Glass Knifefish

Glass Knifefish (Eigenmannia Virescens)

Glass Knifefish, also known as Glass Catfish, are fascinating, transparent fish with elongated, knife-like bodies. It moves in a graceful manner by rippling by a long fin that stretches the length of its belly, thus allowing it to swim forwards or backward with ease.

This fascinating nocturnal possess a mildly discharging neurogenic electric organ and ampullary electroreceptors distributed throughout its body. This enables the fish to both detect and emit electrical impulses. Primarily used for electro-location, navigation, and communication, these electrosensory systems are relatively weak compared to other electric fish and pose no threat to aquarium enthusiasts. Their nearly invisible appearance makes them a unique and eye-catching addition to any larger aquarium.

In captivity, Glass Knifefish can grow up to 18 inches in length, although 12-14 inches is usually considered an average size. Glass Knifefish are shy and timid fish. Unlike many other knifefish species, they thrive in groups of their own kind and should be kept in groups of at least 5 to feel secure. Within the group, they establish a hierarchy of dominant and submissive fish but generally do not inflict harm upon one another.

Suitable tankmates include other non-aggressive, similarly-sized fish such as larger tetras, peaceful cichlids, and Corydoras catfish. It's essential to avoid fin-nippers or overly boisterous species that may stress these timid fish.

Glass Knifefish are carnivorous, primarily feeding on insect larvae, small crustaceans, and worms in the wild. In captivity, they can be offered a varied diet of live and frozen foods such as bloodworms, brine shrimp, and daphnia. They tend to be more active during the night, so offering them food in the evening is recommended.

Glass Knifefish prefers a dimly lit tank with plenty of hiding spots and dense plant cover. A sandy substrate is recommended for their delicate barbels as these fish like to scavenge for food. Due to their nocturnal behavior, knifefish should have a variety of shady hiding spots during the day, such as wide PVC pipes, horizontally positioned flowerpots, secure rocky caves or overhangs, and large driftwood clusters. Without such hiding spots, they may become stressed and attempt to squeeze into any dark space available, potentially causing injury to themselves.

As nocturnal fish, Glass Knifefish are sensitive to intense light, so the aquarium lighting should not be too bright. If some parts of the tank need bright lighting, use broad-leaved aquatic plants and floating species to help diffuse the light. Including dark areas in the tank where the fish can retreat during the day as needed is crucial.

A well-established filtration system, along with a supply of highly oxygenated water and moderate water flow, is essential for the proper care of the Glass Knifefish. Diligent maintenance routine that includes weekly water changes of 30-50% of the tank volume. Since knifefish are sensitive to poor water conditions., water tests must be done weekly to ensure levels are well within recommended parameters.
Knifefish do not have scales, making them susceptible to injuries and infections. Therefore, installing a UV sterilizer in the tank may be wise to eliminate pathogens and safeguard against the need for using chemical treatment in their water.

The minimum aquarium size of 60 gallons for juveniles, with an ideal community tank size of 100 gallons or more for adult Glass Knifefish. Maintain a pH of 6.0-7.5, a hardness between 5-12 dGH, and a temperature range of 75-82°F (24-28°C).

Glass Knifefish, like many other fish species, have the potential to jump out of the aquarium if given the opportunity. To minimize this risk, it is essential to have a well-fitted and secure lid or cover on the tank. This will prevent the fish from jumping out and help maintain the tank's water quality by reducing evaporation and limiting the introduction of foreign contaminants.