Taxonomy & naming
Lebiasina astrigata was described by the British ichthyologist Charles Tate Regan in 1903. The genus Lebiasina, established by Valenciennes in 1847, is placed within the family Lebiasinidae — the pencilfish family — which in turn belongs to the order Characiformes. Lebiasinidae comprises a morphologically diverse assemblage including the pencilfish (subfamily Nannostominae), the splashing tetras (Copellinae), and the lebiasinines (Lebiasininae) to which Lebiasina belongs. Eschmeyer's Catalog of Fishes treats Lebiasina astrigata Regan, 1903 as the valid name.
The genus Lebiasina contains roughly a dozen recognised species distributed across northern South America, occupying both Pacific-slope and Atlantic-slope drainages. The lebiasinines are often regarded as the most plesiomorphic lineage within the family, retaining a more generalised body form than the highly modified pencilfish. Lebiasina species are sometimes confused with one another due to overlapping pigmentation patterns, and species-level identification can require close attention to scale counts and the extent of markings.
Morphology
Lebiasina astrigata is a small, moderately elongate fish with a cylindrical to slightly compressed body, a blunt snout, and a moderately large mouth adapted for opportunistic feeding. Like other lebiasinines it lacks the adipose fin, and the caudal fin is forked. The body is covered in relatively large scales. Coloration is generally brownish to olivaceous dorsally, paler on the flanks and venter, with a series of dark blotches or a broken lateral band that may vary in intensity with mood, condition, and preservation.
The specific epithet astrigata refers to the absence or reduction of striping — the name derives from Latin, with the prefix a- (without) and strigata (striped), indicating a less distinctly banded pattern compared to other Lebiasina. In life, some iridescence along the flanks may be apparent under oblique light. Size data for this species is sparse in the available sources; as with other small lebiasinines it is likely to reach somewhere in the range of 2–3 in total length at maturity, though precise maximum size should be treated as approximate pending verified records.
Habitat
Lebiasina astrigata is recorded from Pacific-slope drainages of Colombia and Ecuador, a region characterised by short, fast-descending rivers and streams that drain the western Andes to the Pacific Ocean. These streams vary from relatively clear upland riffles to murky, tea-stained lowland channels, with water conditions that fluctuate substantially between wet and dry seasons.
Like other Lebiasina species, L. astrigata is associated with shallow, often structurally complex habitats — stream margins with leaf litter, submerged root masses, and overhanging vegetation providing cover. The genus is notable for tolerance of hypoxic conditions; lebiasinines can use aerial respiration and access atmospheric oxygen directly, allowing them to persist in stagnant pools, irrigation ditches, and small watercourses that other fishes abandon during the dry season. Water temperatures in these Pacific-slope streams typically range from the low to mid 20s Celsius, with pH varying from slightly acidic to near-neutral depending on substrate and catchment geology.
Feeding
Lebiasina species are opportunistic carnivore-omnivores, feeding primarily on small invertebrates including aquatic insects, insect larvae, terrestrial invertebrates that fall onto the water surface, and small crustaceans. The relatively large mouth for a fish of this size suggests a preference for larger prey items relative to pencilfish or small characins.
In captivity, L. astrigata and its congeners accept a wide range of foods without difficulty: small live and frozen invertebrates such as Daphnia, brine shrimp, bloodworm, and chopped earthworm, as well as good-quality small pellets and flake. The species is an active forager and benefits from varied feeding to maintain condition. It may be bold enough to take prey from the surface film, reflecting an opportunistic surface-feeding component in the wild.
Mating
Specific courtship data for Lebiasina astrigata are not well documented in the available sources. Based on what is known of the genus and the broader Lebiasinidae, lebiasinine fishes are egg-scattering open spawners without parental care, depositing adhesive or semi-adhesive eggs among fine-leaved plants, leaf litter, or other substrate. Males likely engage in brief, active pursuit of females during spawning events rather than elaborate sustained courtship displays.
As with many small characoids from seasonally variable environments, reproductive activity is probably linked to seasonal cues — rising water temperatures, changes in photoperiod, or the onset of wet-season conditions — though captive specimens may spawn in the aquarium with little prompting when in good condition.
Breeding
Lebiasina astrigata has not been widely documented in the aquarium breeding literature, and detailed captive-breeding accounts are sparse. Based on the general lebiasinine pattern, spawning likely involves egg-scattering over fine-leaved plants or spawning substrate, with small to moderate clutches of adhesive eggs deposited over short spawning sessions. Adults do not guard eggs or fry and will consume eggs given the opportunity, so removing adults or harvesting the spawning medium after spawning is advisable.
Eggs are expected to hatch within several days at typical tropical temperatures, with fry becoming free-swimming shortly after. First foods for the fry would be infusoria and rotifers, graduating to newly hatched Artemia nauplii as size permits. Specific incubation times and fry sizes for this species are not captured in the available sources, and aquarists should treat any figures from general Lebiasina accounts as indicative rather than verified for L. astrigata specifically.
In the aquarium
Lebiasina astrigata is seldom encountered in the mainstream aquarium trade and is primarily of interest to enthusiasts of South American small fishes and Lebiasinidae specialists. It is a robust, undemanding fish suited to a species tank or a community of similarly sized, peaceful fishes that will not outcompete it. A tank of 23.5–31.5 in with subdued lighting, a dark substrate, leaf litter, and dense planting at the margins provides conditions close to its natural habitat and encourages natural behaviour.
Water parameters should be soft to moderately hard, slightly acidic to neutral (pH 6.0–7.5), and temperatures in the range of 72–81 °F. Good filtration and regular partial water changes are important, though the species' tolerance for marginal conditions means it is more forgiving of lapses than many characins. It is best kept in a small group, as a solitary fish tends to be shy. Feeding is straightforward; offer a varied diet of small live and frozen invertebrates alongside a quality dried food as a staple. Availability in the hobby is intermittent and largely through specialist importers or hobbyist networks rather than general retail.
Conservation
Lebiasina astrigata has not been assessed by the IUCN Red List and carries no formal conservation status at this time. Its Pacific-slope habitat in Colombia and Ecuador falls within a region that has experienced significant pressure from agricultural expansion, particularly for banana, oil palm, and shrimp farming, as well as from gold mining and deforestation of riparian corridors. These threats apply broadly to Pacific-slope stream fishes in this region and are of concern even where individual species have not been formally evaluated.
The genus Lebiasina as a whole is not regarded as globally threatened, and the tolerance of individual species for degraded conditions likely provides some buffer. However, the restricted ranges of many lebiasinine species and their association with specific drainage systems mean that localised habitat loss can have disproportionate effects. A formal IUCN assessment for L. astrigata would help clarify whether its range and population trends warrant concern. In the interim, the absence of a status designation should not be read as evidence that the species is secure.