I don't know if this is related or not, but I have caught redbreast down here that have yellow filets. Actually quite a few had them this spring. Mostly the larger ones had it. The meat looked healthy. We also used to catch a type of redbreast on the Susquehanna River that had yellow meat. Every last one of them did. Meat tasted good though. But the meat posted on these pics doesn't look so healthy. It will be interesting to see what causes this in the crappie. Hope its nothing too serious.