These fish are a cross between two kinds of sunfish. The most common cross is between bluegill sunfish and green sunfish. This hybrid is an aggressive feeder and grows more rapidly than regular bluegill. In new ponds, the hybrid can be substituted for up toe one-half the usual bluegill stocking rate. To add variety to an established fishing lake 50 to 100, 2 to 4 inch hybrids can be stocked per surface acre of water.