The Black Widow Tetra is an ideal and popular community aquarium fish that can be kept with many other fish species. Such as Corydoras, Plecos, more temperant Barbs such as the Denison Barb and other similar tetras also from Brazil, including the Black Phantom Tetra.
More aggressive barbs such as Tiger and Black Ruby Barbs should be avoided, especially with the longfin variant of the Black Widow Tetra.