odinthejd;3986882; said:
Maybe they have grown up with each other since being fry???
I've grown out broods of fry together oin many occasions and saw plenty of aggression within the brood as they grew. I think there is a lot more to it than just raising them together and I think growing fish out together is an over emphasized method of avoiding aggression...
FishFreak95;3986904; said:
Ive seen overcrowded tanks tend to have less aggression but I do not support it. Maybe they are so cramped they have no room to fight
I think this explaination is much closer to the truth. Red Devils and most other CA fish are territorial, meaning they will fight very aggressively to defent their territoty. But when a tank is grossly overstocked the fish do not claim a territory.
I refer to this as holding tank syndrom. This is also the reason fish in pet shops often coexist in situations (short term) that we could not get them to (long term) in our homes.
David R;3987228; said:
Same reason african cichlid keepers tend to overstock their tanks. If you took out half the fish you'd probably see a lot more fighting/damage. None of the fish have room to form a territory and there are enough fish to spread the aggression between.
I tend to disagree here. Many of the African Cichlid species are colony fish and thus have evolved to live in groups. Red Devils (as mentioned here) and most other CA Cichlids have evolved to be solitary or pairing fish...
dlp40;3988958; said:
One such place in my area had a 14" male FH in with 20 6" Blood parrots in a 90 Galllon with one AC 500 for filtration. But then just the other week the FH kicked the bucket and the tank was drained. He died of some terrible face eating bacteria. It was bad for about three months before he died, poor guy.
Poor water quality is another way to lower aggression... not a very good idea and will yield many other undesirable results, but it'll work...
Another detail regarding heavily stocked tanks...
There will always be a "pecking order"... but when the toughest fish realizes in the process of fighting a weaker fish, he will likely get injured and thus not be at his best, he will not want to risk injury making him vulnerable to attack from the #2 fish...
While it is possible to find a point of equilibrium in such a tank that "no aggression" is the result, it's a very touchy situation. If the balance is tilted and the pecking order is disturbed, there will likely be a lot of blood shed as the pendulum swings...