What environment does a black ghost knife fish live?

The black ghost knifefish, Apteronotus albifrons, is found in slow-moving, blackwater rivers and streams in the Amazon and Orinoco river basins of South America. These rivers have soft, acidic water with a pH between 4 and 6, and a temperature range between 77 and 86 °F (25 and 30 °C). The black ghost knife fish lives in deep, tannin-stained waters, where the tannins from decaying vegetation give the water a dark, tea-like color. This coloration helps the fish camouflage itself from predators and prey. The black ghost knife fish is also found in areas with dense aquatic vegetation, which it uses for cover and foraging.