Oscars

do you have enough hiding places for both of them? im assuming you are feeding live based on the other tankmates, feeding live encourages aggression (not to mention can introduce parasites/diseases as well a sbeing nutritionally inferior to high quality pellets). if you have to feed live than you have to, so it sounds like there is nothing you can do about that. is there a size difference in the 2 oscars? if so that probably has a lot to do with the aggression.

:hi: Could be a number of reasons but could use more info to be sure. What size tank do you have? How big are the "O"s? Was the tank fully cycled before you put them in? What type of filtration? What are your parameters? That being said, if the 'rock' has sharp edges, remove it! 'O's are very clumsy & can hurt themselves on sharp rocks or decorations. Feed them a quality flake or pellet for nutrition 80% of the time w/ treats in between (shrimp, bloodworms ect.) Watch for signs of aggression (some'O's just don't get along) & be prepared to separate them if 'horseplay' turns to constant 'battle royale'!