Characin Fishes Family
A Family of Characinoides Genus.. Including Tetra etc...
Aquarium Fish Guide
Only 3 or 4? That doesn't sound quite right. Try at least 8, the more the merrier. And the fish in the picture is cardinal tetra, not neon tetra.
Let's do Some Zoology!
Black-winged Hatchetfish (Carnegiella marthae) …a species of freshwater hatchetfish (Gasteropelecidae) that is native to South America, Primarily the Rio Negro and the Orinoco. Like other freshwater hatchetfish C. marthae lives close to the water’s surface and feed mainly insects, which are caught by jumping and gliding out of the water.