It is not much use having a fish tank without fish!  There are breeders of fish right here in Australia that can give you expert advice on aquarium fish keeping.  The types of fish you can keep here in Australia are: Goldfish, Salt Water Tropical Fish, Fresh Water Tropical Fish and a range of other aquatic animals such as walking fish.  If you decide to go for walking fish you need a very strong tank filter because they are quite messy. 

Some fish will also jump out of your tank so don't forget you need a lid or you might end up with your fish on the floor!