Taxonomy & naming
Petrocephalus boboto was described by Sébastien Lavoué and John P. Sullivan in a 2014 revision of Congo River Petrocephalus published in the journal ZooKeys. The description rests on a single holotype, a specimen of 2.24 in standard length collected in September 2010 from the main channel of the Congo River at Yangambi, in what was then Orientale Province (now Tshopo Province), Democratic Republic of the Congo. No other specimen has been reported since. The authors separated it from its congeners by a combination of three distinct black spots (at the pectoral-fin origin, the caudal-fin origin and the dorsal-fin base), the arrangement of electroreceptor clusters on the head, fin-ray counts of 23 branched dorsal rays and 34 branched anal rays, and a triphasic electric-organ discharge waveform unique among the species compared.
The genus Petrocephalus belongs to Mormyridae, a family found exclusively in African fresh water and restricted almost entirely to weakly electric fishes. Mormyridae sits within Osteoglossiformes, the bonytongues, one of the oldest surviving lineages of teleost fish; the order takes its name from a toothed bone on the floor of the mouth that bites against the roof, a feature these fish share across radiations on four continents. Catalog of Fishes treats Petrocephalus boboto as a valid species.
The genus name Petrocephalus comes from the Greek petros, "stone", and kephale, "head", a reference to the compact, rounded skull of these fish, which lack the elongated trunk-like snout seen in relatives such as Gnathonemus. The species epithet boboto is a Lingala word meaning "peace".
Morphology
Petrocephalus boboto is known only from its 2.24 in standard-length holotype, making it one of the smaller described members of the genus; no larger specimen or total-length measurement has been published. FishBase records the color as gray to silvery, marked with the three black spots that Lavoué and Sullivan used to distinguish it from other Congo River Petrocephalus: one at the base of the pectoral fin, one at the base of the caudal fin, and one at the base of the dorsal fin.
Like other members of its genus, P. boboto has the compact, rounded head and small, underslung mouth typical of Petrocephalus, in contrast to the trunk-like schnauzenorgan carried by some other mormyrid genera. It carries a weak electric organ in the caudal peduncle that produces a species-specific, triphasic (three-phase) electric-organ discharge; Lavoué and Sullivan used the waveform, alongside fin-ray counts and electroreceptor-cluster patterning, to separate it from visually similar congeners, a common necessity in Petrocephalus because several species look nearly identical and are confidently told apart only by their discharge signature. As in mormyrids generally, the brain is unusually large relative to body size, with an enlarged cerebellum that processes the constant stream of electrosensory information the fish uses to navigate and feed.
Habitat
The only known specimen of Petrocephalus boboto was collected from the main channel of the Congo River at Yangambi, a research-station town on the river in Tshopo Province, DRC. FishBase and the original description both treat the species as riverine and note that it is most active at dusk, in keeping with the generally crepuscular and nocturnal habits of mormyrids, which rely on electrolocation rather than vision to navigate in dark or turbid water.
No water-chemistry data were recorded at the collection site, and with only one specimen ever documented, the species' full range within the Congo system is unknown. Congo basin river and floodplain habitats are broadly warm, often soft and tannin-stained, but those figures should not be read as measurements specific to P. boboto; the water conditions at Yangambi have not been separately published, and data on this species remain sparse.
Feeding
No dietary study has been published for Petrocephalus boboto specifically. Mormyrids as a family are benthic foragers that use their electric sense to detect small invertebrates hidden in sediment, sand and detritus, typically feeding after dark when their electrolocation gives them an advantage over sight-hunting predators and competitors. Aquatic insect larvae, small crustaceans and worms make up the bulk of the diet in the family generally.
Whether P. boboto follows this pattern closely, or differs in some way tied to its Congo River channel habitat, has not been documented. Given that the species is known from a single museum specimen, statements about its feeding ecology beyond the general pattern for Petrocephalus and Mormyridae would be speculation rather than recorded fact.
Mating
Nothing has been recorded about courtship or spawning behavior in Petrocephalus boboto; the species is known from one preserved specimen, not from field observation of living fish. In mormyrids generally, the electric-organ discharge is thought to carry information used in courtship and species recognition, and the distinctive triphasic waveform that helped distinguish P. boboto from its congeners in the original description may plausibly serve a similar role in the wild, but this has not been studied in this species.
Many African mormyrids time reproduction to seasonal river and floodplain cycles, spawning as rising water opens up new habitat and food. Whether P. boboto follows that pattern is unknown; the Congo River at Yangambi is a large main-channel habitat rather than a floodplain, and the species' reproductive timing has not been described.
Breeding
Breeding has not been recorded for Petrocephalus boboto in the wild or in captivity, and the species has never been kept or bred in an aquarium. This gap is consistent with mormyrids generally, which are essentially not bred in the hobby and whose reproductive biology remains poorly understood even for species that are commonly traded; captive spawning is rare across the whole family, and wild breeding behavior is documented for only a handful of the roughly 200 mormyrid species.
What little is known about mormyrid reproduction elsewhere in the family points to seasonal, flood-triggered spawning, with the species-specific electric-organ discharge apparently playing some part in courtship and mate recognition. Egg-guarding among vegetation has been suggested for a few better-studied mormyrids, but there is no evidence either way for P. boboto, and no breeding data of any kind have been published for it.
In the aquarium
Petrocephalus boboto is not an aquarium fish. It is known from a single scientific specimen collected in 2010, has never been reported in the ornamental trade, and no aquarium husbandry record exists for it. Any care information here is necessarily drawn from Mormyridae in general rather than from this species specifically, and should be read as a reference framework, not a species account.
Mormyrids as a family are best kept in soft, slightly acidic to neutral, warm water — roughly 75–82 °F — over a soft sand substrate that lets them probe for food, with dim lighting and cover that suits their nocturnal habits. They are notably sensitive to poor water quality and to some medications, particularly copper-based treatments, and are usually kept in species groups because individuals of many Petrocephalus and related genera can be territorial toward their own kind in close quarters. None of this has been tested against P. boboto itself, which remains, as far as published records show, entirely unknown outside the single museum specimen that defines it.
Conservation
The IUCN Red List has not evaluated Petrocephalus boboto (Not Evaluated). This is unsurprising for a species known from a single specimen and a single locality: there is no population data, range estimate or threat assessment on which a conservation status could be based.
The species was one of several new Petrocephalus described from the Congo River basin in Lavoué and Sullivan's 2014 revision, work that drew on decades-old and recently collected material to sort out a genus whose diversity had been undercounted. That a fish this recently described is still known from a single fish caught in one river channel says more about how incompletely the Congo basin's fish fauna has been surveyed than it does about the species' actual rarity or risk. Any future assessment would need targeted collecting at Yangambi and elsewhere on the Congo to establish whether P. boboto is a genuine single-locality endemic or simply an undersampled, more widely distributed fish.