Gilbertolus atratoensis is a small but remarkably specialised predatory characin from the Atrato River drainage of northwestern Colombia. Its distinctive upturned mouth and enlarged, fang-like teeth are adaptations for snatching insects from the water surface or striking at small fish from below — a unique hunting strategy among characins. It grows to only 12 cm but is a fierce, active predator that should not be underestimated by the species it can consume.
In the aquarium, Gilbertolus atratoensis does best in a species-specific or specialist blackwater setup of at least 200 litres, with soft, acidic water, tannin-stained conditions, and floating plants that help it feel secure at the surface. It is a surface and upper-water-column fish that hunts in the surface film and should be provided with a tightly fitting lid as it will jump readily.
This species is rarely available in the trade and represents a genuine specialist find for aquarists interested in unusual predatory characins and Colombian blackwater biotopes. Feeding on live or frozen invertebrates — crickets, mealworms, frozen bloodworm, and small live fish — is recommended. Its fascinating hunting posture and rarity make it a prized oddity.
