequei. Like other members of its genus, it is presumed to be a bottom-foraging invertebrate feeder, using its electric sense to locate small prey such as insect larvae and worms hidden in mud and sediment, but this has not been confirmed by gut-content or field-feeding studies specific to this species. Nothing about diet in captivity has been documented, since the species is not established in the aquarium trade.
Mating
No published account describes courtship, pairing, or mate selection in Petrocephalus levequei. Mormyrids in general are thought to use their species-specific electric organ discharge to recognise potential mates and maintain shoal cohesion, but because no discharge waveform has been recorded for this species, even that general pattern cannot be confirmed for it specifically. Reproductive behaviour of P. levequei in the wild remains undescribed.
Breeding
Breeding has not been documented for Petrocephalus levequei, in the wild or in captivity. No spawning account, fecundity estimate, or description of parental care has been published for this species, and none should be assumed by extension from better-studied Petrocephalus or Mormyridae relatives.
In the aquarium
Petrocephalus levequei is essentially absent from the aquarium hobby; it is not an established trade species, and no aquarium care record specific to it has been published. If a specimen were ever encountered, general mormyrid husbandry would apply: a soft sand substrate for probing, subdued lighting with ample cover such as driftwood or dense planting, and live or frozen invertebrate foods, since mormyrids as a group are reluctant to take dried food. Mormyrids are also notably sensitive to poor water quality and to some common medications, so cautious acclimation and conservative dosing matter more with this family than with most community fish.
None of this reflects direct experience with P. levequei — it is drawn from general practice for its genus rather than any documented history of the species in a tank.
Conservation
The IUCN Red List assesses Petrocephalus levequei as Near Threatened, in an assessment dated 2 January 2020 (Red List version 2020.2). Its known range is narrow, centred on the Rokel River system and the Atlantic Guinean coastal slope of Sierra Leone, with only a possible, unconfirmed extension into Liberia — a limited range that offers little buffer against localised habitat change. Assessment-level detail on the specific threats behind the Near Threatened rating is not available in the sources consulted for this account, so no particular pressure should be assumed to be driving it.