I don't know if you mean as tropical fish food or to use as bait for catching fish, if you mean for catching them then I can tell you with certainty take carp for instance they will eat anything you offer if they are in the right mood, I've caught 30 pounders on dog biscuits often, I've also caught them on plain old white bread and obviously commercially sold regular bait, what works one day might never work again if you try it every day for a month or more, for catching it's just best to take a variety and if one doesn't work try another, I've just bought some bloodworm and pineapple boilies which I will be heading of to the local lake tomorrow to try amongst various other offerings of course, fingers crossed one of them works.
BP