my personal experience with my frt:i had a 7" frt in a 60 gallon tank with a 8" flounder,shovelnose sturgeon,flatnose sturgeon and a spotted gar.everything was ok in the beginning.and ofcourse i fed some of my fish feeders.til one day my gars tail had a bit in it .next my flatnose sturgeon had its tail bitten.next sturgeon died.then i purchased a 6" vampire pleco,so now i also fed my algae waffers.once my frt got a bit of the waffers it went crazy.a couple days later my frt had the pleco by the mouth.then my shovelnose was bitten then died later and finally it killed my flounder.after that i seperated them.i guess after introducing new foods to my frt and based upon how much he liked it,he would do anything to eat it.