Glass Knifefish

Eigenmannia virescens is widespread across the Amazon, Orinoco, and Río de la Plata basins, inhabiting slow-moving, vegetated waters with soft substrate. Its body is highly translucent — the viscera are visible through the flanks — with a greenish or yellowish tint giving it its common name. Unlike Apteronotus species it produces a wave-type EOD at lower frequency and is notably more tolerant of conspecifics when kept in groups of 4 or more. It is active at night and can be trained to accept frozen foods. A rewarding entry-level knifefish that forms the backbone of many South American biotope displays.

Water: 23-28°C, pH 6.0-7.5, soft to moderately hard; clean water with moderate flow. Tank: Minimum 200L; fine sand; PVC tubes or bamboo hides; low lighting; planted tank suitable. Feeding: Carnivore; live/frozen bloodworms, brine shrimp, tubifex; feeds mainly at dusk and night. Breeding: Egg-scatterer in vegetation; rarely achieved in captivity without hormonal induction. Compatibility: Can be kept in groups; peaceful with similarly sized non-electric fish.