there has been reported spawning of the RTC in queensland... came from a reputable person so i have no reason not to believe him....
i dont reckon they would last long in a river system like the swan river as its fished pretty heavily and if you've ever kept a RTC you know it'll eat almost anything that finds its way to the mouth... they arent an aggressive fish like a mangrove jack.... and will generally only consume their food whole as they dont have teeth... but rather top and a bottom plate that crushes their food... no threat to human swimmers unless they get big enough to swallow you whole... lol.... very much doubt that could happen... and their temperature survival range is much warmer water... they slow down in cooler water and IMO would prob die in cold water... very sensitive to bad water conditions.... and prone to gill flukes and parasite infections when exposed to these and other pathogens...
and p.s. matty a breeding pair is a pair of fish that have deemed to have spawned together at least once... other wise its just a pair of fish (m/f)