I think in the photo of that tank there's Praecox rainbows and a Bolivian Ram which are not Australian native, though I did have an assortment of in my 6 foot tank. That 4 foot is currently a temporary home for the 6ft inhabitants as its meant to be getting replaced. Damn rain keeps ruining that plan!

There's definitely Crimson Spotted and Goyder River rainbows in there. I really like rainbows. When the 6ft is replaced I'm going to stock it with a massive group of just one type of rainbow. Thinking of doing a reverse under gravel filter with a sump. Bit of fun engineering to make it work without risking overflowing isssues, and should result in a spectacular amount of biological filtration. And hopefully bugger all maintenance, cause cleaning is boring.