I know many aquarists don´t like to perceive geography, or continental divisions as important factors when combining cichlid species,
but the differences in inate aggression tendancys are significant between Central American cichlids, and those from west of the Andes that live in in sparsly inhabited cichñid communities,
from those from east of the Andes that live in areas, where evolution has forced species diversity cichlids to coexist.
In Central America, and rivers west of the Andes, often only two or a few cichliids share an entire river system and its tributaries, millions of gallons.
Whereas east of the Andes various cichlids are combined ind forced to coexist.
When we as aquarists buck natural trends by ignoring those diametrically opposed evolutionary norms, that mother nature set up,
in our realistally tiny tanks, its no surprise sometimes things go haywire.
Here in Panama, I often only find only 2 species of cichlids living a vast area in the same river system,
but even then, they are often inhabit separate flow rate areas, so seldom impede on each others turf.
Andinoacara coeruleopunctatus prefer oxbows, and slower flow areas,

while Darienheros, riffles and faster current streams.
Geophagus crassilabris riffles,

while Istmoheros more sedate flow rate areas.
