I've never seen a streak of red meat on crappie (or bream) but with certain bass and catfish you wont want to eat that. I believe it's a blood line in the side of the fillet and it's a very strong taste that isnt good to eat. To me, it's easier to roll that out of the fillet with the fork instead of trying to cut it out of the raw meat. All bass and catfish doesnt have it but alot do...maybe something to do with the size of the fish.
Health nuts are going to feel stupid someday, lying in hospitals dying of nothing.