I had four oscars in my 160 gallon tank, 2 albinos 2 tigers they are only 3" long or so. Today I got off work 1 of the tigers was dead and the other was injured pretty bady he had to be put down. Now the 2 albino's swim around rubbing there bodies together swimming in circles no hostility what-so-ever. This behavior came out of no where. They even chase my pleco away from the one corner of the tank. I put my other oscar in the tank with them while I was setting up my new bigger tank and they started attacking him so I had to put him in my already cycled 30 gallon tank until I can figure out what is going on. If they were just aggresive you think they would be so towards each other. I am just upset and confused at the moment. They have all been together for 2 months. I was reading the site and thought maybe they were pairing off but they are still babies no where near big enough to mate or can they 'pair off' at such a young age. I have a video camera just waiting on a mem. card so I can show you the way they are acting - Please Help - Jon

You are correct, they are too young to pair off at the moment. I don't think anyone could give you the absolute conclusive answer to why this has happened, we can really only surmise. You've probably got two Oscars that have ganged up on the others and given them a dam good kicking. However, please check your water conditions just to make sure that it isn't something else that may have something to do with the death of these Oscars. What you've got to remember that Oscars aren't aggressive cichlids, they are actually quite placid. Unfortunately, you do get a few the are aggressive. This can sometimes upset the whole tank. Of all the Oscars I've ever had, I've never had a problem with serious aggression, so that tells you that this kind of problem doesn't crop up all the time.

In my opinion, you should only keep two Oscars together, unless you have got a very large aquarium. Okay, if you want to pair some off, you have to keep more than two but in the longer run, just stick to the two Oscars. There is always the exception as somebody will probably say on here. My philosophy is, better safe than sorry.

I don't think there's anything written in stone that says exactly how it should be done. You'll find that lots of people do things in a different way and have success.

As OFL quite rightly says there are different ways that people keep their fish and if it works for them then that is ok and if it has worked then its difficult to say that its wrong. Your problem puzzles me as i have grown on batches of Oscars quite a few times with no problems with aggression. if we look at the way Oscars spawn we see that they they produce large shoals like many fish to ensure the survival of the species. When they are young they shoal together and this is true of Oscars until they are adult size. How do i know this, well iv'e watched it happen as i was lucky enough to have a friend who grew on 12 Albino Oscars for me in a large pond. Not until these fish were 8-10 inches did the fish start to move off from the shoal that they had lived happily in since i first hatched them. I have never read of any studies on Oscars in the wild as they are growing on so i can only go on my experience. When the first few albinos came into the country i had four and grew them on with a single red Oscar and a red tiger Oscar with no problem. The only problem i have ever had with aggression in Oscars is that red and tiger Oscars will attack and bite out the eyes of Albino's. Returning to your problem there is probably a logical answer to it but im afraid i dont know what it is.

It would be wise to test water for ph, ammonia, nitrite, and nitrate as previously stated. However, I do not think that is a bigger issue here. I'm guessing at least one of the oscars that killed the others, if not two or three were males that ganged up on other males or possibley females. It is possible that your two albinos are trying to mate, however quite a bit early, though this seems a little unlikely and odd. I would not worry about it unless more aggression problems occur with the two albinos.

About how many gallons is the bigger tank your planning to setup?

A video would be helpful.

Hope it works out,
Art

I think you are just unlucky and have 1 or 2 really aggresive oscars. My friend had 4 oscars, 2 albinos who were the larger and 2 tigers. The 2 tigers used to go underneath the albinos and attack them. He was gonna take them back to a shop so i put one in with my oscars and this oscar did exactly the same thing. Some oscars are just really aggresive.