black widow tetra's are ace if you keep them in a tank with lots of light the black line on them goes lighter and if you keep them in a dim tank the black line gets darker.

Cute tetra.. they were my brother's first fish, years ago. They died about a month ago. They got eaten by a cichlid! ( they were about 4 years old. )

i have found, the happier the fish - the darker they become. they are supposed to be black. if they are silver then there is something stressing them

i have 2 of those in my tank the one has dark fins and the other has red fins but they are a nice fish :woo: