Taxonomy & naming
Pollimyrus pedunculatus was described by the ichthyologists Léon David and Max Poll in 1937. It belongs to the family Mormyridae — the elephantnoses and mormyrids — within the order Osteoglossiformes, the bonytongue fishes, one of the oldest surviving lineages of teleosts. David and Poll published extensively on the fish fauna of the Belgian Congo during this period, and several other Mormyridae species bearing their names — among them Petrocephalus congicus and Campylomormyrus luapulaensis — were described in the same body of work.
The parenthetical form of the authority citation indicates that the original 1937 description did not place the species in the genus Pollimyrus, which was not established until 1971, when the ichthyologist Jacques Taverne split a group of smaller-bodied mormyrids away from the broader genus Marcusenius. David and Poll's original generic placement for this species, its precise type locality, and any subsequent synonymy are not confirmed in the sources reviewed for this account, and this article does not speculate about them beyond noting the pattern shared with several of its congeners.
Morphology
Specific measurements for Pollimyrus pedunculatus were not found in the sources reviewed for this account. Species in the genus Pollimyrus are, without exception, small mormyrids — most mature under about 6 in — but no maximum-length figure specific to this species could be confirmed here, and none is substituted in its place.
As in every mormyrid, an electric organ near the base of the tail generates a weak, pulse-type electric field that Pollimyrus pedunculatus reads through electroreceptors spread across its skin — the sense that compensates for the family's generally poor eyesight in murky or nighttime water. Mormyrids also carry one of the highest brain-to-body mass ratios of any vertebrate group, with an enlarged cerebellum devoted to processing this electrosensory stream. No electric organ discharge waveform specific to this species has been published in the sources reviewed here.
Habitat
No confirmed locality record for Pollimyrus pedunculatus was found in the sources reviewed for this account. Because Léon David and Max Poll's 1937 work centered on the ichthyofauna of the Belgian Congo, the species is presumed to originate from the Congo basin, but no specific country, river system, or drainage has been confirmed for it here, and its range should be treated as unresolved rather than established.
Mormyrids in general favor slow, turbid, structure-rich water — backwaters, flooded margins, and quiet river reaches with cover from roots or vegetation — where an electric sense outperforms eyesight. Water chemistry and temperature data specific to Pollimyrus pedunculatus are not documented in the sources reviewed for this account.
Feeding
No diet study specific to Pollimyrus pedunculatus was found in the sources reviewed for this account. Mormyrids as a group are bottom-foraging invertebrate feeders, using electrolocation to find insect larvae, worms, and small crustaceans hidden in mud, silt, and leaf litter before taking them with a quick strike of the mouth. This species is presumed to feed the same way, though that has not been confirmed specifically for it.
Mating
Courtship and mating behavior have not been described for Pollimyrus pedunculatus. In mormyrids generally, the electric organ discharge is more than a navigation tool: its pulse pattern is species- and often sex-specific, and it is thought to play a part in recognizing potential mates and in shoal cohesion. The related species Pollimyrus isidori has been studied closely enough to show that males produce distinct acoustic and electric signals during courtship, but that behavior has not been demonstrated for Pollimyrus pedunculatus and is not assumed here.
Breeding
Breeding has not been recorded for Pollimyrus pedunculatus, in the wild or in captivity, in any source reviewed for this account. Spawning behavior, egg or larval description, and parental care are all unknown for this species. As with most small Congo basin mormyrids, any account of its reproduction at present would be speculation, and none is offered here.
In the aquarium
Pollimyrus pedunculatus has essentially no documented presence in the aquarium hobby; no keeping reports, husbandry notes, or import records specific to this species were found in the sources reviewed here. What follows describes general practice for small mormyrids rather than any track record established for this particular fish.
Mormyrids as a group need a soft substrate for probing, ample cover, dim lighting, and stable water with low turbidity; the family is also known for unusual sensitivity to some medications and to poor water quality, which argues for gradual acclimation and conservative dosing whenever a mormyrid is treated for disease. They typically refuse dry foods and need live or frozen invertebrate foods such as bloodworm and brine shrimp, offered after the lights dim to match their nocturnal foraging habit. None of this has been verified specifically for Pollimyrus pedunculatus, but it reflects standard practice across the family it belongs to.
Conservation
Pollimyrus pedunculatus does not appear to carry a current IUCN Red List assessment, based on the sources reviewed for this account. No population trend, range size, or specific threat has been documented for this species.
Many small, narrowly distributed Congo basin mormyrids have never been formally assessed, and the general pressures facing Central African freshwater systems — habitat degradation, siltation, and water-quality decline — are the kind of long-term risk that could affect any of them. No such threat has been documented specifically for Pollimyrus pedunculatus, and none is asserted here.