Aussie natives Stocking.

muuray cod maninly although your pond is tall it isnt very wide so, i think a cod and a few crays wuld do. maybe 2 cods but eventually you;'ll need to seperate them
 
hmm last tiem i checked discus werent illegal, nor were they terribly expensive except for super high quality ones which woulnt cost more then 250 bux.

look as ignorant as this sounds illegals are here theyll keep coming in. there hasnt been one true predator aka non cichlid found in aussie water
 
Cammo, didn't take it personally except maybe that last bit, I was just pointing out my view as someone who has kept natives for many years and moved onto other things. I have to say, I'm not suprised about the stocking pbass in a dam although I would have expected DPI to have been notified about their escape. I have pretty good contacts in the fisheries including those who work sepcifically on introduced species and they haven't heard about it. With the number of people breeding them now the price has dropped to where you can get baby monocs for less than $10 off the breeders. This puts them in the price range of less "serious" fish keepers and as a result, more at risk of being dumped/stocked once their eventual size is realised. Most of the other exotics available are unable to be readily bred or don't produce many offspring (rays for example) so I don't think the price will ever fall to the point where they will be considered expendable by their owners.
 
For those who are interested, red devils, oscars, peacocks (Aulonocara) [I've no idea how they survived] amongst other things have been caught in the Ross River in Townsville. In fact, I think Gleesons weir, about halfway down the river has the highest amount of fish biodiversity (largest number of species) of any freshwater system in Australia? Of course, that's simply due to the fact that many un-educated or negligent red necks inhabit this place and would rather throw their pets into the river than sell it, or find suitable accommadation for it.