Fish Id??

  • We are currently upgrading MFK. thanks! -neo
To me it looks like about 300 species of South American cichlids, because at that size and age most look alike.
If it was sold as a green terror, it probably is (or at least in the Aequidens/Andinoacara clade) because they are common in the trade.
The line below the eye, is a South American trait.
Take this young Andinoacara coerleopunctatus below (very close cousin to a G.T.)
4AA4C228-0722-4F7C-8AB8-2731FB0AD85C_1_201_a.jpeg
Same line below the eye, same mid body blotch, and note how the caudal spot, does not cover the entire height of the caudal, and is not centered.
In Central Americans
The caudal spot often more centered and spans almost the entire height of the caudal.

In most South American cichlids the spot is situated in the upper half of the caudel, and doesn't fill the entire space
As in this Mesoheros gephyum

or festae.

Other South Americans could be from the genus Aequidens, Cichlasoma, or even the Geophagus braziliensus clade.
 
Based on the overall shape and the blue coloring at the bottom of the gills it looks like A. rivulatus to me.
 
MonsterFishKeepers.com