I'll just let you know before someone freaks out about it lol, but my axies too love to eat an occasional fish! However, goldfish can be very aggresive and even tear up axie gills. But the problem with store bought fish is that they are bred in huge breeding tubs and are heavily inbred and can carry parasites, bacterial/fungal infections, and disease. I have tried all finds of food with my axies and what I have settled on is a diet mainly of redworms (my axies love them although some caudatas won't touch them), chopped up nightcrawlers, and Indiana University pellets. The pellets would be impossible for you to get in Ausie but the worms are great because of their nutrition and axies love them! I also feed my axies frozen bloodworms, frozen beefheart (half a small cube each once a month becase axies aren't good at digesting mammal flesh), occasionally crickets, and I have even fed them frozen krill as an occasional treat, and about 1 guppy each every other month (they are bred at my own house by myself and I have never had any disease or anything of that nature). Just thought I'd tell you a few food options for axies, but as I'm sure you've been told a million times variety is key!