Taxonomy & naming
Stomatorhinus ivindoensis was described by John P. Sullivan and Carl D. Hopkins in 2005. 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. Sullivan and Hopkins worked extensively on the molecular systematics and electric-organ-discharge diversity of African mormyrids in the early 2000s, and their description of S. ivindoensis sits within that broader program of resolving species boundaries in genera — Stomatorhinus among them — where external appearance alone is an unreliable guide. Eschmeyer's Catalog of Fishes lists Stomatorhinus ivindoensis as a currently valid species; no subsequent synonymy has been documented for this article.
The genus Stomatorhinus was erected by George Albert Boulenger for a group of small, blunt-snouted Central African mormyrids distinguished by a small mouth set low and near the tip of the snout, rather than the elongated chin barbel — the schnauzenorgan — that marks the related genus Gnathonemus. The Belgian ichthyologist Max Poll added many further species to the genus in the mid-twentieth century, and Sullivan and Hopkins's early-2000s work added more still, bringing the genus to roughly twenty recognized species. The specific epithet ivindoensis follows the standard Latin toponymic pattern, built with the locative suffix -ensis to mean 'of' or 'from' a place — in this case an evident reference to the Ivindo River, a right-bank tributary of the Ogooué River in northeastern Gabon. Whether the original description confirms this river as the exact type locality is not established in the sources available for this article.
Morphology
No published measurements of maximum length, fin-ray counts, or other morphometrics specific to Stomatorhinus ivindoensis were accessible for this article. As a member of Stomatorhinus, it can be expected to share the general build of the genus: a laterally compressed body, a blunt, rounded snout, and a small, inferior mouth set toward the underside of the head rather than at its tip — the defining trait that separates the genus from trunk-nosed relatives such as Gnathonemus. Most Stomatorhinus species are modest fish, mostly under 4 in in length, though no figure specific to this species is documented.
Like every mormyrid, S. ivindoensis almost certainly carries a weak electric organ near the base of the tail. The organ generates a pulsed discharge, used across the family for electrolocation and, in many species, for communication and mate or rival recognition. Sullivan and Hopkins's broader research program placed considerable weight on electric-organ-discharge waveforms as a tool for telling similar-looking Stomatorhinus species apart, but no discharge recording or other electrophysiological data specific to S. ivindoensis were found in the sources reviewed for this article.
Habitat
No confirmed locality record for Stomatorhinus ivindoensis was found in the sources reviewed for this article. The genus Stomatorhinus as a whole is a Central and West-Central African group, its species recorded mainly from forest streams and swamp habitat, and the species epithet ivindoensis points toward the Ivindo–Ogooué river system of Gabon as a probable point of origin. That inference rests on the name alone, though, and no source available for this account confirms a country, river system, or drainage for the species.
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 ivindoensis, and no water temperature or chemistry data specific to this species have been published.
Feeding
No diet study specific to Stomatorhinus ivindoensis has been located in the sources reviewed for this article. 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 mate-recognition behavior have not been described for Stomatorhinus ivindoensis. 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 part in mate recognition and shoal cohesion — a line of research Hopkins's laboratory helped establish. Whether any of that applies to S. ivindoensis is unknown; no discharge recording or courtship observation for the species has been located.
Breeding
There is no published record of Stomatorhinus ivindoensis 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 in well-studied genera, 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 ivindoensis 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 ivindoensis, but it reflects standard practice across the family it belongs to.
Conservation
Stomatorhinus ivindoensis does not appear to carry a current IUCN Red List assessment, based on the sources reviewed for this article. No population trend, range size, or specific threat has been documented for this species.
Many small, narrowly known Central African mormyrids described from limited museum material in the early 2000s 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, damming, and degradation of Central African forest-stream habitat are the kind of long-term pressures that could affect a poorly known species like this one, but no such threat has been documented specifically for Stomatorhinus ivindoensis, and none is asserted here.