Glass knifefish

The Glass Knifefish, also known as the Eigenmannia virescens or sometimes referred to as the Green Knifefish, is a unique freshwater species native to South America, particularly found in river basins such as the La Plata River Basin and east of the Andes. This knifefish species is widely distributed in these regions and is known for its distinct transparent or translucent body, which often has a slight greenish hue. Its elongated, knife-like shape, combined with its nearly invisible appearance, allows it to blend seamlessly into its surroundings, especially in waters rich with aquatic plants and substrate rich in plant debris.

Though moderately well-known among aquarium enthusiasts, this species is often sought by those interested in more exotic or unusual fish. Their interesting behavior and striking appearance make them a fascinating addition to any home aquarium, though their care requires a bit more expertise than more common freshwater fish.