Oscar Aggression

[BHA]

I have an oscar that is a little over a foot long and I have had him since he was very small. He recently has shown a lot of aggression. I put my hand in the tank today and he bit my finger and when I put the net in he bites at the mesh. He has never shown aggression like this since I have had him. Any advice on what could be causing this?
thanks

 

[Octofasciata Aficionado]

Any changes to the tank? Temp maybe?

 

[BHA]

no its all the same. the only change was that i use to feed him goldfish all the time but i stopped and feed him pellet food now. I threw in some goldfish as a "treat" and now he is acting aggressively. Is the goldfish the reason?

 

[uncwnells]

how big is the tank?

 

[BHA]

85 gallons

 

[Octofasciata Aficionado]

If that's the only change that would be my first guess. Is the aggression a problem, or were you just wonder about the cause?

 

[BHA]

He has just never acted like that and i was wondering what could have happened.

 

[BALLER34IG]

IMO oscars are like any aggressive cichlid. Once you give them live food it triggers the hunters aggression to kill and defend anything. Even if you stop the trigger is still there for anything that comes in his tank. Lower the temp in the tank a few degrees and raise it back up again in a few days and keep away from the live treats for a few weeks. Its his tank and he wants nothing in it.

 

[pelleeklund]

Agreed, got to be the feeders. Brought out the killer in him. If you take him off live he should get back to normal.

 

[adriggsvt]

Cesar says you need to take charge. Give him a "TSSSS" and tug his leash.