Redear Sunfish, or Shellcracker, are a species of Sunfish similar to bluegill. They coexist well with bluegill and are stocked along with them at initial pond stocking.
Shellcrackers do not reproduce at a high enough rate to support a thriving bass population by themselves, so they are stocked in combination with bluegill. A typical combination is 83% bluegill and 15% Shellcracker.