Cute idea, but you have to keep in mind the whole liquids thing. I remember reading somewhere that the TSA allows more than 3 oz with fish because since a fish is living in it, it's obviously not toxic or lighter fluid or anything. I'd call ahead to the airport to see their policies, otherwise it might be best to just ship the fish and have it arrive a few days after you get home. Oh, but then you might have to do the transhipper thing :P So yeah, I'd say call ahead.
I know in Canada they let you carry 1L of liquids TOTAL. No More than 100mL per item. Had to throw away my sunscreen when I flew last weekend. >.> Shame, I'd be bringing home a prize from Big Al's if we could, and if they allowed it. I would check with the airline and the security people. Probably not tho.