Taxonomy & naming
Pollimyrus schreyeni was described by the Belgian ichthyologist Max Poll in 1972. Poll spent much of his career at the Royal Museum for Central Africa in Tervuren, Belgium, and published extensively on the freshwater fishes of the Congo basin and other Central African river systems, with a particular focus on the family Mormyridae. The authority carries no parentheses, meaning Poll placed the species directly in the genus Pollimyrus at the time of description, rather than a later reviser moving it there from an older genus such as Marcusenius or Mormyrus — the more usual history for small mormyrids first described earlier in the twentieth century.
Pollimyrus belongs to the family Mormyridae — the elephantnoses and mormyrids, a family restricted entirely to the fresh and brackish waters of Africa — within the order Osteoglossiformes, the bonytongue fishes. Osteoglossiformes is one of the oldest surviving lineages of teleosts, named for a bony, tooth-bearing structure on the floor of the mouth that bites against toothed plates on the roof. Within Mormyridae, Pollimyrus is a genus of several dozen small-bodied species known collectively as the dwarf stonebashers, set apart from larger-mouthed relatives such as Mormyrus and the trunk-nosed Gnathonemus by a comparatively short snout and modest adult size. The precise type locality of P. schreyeni, and any taxonomic revision or synonymy it may have undergone since 1972, are not confirmed in the sources available for this account.
Morphology
No species-specific size record or detailed morphological description of Pollimyrus schreyeni could be confirmed for this account. Like its congeners, it is presumed to be a small fish — most Pollimyrus species run well under 4 in in standard length — with the laterally compressed body, short blunt head, and modestly sized mouth typical of the dwarf stonebasher group, rather than the elongated chin barbel (the schnauzenorgan) that marks the far better-known trunk-nosed elephantnose, Gnathonemus petersii.
As in every mormyrid, an electric organ situated in the caudal peduncle generates a weak, species-specific pulse discharge, sensed through electroreceptors spread across the skin. This electric sense supports navigation and prey detection in dark or turbid water, and it also does most of the work of separating look-alike species — visual identification within Pollimyrus is notoriously unreliable, and the discharge waveform, not body shape or coloration, is the more dependable marker between congeners. No electric organ discharge has been published for P. schreyeni specifically.
Habitat
Pollimyrus schreyeni is an African species, as is every member of the family Mormyridae, which is restricted to the continent's fresh and brackish waters. Beyond that, no country, river system, or specific habitat description for this species has been confirmed in the sources available for this account, and the original 1972 description was not accessible to verify a type locality.
General Pollimyrus biology offers only a broad expectation rather than a documented fact for this species: most dwarf stonebashers occupy slow-flowing, structure-rich river reaches — backwaters, flooded margins, and vegetated or leaf-littered stretches — where low visibility favors an electric sense over eyesight. Whether P. schreyeni fits that pattern, or occupies different habitat entirely, has not been established.
Feeding
Feeding ecology has not been documented for Pollimyrus schreyeni specifically. Mormyrids as a family are bottom-foraging invertebrate feeders, using electrolocation to find small prey such as insect larvae, worms, and tiny crustaceans hidden in sediment and leaf litter, then taking them with a quick strike of a small, precise mouth. This pattern is presumed to extend to P. schreyeni, but it has not been confirmed by direct observation.
No aquarium feeding record exists for this species, since it has no established presence in the trade. Small mormyrids of similar size are generally offered live or frozen invertebrate foods such as bloodworm and brine shrimp, given after dark to match a naturally crepuscular or nocturnal foraging rhythm.
Mating
Mormyrid electric organ discharges are understood to carry more than navigational information: the pulse waveform is species-specific and, in several studied species, appears to function in courtship and in recognizing the sex or identity of other fish. The best-documented case is the congener Pollimyrus isidori, in which males have been shown to combine their electric discharge with acoustic signals — pulsed grunts and moans — during courtship, in research associated with the physiologist Bruce Crawford and colleagues. That acoustic-plus-electric courtship system has been demonstrated specifically in P. isidori; it has not been shown in P. schreyeni, and extending it to this species without direct study would be a mistake. No mating behavior at all has been recorded for P. schreyeni.
Breeding
No spawning account, wild or captive, has been published for Pollimyrus schreyeni. Breeding biology across the genus is poorly known in general, and confirmed captive reproduction is rare even among the handful of Pollimyrus species that reach the aquarium trade; the specimens that do appear are wild-caught. Egg number, incubation period, and any parental care cannot be stated for this species without inventing detail the available literature does not support.
In the aquarium
Pollimyrus schreyeni has no established presence in the aquarium hobby — no trade history, care sheet, or keeper account for this species could be confirmed for this profile, and nothing here should be read as evidence otherwise. What follows is drawn from general practice for keeping small mormyrids, not from any documented experience with this species.
A soft, sand-based substrate suits a fish presumed to forage by probing the bottom, along with dim lighting and ample cover such as driftwood, root tangles, or leaf litter. Mormyrids as a group tolerate poor water quality poorly and react badly to many common medications, so stable, mature water and conservative dosing matter more here than for most community fish. They can also be territorial toward their own kind, and a lone specimen or an established group large enough to spread out aggression tends to fare better than an unbalanced pair. Live or frozen invertebrate foods offered after dark would suit its presumed foraging habits better than daytime flake feeding — though again, this is inference from the genus, not documented experience with this species.
Conservation
Pollimyrus schreyeni has not been assessed on the IUCN Red List; its conservation status is Not Evaluated. No population trend, distribution survey, or species-specific threat has been documented for this fish.
Many small, narrowly known African mormyrids share this gap: a taxonomic description is often the only published record a species has, and formal conservation assessment lags well behind species discovery across the family. That absence of assessment should be read as a gap in survey effort rather than as evidence that the species is either secure or at risk.