I have a big problem with everyone saying that compatablity is a yes or no answer. Everyone has had exceptions to the quote unquote golden rule. You should always know what genuss' will fight and keep them in appropriate tanks. The most important rule is to have options!!! You can add any fish to a tank and think nothing of it, but one of the existing fish beats the crap out of it which is against the rule that is given. So ideally you should have a tank set up in case there happens to be a real aggression issue. If your trying to keep fish that are known to be aggressive towards each other, than having another tank setup is essential. I have kept many fish that 'aren't supposed' to be kept together for long periods of time. I have also tried to add a fish to a tank that should be no problem whatsoever, but was not the case. The golden rule, options, options, options. Regards, Tim