extremely aggressive discus- HELP!

[lafleur]

Hi all,

One week ago i bought 3 new discus for my tank (that already had 3) and one of the older discus is EXTREMELY aggressive and dominant to all other discus now, including his old tankmates! The other discus are now showing signs of fin damage and the dominant one likes to "box" them into a corner of my tank and not let them go anywhere or eat.

Any suggestions? He has never been like this before.

[Hollowman]

Hi Lafleur,

First things first, you have risked the lives of all of your fish just by not following the most basic discus rule, which is quarrentining new fish. Your new fish might have carried in a pathogen which can attack the old fish, and vice-versa. :(

Ok, the agression thing is just nature, these fish are Cichlids, and therefore very territorial and they do have a dominance ranking in the tank.
Is the tank planted or BB? Sometimes you can take the offender out for a few days, re-arrange the plants, ornaments, wood, and reintroduce the fish and being in unfamiliar surroundings will settle in again.....until it finds out it is top of the tree again. :shock:
How big/old are the fish? could be a male female thing.
As for feeding, try feeding at both ends of the tank so the aggressor can have his, and the others get a chance to feed too.

hth

Hollowman

[lafleur]

Actually they were bought from a friend who is a breeder, i watched them grow from fry and see her tank every week, thats why i felt there was no need to quarantine. I have already tried re-arranging the planted tank but it just doesnt seem to work. Any other ideas?

[Hollowman]

Ok, at least getting your fish from the same supplier helps a little, but there is always a need for QT imo.

What are there size?