you know these fish are somewhat mysterious everyone has their own theories, think that everyone else is wrong. people argue that they are only brackish, but in reality can live in a variety of conditions. these fish are not bred in captivity, they are all caught in the wild and live in estuaries and swamps, in environments, like the estuaries, where the salt content and water temperature can varie. I agree, wal-mart should not stock them (or any fish for that matter) but I have noticed they do live longer then the other wal-mart fish. they have some in a cold water tank, and some in a warm water tank, and they are out living the other fish easily in both, however the ones in the warm water tanks are more active. they do prefer brackish, but will live just fine in fresh water. I have a 7 inch dragon in a 29 gallon FW tropical tank with 2 angels, 3 scissortails, and one golden wonder killi, and it is doing marvelous. bit of a picky eater, wouldnt touch the shrimp pellets, bloodworms, or flake food, but finally warmed up to crumpled up dried shrimp. extremely peaceful, gets along with all the other fish. only gets annoyed if another fish bumps him on accident, and then all he does is move to another hiding spot, as I have provided many. I even bumped him once, and he just moved. very docile creature, yet very hardy as well. this is why no ones sure how to take care of these boogers because they can handle a wide variety of environments in most cases.