I love it when people think "outside the box." Understanding the nature of all these fish, then picking the combination you want is great fun. All it takes is some imagination, time and a few dollars.
Big fish are big predators...it has to do with efficiency. Big blue cat eat big meals. I found a 50+ pound blue cat with a three pound bass in its belly.
Yellow cat are fierce predators, not only when they eat, but when they defend territory. They kill, then ask questions later. Will they control crappie? Yellow cat are not selective. They will eat what they can. But, they like to find a a place, hang out, ambush, and be still. They move when something doesn't come by. Can they control crappie? Sure, if crappie come to them. But, yellow cat grow up and want big meals...see the comment above.
21 inch bass would love to eat 10 inch crappie, but don't bank on them controlling big numbers of small fish.
One of the biggest problems trying to cultivate crappie are the youngest fish. They eat mucho small fish, grow to three or four inches, and mourn the loss of groceries. In the meantime, 14-18 inch bass will chase papermouths. So, to control crappie, you need to be overstocked with bass in the medium size ranges. Then, you are dealing with overcrowded bass overeating the food chain. Figure out how to balance crappie with bass, provide a consistent food supply for crappie to grow, and you will be on to something pond owners will love.
I have confidence someone out there will figure out how to do it. Go get 'em.
