Green terrors are great fish to have. My first ever male was purchased at about 4 cm but I've had him for three years and he is now about 27 cm long and 9 cm high. I had a breeding pair and had 4 loads of babies. I kept one from the first batch that is now about 19 cm long. Wouldn't trade these fish.
In my honest opinion here is another cichlid who is vastly undeserving of its name. Although they can be aggressive, they lack the physical skill to truly dominate other fish. Their fins are long and flowing, which reduces speed; their jaws are week and tear easily; and their scales can easily be displaced by another fish. Even more so than all that, they lack the mental toughness to live with the heavy duty Central American cichlids. It seems that all it takes is one or two minor disputes for them to stress out and stop eating. From there, they just seem to waste away. They just cannot tolerate the normal day to day rough and tumble activites that occur in most cichlid tanks. I recently lost a 23 cm male to a 20 cm false red terror. It was not so much the physical damage that killed the green terror, I think it was the mental damage. After the two fish fought, the green terror became skittish and stopped eating. He hid constantly for 2 days, until I found its mostly undamaged body behind a rock. The negligible amount of damage done to it suggests that simple stress killed it. In my opinion, these fish are best left to speices tanks where they don't have to fight or compete.
I had a 28 cm Green Terror in a 1000 L tank with a 35 cm Red Devil. The RD and the GT lived together for 3 years. On the 3rd year the RD started beating up on the GT. Two months after he started to pick on the GT, the RD was getting scales removed. I thought the GT could not do it because he was smaller. One day I saw the the RD speed across the tank. I looked and saw the GT biting the 35 cm RD. I never knew GT's could be so strong and fearless, but then again the devil made him do it. I put the RD in another tank so he and the GT could live in peace.
I see a lot of comments about how aggressive this fish is. When you have a big tank (at least 500 liters) the aggression will be a lot less. Sure, there will still be fights, after all they are big cichlids, but the chance that they kill another fish is greatly reduced. I also want to add that this fish is not THAT hardy, because I never got a sick fish except for 2 Green Terrors who stopped eating out of nowhere. They didn't die though, and I got them to eat again.
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