I agree with newworld
Looks like Mesoheros gephyrus, from the rivers west of the Andes.
You can tell its South American by where the spot in the caudal peduncle is located in the upper fleshy half of the peduncle
I edited your shot to get a closer more detailed look.
Below are a couple I had, sometimes sold as M ornatum..
Note the spot of the 2nd shot, in the top half of the peduncle