Dyed fish is just sick......and very unethical. But if your fish is marketed as blueberry from the state of Selangor, Malaysia, I think I may know which shop is marketing it. If you're paying premium (I mean really premium price), you should expect your fish to be competition grade or at least has the potential for competition.
I know of only one dealer that markets his arowana in Malaysia as blueberry. And it doesn't come cheap. They are sort of one category below crossbelly.
You see, usually the belly part of a blue based arowana does not really have much colours. A lot of them are just white or off white. Some of them may be yellow. But there are some that has the base colours on all the scales including those scales on the belly. So the whole fish looks coloured. It is different from crossbelly as in crossbelly or polkadot have a dark intense base core colour on almost all scales on the body (hence polkadot).
But if it's not a dyed fish, it's a good quality one.
