Instructions
Determine the aggression level of the fish. If you see your fish bullying, chasing, or nipping at other fish, there is a good chance it is a true green terror cichlid. If the fish is somewhat more peaceful, it is possibly a blue acara. Green terrors are most often confused with the blue acara cichlid, and at one time they were thought to be the same species. Most cichlids are aggressive to some degree, so temperament can sometimes be deceiving when trying to determine true and false green terrors.
Examine the size of the fish. Both green terror cichlids and blue acaras grow to about 8 inches long. However, another false green terror, the gold saum, grows to between 9 and 13 inches long. If you have a particularly large fish, you can be relatively sure it is a false green terror.
Observe the frontal bump on the head of the fish. This bump is a hump-like protrusion that mature fish develop. This hump may grow both up and out, and sometimes projects slightly over the front of the head. Green terrors develop much larger humps than blue acaras. However, the gold saum also tends to develop a large hump, so more than this one determining factor will need to be taken into account.
Observe what the fish likes to eat. Gold saums are omnivorous. They are not choosy about what they eat, and have no problem taking herbivorous or meaty foods. Blue acaras and green terrors, on the other hand, are both carnivorous. If the fish you have does not like to eat herbivorous foods, it is most likely either a green terror or blue acara.
Look at the coloring at the edges of the fish's fins. True green terror males develop bright yellow, red, or white markings around the edges of their fins. Blue acara fish are completely a bluish color, with no brilliant markings around the fins.
Look at where the fish tend to swim in the aquarium. True green terror cichlids like to swim in the bottom and middle regions of the aquarium. False green terrors tend to swim in all areas of the aquarium, without sticking to one region.
How to Tell a True Green Terror From a False Green Terror
The green terror is a type of cichlid, a freshwater fish. Green terror cichlids grow to be about 8 inches long. They are aggressive and require a large amount of space. However, green terror cichlids make up for their difficult keeping by being stunningly colored and patterned. Green terror cichlid males appear in metallic shades of greens, browns, blues, and yellows. Females are a more all-over green color. These fancy fish are often confused with other fish, such as the blue acara and the gold saum, which are sometime sold as green terrors, although they are not.