hi i had 4 oscars 4 barbs 2 plecs but 2 of my oscars are killing the others off i only have 1plec 3 oscars left one oscars i batterd my tank is 5foot long 3 foot deep ????????

Well, for a start, your tank is not big enough for all those fish so you are going to increase the chance of aggression. What kind of barbs? Obviously if you are talking about the small barbs, they are always going to be a potential snack. Even if they are tinfoil barbs, if they are small, they are going to be at great risk. It seems that you have obviously copped a couple of very aggressive Oscars, I've never actually had this problem myself, it may be a case that you have to re-home all but the two offending fish, or get rid of the aggressive fish.

they was large tinfoil barbs the only fish they have left a lone is my big plec ???

How big are the Oscars that are doing the killing? I'm quite surprised that they managed to kill the tinfoil barbs, they are normally pretty quick fish, quite a lot quicker than Oscars.Well, if I was you, I would get the plec out quickly before that becomes the last victim.

Its possible that the 2 oscars are in the process of mating, so they may be getting more aggressive and territorial.

JTU188 wrote:


that's what came to mind, when i was thinking about this situation.
do you observe any mating signs or behaviour between the oscars?
Any slate cleaning done by the 2 of them?
how do they respond to eachother when they're not killing tankmates?

How big and how old are your fish?
Have they actually reached maturity?
if not ,that would rule out aggression due to mating behaviour...

How big are the oscars, are they mature. Breeding oscars are really mean as they dont want other fish around when they have eggs

Some oscars are just mean mean mean. A friend of mine had 4 oscars. 2 were about 10inches and the smaller ones about 5inches. the smaller ones would swim underneath the bigger ones and swim up and attack the larger ones. he eventually had to rehome the aggressive oscars.

If your oscars are not trying to breed then you have to think about rehoming either them or the other fish

My oscar is a bastard fish regarless what is in the tank, and they are aggressive anyway. some fish just arent meant to have friends, lol