Taxonomy & naming
Lebiasina chucuriensis was described by Ardila Rodríguez in 2001. The type series is based on holotype CAR 150424, collected from the quebrada La Carbonera — a small tributary of the río La Llana — in the municipio of San Vicente de Chucurí, department of Santander, Colombia. That stream drains into the Magdalena River basin, making this species part of the diverse Magdalena ichthyofauna that has been the focus of considerable taxonomic attention since the late twentieth century.
The genus Lebiasina belongs to the family Lebiasinidae — the pencilfishes and their allies — within the order Characiformes. Lebiasinidae is a Neotropical family ranging from Panama south through the Andes and lowland South America, containing around eight genera including the familiar pencilfish genus Nannostomus. Within the family, Lebiasina is one of the larger-bodied genera, differing from the slender pencilfishes in its more robust form and upland stream habits. Eschmeyer's Catalog of Fishes records the valid name as Lebiasina chucuriensis Ardila Rodríguez, 2001.
Morphology
Lebiasina chucuriensis reaches a maximum recorded length of 6 in total length, placing it among the larger members of the genus. Like other Lebiasina species it is an elongate, moderately robust fish with a rounded snout, large eyes, and the typical Characiform forked tail. The body is laterally compressed and streamlined — well-suited to life in flowing water — with a dorsal fin positioned well back, roughly above the anal fin origin.
Color pattern in Lebiasina species typically involves a series of dark spots or blotches along the lateral line, sometimes forming a broken horizontal stripe, and a pale to silvery ground color on the flanks. Detailed scale-count and color descriptions for L. chucuriensis specifically are not widely published in the accessible literature, and precise meristic data should be sought in the original description. The species is unlikely to be confused with sympatric fishes given its size and lebiasinid body plan.
Habitat
Lebiasina chucuriensis is known from the quebrada La Carbonera and associated small streams of the río La Llana system in the department of Santander, Colombia — a tributary network that feeds the Magdalena River in northern Colombia, between the main Andes cordillera and the Magdalena valley. FishBase records the species as benthopelagic in freshwater habitats of this Magdalena basin region.
The genus Lebiasina as a whole is characteristic of upland and hill streams in the Andes and other elevated terrain of northern South America. These streams are typically well-oxygenated, clear to lightly tannin-stained, and flow over rocky or sandy substrates with riparian vegetation providing shade and leaf litter. Water temperatures in Andean foothill streams of northern Colombia are moderate, and related species such as L. multimaculata have been recorded in water with pH broadly in the neutral range. The Magdalena basin is one of Colombia's great biogeographic zones, with high fish endemism reflecting the geological isolation of sub-basins by ridges and gorges.
Feeding
No specific dietary study of Lebiasina chucuriensis appears in the accessible literature. By analogy with congeners and with other small-to-medium Characiformes of Andean foothill streams, the species is presumed to be an opportunistic carnivore or omnivore, taking aquatic and terrestrial invertebrates — insect larvae, small crustaceans, and surface-fallen insects — as well as any available plant matter or detritus.
Lebiasina species are active, surface-oriented foragers in life, which is consistent with their streamlined body and upturned or terminal mouth. In the aquarium, the related species in the genus have been maintained on live and frozen invertebrate foods, high-protein prepared foods, and occasional plant-based items. Any aquarist keeping L. chucuriensis should default to a similar varied, protein-rich diet supplemented with live or frozen foods to maintain condition.
Mating
No detailed behavioral observations of courtship or mating in Lebiasina chucuriensis are published in the accessible literature. Within the family Lebiasinidae, reproductive strategies vary by genus: some genera such as Copella practise above-water leaf-spawning with male splash-guarding, while others scatter eggs more conventionally among submerged vegetation without parental care.
Lebiasina itself is generally reported as a substrate-spawning or open-water egg-scattering genus rather than a leaf-spawner, with males likely displaying lateral coloration and fin extension before females. Given the family context — small clutches, adhesive or semi-adhesive eggs, and at least in some allied genera a degree of selective spawning site choice — hobbyists observing spawning behavior in this species would contribute genuinely to what is known.
Breeding
Captive breeding records for Lebiasina chucuriensis are not documented in the accessible literature. Based on family-level patterns for Lebiasinidae and the genus Lebiasina, the species is expected to be an egg-depositing spawner, with adhesive eggs placed on a substrate or among fine-leaved vegetation. Parental care, if any, is likely minimal or absent, consistent with most Characiformes.
For aquarists attempting to breed the species, a setup mimicking the natural stream environment — well-oxygenated, slightly acidic to neutral water, with a substrate of fine gravel and leaf litter, and bunches of fine-leaved plants or spawning mops — would be a reasonable starting point. Separating eggs or fry from adults after spawning is advisable given the general absence of parental care in the family. Fry would require very fine live or prepared foods at first, graduating to small invertebrates as they grow.
In the aquarium
Lebiasina chucuriensis is a specialist aquarium fish, rarely imported and essentially absent from the mainstream trade. Its natural upland-stream origin points toward a tank setup with good water movement and oxygenation, a moderate temperature in the low-to-mid 20s Celsius, and slightly acidic to neutral water — approximating the clean, cool-ish Andean foothill streams of northern Colombia. A long, well-filtered aquarium with open swimming space and shaded retreat zones using overhanging plants or driftwood would suit the species well.
Given its size — to nearly 6 in — a tank of at least 39.5 in in length is appropriate for a small group. Like other lebiasinids, the species is likely best kept with similarly sized, robust companions rather than small or slow-moving fish it might outcompete. Its rarity in the trade means that any aquarist acquiring this species is in a position to document husbandry details that are genuinely absent from the published record.
Conservation
Lebiasina chucuriensis is assessed as Least Concern on the IUCN Red List, with the assessment conducted on 10 October 2014. The Least Concern rating indicates that at the time of assessment the species did not meet the quantitative thresholds for a threatened category, and that no immediate severe decline was detected across its range in the northern Colombian Magdalena basin.
Nonetheless, the Magdalena River basin faces ongoing pressures typical of developed tropical river systems: agricultural runoff, sedimentation from cattle pasture and crop farming, deforestation of riparian corridors, and hydrological alteration from water extraction and small-scale damming of hill streams. As a species known from a restricted area of the Santander department, L. chucuriensis would be vulnerable to localized habitat degradation. Its status should be re-evaluated as survey data from the Colombian Andes improves, particularly given the taxonomic activity in Magdalena-basin lebiasinids in recent decades.