Can an aggressive fish be "conditioned"?

[underwaternut]

I've had a Peacock (gorgeous-strongly resembles a Lwanda Red Top) for about a year. Up until now he's be fairly peaceful. All of the sudden he started chasing everything in the tank. I caught him in one of my larger nets and wound up overlapping the net (so he couldn't escape) while I tried to figure out what to do. After a couple of hours I decided to let him loose to see what effect his "punishment" might have on his behavior. He brooded for a while in he corner but after that he came out and was acting normal. He swam past other fish minding his own business and I observed him for the rest of the evening. However, the next day he was back at it chasing fish three times his size. So, back in the net for some more "quite time". He's fine in the net. I mean he doesn't go bezerk even when other fish swim by so that got me wondering. Would restraining a fish who isn't normally an aggressive fish cause them to modify their behavior? What do you think?

 

[rich311k]

I think a fish will be true to his nature. He is probably sexually mature now, and he will continue to be aggressive and protect his turf.

 

[manoosie]

I tried that exact thing a few days ago. I doubt it will work, I am thinking my yellow lab needs more males...

 

[Zagz]

I tried that exact thing a few days ago. I doubt it will work, I am thinking my yellow lab needs more males...

Your female is getting aggressive? :?

 

[Tiffi]

Fishes can't think about the connection between chasing others and having to sit in a net as punishment. Either they will forget after a while what happened to them, or if they are cleverer they will do it when you're not around. I just think fishes cannot reason!

 

[TankGirl]

I had a peacock that totally ruled a tank with haps and mbuna. He was a total terror and I wound up having to sell him off and completely redo the tank. He was gorgeous (click on the gallery link in my sig) and I really hated to get rid of him, but he needed to be in at least a 90g with many more peacocks.

I don't think there is any way to modify their behavior, except drastic changes in environment and tank mates.

 

[Puriti]

I had a male betta that went after my dwarf gouramis (one of my first male bettas for my first tank) and I sat there for probably a half hour and everytime he went after my dwarf gourami I scooped him up in the net, took him out of the water (just above the tank water) for 2-3 seconds then put him back in. I did this maybe about 4 or 5 times that one day and maybe 1 or 2 after that a couple times, but that betta didn't bite my dwarf gourami again for as long as I had him(as far as I could tell anyways), I mean he flared at them but he didn't ATTACK him and he turned out to be a pretty good fish considering the brat he was the first week I had him.... But that's just my experience in that :? I dunno about other fish though...

 

[Zagz]

I don't believe fish can be conditioned to not be aggressive, esp if it is in their nature to be aggressive.

 

[Puriti]

Yeah, even if my fish was "trained" not to go after my gourami didn't take the agressiveness out of him

 

[TomK2]

Well, I had an Angel that was agressive. It was added to the tank with three similarly sized new angles, to join four smaller established Angel residents. It proceeded on harrassing first the larger angels, then when they were dead, the smaller ones. I saved one large angel by putting it in a QT, but when it went back in with the agressor things started all over again.

So I put the agressor in the QT for a few days, redecorated the main tank, let the main tank settle down for those few days, then re-intoroduced the agressor. The harrasment repeated. I put the agressor back in the QT, again rearranged the main tank decor, let the main tank settle down, and kept the agressor in the QT for 2 weeks. During the 2 weeks in the QT I repeatedly rearranged the decor in the QT every few days to try and bewilder the agressor.This time, when it was reintroduced the agression was markedly less (really just posturing, no actual harrassment), and after a few days it was buddies with the other large angel and peace has prevailed since.

I was lucky, I guess, but I think that putting the agressor into isolation, "bewildering" it with repeated redecorating, and letting the main tank settle down and become established and confident worked. The theory was that the main tank would feel established, confident, at home, and unwilling to put up with a newcomers agression, and when the agressor went back in it would be a little confused and less confident, looking to fit in rather than fight .

Chastising or harrassing an agressor by netting it or chasing it around while it is still in the main tank won't work. If anything, it would feel threatened and want to fight more for its turf. But if you can convince it that it is no longer on its home turf, perhaps it will settle in with the other fish? If you have a QT, its worth a try.

 

[Feeding_Frenzy]

overstocking helps reduce agggression down because overcrowding makes it more difficult for the fish to establish a territory, this reduces aggression. This technique is called controlled crowding The overcrowding does mean that good filtration & plenty of water changes are essential