If you look at the location of the original poster, you can see that they are from Canada. The weather loach is a big problem in many places due to the fact that it can survive a more temperate climate, and it doesn't surprise me that Australia has banned it. You mates are probably the best in the world at protecting your native species, but the price you pay for that is a reduced list of exotic species which you may keep. Still, though, I have to tip my hat to you lot.