Would an asian market have them? I can get crayfish from the lfs but crayfish can get messy. Is there a chemical in cooked that makes them unsafe? Or is it just the preservatives?
Possibly, have no clue what you have in your area. Fresh/live contains more nutrients. You still have to freeze them, then I always tried to feed within 30 days. I kept a constant fresh source on hand as seafood doesn't keep long, even in a freezer. Personally I would be VERY leery about feeding anything sourced from a LFS due to the numerous pathogens found in every LFS. Good way to kill your fish.