Ky marine biologist Paul Rister wrote about this phenomenon. There exists 2 groups of fish. Shallow water and deep water breeds of the same species. Also keep in mind that fish seldom roam more than 1-1/2 miles from place of spawn. I believe this as I live on Ky Lake and am witness to it. Fish tracked by radio seem to confirm this. Tim Broadbent, also a marine biologist, confirmed the roaming range of most crappie.

I will ask him again about this phenomenon at the KY Crappie Camp next Saturday (if I remember).