Interesting question, they all seem to keep to themselves. The JD can get a little snippy, but nothing major. The RD/Midas used to chase the Blackbelt, but that all stopped when the Blackbelt quit swimming/running away. They locked lips and then called it quits, haven't been aggressive towards each other for weeks. Right now, the RT is low on the foodchain, but I'm sure that will change when she gets bigger.