Glass Knifefish (Eigenmannia virescens) Care Guide
Eigenmannia virescens is a gregarious South American electric knifefish with a translucent green body that tolerates conspecifics.
Overview
Eigenmannia virescens, the glass or green knifefish, is a weakly electric freshwater fish of the family Sternopygidae from South America. The body is elongated and translucent green, and the species relies on electric organ discharge for species and sex recognition.
Taxonomy
- Family: Sternopygidae
- Genus: Eigenmannia
- Scientific name: Eigenmannia virescens
- Common synonym: Green Knifefish
Habitat
FishBase reports the species as widely distributed east of the Andes from the Orinoco to the La Plata basins, with Wikipedia adding records from the Magdalena basin to the Rio de la Plata. It prefers deep still waters in ponds and creeks over plant-debris substrate and reaches about 44 cm SL.
Tank requirements
- Minimum tank volume: 400 L
- Temperature: 24-28 °C (75-82 °F)
- pH: 6-7.5
- GH: 4-15 °dGH
- Group size: keep in groups of 4 or more
- Lifespan: 6-12 years
- Substrate: sand
Diet
The glass knifefish is a carnivore. It is fed once daily on meaty and live foods in the aquarium.
Compatibility
FishBase describes the species as gregarious, timid and nocturnal. Unlike the territorial Apteronotus knifefishes it tolerates conspecifics and is best kept in groups. It is peaceful and occupies the middle of the water column; suitable tankmates include larger tetras and Corydoras, while aggressive fish and tiny fry should be avoided.
Conservation status
IUCN Red List: Least Concern (assessed 2020).