Used to keep one as a "Wet Pet" years ago and they will come to the glass and can be trained to eat out of your hand. They make a great solo fish. To keep them in a native tank with other fish they are going to need "room" as they are aggressive buggers. This species can be kept in a community tank with other fish (sunfish, small bass) until they get to be @ 5 inches at which point they turn into murderous little psychos. I have even seen them kill bass larger than them. Yours looks already to be that "psycho" size. Any other fish you put with them need to be bigger than what they can get in their mouth. I've had these fish attack swimming lures as big as them while fishing for bass. Again, they are aggressive.
One thing I've always wanted to try is to "crowd" them. Let's say you put 3 red breast sunfish in a 55, 70 or 90. They will develop territories, aggressively defend them and most likely murder each other. But what might be interesting to try would be to put 5 to 7 sunfish in that same tank footprint so they are too distracted with each other to develop those territories. I believe Brain Zimmerman did this; you can contact him here...He is a Native Fish guru.
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