Above Astyanax and Brycon tetras (possibly Brycomamericus)caught on 8.2, hard water.
Below Brycon behreae, or guatemalensis
Ctenolucius beani
below one of the vampire tetras genus Roeboides
Below in the tank, with mountain mullet (Dajaus monticola) species that also do a good job at dithering
Most of these are young, 4 "to 6", and are perfect dither species for medium to large cichlids, but they can get larger.
I've seen them 12" to maybe 14".
They range from the Carolinas, Florida, and Texas, in North America to Brazil in S America.
One we caught here in Panama I considered too big for my 180 gal, so my guide Dani took it home for dinner.