I'd like to offer a differing opinion.
I don't think game fish choose what to eat. I think they eat whatever is available that they can catch. In a lake or pond, they don't differentiate between fish with spines and fish without spines. If they are hungry, or have that instinctive need to consume something, they will. Largemouth bass for example, feed for three reasons. One, they are hungry. At that point, they'll eat whatever is moving and fits into their mouths, whether it's a bluegill or bullhead or a shiner. Second, they react to something moving into their "zone". Bass will attack and eat something in their zone because that's what they instinctively do. Third, when they are defending a territory or a nest, it doesn't matter who invades...they'll dispose of it whether they eat it or not. If a bass gets a negative response from whatever it puts into its mouth, they'll spit it out. But, if its smells like a fish, acts like a fish or barks like a fish...it's a fish...and they'll eat it.
