Aussie Aussie Aussie! lol... glad to see our native fish are liked so much! However, this fish does have a nasty bite....I would be interested to see what tank mates you keep with him later down the track.
Completely (partially?) off subject...if any of you are into conservation and are not illiterate, the book Four Fish delves heavily into breeding programs for the Barramundi and using it as a replacement fish for food production.
Well...heavily might be an exaggeration...they talk heavily about breeding sea bass and cod and how barramundi breeding is a better fit for food production and sustainability.
I have a 6 inch sea bass in my 422 tank. Keeping with EBH, arowana and soon hock. Just make sure all the fish mates are bigger than the sea bass, otherwise they will become it's main course dinner, lol.