''Melanosternarchus'' is a genus of

ghost knifefish The ghost knifefishes are a family, Apteronotidae, of ray-finned fishes in the order Gymnotiformes. These fish are native to Panama and South America. They inhabit a wide range of freshwater habitats, but more than half the species in the family ...

found in the

Amazon Amazon most often refers to: * Amazons, a tribe of female warriors in Greek mythology * Amazon rainforest, a rainforest covering most of the Amazon basin * Amazon River, in South America * Amazon (company), an American multinational technology c ...

basin of

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

South America. The single species in this genus, ''Melanosternarchus amaru'' is primarily found in the deep channels of large

blackwater river A blackwater river is a type of river with a slow-moving channel flowing through forested swamps or wetlands. As vegetation decays, tannins leach into the water, making a transparent, acidic water that is darkly stained, resembling black te ...

s. This species can be recognized by its large mouth, slender body and an absence of scales on its nape and dorsum. Its maximum recorded size is 272 mm (10.7 inches).

References

Fish of South America Apteronotidae Monotypic freshwater fish genera {{Gymnotiformes-stub