Two questions about Oscars

An Oscar is, well. . . ., an Oscar. Feeding is not an issue. The temperament is unique to each fish, not species. An Oscar should be called a "Surprise Fish" because you never know how they will react. Some have known to be docile and tolerant of other fish and some are the complete opposite. I have one of each. For their own safety I have them in different tanks. One is in a 90 with a pink convict and a common plec and the other is in a 100 with 6 other fish. (3-Kadangos, 2-convicts, 1 Gibb plec)
 
I'd be concerned about blood parrots because they have no real way to defend themselves since they cannot use their mouths. They can also be extremely shy and nervous (which means they may be stressed a lot in this type of situation) or aggressive (which will mean getting bet up by the Oscar). But that's just my opinion.
 
I did keep an oscar for 5 years (but I made the mistake of homing him in a 55 gallon)... He was a sweetheart, he wouldn't bother anybody. But I have heard horror stories. Is there any sort of way to test a fish's aggressiveness?
 
i have a juvenielle oscar in with various other tropical fish, but i know that some day in the not too distant future he will need to either have his own tank or live with like sized and tempermant fish.

powellmacaque, i think the only way to test that is to see how a particular fish interacts with other fish.
 
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