The indo is lighter in color and will not always have the red teeth of the australian counter part. also the collection of the indo tusk may have been by a violent form, and i have seen some of these fish refuse to eat and hide in the corner of the tank. Also it is rare to find a small australian tusk in the trade so take a second look if you see one under 5" and under $80 as it is more than likley not australian. And do not belive the LFS if they say other wise, as I have seen a LFS try to sell an indo of 3" as a baby australian, and I visualy was able to tell it was not. This is an awsome fish, and a longer QT time is needed as this fish is subject to high stress. I give it a 4 of 5 for being hardy, and a 3 for the indo as not recomended.