I mainly bass fish, when I accidentally catch a blue cat I throw it back, when I accidentally catch a flat head it goes home with me.
Yellow cats prefer live prey, Blue cats are the buzzards of the water, they’ll eat on a rotten carcass.
Surely you jest or you are passing on information that someone who doesn't know what they are talking about stated. Blue cat are probably the most efficient of all predator fish. But I'd expect such from a bass fisherman.