Taxonomy & naming
Gymnotus pedanopterus was described by Francisco Mago-Leccia in 1994, part of his major revision of the genus Gymnotus that split what had been a handful of recognized species into the more than 40 known today. It belongs to the family Gymnotidae within the order Gymnotiformes, the New-World electric knifefishes — a group of bony fishes defined by an electric organ running the length of the body and by a long ribbon-like anal fin that provides essentially all of their propulsion. Every gymnotiform in this order generates a weak electric field around itself and reads the way that field is distorted by its surroundings, a sense called electrolocation, and uses the same discharges to signal identity, sex and intent to other fish — electrocommunication.
Gymnotus is the banded-knifefish genus: stout, boldly barred, pulse-type electric fish, and the only genus in the order that has spread north out of South America into Central America and as far as southern Mexico. Despite the shared common name, gymnotiforms are not related to the Asian featherback and clown knifefishes (Chitala, Notopterus) — those are bonytongues from an entirely different lineage, and the knife-shaped body is convergent, not inherited. The Catalog of Fishes (Eschmeyer, CAS) is the authority for the valid name Gymnotus pedanopterus.
Morphology
Gymnotus pedanopterus has the classic banded-knifefish build: a stout, laterally compressed, elongate body without a dorsal fin, tapering toward the tail and driven almost entirely by a very long anal fin running most of the length of the underside. FishBase records 222–290 anal soft rays and 96–99 vertebrae in the species — an unusually high ray count even for the genus, reflecting the fine, wave-like undulations of that fin that let the fish glide forward or reverse with no need to turn. The body is patterned with the bold dark bars typical of Gymnotus, which is the basis for the common name "zebra knifefish".
As in all gymnotiforms, an electric organ runs along the body and the skin carries the sensory pores (electroreceptors) that read the field it produces; G. pedanopterus generates a pulse-type discharge — brief, discrete pulses rather than the continuous wave of species like the ghost knifefishes — well suited to a benthic, sluggish-water lifestyle. The species is scaleless like its relatives, a point that matters directly to how sensitive it is to water quality and medication in captivity. FishBase gives a maximum length of 11 in total length; Seriously Fish gives an equivalent figure of roughly 11 in.
Habitat
The species is known from the upper Orinoco drainage in southern Venezuela — Territorio Amazonas and Estado Apure, including the Río Casiquiare and the Río Orinoco itself — and from Rio Negro tributaries in Brazil (Río Demini, Río Tarumã-Açu, Río Cueiras). GBIF specimen records add further Venezuelan localities along the same Orinoco system, including Caño Esmeralda, El Pozo de Lucas, Caño Chola and Caño Temblador. Seriously Fish also lists Peru within its range. This is classic Amazon/Orinoco blackwater and whitewater country, and G. pedanopterus is consistently recorded as benthic — living on or near the bottom.
It favors sluggish or still, turbid water, and within its rivers it is found in the deeper main channels rather than shallow margins. That combination — dim light, murky water, a bottom orientation — is exactly the setting where an electric sense outperforms eyesight, and it is no surprise that the genus Gymnotus, hunting at night over featureless mud and sand, relies on electrolocation to find food and find its way. Water temperatures in its range run tropical, in the roughly 72–82 °F band typical of Amazon and Orinoco lowland rivers.
Feeding
Gymnotus species are nocturnal predators, and G. pedanopterus fits that pattern: it hunts after dark over the substrate, using its electric sense to locate prey that eyesight alone would miss in turbid water. Seriously Fish reports that in the aquarium the species takes live and frozen meaty foods readily — bloodworm, prawn, earthworm and tubifex among them — but consistently rejects dried foods, a preference that matches its role as an active hunter of live or freshly-dead animal prey rather than a scavenger of plant or flake material.
