Elegant Pencilfish

Geographic Origin and Biotope: Amazon River Basin (Santarém Region, Brazil). Frequents flood lakes, oxbow lakes and debris-laden "Igarapés" in forested areas in dim light.

Taxonomy and Morphology: Elegant Pencilfish (Nannostomus limatus). Intermediate morphology between the large N. beckfordi and the tiny N. marginatus. Very slender, has a classic horizontal posture.

Social Behavior: Stationary gregarious. Less inclined to endless duels than the beckfordi. Hovers quietly among the plants waiting for the current to bring small organisms.

Coloration and Sexual Dimorphism: Cream-bronze base color with a thick dark line (sometimes dotted or broken) and an evident red and black spot on the anal fins (especially in males). It differs in the elegance of the pattern compared to beckfordi. Females are pale.

Aquarium Setup: 60 cm (24 inches) tank richly planted (Limnophila, Cabomba). It is essential to insert visual barriers of woods and plants to limit the stress induced by the open visual field.

Diet and Feeding: Acute micropredator. Very timid at mealtime, refuses foods that fall quickly (hard granules) preferring floating live foods (midges) or suspended brine shrimp nauplii.

Water Quality: Soft and acidic water. Does not appreciate sudden changes but tolerates weak currents if the aquarium is well shielded by woods and plants.

Compatibility and Tankmates: Excellent inhabitant for small Amazonian "Blackwater" tanks, to be combined with peaceful fish (Corydoras, small Loricariids, Marbled Hatchetfish / Carnegiella strigata).

Aquarium Reproduction: Very rarely intentionally bred. They release very few eggs among mosses (Vesicularia dubyana) and ruthlessly eat their own brood immediately after the act.

Risks and Diseases: Commercial extinction: Given the difficulty in distinguishing it (often sold as "Pencilfish sp. or female N. beckfordi") the aquarist risks finding unpaired specimens unable to form hierarchies, which leads them to death from solitary stress.