Black Phantom Tetra --- Hyphessobrycon megalopterus.... The black phantom tetra (Hyphessobrycon megalopterus) is a freshwater fish of the characin family (family Characidae) of order Characiformes. It is native to the Paraguay, Guaporé, and Mamore river basins in Brazil and Bolivia. This fish is of roughly tetragonal shape, light grey in coloring, with a black patch, surrounded by iridescent silver edging, posterior of the gills on each side. The male's fins are black, as is the female's dorsal fin; the female's pelvic, anal, and adipose fins are reddish in color. A long-finned variety, apparently developed by captive breeders, is sometimes sold (the male has elongated dorsal and anal fins even in the wild form). The black phantom tetra reaches a maximum overall length of approximately 4.5 cm (1.75 in). The black phantom tetra's natural diet consist of small crustaceans, insects, and worms. Should be Kept in a school of 5 or more fish, the Black Phantom Tetra will retain its full coloration. However, a solo tetra will most likely lose all of its color. By utilizing tall plants, and driftwood, this mid-level swimmer will be much more visible to observers as the fish will be less inclined to be skittish.