In the wild, banded knifefishes of this kind take small invertebrates and other prey items encountered on or near the bottom; the genus as a whole is known for tough, adaptable, air-breathing (facultatively) predators able to work oxygen-poor floodplain and swamp water as well as flowing river channels. Feeding this species well in captivity means offering it substantial, meaty items after dark, when it becomes active, rather than expecting it to compete for food during the day.
Mating
As in other gymnotiforms, electric organ discharges carry social information in Gymnotus — a signature that differs by species and likely by sex, used to identify rivals and potential mates in the dark. Courtship in the genus is therefore understood to involve an exchange of these discharges alongside physical approach, though the specifics have not been documented for G. pedanopterus itself; most of what is known about gymnotiform electric courtship in general comes from laboratory work on other, better-studied species.
What is well established for the genus is that Gymnotus shows real parental care, unusual among fishes generally: research on the widespread congener Gymnotus carapo documents male guarding of free-swimming embryos, and the same pattern of male-guarded broods is presumed to extend across the genus. Nothing specific to nest-site choice, spawning trigger or courtship display has been confirmed in the wild or in captivity for G. pedanopterus — the species is data-sparse on this point, and any account beyond the genus-level pattern would be guesswork.
Breeding
Gymnotus pedanopterus has, as far as the available literature shows, never been deliberately bred in the aquarium hobby, and reproduction has not been documented for the species even in the wild beyond the inference drawn from its genus. Gymnotidae as a family are known for a guarded-nest strategy: the male builds and defends a nest — often a sheltered hollow among vegetation or debris, sometimes a foam or bubble mass — into which the female spawns, and the male then guards the eggs and larvae through to independence. This pattern is documented directly in Gymnotus carapo and is presumed, on genus-level grounds, to apply to G. pedanopterus as well.
For the aquarist, the honest position is that this is an essentially unknown quantity in captivity: no breeding protocol exists, no aquarium spawning has been reported, and the trade almost certainly runs on wild-collected fish. Given its lack of an IUCN assessment and its narrow-looking known range along the upper Orinoco and Rio Negro, that collection pressure is worth keeping in mind rather than something to shrug off.
In the aquarium
Gymnotus pedanopterus is rarely kept and rarely offered, but the guidance for the genus is consistent and well supported by the cache: Seriously Fish flags it as highly territorial toward its own species, recommending one fish per tank, and as a scaleless fish it is markedly sensitive to copper-based medications and to many standard aquarium treatments, so doses should be reduced and copper avoided outright. Reported water parameters are 72–82 °F, pH 6.0–7.0, and moderate hardness of roughly 2–12°H — soft, near-neutral, tropical river water, matching its blackwater and turbid-channel origins.
As a nocturnal, electroreceptive predator it needs dim lighting, secure cover to retreat into by day, and a soft or sandy bottom it can work over after dark; small fish and shrimp are not safe tankmates, since it will hunt anything bite-sized once active. It accepts live and frozen meaty foods but has been reported to reject dried food outright, so a keeper should plan on bloodworm, prawn, earthworm and tubifex rather than flake or pellet. Given how little is documented about its captive husbandry, this is a fish for an experienced keeper prepared to work from first principles and the wider Gymnotus literature, not a beginner's animal.
Conservation
Gymnotus pedanopterus has not been evaluated by the IUCN Red List — its global status is Not Evaluated (NE), reflecting how little targeted conservation attention the species has received rather than any known population decline. What is documented is a comparatively narrow known range centered on the upper Orinoco drainage in southern Venezuela and Rio Negro tributaries in Brazil, with further records from Peru, meaning it is not obviously a wide-ranging, secure species in the way many Amazon-basin fishes are.
No species-specific threats have been documented in the sources reviewed here, and nothing should be asserted beyond that. As with many narrow-range Amazon and Orinoco basin endemics, the general pressures worth watching are habitat change, water-quality decline and any collection for the aquarium trade — but for G. pedanopterus specifically the honest summary is that the conservation picture is data-sparse, and an NE listing should be read as a gap in assessment, not a clean bill of health.