Taxonomy & naming
Stomatorhinus puncticulatus was described by George Albert Boulenger in 1899, part of a long run of small Central African mormyrids he named around the turn of the twentieth century from museum material assembled during Belgian survey and collecting expeditions into the Congo Free State. 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, named for a bony, toothed structure on the tongue that bites against toothed plates on the roof of the mouth. Eschmeyer's Catalog of Fishes lists Stomatorhinus puncticulatus as a currently valid species; the precise type locality is not confirmed in the sources reviewed for this account.
The genus Stomatorhinus was erected by Boulenger in this same period for a distinct group of small, blunt-snouted Congo basin mormyrids, distinguished by a small mouth set low and near the tip of the snout rather than on an elongated chin barbel. The Belgian ichthyologist Max Poll, who dominated mid-twentieth-century work on Congo basin fishes, described several further species in the genus in the decades that followed, and Stomatorhinus now holds close to twenty recognized species. No synonymy specific to S. puncticulatus is documented in the sources consulted here.
Morphology
No measurements or meristic counts specific to Stomatorhinus puncticulatus have been located in the sources reviewed for this account, so no maximum length can be given with confidence. The species epithet — puncticulatus, built from the Latin punctum ('point' or 'dot') with a diminutive and the adjectival suffix -atus, meaning roughly 'finely spotted' or 'marked with small dots' — points to a pattern noted in Boulenger's original diagnosis, though the full original description is not accessible in the sources reviewed for this account.
Like other Stomatorhinus, it presumably carries the compact body and small, inferior mouth set close to the tip of a short, unproduced snout that defines the genus, rather than the elongated chin appendage — the schnauzenorgan — of the related genus Gnathonemus. Most species in the genus are modest fish, mostly maturing under about 4 in. As in every mormyrid, an electric organ near the base of the tail generates a weak, pulse-type discharge, read through electroreceptors spread across the skin and used to navigate and locate prey in murky or nighttime water where eyesight is of limited use. No electric organ discharge waveform specific to Stomatorhinus puncticulatus has been published in the sources reviewed here.
Habitat
No confirmed locality record for Stomatorhinus puncticulatus was found in the sources reviewed for this account, beyond its general placement in the Congo basin fauna that Boulenger was describing at the time. The genus Stomatorhinus as a whole is a Congo basin group, its species recorded mainly from forest streams and swamp habitat across the central African rainforest block, but nothing in the available sources ties this particular species to a specific country, river system, or drainage, and none is assigned here.
Congeners in the genus generally occupy soft, slow-moving or still tropical forest water — shaded streams, flooded forest margins, and swamp habitat with abundant leaf litter and submerged root cover — the kind of low-visibility setting where an electric sense outperforms eyesight. That is a genus-level generalization rather than a measurement taken for Stomatorhinus puncticulatus, and water temperature and chemistry data specific to this species are not documented.
Feeding
No diet study specific to Stomatorhinus puncticulatus has been located 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 small, downturned 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 Stomatorhinus puncticulatus. In mormyrids generally, the electric organ discharge carries more than navigational information: its pulse pattern is species-specific and, in several studied genera, sex-specific as well, and it is thought to play a role in mate recognition and shoal cohesion. Whether that holds for Stomatorhinus puncticulatus is unknown — no courtship study of this species has been located, and nothing should be assumed from better-studied relatives.
Breeding
There is no published record of Stomatorhinus puncticulatus breeding, in the wild or in captivity. Spawning behavior, egg or larval description, and parental care are all unknown for this species. Breeding biology across Mormyridae is poorly documented even for well-studied genus members, and for a species with no confirmed distribution and no aquarium history, a specific account of its reproduction would be invention rather than fact.
In the aquarium
Stomatorhinus puncticulatus has 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, fine substrate they can probe with the mouth, ample cover, dim lighting, and stable, clean water with low turbidity; the family is also known for unusual sensitivity to a number of common aquarium medications and to poor water quality, which argues for cautious acclimation and conservative dosing whenever a mormyrid needs treatment. They typically refuse dry foods and need live or frozen invertebrate foods such as bloodworm and brine shrimp, offered after the lights dim to suit their nocturnal foraging habit. None of this has been verified specifically for Stomatorhinus puncticulatus, but it reflects standard practice across the family it belongs to.
Conservation
Stomatorhinus puncticulatus 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 known Congo basin mormyrids named during Boulenger's era have received little research attention since, and this species fits that pattern — a name that persists in the taxonomic record with essentially no accompanying ecological or conservation data. Deforestation and degradation of Congo basin forest streams and swamp habitat are the kind of long-term pressure that could affect a poorly known species like this one, but no such threat has been documented specifically for Stomatorhinus puncticulatus, and none is asserted here.