Taxonomy & naming
Lebiasina yepezi was described by Netto-Ferreira and colleagues in 2011, in a paper published in Neotropical Ichthyology 9(4):767–775. The type locality is the Serra Parima-Tapirapecó mountains along the Brazil-Venezuela border, a remote highland region that forms the headwaters of three major drainages: the rio Negro, the rio Branco (itself part of the Amazon system), and the upper rio Orinoco. Eschmeyer's Catalog of Fishes is the authority for the valid name Lebiasina yepezi Netto-Ferreira et al., 2011.
The genus Lebiasina belongs to the family Lebiasinidae, a Neotropical family that includes the pencilfish (Nannostomus) and splash tetras (Copella, Pyrrhulina) among others. Lebiasinids are generally small to medium-sized characiforms of slow, vegetated tropical waters. Within Lebiasina, yepezi is distinguished by a combination of osteological and external characters: the triangular mesethmoid without lateral projections sets it apart from several congeners, alongside the pattern of four longitudinal dark stripes on the trunk. The specific epithet honours a person or locality associated with the type material, though full biographical detail was not recovered for this entry.
Morphology
Lebiasina yepezi is a moderately elongate lebiasinid reaching 6 in standard length in preserved specimens, making it one of the larger members of its genus. The body is fusiform and somewhat laterally compressed, typical of the genus, with a relatively large mouth suited to a carnivorous to omnivorous diet.
The most striking feature of the external colour pattern is the four black longitudinal stripes running along the trunk from behind the head toward the caudal peduncle, a character noted in the original description as diagnostic within Lebiasina. The background body colour is not fully detailed in available sources but is typical of the genus: pale to silvery with the dark stripes providing strong contrast. Internally, the triangular mesethmoid lacking lateral projections distinguishes yepezi from related species in osteological examination. As with most lebiasinids, females are likely deeper-bodied than males when gravid, though detailed sexual dimorphism data are sparse.
Habitat
Lebiasina yepezi is endemic to the headwaters draining the Serra Parima-Tapirapecó mountain range on the Brazil-Venezuela border. Its known distribution spans the rio Parima and rio Uraricoera in the rio Branco drainage, the rio Marari in the upper rio Negro drainage, and the upper rio Orinoco in Venezuela, making it one of the few freshwater fishes naturally straddling this Amazonian-Orinoco divide at high elevation.
Like other lebiasinids, it inhabits freshwater, benthopelagic environments in tropical conditions. The family as a whole favours slow-moving to still waters with heavy aquatic vegetation, soft substrates, and abundant organic matter. Water chemistry in the Guiana Shield headwaters where this species occurs is characteristically soft and acidic, with pH in the range of roughly 5.5–7.0 and low mineral content, though exact field measurements for yepezi's specific localities are not available in the sources consulted. Temperatures in the tropical lowland portions of its range fall in the 72–82 °F band typical for the broader region.
Feeding
The trophic level of 3.6 reported on FishBase places Lebiasina yepezi in the lower-carnivore to omnivore range, consistent with other Lebiasina species that prey primarily on small invertebrates, insects, and other available animal matter supplemented by plant material. In its native headwater streams, the diet likely includes aquatic insect larvae, small crustaceans, terrestrial insects falling onto the water surface, and possibly smaller fishes.
In the aquarium, family-level data suggest that lebiasinids generally accept a variety of small live and frozen foods — brine shrimp, mosquito larvae, Drosophila, and similar invertebrates — alongside good-quality dry foods. Feeding in the evening or at dusk may elicit the most natural foraging behaviour, as many lebiasinids are crepuscular in activity. Species-specific feeding observations for L. yepezi in captivity are essentially absent from the available literature.
Mating
No direct observations of mating behaviour in Lebiasina yepezi appear in the published literature or hobby sources consulted. Within the broader family Lebiasinidae, reproductive strategies vary considerably: pencilfish (Nannostomus) scatter adhesive eggs among fine-leaved plants; some Pyrrhulina deposit eggs on leaves and may show brief paternal guarding; the splash tetras (Copella arnoldi) famously spawn out of water on overhanging leaves. Lebiasina itself is among the less-studied lebiasinid genera for reproductive biology.
Based on general lebiasinid patterns and the genus's morphology, egg-scattering spawning among vegetation is the most likely mode, with the male displaying to the female prior to the spawning act. Given the species' size and the robustness typical of the genus, conditioning on live and varied foods would be the standard preparatory step for any breeding attempt in captivity.
Breeding
No captive breeding records for Lebiasina yepezi are available in the sources consulted. The species appears to be essentially absent from the mainstream aquarium trade as of 2026, which means the accumulated husbandry knowledge that exists for popular lebiasinids such as pencilfish does not directly apply here.
Inference from family-level biology suggests that breeding, if achieved, would likely involve adhesive eggs deposited among fine-leaved plants or on smooth surfaces, with little or no parental care. Incubation at tropical temperatures of around 75–81 °F would be expected to produce fry within days. The relatively large adult size (6 in SL) implies fry larger than those of pencilfish, potentially less dependent on the finest first foods, but these remain speculations pending actual captive reproduction records. Anyone successfully breeding this species would be adding meaningfully to the documented husbandry of the genus.
In the aquarium
Lebiasina yepezi is a rarely encountered species in the aquarium hobby; it does not appear in regular trade as of this writing, and most references to its care come from family-level generalizations rather than first-hand keeping experience. Its size — up to 6 in SL — means it requires a spacious aquarium of at least 39.5–47 in length. A setup with soft, slightly acidic water (pH 5.5–7.0), dim to moderate lighting, dense planting or floating cover, and a dark substrate would approximate its native Guiana Shield headwater environment.
Lebiasinids are generally timid and benefit from being kept with calm, similarly sized tankmates that will not outcompete them for food. Given the family's tendency toward crepuscular activity, open areas for swimming alongside dense refuges would suit the species. Water temperature in the 72–81 °F range is appropriate. Any specimens appearing in the trade would almost certainly be wild-caught, sourcing from a restricted and remote range — aquarists encountering the species should treat it with corresponding care and priority.
Conservation
Lebiasina yepezi is assessed as Least Concern (LC) on the IUCN Red List, with the assessment dating to 2020. The species occurs across the headwaters of three major drainages — the rio Negro, rio Branco, and upper rio Orinoco — which together give it a range that, while remote and restricted to highlands around the Serra Parima-Tapirapecó, is not confined to a single small water body in the manner of many threatened endemics.
The Serra Parima-Tapirapecó region is a largely intact and relatively inaccessible highland landscape, and large portions of it fall within protected areas on both the Brazilian and Venezuelan sides of the border. These factors — distributional breadth across multiple drainages and low anthropogenic pressure in its core habitat — underpin the LC designation. However, its remote headwater distribution means population monitoring is limited, and shifts in land use, mining pressure in the Guiana Shield, or climate-driven hydrological change could affect the species in ways that current data do not capture.