They are native to South America, mainly Colombia, Venezuela and Brazil, in the basins of the Amazon, Orinoco and Negro rivers. They inhabit warm and acid waters, where the arboreal vegetation produces shade.
It is a peaceful fish, which lives very well in groups of more than six individuals. If the group has less than six individuals, you can share the aquarium with Neon Tetra individuals. It serves as an indicator fish, because if there are predatory fish in the aquarium, other more timid fish can move more calmly in the presence of the Neon Cardinal, since they form tight groups when feeling scared.