There are 16 valid species of Cichla, in S America and some are restricted to quite small localities.
It might help narrow things down by knowing catch location, if caught in SA.
Otherwise the distinctions could be as small as number of spots (or the lack thereof) on the anal fin, or count of bars below the dorsal.
If "not" caught in SA but some other spot where feral Cichla are common (Florida, Panama, etc etc) the possibility of a hybrid is always there.
It might help narrow things down by knowing catch location, if caught in SA.
Otherwise the distinctions could be as small as number of spots (or the lack thereof) on the anal fin, or count of bars below the dorsal.
If "not" caught in SA but some other spot where feral Cichla are common (Florida, Panama, etc etc) the possibility of a hybrid is always there.